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
 457         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 458             !wpa_s->scan_req) {
 459                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 460                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 461                 return;
 462         }
 463
 464         if (wpa_s->conf->ap_scan != 0 &&
 465             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 466                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 467                         "overriding ap_scan configuration");
 468                 wpa_s->conf->ap_scan = 0;
 469                 wpas_notify_ap_scan_changed(wpa_s);
 470         }
 471
 472         if (wpa_s->conf->ap_scan == 0) {
 473                 wpa_supplicant_gen_assoc_event(wpa_s);
 474                 return;
 475         }
 476
 477 #ifdef CONFIG_P2P
 478         if (wpas_p2p_in_progress(wpa_s)) {
 479                 if (wpa_s->sta_scan_pending &&
 480                     wpas_p2p_in_progress(wpa_s) == 2 &&
 481                     wpa_s->p2p_cb_on_scan_complete) {
 482                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 483                                 "mode scan during P2P search");
 484                 } else {
 485                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 486                                 "while P2P operation is in progress");
 487                         wpa_s->sta_scan_pending = 1;
 488                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 489                         return;
 490                 }
 491         }
 492 #endif /* CONFIG_P2P */
 493
 494         if (wpa_s->conf->ap_scan == 2)
 495                 max_ssids = 1;
 496         else {
 497                 max_ssids = wpa_s->max_scan_ssids;
 498                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 499                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 500         }
 501
 502         scan_req = wpa_s->scan_req;
 503         wpa_s->scan_req = 0;
 504
 505         os_memset(&params, 0, sizeof(params));
 506
 507         prev_state = wpa_s->wpa_state;
 508         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 509             wpa_s->wpa_state == WPA_INACTIVE)
 510                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 511
 512         /*
 513          * If autoscan has set its own scanning parameters
 514          */
 515         if (wpa_s->autoscan_params != NULL) {
 516                 scan_params = wpa_s->autoscan_params;
 517                 goto scan;
 518         }
 519
 520         if (scan_req != 2 && wpa_s->connect_without_scan) {
 521                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 522                         if (ssid == wpa_s->connect_without_scan)
 523                                 break;
 524                 }
 525                 wpa_s->connect_without_scan = NULL;
 526                 if (ssid) {
 527                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 528                                    "without scan step");
 529                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 530                         return;
 531                 }
 532         }
 533
 534 #ifdef CONFIG_P2P
 535         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 536             wpa_s->go_params) {
 537                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 538                            "P2P group formation");
 539                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 540                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 541                 params.num_ssids = 1;
 542                 goto ssid_list_set;
 543         }
 544 #endif /* CONFIG_P2P */
 545
 546         /* Find the starting point from which to continue scanning */
 547         ssid = wpa_s->conf->ssid;
 548         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 549                 while (ssid) {
 550                         if (ssid == wpa_s->prev_scan_ssid) {
 551                                 ssid = ssid->next;
 552                                 break;
 553                         }
 554                         ssid = ssid->next;
 555                 }
 556         }
 557
 558         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 559                 wpa_s->connect_without_scan = NULL;
 560                 wpa_s->prev_scan_wildcard = 0;
 561                 wpa_supplicant_assoc_try(wpa_s, ssid);
 562                 return;
 563 #ifndef ANDROID
 564         } else if (wpa_s->conf->ap_scan == 2) {
 565                 /*
 566                  * User-initiated scan request in ap_scan == 2; scan with
 567                  * wildcard SSID.
