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 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 439 {
 440         struct wpa_supplicant *wpa_s = eloop_ctx;
 441         struct wpa_ssid *ssid;
 442         int scan_req = 0, ret;
 443         struct wpabuf *extra_ie = NULL;
 444         struct wpa_driver_scan_params params;
 445         struct wpa_driver_scan_params *scan_params;
 446         size_t max_ssids;
 447         enum wpa_states prev_state;
 448
 449         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 450                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 451                 return;
 452         }
 453
 454         if (wpa_s->disconnected && !wpa_s->scan_req) {
 455                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 456                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 457                 return;
 458         }
 459
 460         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 461             !wpa_s->scan_req) {
 462                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 463                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 464 #ifdef CONFIG_P2P
 465                 wpa_s->sta_scan_pending = 0;
 466 #endif /* CONFIG_P2P */
 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         } else if (wpa_s->conf->ap_scan == 2) {
 570                 /*
 571                  * User-initiated scan request in ap_scan == 2; scan with
 572                  * wildcard SSID.
 573                  */
 574                 ssid = NULL;
 575         } else {
 576                 struct wpa_ssid *start = ssid, *tssid;
 577                 int freqs_set = 0;
 578                 if (ssid == NULL && max_ssids > 1)
 579                         ssid = wpa_s->conf->ssid;
 580                 while (ssid) {
 581                         if (!wpas_network_disabled(wpa_s, ssid) &&
 582                             ssid->scan_ssid) {
 583                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 584                                                   ssid->ssid, ssid->ssid_len);
 585                                 params.ssids[params.num_ssids].ssid =
 586                                         ssid->ssid;
 587                                 params.ssids[params.num_ssids].ssid_len =
 588                                         ssid->ssid_len;
 589                                 params.num_ssids++;
 590                                 if (params.num_ssids + 1 >= max_ssids)
 591                                         break;
 592                         }
 593                         ssid = ssid->next;
 594                         if (ssid == start)
 595                                 break;
 596                         if (ssid == NULL && max_ssids > 1 &&
 597                             start != wpa_s->conf->ssid)
 598                                 ssid = wpa_s->conf->ssid;
 599                 }
 600
 601                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 602                         if (wpas_network_disabled(wpa_s, tssid))
 603                                 continue;
 604                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 605                                 int_array_concat(&params.freqs,
 606                                                  tssid->scan_freq);
 607                         } else {
 608                                 os_free(params.freqs);
 609                                 params.freqs = NULL;
 610                         }
 611                         freqs_set = 1;
 612                 }
 613                 int_array_sort_unique(params.freqs);
 614         }
 615
 616         if (ssid && max_ssids == 1) {
 617                 /*
 618                  * If the driver is limited to 1 SSID at a time interleave
 619                  * wildcard SSID scans with specific SSID scans to avoid
 620                  * waiting a long time for a wildcard scan.
