wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10
  11 #include "utils/common.h"
  12 #include "utils/eloop.h"
  13 #include "common/ieee802_11_defs.h"
  14 #include "config.h"
  15 #include "wpa_supplicant_i.h"
  16 #include "driver_i.h"
  17 #include "wps_supplicant.h"
  18 #include "p2p_supplicant.h"
  19 #include "p2p/p2p.h"
  20 #include "hs20_supplicant.h"
  21 #include "notify.h"
  22 #include "bss.h"
  23 #include "scan.h"
  24
  25
  26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  27 {
  28         struct wpa_ssid *ssid;
  29         union wpa_event_data data;
  30
  31         ssid = wpa_supplicant_get_ssid(wpa_s);
  32         if (ssid == NULL)
  33                 return;
  34
  35         if (wpa_s->current_ssid == NULL) {
  36                 wpa_s->current_ssid = ssid;
  37                 if (wpa_s->current_ssid != NULL)
  38                         wpas_notify_network_changed(wpa_s);
  39         }
  40         wpa_supplicant_initiate_eapol(wpa_s);
  41         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  42                 "network - generating associated event");
  43         os_memset(&data, 0, sizeof(data));
  44         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  45 }
  46
  47
  48 #ifdef CONFIG_WPS
  49 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  50                            enum wps_request_type *req_type)
  51 {
  52         struct wpa_ssid *ssid;
  53         int wps = 0;
  54
  55         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  56                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  57                         continue;
  58
  59                 wps = 1;
  60                 *req_type = wpas_wps_get_req_type(ssid);
  61                 if (!ssid->eap.phase1)
  62                         continue;
  63
  64                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  65                         return 2;
  66         }
  67
  68 #ifdef CONFIG_P2P
  69         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p) {
  70                 wpa_s->wps->dev.p2p = 1;
  71                 if (!wps) {
  72                         wps = 1;
  73                         *req_type = WPS_REQ_ENROLLEE_INFO;
  74                 }
  75         }
  76 #endif /* CONFIG_P2P */
  77
  78         return wps;
  79 }
  80 #endif /* CONFIG_WPS */
  81
  82
  83 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  84 {
  85         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  86         int count = 0;
  87         while (ssid) {
  88                 if (!wpas_network_disabled(wpa_s, ssid))
  89                         count++;
  90                 ssid = ssid->next;
  91         }
  92         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
  93             wpa_s->conf->auto_interworking)
  94                 count++;
  95         return count;
  96 }
  97
  98
  99 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 100                                      struct wpa_ssid *ssid)
 101 {
 102         while (ssid) {
 103                 if (!wpas_network_disabled(wpa_s, ssid))
 104                         break;
 105                 ssid = ssid->next;
 106         }
 107
 108         /* ap_scan=2 mode - try to associate with each SSID. */
 109         if (ssid == NULL) {
 110                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 111                         "end of scan list - go back to beginning");
 112                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 113                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 114                 return;
 115         }
 116         if (ssid->next) {
 117                 /* Continue from the next SSID on the next attempt. */
 118                 wpa_s->prev_scan_ssid = ssid;
 119         } else {
 120                 /* Start from the beginning of the SSID list. */
 121                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 122         }
 123         wpa_supplicant_associate(wpa_s, NULL, ssid);
 124 }
 125
 126
 127 static int int_array_len(const int *a)
 128 {
 129         int i;
 130         for (i = 0; a && a[i]; i++)
 131                 ;
 132         return i;
 133 }
 134
 135
 136 static void int_array_concat(int **res, const int *a)
 137 {
 138         int reslen, alen, i;
 139         int *n;
 140
 141         reslen = int_array_len(*res);
 142         alen = int_array_len(a);
 143
 144         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 145         if (n == NULL) {
 146                 os_free(*res);
 147                 *res = NULL;
 148                 return;
 149         }
 150         for (i = 0; i <= alen; i++)
 151                 n[reslen + i] = a[i];
 152         *res = n;
 153 }
 154
 155
 156 static int freq_cmp(const void *a, const void *b)
 157 {
 158         int _a = *(int *) a;
 159         int _b = *(int *) b;
 160
 161         if (_a == 0)
 162                 return 1;
 163         if (_b == 0)
 164                 return -1;
 165         return _a - _b;
 166 }
 167
 168
 169 static void int_array_sort_unique(int *a)
 170 {
 171         int alen;
 172         int i, j;
 173
 174         if (a == NULL)
 175                 return;
 176
 177         alen = int_array_len(a);
 178         qsort(a, alen, sizeof(int), freq_cmp);
 179
 180         i = 0;
