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