 621                  */
 622                 if (!wpa_s->prev_scan_wildcard) {
 623                         params.ssids[0].ssid = NULL;
 624                         params.ssids[0].ssid_len = 0;
 625                         wpa_s->prev_scan_wildcard = 1;
 626                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 627                                 "wildcard SSID (Interleave with specific)");
 628                 } else {
 629                         wpa_s->prev_scan_ssid = ssid;
 630                         wpa_s->prev_scan_wildcard = 0;
 631                         wpa_dbg(wpa_s, MSG_DEBUG,
 632                                 "Starting AP scan for specific SSID: %s",
 633                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 634                 }
 635         } else if (ssid) {
 636                 /* max_ssids > 1 */
 637
 638                 wpa_s->prev_scan_ssid = ssid;
 639                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 640                         "the scan request");
 641                 params.num_ssids++;
 642         } else {
 643                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 644                 params.num_ssids++;
 645                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 646                         "SSID");
 647         }
 648 #ifdef CONFIG_P2P
 649 ssid_list_set:
 650 #endif /* CONFIG_P2P */
 651
 652         wpa_supplicant_optimize_freqs(wpa_s, &params);
 653         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 654
 655 #ifdef CONFIG_HS20
 656         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 657                 wpas_hs20_add_indication(extra_ie);
 658 #endif /* CONFIG_HS20 */
 659
 660         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 661                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 662                         "generated frequency list");
 663                 params.freqs = wpa_s->next_scan_freqs;
 664         } else
 665                 os_free(wpa_s->next_scan_freqs);
 666         wpa_s->next_scan_freqs = NULL;
 667
 668         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 669                 wpa_s->conf, &params.num_filter_ssids);
 670         if (extra_ie) {
 671                 params.extra_ies = wpabuf_head(extra_ie);
 672                 params.extra_ies_len = wpabuf_len(extra_ie);
 673         }
 674
 675 #ifdef CONFIG_P2P
 676         if (wpa_s->p2p_in_provisioning ||
 677             (wpa_s->show_group_started && wpa_s->go_params)) {
 678                 /*
 679                  * The interface may not yet be in P2P mode, so we have to
 680                  * explicitly request P2P probe to disable CCK rates.
 681                  */
 682                 params.p2p_probe = 1;
 683         }
 684 #endif /* CONFIG_P2P */
 685
 686         scan_params = &params;
 687
 688 scan:
 689         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 690
 691         wpabuf_free(extra_ie);
 692         os_free(params.freqs);
 693         os_free(params.filter_ssids);
 694
 695         if (ret) {
 696                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 697                 if (prev_state != wpa_s->wpa_state)
 698                         wpa_supplicant_set_state(wpa_s, prev_state);
 699                 /* Restore scan_req since we will try to scan again */
 700                 wpa_s->scan_req = scan_req;
 701                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 702         }
 703 }
 704
 705
 706 /**
 707  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 708  * @wpa_s: Pointer to wpa_supplicant data
 709  * @sec: Number of seconds after which to scan
 710  * @usec: Number of microseconds after which to scan
 711  *
 712  * This function is used to schedule a scan for neighboring access points after
 713  * the specified time.
 714  */
 715 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 716 {
 717         /* If there's at least one network that should be specifically scanned
 718          * then don't cancel the scan and reschedule.  Some drivers do
 719          * background scanning which generates frequent scan results, and that
 720          * causes the specific SSID scan to get continually pushed back and
 721          * never happen, which causes hidden APs to never get probe-scanned.
 722          */
 723         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 724             wpa_s->conf->ap_scan == 1) {
 725                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 726
 727                 while (ssid) {
 728                         if (!wpas_network_disabled(wpa_s, ssid) &&
 729                             ssid->scan_ssid)
 730                                 break;
 731                         ssid = ssid->next;
 732                 }
 733                 if (ssid) {
 734                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 735                                 "ensure that specific SSID scans occur");
 736                         return;
 737                 }
 738         }
 739
 740         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 741                 sec, usec);
 742         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 743         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 744 }
 745
 746
 747 /**
 748  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 749  * @wpa_s: Pointer to wpa_supplicant data
 750  * @sec: Number of seconds after which to scan
 751  * @usec: Number of microseconds after which to scan
 752  *
 753  * This function is used to schedule periodic scans for neighboring
 754  * access points after the specified time.
 755  */
 756 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 757                                       int sec, int usec)
 758 {
 759         if (!wpa_s->sched_scan_supported)
 760                 return -1;
 761
 762         eloop_register_timeout(sec, usec,
 763                                wpa_supplicant_delayed_sched_scan_timeout,
 764                                wpa_s, NULL);
 765
 766         return 0;
 767 }
 768
 769
 770 /**
 771  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 772  * @wpa_s: Pointer to wpa_supplicant data
 773  *
 774  * This function is used to schedule periodic scans for neighboring
 775  * access points repeating the scan continuously.