 181         j = 1;
 182         while (a[i] && a[j]) {
 183                 if (a[i] == a[j]) {
 184                         j++;
 185                         continue;
 186                 }
 187                 a[++i] = a[j++];
 188         }
 189         if (a[i])
 190                 i++;
 191         a[i] = 0;
 192 }
 193
 194
 195 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 196                                 struct wpa_driver_scan_params *params)
 197 {
 198         int ret;
 199
 200         wpa_supplicant_notify_scanning(wpa_s, 1);
 201
 202         ret = wpa_drv_scan(wpa_s, params);
 203         if (ret) {
 204                 wpa_supplicant_notify_scanning(wpa_s, 0);
 205                 wpas_notify_scan_done(wpa_s, 0);
 206         } else {
 207                 wpa_s->scan_runs++;
 208                 wpa_s->normal_scans++;
 209         }
 210
 211         return ret;
 212 }
 213
 214
 215 static void
 216 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 217 {
 218         struct wpa_supplicant *wpa_s = eloop_ctx;
 219
 220         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 221
 222         if (wpa_supplicant_req_sched_scan(wpa_s))
 223                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 224 }
 225
 226
 227 static void
 228 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 229 {
 230         struct wpa_supplicant *wpa_s = eloop_ctx;
 231
 232         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 233
 234         wpa_s->sched_scan_timed_out = 1;
 235         wpa_supplicant_cancel_sched_scan(wpa_s);
 236 }
 237
 238
 239 static int
 240 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 241                                 struct wpa_driver_scan_params *params,
 242                                 int interval)
 243 {
 244         int ret;
 245
 246         wpa_supplicant_notify_scanning(wpa_s, 1);
 247         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 248         if (ret)
 249                 wpa_supplicant_notify_scanning(wpa_s, 0);
 250         else
 251                 wpa_s->sched_scanning = 1;
 252
 253         return ret;
 254 }
 255
 256
 257 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 258 {
 259         int ret;
 260
 261         ret = wpa_drv_stop_sched_scan(wpa_s);
 262         if (ret) {
 263                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 264                 /* TODO: what to do if stopping fails? */
 265                 return -1;
 266         }
 267
 268         return ret;
 269 }
 270
 271
 272 static struct wpa_driver_scan_filter *
 273 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 274 {
 275         struct wpa_driver_scan_filter *ssids;
 276         struct wpa_ssid *ssid;
 277         size_t count;
 278
 279         *num_ssids = 0;
 280         if (!conf->filter_ssids)
 281                 return NULL;
 282
 283         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 284                 if (ssid->ssid && ssid->ssid_len)
 285                         count++;
 286         }
 287         if (count == 0)
 288                 return NULL;
 289         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 290         if (ssids == NULL)
 291                 return NULL;
 292
 293         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 294                 if (!ssid->ssid || !ssid->ssid_len)
 295                         continue;
 296                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 297                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 298                 (*num_ssids)++;
 299         }
 300
 301         return ssids;
 302 }
 303
 304
 305 static void wpa_supplicant_optimize_freqs(
 306         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 307 {
 308 #ifdef CONFIG_P2P
 309         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 310             wpa_s->go_params) {
 311                 /* Optimize provisioning state scan based on GO information */
 312                 if (wpa_s->p2p_in_provisioning < 5 &&
 313                     wpa_s->go_params->freq > 0) {
 314                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 315                                 "preferred frequency %d MHz",
 316                                 wpa_s->go_params->freq);
 317                         params->freqs = os_zalloc(2 * sizeof(int));
 318                         if (params->freqs)
 319                                 params->freqs[0] = wpa_s->go_params->freq;
 320                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 321                            wpa_s->go_params->freq_list[0]) {
 322                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 323                                 "channels");
 324                         int_array_concat(&params->freqs,
 325                                          wpa_s->go_params->freq_list);
 326                         if (params->freqs)
 327                                 int_array_sort_unique(params->freqs);
 328                 }
 329                 wpa_s->p2p_in_provisioning++;
 330         }
 331 #endif /* CONFIG_P2P */
 332
 333 #ifdef CONFIG_WPS
 334         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 335                 /*
 336                  * Optimize post-provisioning scan based on channel used
 337                  * during provisioning.