 568                  */
 569                 ssid = NULL;
 570 #endif
 571         } else {
 572                 struct wpa_ssid *start = ssid, *tssid;
 573                 int freqs_set = 0;
 574                 if (ssid == NULL && max_ssids > 1)
 575                         ssid = wpa_s->conf->ssid;
 576                 while (ssid) {
 577                         if (!wpas_network_disabled(wpa_s, ssid) &&
 578                             ssid->scan_ssid) {
 579                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 580                                                   ssid->ssid, ssid->ssid_len);
 581                                 params.ssids[params.num_ssids].ssid =
 582                                         ssid->ssid;
 583                                 params.ssids[params.num_ssids].ssid_len =
 584                                         ssid->ssid_len;
 585                                 params.num_ssids++;
 586                                 if (params.num_ssids + 1 >= max_ssids)
 587                                         break;
 588                         }
 589                         ssid = ssid->next;
 590                         if (ssid == start)
 591                                 break;
 592                         if (ssid == NULL && max_ssids > 1 &&
 593                             start != wpa_s->conf->ssid)
 594                                 ssid = wpa_s->conf->ssid;
 595                 }
 596
 597                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 598                         if (wpas_network_disabled(wpa_s, tssid))
 599                                 continue;
 600                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 601                                 int_array_concat(&params.freqs,
 602                                                  tssid->scan_freq);
 603                         } else {
 604                                 os_free(params.freqs);
 605                                 params.freqs = NULL;
 606                         }
 607                         freqs_set = 1;
 608                 }
 609                 int_array_sort_unique(params.freqs);
 610         }
 611
 612         if (ssid && max_ssids == 1) {
 613                 /*
 614                  * If the driver is limited to 1 SSID at a time interleave
 615                  * wildcard SSID scans with specific SSID scans to avoid
 616                  * waiting a long time for a wildcard scan.
 617                  */
 618                 if (!wpa_s->prev_scan_wildcard) {
 619                         params.ssids[0].ssid = NULL;
 620                         params.ssids[0].ssid_len = 0;
 621                         wpa_s->prev_scan_wildcard = 1;
 622                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 623                                 "wildcard SSID (Interleave with specific)");
 624                 } else {
 625                         wpa_s->prev_scan_ssid = ssid;
 626                         wpa_s->prev_scan_wildcard = 0;
 627                         wpa_dbg(wpa_s, MSG_DEBUG,
 628                                 "Starting AP scan for specific SSID: %s",
 629                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 630                 }
 631         } else if (ssid) {
 632                 /* max_ssids > 1 */
 633
 634                 wpa_s->prev_scan_ssid = ssid;
 635                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 636                         "the scan request");
 637                 params.num_ssids++;
 638         } else {
 639                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 640                 params.num_ssids++;
 641                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 642                         "SSID");
 643         }
 644 #ifdef CONFIG_P2P
 645 ssid_list_set:
 646 #endif /* CONFIG_P2P */
 647
 648         wpa_supplicant_optimize_freqs(wpa_s, &params);
 649         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 650
 651 #ifdef CONFIG_HS20
 652         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 653                 wpas_hs20_add_indication(extra_ie);
 654 #endif /* CONFIG_HS20 */
 655
 656         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 657                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 658                         "generated frequency list");
 659                 params.freqs = wpa_s->next_scan_freqs;
 660         } else
 661                 os_free(wpa_s->next_scan_freqs);
 662         wpa_s->next_scan_freqs = NULL;
 663
 664         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 665                 wpa_s->conf, &params.num_filter_ssids);
 666         if (extra_ie) {
 667                 params.extra_ies = wpabuf_head(extra_ie);
 668                 params.extra_ies_len = wpabuf_len(extra_ie);
 669         }
 670
 671 #ifdef CONFIG_P2P
 672         if (wpa_s->p2p_in_provisioning ||
 673             (wpa_s->show_group_started && wpa_s->go_params)) {
 674                 /*
 675                  * The interface may not yet be in P2P mode, so we have to
 676                  * explicitly request P2P probe to disable CCK rates.
 677                  */
 678                 params.p2p_probe = 1;
 679         }
 680 #endif /* CONFIG_P2P */
 681
 682         scan_params = &params;
 683
 684 scan:
 685         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 686
 687         wpabuf_free(extra_ie);
 688         os_free(params.freqs);
 689         os_free(params.filter_ssids);
 690
 691         if (ret) {
 692                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 693                 if (prev_state != wpa_s->wpa_state)
 694                         wpa_supplicant_set_state(wpa_s, prev_state);
 695                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 696         }
 697 }
 698
 699
 700 /**
 701  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 702  * @wpa_s: Pointer to wpa_supplicant data
 703  * @sec: Number of seconds after which to scan
 704  * @usec: Number of microseconds after which to scan
 705  *
 706  * This function is used to schedule a scan for neighboring access points after
 707  * the specified time.