 776  */
 777 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 778 {
 779         struct wpa_driver_scan_params params;
 780         struct wpa_driver_scan_params *scan_params;
 781         enum wpa_states prev_state;
 782         struct wpa_ssid *ssid = NULL;
 783         struct wpabuf *extra_ie = NULL;
 784         int ret;
 785         unsigned int max_sched_scan_ssids;
 786         int wildcard = 0;
 787         int need_ssids;
 788
 789         if (!wpa_s->sched_scan_supported)
 790                 return -1;
 791
 792         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 793                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 794         else
 795                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 796         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 797                 return -1;
 798
 799         if (wpa_s->sched_scanning) {
 800                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 801                 return 0;
 802         }
 803
 804         need_ssids = 0;
 805         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 806                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 807                         /* Use wildcard SSID to find this network */
 808                         wildcard = 1;
 809                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 810                            ssid->ssid_len)
 811                         need_ssids++;
 812
 813 #ifdef CONFIG_WPS
 814                 if (!wpas_network_disabled(wpa_s, ssid) &&
 815                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 816                         /*
 817                          * Normal scan is more reliable and faster for WPS
 818                          * operations and since these are for short periods of
 819                          * time, the benefit of trying to use sched_scan would
 820                          * be limited.
 821                          */
 822                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 823                                 "sched_scan for WPS");
 824                         return -1;
 825                 }
 826 #endif /* CONFIG_WPS */
 827         }
 828         if (wildcard)
 829                 need_ssids++;
 830
 831         if (wpa_s->normal_scans < 3 &&
 832             (need_ssids <= wpa_s->max_scan_ssids ||
 833              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 834                 /*
 835                  * When normal scan can speed up operations, use that for the
 836                  * first operations before starting the sched_scan to allow
 837                  * user space sleep more. We do this only if the normal scan
 838                  * has functionality that is suitable for this or if the
 839                  * sched_scan does not have better support for multiple SSIDs.
 840                  */
 841                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 842                         "sched_scan for initial scans (normal_scans=%d)",
 843                         wpa_s->normal_scans);
 844                 return -1;
 845         }
 846
 847         os_memset(&params, 0, sizeof(params));
 848
 849         /* If we can't allocate space for the filters, we just don't filter */
 850         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 851                                         sizeof(struct wpa_driver_scan_filter));
 852
 853         prev_state = wpa_s->wpa_state;
 854         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 855             wpa_s->wpa_state == WPA_INACTIVE)
 856                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 857
 858         if (wpa_s->autoscan_params != NULL) {
 859                 scan_params = wpa_s->autoscan_params;
 860                 goto scan;
 861         }
 862
 863         /* Find the starting point from which to continue scanning */
 864         ssid = wpa_s->conf->ssid;
 865         if (wpa_s->prev_sched_ssid) {
 866                 while (ssid) {
 867                         if (ssid == wpa_s->prev_sched_ssid) {
 868                                 ssid = ssid->next;
 869                                 break;
 870                         }
 871                         ssid = ssid->next;
 872                 }
 873         }
 874
 875         if (!ssid || !wpa_s->prev_sched_ssid) {
 876                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 877
 878                 if (wpa_s->sched_scan_interval == 0)
 879                         wpa_s->sched_scan_interval = 10;
 880                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 881                 wpa_s->first_sched_scan = 1;
 882                 ssid = wpa_s->conf->ssid;
 883                 wpa_s->prev_sched_ssid = ssid;
 884         }
 885
 886         if (wildcard) {
 887                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 888                 params.num_ssids++;
 889         }
 890
 891         while (ssid) {
 892                 if (wpas_network_disabled(wpa_s, ssid))
 893                         goto next;