 338                  */
 339                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 340                         "that was used during provisioning", wpa_s->wps_freq);
 341                 params->freqs = os_zalloc(2 * sizeof(int));
 342                 if (params->freqs)
 343                         params->freqs[0] = wpa_s->wps_freq;
 344                 wpa_s->after_wps--;
 345         }
 346
 347         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 348         {
 349                 /* Optimize provisioning scan based on already known channel */
 350                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 351                         wpa_s->wps_freq);
 352                 params->freqs = os_zalloc(2 * sizeof(int));
 353                 if (params->freqs)
 354                         params->freqs[0] = wpa_s->wps_freq;
 355                 wpa_s->known_wps_freq = 0; /* only do this once */
 356         }
 357 #endif /* CONFIG_WPS */
 358 }
 359
 360
 361 #ifdef CONFIG_INTERWORKING
 362 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 363                                            struct wpabuf *buf)
 364 {
 365         if (wpa_s->conf->interworking == 0)
 366                 return;
 367
 368         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 369         wpabuf_put_u8(buf, 4);
 370         wpabuf_put_u8(buf, 0x00);
 371         wpabuf_put_u8(buf, 0x00);
 372         wpabuf_put_u8(buf, 0x00);
 373         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 374
 375         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 376         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 377                       1 + ETH_ALEN);
 378         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 379         /* No Venue Info */
 380         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 381                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 382 }
 383 #endif /* CONFIG_INTERWORKING */
 384
 385
 386 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 387 {
 388         struct wpabuf *extra_ie = NULL;
 389 #ifdef CONFIG_WPS
 390         int wps = 0;
 391         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 392 #endif /* CONFIG_WPS */
 393
 394 #ifdef CONFIG_INTERWORKING
 395         if (wpa_s->conf->interworking &&
 396             wpabuf_resize(&extra_ie, 100) == 0)
 397                 wpas_add_interworking_elements(wpa_s, extra_ie);
 398 #endif /* CONFIG_INTERWORKING */
 399
 400 #ifdef CONFIG_WPS
 401         wps = wpas_wps_in_use(wpa_s, &req_type);
 402
 403         if (wps) {
 404                 struct wpabuf *wps_ie;
 405                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 406                                                 DEV_PW_DEFAULT,
 407                                                 &wpa_s->wps->dev,
 408                                                 wpa_s->wps->uuid, req_type,
 409                                                 0, NULL);
 410                 if (wps_ie) {
 411                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 412                                 wpabuf_put_buf(extra_ie, wps_ie);
 413                         wpabuf_free(wps_ie);
 414                 }
 415         }
 416
 417 #ifdef CONFIG_P2P
 418         if (wps) {
 419                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 420                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 421                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 422         }
 423 #endif /* CONFIG_P2P */
 424
 425 #endif /* CONFIG_WPS */
 426
 427         return extra_ie;
 428 }
 429
 430
 431 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 432 {
 433         struct wpa_supplicant *wpa_s = eloop_ctx;
 434         struct wpa_ssid *ssid;
 435         int scan_req = 0, ret;
 436         struct wpabuf *extra_ie = NULL;
 437         struct wpa_driver_scan_params params;
 438         struct wpa_driver_scan_params *scan_params;
 439         size_t max_ssids;
 440         enum wpa_states prev_state;
 441
 442         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 443                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 444                 return;
 445         }
 446
 447         if (wpa_s->disconnected && !wpa_s->scan_req) {
 448                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 449                 return;
 450         }
 451
 452         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 453             !wpa_s->scan_req) {
 454                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 455                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 456                 return;
 457         }
 458
 459         if (wpa_s->conf->ap_scan != 0 &&
 460             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 461                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 462                         "overriding ap_scan configuration");
 463                 wpa_s->conf->ap_scan = 0;
 464                 wpas_notify_ap_scan_changed(wpa_s);
 465         }
 466
 467         if (wpa_s->conf->ap_scan == 0) {
 468                 wpa_supplicant_gen_assoc_event(wpa_s);
 469                 return;
 470         }
 471
 472 #ifdef CONFIG_P2P
 473         if (wpas_p2p_in_progress(wpa_s)) {
 474                 if (wpa_s->sta_scan_pending &&
 475                     wpas_p2p_in_progress(wpa_s) == 2 &&
 476                     wpa_s->p2p_cb_on_scan_complete) {
 477                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 478                                 "mode scan during P2P search");
 479                 } else {
 480                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 481                                 "while P2P operation is in progress");
 482                         wpa_s->sta_scan_pending = 1;
 483                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 484                         return;
 485                 }
 486         }
 487 #endif /* CONFIG_P2P */
 488
 489         if (wpa_s->conf->ap_scan == 2)
 490                 max_ssids = 1;
 491         else {
 492                 max_ssids = wpa_s->max_scan_ssids;
 493                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 494                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 495         }
 496
 497         scan_req = wpa_s->scan_req;
 498         wpa_s->scan_req = 0;
 499
 500         os_memset(&params, 0, sizeof(params));
 501
 502         prev_state = wpa_s->wpa_state;
 503         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 504             wpa_s->wpa_state == WPA_INACTIVE)
 505                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 506
 507         /*
 508          * If autoscan has set its own scanning parameters
 509          */
 510         if (wpa_s->autoscan_params != NULL) {
 511                 scan_params = wpa_s->autoscan_params;
 512                 goto scan;
 513         }
 514
 515         if (scan_req != 2 && wpa_s->connect_without_scan) {
 516                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 517                         if (ssid == wpa_s->connect_without_scan)
 518                                 break;
 519                 }
 520                 wpa_s->connect_without_scan = NULL;
 521                 if (ssid) {
 522                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 523                                    "without scan step");
 524                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 525                         return;
 526                 }
 527         }
 528
 529 #ifdef CONFIG_P2P
 530         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 531             wpa_s->go_params) {
 532                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 533                            "P2P group formation");
 534                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 535                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 536                 params.num_ssids = 1;
 537                 goto ssid_list_set;
 538         }
 539 #endif /* CONFIG_P2P */
 540
 541         /* Find the starting point from which to continue scanning */
 542         ssid = wpa_s->conf->ssid;
 543         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 544                 while (ssid) {
 545                         if (ssid == wpa_s->prev_scan_ssid) {
 546                                 ssid = ssid->next;
 547                                 break;
 548                         }
 549                         ssid = ssid->next;
 550                 }
 551         }
 552
 553         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 554                 wpa_s->connect_without_scan = NULL;
 555                 wpa_s->prev_scan_wildcard = 0;
 556                 wpa_supplicant_assoc_try(wpa_s, ssid);
 557                 return;
 558         } else if (wpa_s->conf->ap_scan == 2) {
 559                 /*
 560                  * User-initiated scan request in ap_scan == 2; scan with
 561                  * wildcard SSID.