 708  */
 709 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 710 {
 711 #ifndef ANDROID
 712         /* If there's at least one network that should be specifically scanned
 713          * then don't cancel the scan and reschedule.  Some drivers do
 714          * background scanning which generates frequent scan results, and that
 715          * causes the specific SSID scan to get continually pushed back and
 716          * never happen, which causes hidden APs to never get probe-scanned.
 717          */
 718         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 719             wpa_s->conf->ap_scan == 1) {
 720                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 721
 722                 while (ssid) {
 723                         if (!wpas_network_disabled(wpa_s, ssid) &&
 724                             ssid->scan_ssid)
 725                                 break;
 726                         ssid = ssid->next;
 727                 }
 728                 if (ssid) {
 729                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 730                                 "ensure that specific SSID scans occur");
 731                         return;
 732                 }
 733         }
 734 #endif
 735         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 736                 sec, usec);
 737         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 738         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 739 }
 740
 741
 742 /**
 743  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 744  * @wpa_s: Pointer to wpa_supplicant data
 745  * @sec: Number of seconds after which to scan
 746  * @usec: Number of microseconds after which to scan
 747  *
 748  * This function is used to schedule periodic scans for neighboring
 749  * access points after the specified time.
 750  */
 751 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 752                                       int sec, int usec)
 753 {
 754         if (!wpa_s->sched_scan_supported)
 755                 return -1;
 756
 757         eloop_register_timeout(sec, usec,
 758                                wpa_supplicant_delayed_sched_scan_timeout,
 759                                wpa_s, NULL);
 760
 761         return 0;
 762 }
 763
 764
 765 /**
 766  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 767  * @wpa_s: Pointer to wpa_supplicant data
 768  *
 769  * This function is used to schedule periodic scans for neighboring
 770  * access points repeating the scan continuously.
 771  */
 772 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 773 {
 774         struct wpa_driver_scan_params params;
 775         struct wpa_driver_scan_params *scan_params;
 776         enum wpa_states prev_state;
 777         struct wpa_ssid *ssid = NULL;
 778         struct wpabuf *extra_ie = NULL;
 779         int ret;
 780         unsigned int max_sched_scan_ssids;
 781         int wildcard = 0;
 782         int need_ssids;
 783
 784         if (!wpa_s->sched_scan_supported)
 785                 return -1;
 786
 787         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 788                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 789         else
 790                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 791         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 792                 return -1;
 793
 794         if (wpa_s->sched_scanning) {
 795                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 796                 return 0;
 797         }
 798
 799         need_ssids = 0;
 800         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 801                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 802                         /* Use wildcard SSID to find this network */
 803                         wildcard = 1;
 804                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 805                            ssid->ssid_len)
 806                         need_ssids++;
 807
 808 #ifdef CONFIG_WPS
 809                 if (!wpas_network_disabled(wpa_s, ssid) &&
 810                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 811                         /*
 812                          * Normal scan is more reliable and faster for WPS
 813                          * operations and since these are for short periods of
 814                          * time, the benefit of trying to use sched_scan would
 815                          * be limited.
 816                          */
 817                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 818                                 "sched_scan for WPS");
 819                         return -1;
 820                 }
 821 #endif /* CONFIG_WPS */
 822         }
 823         if (wildcard)
 824                 need_ssids++;
 825
 826         if (wpa_s->normal_scans < 3 &&
 827             (need_ssids <= wpa_s->max_scan_ssids ||
 828              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 829                 /*
 830                  * When normal scan can speed up operations, use that for the
 831                  * first operations before starting the sched_scan to allow
 832                  * user space sleep more. We do this only if the normal scan
 833                  * has functionality that is suitable for this or if the
 834                  * sched_scan does not have better support for multiple SSIDs.