 894
 895                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 896                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 897                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 898                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 899                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 900                                   ssid->ssid, ssid->ssid_len);
 901                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 902                                 ssid->ssid_len;
 903                         params.num_filter_ssids++;
 904                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
 905                 {
 906                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
 907                                 "filter for sched_scan - drop filter");
 908                         os_free(params.filter_ssids);
 909                         params.filter_ssids = NULL;
 910                         params.num_filter_ssids = 0;
 911                 }
 912
 913                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
 914                         if (params.num_ssids == max_sched_scan_ssids)
 915                                 break; /* only room for broadcast SSID */
 916                         wpa_dbg(wpa_s, MSG_DEBUG,
 917                                 "add to active scan ssid: %s",
 918                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 919                         params.ssids[params.num_ssids].ssid =
 920                                 ssid->ssid;
 921                         params.ssids[params.num_ssids].ssid_len =
 922                                 ssid->ssid_len;
 923                         params.num_ssids++;
 924                         if (params.num_ssids >= max_sched_scan_ssids) {
 925                                 wpa_s->prev_sched_ssid = ssid;
 926                                 do {
 927                                         ssid = ssid->next;
 928                                 } while (ssid &&
 929                                          (wpas_network_disabled(wpa_s, ssid) ||
 930                                           !ssid->scan_ssid));
 931                                 break;
 932                         }
 933                 }
 934
 935         next:
 936                 wpa_s->prev_sched_ssid = ssid;
 937                 ssid = ssid->next;
 938         }
 939
 940         if (params.num_filter_ssids == 0) {
 941                 os_free(params.filter_ssids);
 942                 params.filter_ssids = NULL;
 943         }
 944
 945         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 946         if (extra_ie) {
 947                 params.extra_ies = wpabuf_head(extra_ie);
 948                 params.extra_ies_len = wpabuf_len(extra_ie);
 949         }
 950
 951         scan_params = &params;
 952
 953 scan:
 954         if (ssid || !wpa_s->first_sched_scan) {
 955                 wpa_dbg(wpa_s, MSG_DEBUG,
 956                         "Starting sched scan: interval %d timeout %d",
 957                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 958         } else {
 959                 wpa_dbg(wpa_s, MSG_DEBUG,
 960                         "Starting sched scan: interval %d (no timeout)",
 961                         wpa_s->sched_scan_interval);
 962         }
 963
 964         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
 965                                               wpa_s->sched_scan_interval);
 966         wpabuf_free(extra_ie);
 967         os_free(params.filter_ssids);
 968         if (ret) {
 969                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 970                 if (prev_state != wpa_s->wpa_state)
 971                         wpa_supplicant_set_state(wpa_s, prev_state);
 972                 return ret;
 973         }
 974
 975         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 976         if (ssid || !wpa_s->first_sched_scan) {
 977                 wpa_s->sched_scan_timed_out = 0;
 978                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 979                                        wpa_supplicant_sched_scan_timeout,
 980                                        wpa_s, NULL);
 981                 wpa_s->first_sched_scan = 0;
 982                 wpa_s->sched_scan_timeout /= 2;
 983                 wpa_s->sched_scan_interval *= 2;
 984         }
 985
 986         return 0;
 987 }
 988
 989
 990 /**
 991  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 992  * @wpa_s: Pointer to wpa_supplicant data
 993  *
 994  * This function is used to cancel a scan request scheduled with
 995  * wpa_supplicant_req_scan().
 996  */
 997 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 998 {
 999         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1000         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1001 }
1002
1003
1004 /**
1005  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1006  * @wpa_s: Pointer to wpa_supplicant data
1007  *
1008  * This function is used to stop a periodic scheduled scan.