 562                  */
 563                 ssid = NULL;
 564         } else {
 565                 struct wpa_ssid *start = ssid, *tssid;
 566                 int freqs_set = 0;
 567                 if (ssid == NULL && max_ssids > 1)
 568                         ssid = wpa_s->conf->ssid;
 569                 while (ssid) {
 570                         if (!wpas_network_disabled(wpa_s, ssid) &&
 571                             ssid->scan_ssid) {
 572                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 573                                                   ssid->ssid, ssid->ssid_len);
 574                                 params.ssids[params.num_ssids].ssid =
 575                                         ssid->ssid;
 576                                 params.ssids[params.num_ssids].ssid_len =
 577                                         ssid->ssid_len;
 578                                 params.num_ssids++;
 579                                 if (params.num_ssids + 1 >= max_ssids)
 580                                         break;
 581                         }
 582                         ssid = ssid->next;
 583                         if (ssid == start)
 584                                 break;
 585                         if (ssid == NULL && max_ssids > 1 &&
 586                             start != wpa_s->conf->ssid)
 587                                 ssid = wpa_s->conf->ssid;
 588                 }
 589
 590                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 591                         if (wpas_network_disabled(wpa_s, tssid))
 592                                 continue;
 593                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 594                                 int_array_concat(&params.freqs,
 595                                                  tssid->scan_freq);
 596                         } else {
 597                                 os_free(params.freqs);
 598                                 params.freqs = NULL;
 599                         }
 600                         freqs_set = 1;
 601                 }
 602                 int_array_sort_unique(params.freqs);
 603         }
 604
 605         if (ssid && max_ssids == 1) {
 606                 /*
 607                  * If the driver is limited to 1 SSID at a time interleave
 608                  * wildcard SSID scans with specific SSID scans to avoid
 609                  * waiting a long time for a wildcard scan.
 610                  */
 611                 if (!wpa_s->prev_scan_wildcard) {
 612                         params.ssids[0].ssid = NULL;
 613                         params.ssids[0].ssid_len = 0;
 614                         wpa_s->prev_scan_wildcard = 1;
 615                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 616                                 "wildcard SSID (Interleave with specific)");
 617                 } else {
 618                         wpa_s->prev_scan_ssid = ssid;
 619                         wpa_s->prev_scan_wildcard = 0;
 620                         wpa_dbg(wpa_s, MSG_DEBUG,
 621                                 "Starting AP scan for specific SSID: %s",
 622                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 623                 }
 624         } else if (ssid) {
 625                 /* max_ssids > 1 */
 626
 627                 wpa_s->prev_scan_ssid = ssid;
 628                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 629                         "the scan request");
 630                 params.num_ssids++;
 631         } else {
 632                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 633                 params.num_ssids++;
 634                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 635                         "SSID");
 636         }
 637 #ifdef CONFIG_P2P
 638 ssid_list_set:
 639 #endif /* CONFIG_P2P */
 640
 641         wpa_supplicant_optimize_freqs(wpa_s, &params);
 642         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 643
 644 #ifdef CONFIG_HS20
 645         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 646                 wpas_hs20_add_indication(extra_ie);
 647 #endif /* CONFIG_HS20 */
 648
 649         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 650                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 651                         "generated frequency list");
 652                 params.freqs = wpa_s->next_scan_freqs;
 653         } else
 654                 os_free(wpa_s->next_scan_freqs);
 655         wpa_s->next_scan_freqs = NULL;
 656
 657         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 658                 wpa_s->conf, &params.num_filter_ssids);
 659         if (extra_ie) {
 660                 params.extra_ies = wpabuf_head(extra_ie);
 661                 params.extra_ies_len = wpabuf_len(extra_ie);
 662         }
 663
 664 #ifdef CONFIG_P2P
 665         if (wpa_s->p2p_in_provisioning ||
 666             (wpa_s->show_group_started && wpa_s->go_params)) {
 667                 /*
 668                  * The interface may not yet be in P2P mode, so we have to
 669                  * explicitly request P2P probe to disable CCK rates.
 670                  */
 671                 params.p2p_probe = 1;
 672         }
 673 #endif /* CONFIG_P2P */
 674
 675         scan_params = &params;
 676
 677 scan:
 678         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 679
 680         wpabuf_free(extra_ie);
 681         os_free(params.freqs);
 682         os_free(params.filter_ssids);
 683
 684         if (ret) {
 685                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 686                 if (prev_state != wpa_s->wpa_state)
 687                         wpa_supplicant_set_state(wpa_s, prev_state);
 688                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 689         }
 690 }
 691
 692
 693 /**
 694  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 695  * @wpa_s: Pointer to wpa_supplicant data
 696  * @sec: Number of seconds after which to scan
 697  * @usec: Number of microseconds after which to scan
 698  *
 699  * This function is used to schedule a scan for neighboring access points after
 700  * the specified time.