 835                  */
 836                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 837                         "sched_scan for initial scans (normal_scans=%d)",
 838                         wpa_s->normal_scans);
 839                 return -1;
 840         }
 841
 842         os_memset(&params, 0, sizeof(params));
 843
 844         /* If we can't allocate space for the filters, we just don't filter */
 845         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 846                                         sizeof(struct wpa_driver_scan_filter));
 847
 848         prev_state = wpa_s->wpa_state;
 849 #ifndef ANDROID_P2P
 850         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 851             wpa_s->wpa_state == WPA_INACTIVE)
 852                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 853 #endif
 854
 855         if (wpa_s->autoscan_params != NULL) {
 856                 scan_params = wpa_s->autoscan_params;
 857                 goto scan;
 858         }
 859
 860         /* Find the starting point from which to continue scanning */
 861         ssid = wpa_s->conf->ssid;
 862         if (wpa_s->prev_sched_ssid) {
 863                 while (ssid) {
 864                         if (ssid == wpa_s->prev_sched_ssid) {
 865                                 ssid = ssid->next;
 866                                 break;
 867                         }
 868                         ssid = ssid->next;
 869                 }
 870         }
 871
 872         if (!ssid || !wpa_s->prev_sched_ssid) {
 873                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 874
 875                 if (wpa_s->sched_scan_interval == 0)
 876                         wpa_s->sched_scan_interval = 10;
 877                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 878                 wpa_s->first_sched_scan = 1;
 879                 ssid = wpa_s->conf->ssid;
 880                 wpa_s->prev_sched_ssid = ssid;
 881         }
 882
 883         if (wildcard) {
 884                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 885                 params.num_ssids++;
 886         }
 887
 888         while (ssid) {
 889                 if (wpas_network_disabled(wpa_s, ssid))
 890                         goto next;
 891
 892                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 893                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 894                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 895                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 896                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 897                                   ssid->ssid, ssid->ssid_len);
 898                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 899                                 ssid->ssid_len;
 900                         params.num_filter_ssids++;
 901                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
 902                 {
 903                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
 904                                 "filter for sched_scan - drop filter");
 905                         os_free(params.filter_ssids);
 906                         params.filter_ssids = NULL;
 907                         params.num_filter_ssids = 0;
 908                 }
 909
 910                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
 911                         if (params.num_ssids == max_sched_scan_ssids)
 912                                 break; /* only room for broadcast SSID */
 913                         wpa_dbg(wpa_s, MSG_DEBUG,
 914                                 "add to active scan ssid: %s",
 915                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 916                         params.ssids[params.num_ssids].ssid =
 917                                 ssid->ssid;
 918                         params.ssids[params.num_ssids].ssid_len =
 919                                 ssid->ssid_len;
 920                         params.num_ssids++;
 921                         if (params.num_ssids >= max_sched_scan_ssids) {
 922                                 wpa_s->prev_sched_ssid = ssid;
 923                                 do {
 924                                         ssid = ssid->next;
 925                                 } while (ssid &&
 926                                          (wpas_network_disabled(wpa_s, ssid) ||
 927                                           !ssid->scan_ssid));
 928                                 break;
 929                         }
 930                 }
 931
 932         next:
 933                 wpa_s->prev_sched_ssid = ssid;
 934                 ssid = ssid->next;
 935         }
 936
 937         if (params.num_filter_ssids == 0) {
 938                 os_free(params.filter_ssids);
 939                 params.filter_ssids = NULL;
 940         }
 941
 942         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 943         if (extra_ie) {
 944                 params.extra_ies = wpabuf_head(extra_ie);
 945                 params.extra_ies_len = wpabuf_len(extra_ie);
 946         }
 947
 948         scan_params = &params;
 949
 950 scan:
 951         if (ssid || !wpa_s->first_sched_scan) {
 952                 wpa_dbg(wpa_s, MSG_DEBUG,
 953                         "Starting sched scan: interval %d timeout %d",
 954                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 955         } else {
 956                 wpa_dbg(wpa_s, MSG_DEBUG,
 957                         "Starting sched scan: interval %d (no timeout)",
 958                         wpa_s->sched_scan_interval);
 959         }
 960
 961         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
 962                                               wpa_s->sched_scan_interval);
 963         wpabuf_free(extra_ie);
 964         os_free(params.filter_ssids);
 965         if (ret) {
 966                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 967                 if (prev_state != wpa_s->wpa_state)
 968                         wpa_supplicant_set_state(wpa_s, prev_state);
 969                 return ret;
 970         }
 971
 972         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 973         if (ssid || !wpa_s->first_sched_scan) {
 974                 wpa_s->sched_scan_timed_out = 0;
 975                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 976                                        wpa_supplicant_sched_scan_timeout,
 977                                        wpa_s, NULL);
 978                 wpa_s->first_sched_scan = 0;
 979                 wpa_s->sched_scan_timeout /= 2;
 980                 wpa_s->sched_scan_interval *= 2;
 981         }
 982
 983         return 0;
 984 }
 985
 986
 987 /**
 988  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 989  * @wpa_s: Pointer to wpa_supplicant data
 990  *
 991  * This function is used to cancel a scan request scheduled with
 992  * wpa_supplicant_req_scan().