1009  */
1010 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1011 {
1012         if (!wpa_s->sched_scanning)
1013                 return;
1014
1015         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1016         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1017         wpa_supplicant_stop_sched_scan(wpa_s);
1018 }
1019
1020
1021 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1022                                     int scanning)
1023 {
1024         if (wpa_s->scanning != scanning) {
1025                 wpa_s->scanning = scanning;
1026                 wpas_notify_scanning(wpa_s);
1027         }
1028 }
1029
1030
1031 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1032 {
1033         int rate = 0;
1034         const u8 *ie;
1035         int i;
1036
1037         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1038         for (i = 0; ie && i < ie[1]; i++) {
1039                 if ((ie[i + 2] & 0x7f) > rate)
1040                         rate = ie[i + 2] & 0x7f;
1041         }
1042
1043         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1044         for (i = 0; ie && i < ie[1]; i++) {
1045                 if ((ie[i + 2] & 0x7f) > rate)
1046                         rate = ie[i + 2] & 0x7f;
1047         }
1048
1049         return rate;
1050 }
1051
1052
1053 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1054 {
1055         const u8 *end, *pos;
1056
1057         pos = (const u8 *) (res + 1);
1058         end = pos + res->ie_len;
1059
1060         while (pos + 1 < end) {
1061                 if (pos + 2 + pos[1] > end)
1062                         break;
1063                 if (pos[0] == ie)
1064                         return pos;
1065                 pos += 2 + pos[1];
1066         }
1067
1068         return NULL;
1069 }
1070
1071
1072 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1073                                   u32 vendor_type)
1074 {
1075         const u8 *end, *pos;
1076
1077         pos = (const u8 *) (res + 1);
1078         end = pos + res->ie_len;
1079
1080         while (pos + 1 < end) {
1081                 if (pos + 2 + pos[1] > end)
1082                         break;
1083                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1084                     vendor_type == WPA_GET_BE32(&pos[2]))
1085                         return pos;
1086                 pos += 2 + pos[1];
1087         }
1088
1089         return NULL;
1090 }
1091
1092
1093 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1094                                              u32 vendor_type)
1095 {
1096         struct wpabuf *buf;
1097         const u8 *end, *pos;
1098
1099         buf = wpabuf_alloc(res->ie_len);
1100         if (buf == NULL)
1101                 return NULL;
1102
1103         pos = (const u8 *) (res + 1);
1104         end = pos + res->ie_len;
1105
1106         while (pos + 1 < end) {
1107                 if (pos + 2 + pos[1] > end)
1108                         break;
1109                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1110                     vendor_type == WPA_GET_BE32(&pos[2]))
1111                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1112                 pos += 2 + pos[1];
1113         }
1114
1115         if (wpabuf_len(buf) == 0) {
1116                 wpabuf_free(buf);
1117                 buf = NULL;
1118         }
1119
1120         return buf;
1121 }
1122
1123
1124 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1125         const struct wpa_scan_res *res, u32 vendor_type)
1126 {
1127         struct wpabuf *buf;
1128         const u8 *end, *pos;
1129
1130         if (res->beacon_ie_len == 0)
1131                 return NULL;
1132         buf = wpabuf_alloc(res->beacon_ie_len);
1133         if (buf == NULL)
1134                 return NULL;
1135
1136         pos = (const u8 *) (res + 1);
1137         pos += res->ie_len;
1138         end = pos + res->beacon_ie_len;
1139
1140         while (pos + 1 < end) {
1141                 if (pos + 2 + pos[1] > end)
1142                         break;
1143                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1144                     vendor_type == WPA_GET_BE32(&pos[2]))
1145                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1146                 pos += 2 + pos[1];
1147         }
1148
1149         if (wpabuf_len(buf) == 0) {
1150                 wpabuf_free(buf);
1151                 buf = NULL;
1152         }
1153
1154         return buf;
1155 }
1156
1157
1158 /*
1159  * Channels with a great SNR can operate at full rate. What is a great SNR?
1160  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1161  * rule of thumb is that any SNR above 20 is good." This one
1162  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1163  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1164  * conservative value.