 701  */
 702 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 703 {
 704         /* If there's at least one network that should be specifically scanned
 705          * then don't cancel the scan and reschedule.  Some drivers do
 706          * background scanning which generates frequent scan results, and that
 707          * causes the specific SSID scan to get continually pushed back and
 708          * never happen, which causes hidden APs to never get probe-scanned.
 709          */
 710         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 711             wpa_s->conf->ap_scan == 1) {
 712                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 713
 714                 while (ssid) {
 715                         if (!wpas_network_disabled(wpa_s, ssid) &&
 716                             ssid->scan_ssid)
 717                                 break;
 718                         ssid = ssid->next;
 719                 }
 720                 if (ssid) {
 721                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 722                                 "ensure that specific SSID scans occur");
 723                         return;
 724                 }
 725         }
 726
 727         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 728                 sec, usec);
 729         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 730         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 731 }
 732
 733
 734 /**
 735  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 736  * @wpa_s: Pointer to wpa_supplicant data
 737  * @sec: Number of seconds after which to scan
 738  * @usec: Number of microseconds after which to scan
 739  *
 740  * This function is used to schedule periodic scans for neighboring
 741  * access points after the specified time.
 742  */
 743 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 744                                       int sec, int usec)
 745 {
 746         if (!wpa_s->sched_scan_supported)
 747                 return -1;
 748
 749         eloop_register_timeout(sec, usec,
 750                                wpa_supplicant_delayed_sched_scan_timeout,
 751                                wpa_s, NULL);
 752
 753         return 0;
 754 }
 755
 756
 757 /**
 758  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 759  * @wpa_s: Pointer to wpa_supplicant data
 760  *
 761  * This function is used to schedule periodic scans for neighboring
 762  * access points repeating the scan continuously.
 763  */
 764 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 765 {
 766         struct wpa_driver_scan_params params;
 767         struct wpa_driver_scan_params *scan_params;
 768         enum wpa_states prev_state;
 769         struct wpa_ssid *ssid = NULL;
 770         struct wpabuf *extra_ie = NULL;
 771         int ret;
 772         unsigned int max_sched_scan_ssids;
 773         int wildcard = 0;
 774         int need_ssids;
 775
 776         if (!wpa_s->sched_scan_supported)
 777                 return -1;
 778
 779         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 780                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 781         else
 782                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 783         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 784                 return -1;
 785
 786         if (wpa_s->sched_scanning) {
 787                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 788                 return 0;
 789         }
 790
 791         need_ssids = 0;
 792         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 793                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 794                         /* Use wildcard SSID to find this network */
 795                         wildcard = 1;
 796                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 797                            ssid->ssid_len)
 798                         need_ssids++;
 799
 800 #ifdef CONFIG_WPS
 801                 if (!wpas_network_disabled(wpa_s, ssid) &&
 802                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 803                         /*
 804                          * Normal scan is more reliable and faster for WPS
 805                          * operations and since these are for short periods of
 806                          * time, the benefit of trying to use sched_scan would
 807                          * be limited.
 808                          */
 809                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 810                                 "sched_scan for WPS");
 811                         return -1;
 812                 }
 813 #endif /* CONFIG_WPS */
 814         }
 815         if (wildcard)
 816                 need_ssids++;
 817
 818         if (wpa_s->normal_scans < 3 &&
 819             (need_ssids <= wpa_s->max_scan_ssids ||
 820              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 821                 /*
 822                  * When normal scan can speed up operations, use that for the
 823                  * first operations before starting the sched_scan to allow
 824                  * user space sleep more. We do this only if the normal scan
 825                  * has functionality that is suitable for this or if the
 826                  * sched_scan does not have better support for multiple SSIDs.