 993  */
 994 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 995 {
 996         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 997         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 998 #ifdef ANDROID
 999         wpa_supplicant_notify_scanning(wpa_s, 0);
1000 #endif
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 #ifdef ANDROID_P2P
1026                 if(!wpa_s->sched_scanning)
1027                         wpa_s->scanning = scanning;
1028 #else
1029                 wpa_s->scanning = scanning;
1030 #endif
1031                 wpas_notify_scanning(wpa_s);
1032         }
1033 }
1034
1035
1036 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1037 {
1038         int rate = 0;
1039         const u8 *ie;
1040         int i;
1041
1042         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1043         for (i = 0; ie && i < ie[1]; i++) {
1044                 if ((ie[i + 2] & 0x7f) > rate)
1045                         rate = ie[i + 2] & 0x7f;
1046         }
1047
1048         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1049         for (i = 0; ie && i < ie[1]; i++) {
1050                 if ((ie[i + 2] & 0x7f) > rate)
1051                         rate = ie[i + 2] & 0x7f;
1052         }
1053
1054         return rate;
1055 }
1056
1057
1058 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1059 {
1060         const u8 *end, *pos;
1061
1062         pos = (const u8 *) (res + 1);
1063         end = pos + res->ie_len;
1064
1065         while (pos + 1 < end) {
1066                 if (pos + 2 + pos[1] > end)
1067                         break;
1068                 if (pos[0] == ie)
1069                         return pos;
1070                 pos += 2 + pos[1];
1071         }
1072
1073         return NULL;
1074 }
1075
1076
1077 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1078                                   u32 vendor_type)
1079 {
1080         const u8 *end, *pos;
1081
1082         pos = (const u8 *) (res + 1);
1083         end = pos + res->ie_len;
1084
1085         while (pos + 1 < end) {
1086                 if (pos + 2 + pos[1] > end)
1087                         break;
1088                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1089                     vendor_type == WPA_GET_BE32(&pos[2]))
1090                         return pos;
1091                 pos += 2 + pos[1];
1092         }
1093
1094         return NULL;
1095 }
1096
1097
1098 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1099                                              u32 vendor_type)
1100 {
1101         struct wpabuf *buf;
1102         const u8 *end, *pos;
1103
1104         buf = wpabuf_alloc(res->ie_len);
1105         if (buf == NULL)
1106                 return NULL;
1107
1108         pos = (const u8 *) (res + 1);
1109         end = pos + res->ie_len;
1110
1111         while (pos + 1 < end) {
1112                 if (pos + 2 + pos[1] > end)
1113                         break;
1114                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1115                     vendor_type == WPA_GET_BE32(&pos[2]))
1116                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1117                 pos += 2 + pos[1];
1118         }
1119
1120         if (wpabuf_len(buf) == 0) {
1121                 wpabuf_free(buf);
1122                 buf = NULL;
1123         }
1124
1125         return buf;
1126 }
1127
1128
1129 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1130         const struct wpa_scan_res *res, u32 vendor_type)
1131 {
1132         struct wpabuf *buf;
1133         const u8 *end, *pos;
1134
1135         if (res->beacon_ie_len == 0)
1136                 return NULL;
1137         buf = wpabuf_alloc(res->beacon_ie_len);
1138         if (buf == NULL)
1139                 return NULL;
1140
1141         pos = (const u8 *) (res + 1);
1142         pos += res->ie_len;
1143         end = pos + res->beacon_ie_len;
1144
1145         while (pos + 1 < end) {
1146                 if (pos + 2 + pos[1] > end)
1147                         break;
1148                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1149                     vendor_type == WPA_GET_BE32(&pos[2]))
1150                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1151                 pos += 2 + pos[1];
1152         }
1153
1154         if (wpabuf_len(buf) == 0) {
1155                 wpabuf_free(buf);
1156                 buf = NULL;
1157         }
1158
1159         return buf;
1160 }
1161
1162
1163 /*
1164  * Channels with a great SNR can operate at full rate. What is a great SNR?
