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