 827                  */
 828                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 829                         "sched_scan for initial scans (normal_scans=%d)",
 830                         wpa_s->normal_scans);
 831                 return -1;
 832         }
 833
 834         os_memset(&params, 0, sizeof(params));
 835
 836         /* If we can't allocate space for the filters, we just don't filter */
 837         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 838                                         sizeof(struct wpa_driver_scan_filter));
 839
 840         prev_state = wpa_s->wpa_state;
 841         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 842             wpa_s->wpa_state == WPA_INACTIVE)
 843                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 844
 845         if (wpa_s->autoscan_params != NULL) {
 846                 scan_params = wpa_s->autoscan_params;
 847                 goto scan;
 848         }
 849
 850         /* Find the starting point from which to continue scanning */
 851         ssid = wpa_s->conf->ssid;
 852         if (wpa_s->prev_sched_ssid) {
 853                 while (ssid) {
 854                         if (ssid == wpa_s->prev_sched_ssid) {
 855                                 ssid = ssid->next;
 856                                 break;
 857                         }
 858                         ssid = ssid->next;
 859                 }
 860         }
 861
 862         if (!ssid || !wpa_s->prev_sched_ssid) {
 863                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 864
 865                 if (wpa_s->sched_scan_interval == 0)
 866                         wpa_s->sched_scan_interval = 10;
 867                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 868                 wpa_s->first_sched_scan = 1;
 869                 ssid = wpa_s->conf->ssid;
 870                 wpa_s->prev_sched_ssid = ssid;
 871         }
 872
 873         if (wildcard) {
 874                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 875                 params.num_ssids++;
 876         }
 877
 878         while (ssid) {
 879                 if (wpas_network_disabled(wpa_s, ssid))
 880                         goto next;
 881
 882                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 883                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 884                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 885                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 886                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 887                                   ssid->ssid, ssid->ssid_len);
 888                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 889                                 ssid->ssid_len;
 890                         params.num_filter_ssids++;
 891                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
 892                 {
 893                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
 894                                 "filter for sched_scan - drop filter");
 895                         os_free(params.filter_ssids);
 896                         params.filter_ssids = NULL;
 897                         params.num_filter_ssids = 0;
 898                 }
 899
 900                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
 901                         if (params.num_ssids == max_sched_scan_ssids)
 902                                 break; /* only room for broadcast SSID */
 903                         wpa_dbg(wpa_s, MSG_DEBUG,
 904                                 "add to active scan ssid: %s",
 905                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 906                         params.ssids[params.num_ssids].ssid =
 907                                 ssid->ssid;
 908                         params.ssids[params.num_ssids].ssid_len =
 909                                 ssid->ssid_len;
 910                         params.num_ssids++;
 911                         if (params.num_ssids >= max_sched_scan_ssids) {
 912                                 wpa_s->prev_sched_ssid = ssid;
 913                                 do {
 914                                         ssid = ssid->next;
 915                                 } while (ssid &&
 916                                          (wpas_network_disabled(wpa_s, ssid) ||
 917                                           !ssid->scan_ssid));
 918                                 break;
 919                         }
 920                 }
 921
 922         next:
 923                 wpa_s->prev_sched_ssid = ssid;
 924                 ssid = ssid->next;
 925         }
 926
 927         if (params.num_filter_ssids == 0) {
 928                 os_free(params.filter_ssids);
 929                 params.filter_ssids = NULL;
 930         }
 931
 932         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 933         if (extra_ie) {
 934                 params.extra_ies = wpabuf_head(extra_ie);
 935                 params.extra_ies_len = wpabuf_len(extra_ie);
 936         }
 937
 938         scan_params = &params;
 939
 940 scan:
 941         if (ssid || !wpa_s->first_sched_scan) {
 942                 wpa_dbg(wpa_s, MSG_DEBUG,
 943                         "Starting sched scan: interval %d timeout %d",
 944                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 945         } else {
 946                 wpa_dbg(wpa_s, MSG_DEBUG,
 947                         "Starting sched scan: interval %d (no timeout)",
 948                         wpa_s->sched_scan_interval);
 949         }
 950
 951         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
 952                                               wpa_s->sched_scan_interval);
 953         wpabuf_free(extra_ie);
 954         os_free(params.filter_ssids);
 955         if (ret) {
 956                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 957                 if (prev_state != wpa_s->wpa_state)
 958                         wpa_supplicant_set_state(wpa_s, prev_state);
 959                 return ret;
 960         }
 961
 962         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 963         if (ssid || !wpa_s->first_sched_scan) {
 964                 wpa_s->sched_scan_timed_out = 0;
 965                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 966                                        wpa_supplicant_sched_scan_timeout,
 967                                        wpa_s, NULL);
 968                 wpa_s->first_sched_scan = 0;
 969                 wpa_s->sched_scan_timeout /= 2;
 970                 wpa_s->sched_scan_interval *= 2;
 971         }
 972
 973         return 0;
 974 }
 975
 976
 977 /**
 978  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 979  * @wpa_s: Pointer to wpa_supplicant data
 980  *
 981  * This function is used to cancel a scan request scheduled with
 982  * wpa_supplicant_req_scan().
 983  */
 984 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 985 {
 986         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 987         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 988 }
 989
 990
 991 /**
 992  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
 993  * @wpa_s: Pointer to wpa_supplicant data
 994  *
 995  * This function is used to stop a periodic scheduled scan.