1165  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1166  * rule of thumb is that any SNR above 20 is good." This one
1167  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1168  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1169  * conservative value.
1170  */
1171 #define GREAT_SNR 30
1172
1173 /* Compare function for sorting scan results. Return >0 if @b is considered
1174  * better. */
1175 static int wpa_scan_result_compar(const void *a, const void *b)
1176 {
1177 #define IS_5GHZ(n) (n > 4000)
1178 #define MIN(a,b) a < b ? a : b
1179         struct wpa_scan_res **_wa = (void *) a;
1180         struct wpa_scan_res **_wb = (void *) b;
1181         struct wpa_scan_res *wa = *_wa;
1182         struct wpa_scan_res *wb = *_wb;
1183         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1184         int snr_a, snr_b;
1185
1186         /* WPA/WPA2 support preferred */
1187         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1188                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1189         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1190                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1191
1192         if (wpa_b && !wpa_a)
1193                 return 1;
1194         if (!wpa_b && wpa_a)
1195                 return -1;
1196
1197         /* privacy support preferred */
1198         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1199             (wb->caps & IEEE80211_CAP_PRIVACY))
1200                 return 1;
1201         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1202             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1203                 return -1;
1204
1205         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1206             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1207                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1208                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1209         } else {
1210                 /* Not suitable information to calculate SNR, so use level */
1211                 snr_a = wa->level;
1212                 snr_b = wb->level;
1213         }
1214
1215         /* best/max rate preferred if SNR close enough */
1216         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1217             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1218                 maxrate_a = wpa_scan_get_max_rate(wa);
1219                 maxrate_b = wpa_scan_get_max_rate(wb);
1220                 if (maxrate_a != maxrate_b)
1221                         return maxrate_b - maxrate_a;
1222                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1223                         return IS_5GHZ(wa->freq) ? -1 : 1;
1224         }
1225
1226         /* use freq for channel preference */
1227
1228         /* all things being equal, use SNR; if SNRs are
1229          * identical, use quality values since some drivers may only report
1230          * that value and leave the signal level zero */
1231         if (snr_b == snr_a)
1232                 return wb->qual - wa->qual;
1233         return snr_b - snr_a;
1234 #undef MIN
1235 #undef IS_5GHZ
1236 }
1237
1238
1239 #ifdef CONFIG_WPS
1240 /* Compare function for sorting scan results when searching a WPS AP for
1241  * provisioning. Return >0 if @b is considered better. */
1242 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1243 {
1244         struct wpa_scan_res **_wa = (void *) a;
1245         struct wpa_scan_res **_wb = (void *) b;
1246         struct wpa_scan_res *wa = *_wa;
1247         struct wpa_scan_res *wb = *_wb;
1248         int uses_wps_a, uses_wps_b;
1249         struct wpabuf *wps_a, *wps_b;
1250         int res;
1251
1252         /* Optimization - check WPS IE existence before allocated memory and
1253          * doing full reassembly. */
1254         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1255         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1256         if (uses_wps_a && !uses_wps_b)
1257                 return -1;
1258         if (!uses_wps_a && uses_wps_b)
1259                 return 1;
1260
1261         if (uses_wps_a && uses_wps_b) {
1262                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1263                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1264                 res = wps_ap_priority_compar(wps_a, wps_b);
1265                 wpabuf_free(wps_a);
1266                 wpabuf_free(wps_b);
1267                 if (res)
1268                         return res;
1269         }
1270
1271         /*
1272          * Do not use current AP security policy as a sorting criteria during
1273          * WPS provisioning step since the AP may get reconfigured at the
1274          * completion of provisioning.