1165  */
1166 #define GREAT_SNR 30
1167
1168 /* Compare function for sorting scan results. Return >0 if @b is considered
1169  * better. */
1170 static int wpa_scan_result_compar(const void *a, const void *b)
1171 {
1172 #define IS_5GHZ(n) (n > 4000)
1173 #define MIN(a,b) a < b ? a : b
1174         struct wpa_scan_res **_wa = (void *) a;
1175         struct wpa_scan_res **_wb = (void *) b;
1176         struct wpa_scan_res *wa = *_wa;
1177         struct wpa_scan_res *wb = *_wb;
1178         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1179         int snr_a, snr_b;
1180
1181         /* WPA/WPA2 support preferred */
1182         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1183                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1184         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1185                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1186
1187         if (wpa_b && !wpa_a)
1188                 return 1;
1189         if (!wpa_b && wpa_a)
1190                 return -1;
1191
1192         /* privacy support preferred */
1193         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1194             (wb->caps & IEEE80211_CAP_PRIVACY))
1195                 return 1;
1196         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1197             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1198                 return -1;
1199
1200         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1201             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1202                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1203                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1204         } else {
1205                 /* Not suitable information to calculate SNR, so use level */
1206                 snr_a = wa->level;
1207                 snr_b = wb->level;
1208         }
1209
1210         /* best/max rate preferred if SNR close enough */
1211         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1212             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1213                 maxrate_a = wpa_scan_get_max_rate(wa);
1214                 maxrate_b = wpa_scan_get_max_rate(wb);
1215                 if (maxrate_a != maxrate_b)
1216                         return maxrate_b - maxrate_a;
1217                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1218                         return IS_5GHZ(wa->freq) ? -1 : 1;
1219         }
1220
1221         /* use freq for channel preference */
1222
1223         /* all things being equal, use SNR; if SNRs are
1224          * identical, use quality values since some drivers may only report
1225          * that value and leave the signal level zero */
1226         if (snr_b == snr_a)
1227                 return wb->qual - wa->qual;
1228         return snr_b - snr_a;
1229 #undef MIN
1230 #undef IS_5GHZ
1231 }
1232
1233
1234 #ifdef CONFIG_WPS
1235 /* Compare function for sorting scan results when searching a WPS AP for
1236  * provisioning. Return >0 if @b is considered better. */
1237 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1238 {
1239         struct wpa_scan_res **_wa = (void *) a;
1240         struct wpa_scan_res **_wb = (void *) b;
1241         struct wpa_scan_res *wa = *_wa;
1242         struct wpa_scan_res *wb = *_wb;
1243         int uses_wps_a, uses_wps_b;
1244         struct wpabuf *wps_a, *wps_b;
1245         int res;
1246
1247         /* Optimization - check WPS IE existence before allocated memory and
1248          * doing full reassembly. */
1249         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1250         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1251         if (uses_wps_a && !uses_wps_b)
1252                 return -1;
1253         if (!uses_wps_a && uses_wps_b)
1254                 return 1;
1255
1256         if (uses_wps_a && uses_wps_b) {
1257                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1258                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1259                 res = wps_ap_priority_compar(wps_a, wps_b);
1260                 wpabuf_free(wps_a);
1261                 wpabuf_free(wps_b);
1262                 if (res)
1263                         return res;
1264         }
1265
1266         /*
1267          * Do not use current AP security policy as a sorting criteria during
1268          * WPS provisioning step since the AP may get reconfigured at the
1269          * completion of provisioning.