 996  */
 997 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
 998 {
 999         if (!wpa_s->sched_scanning)
1000                 return;
1001
1002         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1003         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1004         wpa_supplicant_stop_sched_scan(wpa_s);
1005 }
1006
1007
1008 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1009                                     int scanning)
1010 {
1011         if (wpa_s->scanning != scanning) {
1012                 wpa_s->scanning = scanning;
1013                 wpas_notify_scanning(wpa_s);
1014         }
1015 }
1016
1017
1018 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1019 {
1020         int rate = 0;
1021         const u8 *ie;
1022         int i;
1023
1024         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1025         for (i = 0; ie && i < ie[1]; i++) {
1026                 if ((ie[i + 2] & 0x7f) > rate)
1027                         rate = ie[i + 2] & 0x7f;
1028         }
1029
1030         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1031         for (i = 0; ie && i < ie[1]; i++) {
1032                 if ((ie[i + 2] & 0x7f) > rate)
1033                         rate = ie[i + 2] & 0x7f;
1034         }
1035
1036         return rate;
1037 }
1038
1039
1040 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1041 {
1042         const u8 *end, *pos;
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] == ie)
1051                         return pos;
1052                 pos += 2 + pos[1];
1053         }
1054
1055         return NULL;
1056 }
1057
1058
1059 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1060                                   u32 vendor_type)
1061 {
1062         const u8 *end, *pos;
1063
1064         pos = (const u8 *) (res + 1);
1065         end = pos + res->ie_len;
1066
1067         while (pos + 1 < end) {
1068                 if (pos + 2 + pos[1] > end)
1069                         break;
1070                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1071                     vendor_type == WPA_GET_BE32(&pos[2]))
1072                         return pos;
1073                 pos += 2 + pos[1];
1074         }
1075
1076         return NULL;
1077 }
1078
1079
1080 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1081                                              u32 vendor_type)
1082 {
1083         struct wpabuf *buf;
1084         const u8 *end, *pos;
1085
1086         buf = wpabuf_alloc(res->ie_len);
1087         if (buf == NULL)
1088                 return NULL;
1089
1090         pos = (const u8 *) (res + 1);
1091         end = pos + res->ie_len;
1092
1093         while (pos + 1 < end) {
1094                 if (pos + 2 + pos[1] > end)
1095                         break;
1096                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1097                     vendor_type == WPA_GET_BE32(&pos[2]))
1098                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1099                 pos += 2 + pos[1];
1100         }
1101
1102         if (wpabuf_len(buf) == 0) {
1103                 wpabuf_free(buf);
1104                 buf = NULL;
1105         }
1106
1107         return buf;
1108 }
1109
1110
1111 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1112         const struct wpa_scan_res *res, u32 vendor_type)
1113 {
1114         struct wpabuf *buf;
1115         const u8 *end, *pos;
1116
1117         if (res->beacon_ie_len == 0)
1118                 return NULL;
1119         buf = wpabuf_alloc(res->beacon_ie_len);
1120         if (buf == NULL)
1121                 return NULL;
1122
1123         pos = (const u8 *) (res + 1);
1124         pos += res->ie_len;
1125         end = pos + res->beacon_ie_len;
1126
1127         while (pos + 1 < end) {
1128                 if (pos + 2 + pos[1] > end)
1129                         break;
1130                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1131                     vendor_type == WPA_GET_BE32(&pos[2]))
1132                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1133                 pos += 2 + pos[1];
1134         }
1135
1136         if (wpabuf_len(buf) == 0) {
1137                 wpabuf_free(buf);
1138                 buf = NULL;
1139         }
1140
1141         return buf;
1142 }
1143
1144
1145 /*
1146  * Channels with a great SNR can operate at full rate. What is a great SNR?
1147  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1148  * rule of thumb is that any SNR above 20 is good." This one
1149  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1150  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1151  * conservative value.
1152  */
1153 #define GREAT_SNR 30
1154
1155 /* Compare function for sorting scan results. Return >0 if @b is considered
1156  * better. */
1157 static int wpa_scan_result_compar(const void *a, const void *b)
1158 {
1159 #define IS_5GHZ(n) (n > 4000)
1160 #define MIN(a,b) a < b ? a : b
1161         struct wpa_scan_res **_wa = (void *) a;
1162         struct wpa_scan_res **_wb = (void *) b;
1163         struct wpa_scan_res *wa = *_wa;
1164         struct wpa_scan_res *wb = *_wb;
1165         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1166         int snr_a, snr_b;
1167
1168         /* WPA/WPA2 support preferred */
1169         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1170                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1171         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1172                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1173
1174         if (wpa_b && !wpa_a)
1175                 return 1;
1176         if (!wpa_b && wpa_a)
1177                 return -1;
1178
1179         /* privacy support preferred */
1180         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1181             (wb->caps & IEEE80211_CAP_PRIVACY))
1182                 return 1;
1183         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1184             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1185                 return -1;
1186
1187         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1188             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1189                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1190                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1191         } else {
1192                 /* Not suitable information to calculate SNR, so use level */
1193                 snr_a = wa->level;
1194                 snr_b = wb->level;
1195         }
1196
1197         /* best/max rate preferred if SNR close enough */
1198         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1199             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1200                 maxrate_a = wpa_scan_get_max_rate(wa);
1201                 maxrate_b = wpa_scan_get_max_rate(wb);
1202                 if (maxrate_a != maxrate_b)
1203                         return maxrate_b - maxrate_a;
1204                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1205                         return IS_5GHZ(wa->freq) ? -1 : 1;
1206         }
1207
1208         /* use freq for channel preference */
1209
1210         /* all things being equal, use SNR; if SNRs are
1211          * identical, use quality values since some drivers may only report
1212          * that value and leave the signal level zero */
1213         if (snr_b == snr_a)
1214                 return wb->qual - wa->qual;
1215         return snr_b - snr_a;
1216 #undef MIN
1217 #undef IS_5GHZ
1218 }
1219
1220
1221 #ifdef CONFIG_WPS
1222 /* Compare function for sorting scan results when searching a WPS AP for
1223  * provisioning. Return >0 if @b is considered better. */
1224 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1225 {
1226         struct wpa_scan_res **_wa = (void *) a;
1227         struct wpa_scan_res **_wb = (void *) b;
1228         struct wpa_scan_res *wa = *_wa;
1229         struct wpa_scan_res *wb = *_wb;
1230         int uses_wps_a, uses_wps_b;
1231         struct wpabuf *wps_a, *wps_b;
1232         int res;
1233
1234         /* Optimization - check WPS IE existence before allocated memory and
1235          * doing full reassembly. */
1236         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1237         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1238         if (uses_wps_a && !uses_wps_b)
1239                 return -1;
1240         if (!uses_wps_a && uses_wps_b)
1241                 return 1;
1242
1243         if (uses_wps_a && uses_wps_b) {
1244                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1245                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1246                 res = wps_ap_priority_compar(wps_a, wps_b);
1247                 wpabuf_free(wps_a);
1248                 wpabuf_free(wps_b);
1249                 if (res)
1250                         return res;
1251         }
1252
1253         /*
1254          * Do not use current AP security policy as a sorting criteria during
1255          * WPS provisioning step since the AP may get reconfigured at the
1256          * completion of provisioning.