1275          */
1276
1277         /* all things being equal, use signal level; if signal levels are
1278          * identical, use quality values since some drivers may only report
1279          * that value and leave the signal level zero */
1280         if (wb->level == wa->level)
1281                 return wb->qual - wa->qual;
1282         return wb->level - wa->level;
1283 }
1284 #endif /* CONFIG_WPS */
1285
1286
1287 static void dump_scan_res(struct wpa_scan_results *scan_res)
1288 {
1289 #ifndef CONFIG_NO_STDOUT_DEBUG
1290         size_t i;
1291
1292         if (scan_res->res == NULL || scan_res->num == 0)
1293                 return;
1294
1295         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1296
1297         for (i = 0; i < scan_res->num; i++) {
1298                 struct wpa_scan_res *r = scan_res->res[i];
1299                 u8 *pos;
1300                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1301                     == WPA_SCAN_LEVEL_DBM) {
1302                         int snr = r->level - r->noise;
1303                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1304                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1305                                    MAC2STR(r->bssid), r->freq, r->qual,
1306                                    r->noise, r->level, snr,
1307                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1308                 } else {
1309                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1310                                    "noise=%d level=%d flags=0x%x",
1311                                    MAC2STR(r->bssid), r->freq, r->qual,
1312                                    r->noise, r->level, r->flags);
1313                 }
1314                 pos = (u8 *) (r + 1);
1315                 if (r->ie_len)
1316                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1317                 pos += r->ie_len;
1318                 if (r->beacon_ie_len)
1319                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1320                                     pos, r->beacon_ie_len);
1321         }
1322 #endif /* CONFIG_NO_STDOUT_DEBUG */
1323 }
1324
1325
1326 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1327                                       const u8 *bssid)
1328 {
1329         size_t i;
1330
1331         if (wpa_s->bssid_filter == NULL)
1332                 return 1;
1333
1334         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1335                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1336                               ETH_ALEN) == 0)
1337                         return 1;
1338         }
1339
1340         return 0;
1341 }
1342
1343
1344 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1345                             struct wpa_scan_results *res)
1346 {
1347         size_t i, j;
1348
1349         if (wpa_s->bssid_filter == NULL)
1350                 return;
1351
1352         for (i = 0, j = 0; i < res->num; i++) {
1353                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1354                                                       res->res[i]->bssid)) {
1355                         res->res[j++] = res->res[i];
1356                 } else {
1357                         os_free(res->res[i]);
1358                         res->res[i] = NULL;
1359                 }
1360         }
1361
1362         if (res->num != j) {
1363                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1364                            (int) (res->num - j));
1365                 res->num = j;
1366         }
1367 }
1368
1369
1370 /**
1371  * wpa_supplicant_get_scan_results - Get scan results
1372  * @wpa_s: Pointer to wpa_supplicant data
1373  * @info: Information about what was scanned or %NULL if not available
1374  * @new_scan: Whether a new scan was performed
1375  * Returns: Scan results, %NULL on failure
1376  *
1377  * This function request the current scan results from the driver and updates
1378  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1379  * results with wpa_scan_results_free().
1380  */
1381 struct wpa_scan_results *
1382 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1383                                 struct scan_info *info, int new_scan)
1384 {
1385         struct wpa_scan_results *scan_res;
1386         size_t i;
1387         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1388
1389         scan_res = wpa_drv_get_scan_results2(wpa_s);
1390         if (scan_res == NULL) {
1391                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1392                 return NULL;
1393         }
1394         filter_scan_res(wpa_s, scan_res);
1395
1396 #ifdef CONFIG_WPS
1397         if (wpas_wps_in_progress(wpa_s)) {
1398                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1399                         "provisioning rules");
1400                 compar = wpa_scan_result_wps_compar;
1401         }
1402 #endif /* CONFIG_WPS */
1403
1404         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1405               compar);
1406         dump_scan_res(scan_res);
1407
1408         wpa_bss_update_start(wpa_s);
1409         for (i = 0; i < scan_res->num; i++)
1410                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1411         wpa_bss_update_end(wpa_s, info, new_scan);
1412
1413         return scan_res;
1414 }
1415
1416
1417 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1418 {
1419         struct wpa_scan_results *scan_res;
1420         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1421         if (scan_res == NULL)
1422                 return -1;
1423         wpa_scan_results_free(scan_res);
1424
1425         return 0;
1426 }