1270          */
1271
1272         /* all things being equal, use signal level; if signal levels are
1273          * identical, use quality values since some drivers may only report
1274          * that value and leave the signal level zero */
1275         if (wb->level == wa->level)
1276                 return wb->qual - wa->qual;
1277         return wb->level - wa->level;
1278 }
1279 #endif /* CONFIG_WPS */
1280
1281
1282 static void dump_scan_res(struct wpa_scan_results *scan_res)
1283 {
1284 #ifndef CONFIG_NO_STDOUT_DEBUG
1285         size_t i;
1286
1287         if (scan_res->res == NULL || scan_res->num == 0)
1288                 return;
1289
1290         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1291
1292         for (i = 0; i < scan_res->num; i++) {
1293                 struct wpa_scan_res *r = scan_res->res[i];
1294                 u8 *pos;
1295                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1296                     == WPA_SCAN_LEVEL_DBM) {
1297                         int snr = r->level - r->noise;
1298                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1299                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1300                                    MAC2STR(r->bssid), r->freq, r->qual,
1301                                    r->noise, r->level, snr,
1302                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1303                 } else {
1304                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1305                                    "noise=%d level=%d flags=0x%x",
1306                                    MAC2STR(r->bssid), r->freq, r->qual,
1307                                    r->noise, r->level, r->flags);
1308                 }
1309                 pos = (u8 *) (r + 1);
1310                 if (r->ie_len)
1311                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1312                 pos += r->ie_len;
1313                 if (r->beacon_ie_len)
1314                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1315                                     pos, r->beacon_ie_len);
1316         }
1317 #endif /* CONFIG_NO_STDOUT_DEBUG */
1318 }
1319
1320
1321 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1322                                       const u8 *bssid)
1323 {
1324         size_t i;
1325
1326         if (wpa_s->bssid_filter == NULL)
1327                 return 1;
1328
1329         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1330                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1331                               ETH_ALEN) == 0)
1332                         return 1;
1333         }
1334
1335         return 0;
1336 }
1337
1338
1339 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1340                             struct wpa_scan_results *res)
1341 {
1342         size_t i, j;
1343
1344         if (wpa_s->bssid_filter == NULL)
1345                 return;
1346
1347         for (i = 0, j = 0; i < res->num; i++) {
1348                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1349                                                       res->res[i]->bssid)) {
1350                         res->res[j++] = res->res[i];
1351                 } else {
1352                         os_free(res->res[i]);
1353                         res->res[i] = NULL;
1354                 }
1355         }
1356
1357         if (res->num != j) {
1358                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1359                            (int) (res->num - j));
1360                 res->num = j;
1361         }
1362 }
1363
1364
1365 /**
1366  * wpa_supplicant_get_scan_results - Get scan results
1367  * @wpa_s: Pointer to wpa_supplicant data
1368  * @info: Information about what was scanned or %NULL if not available
1369  * @new_scan: Whether a new scan was performed
1370  * Returns: Scan results, %NULL on failure
1371  *
1372  * This function request the current scan results from the driver and updates
1373  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1374  * results with wpa_scan_results_free().
1375  */
1376 struct wpa_scan_results *
1377 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1378                                 struct scan_info *info, int new_scan)
1379 {
1380         struct wpa_scan_results *scan_res;
1381         size_t i;
1382         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1383
1384         scan_res = wpa_drv_get_scan_results2(wpa_s);
1385         if (scan_res == NULL) {
1386                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1387                 return NULL;
1388         }
1389         filter_scan_res(wpa_s, scan_res);
1390
1391 #ifdef CONFIG_WPS
1392         if (wpas_wps_in_progress(wpa_s)) {
1393                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1394                         "provisioning rules");
1395                 compar = wpa_scan_result_wps_compar;
1396         }
1397 #endif /* CONFIG_WPS */
1398
1399         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1400               compar);
1401         dump_scan_res(scan_res);
1402
1403         wpa_bss_update_start(wpa_s);
1404         for (i = 0; i < scan_res->num; i++)
1405                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1406         wpa_bss_update_end(wpa_s, info, new_scan);
1407
1408         return scan_res;
1409 }
1410
1411
1412 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1413 {
1414         struct wpa_scan_results *scan_res;
1415         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1416         if (scan_res == NULL)
1417                 return -1;
1418         wpa_scan_results_free(scan_res);
1419
1420         return 0;
1421 }