1257          */
1258
1259         /* all things being equal, use signal level; if signal levels are
1260          * identical, use quality values since some drivers may only report
1261          * that value and leave the signal level zero */
1262         if (wb->level == wa->level)
1263                 return wb->qual - wa->qual;
1264         return wb->level - wa->level;
1265 }
1266 #endif /* CONFIG_WPS */
1267
1268
1269 static void dump_scan_res(struct wpa_scan_results *scan_res)
1270 {
1271 #ifndef CONFIG_NO_STDOUT_DEBUG
1272         size_t i;
1273
1274         if (scan_res->res == NULL || scan_res->num == 0)
1275                 return;
1276
1277         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1278
1279         for (i = 0; i < scan_res->num; i++) {
1280                 struct wpa_scan_res *r = scan_res->res[i];
1281                 u8 *pos;
1282                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1283                     == WPA_SCAN_LEVEL_DBM) {
1284                         int snr = r->level - r->noise;
1285                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1286                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1287                                    MAC2STR(r->bssid), r->freq, r->qual,
1288                                    r->noise, r->level, snr,
1289                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1290                 } else {
1291                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1292                                    "noise=%d level=%d flags=0x%x",
1293                                    MAC2STR(r->bssid), r->freq, r->qual,
1294                                    r->noise, r->level, r->flags);
1295                 }
1296                 pos = (u8 *) (r + 1);
1297                 if (r->ie_len)
1298                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1299                 pos += r->ie_len;
1300                 if (r->beacon_ie_len)
1301                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1302                                     pos, r->beacon_ie_len);
1303         }
1304 #endif /* CONFIG_NO_STDOUT_DEBUG */
1305 }
1306
1307
1308 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1309                                       const u8 *bssid)
1310 {
1311         size_t i;
1312
1313         if (wpa_s->bssid_filter == NULL)
1314                 return 1;
1315
1316         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1317                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1318                               ETH_ALEN) == 0)
1319                         return 1;
1320         }
1321
1322         return 0;
1323 }
1324
1325
1326 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1327                             struct wpa_scan_results *res)
1328 {
1329         size_t i, j;
1330
1331         if (wpa_s->bssid_filter == NULL)
1332                 return;
1333
1334         for (i = 0, j = 0; i < res->num; i++) {
1335                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1336                                                       res->res[i]->bssid)) {
1337                         res->res[j++] = res->res[i];
1338                 } else {
1339                         os_free(res->res[i]);
1340                         res->res[i] = NULL;
1341                 }
1342         }
1343
1344         if (res->num != j) {
1345                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1346                            (int) (res->num - j));
1347                 res->num = j;
1348         }
1349 }
1350
1351
1352 /**
1353  * wpa_supplicant_get_scan_results - Get scan results
1354  * @wpa_s: Pointer to wpa_supplicant data
1355  * @info: Information about what was scanned or %NULL if not available
1356  * @new_scan: Whether a new scan was performed
1357  * Returns: Scan results, %NULL on failure
1358  *
1359  * This function request the current scan results from the driver and updates
1360  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1361  * results with wpa_scan_results_free().
1362  */
1363 struct wpa_scan_results *
1364 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1365                                 struct scan_info *info, int new_scan)
1366 {
1367         struct wpa_scan_results *scan_res;
1368         size_t i;
1369         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1370
1371         scan_res = wpa_drv_get_scan_results2(wpa_s);
1372         if (scan_res == NULL) {
1373                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1374                 return NULL;
1375         }
1376         filter_scan_res(wpa_s, scan_res);
1377
1378 #ifdef CONFIG_WPS
1379         if (wpas_wps_in_progress(wpa_s)) {
1380                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1381                         "provisioning rules");
1382                 compar = wpa_scan_result_wps_compar;
1383         }
1384 #endif /* CONFIG_WPS */
1385
1386         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1387               compar);
1388         dump_scan_res(scan_res);
1389
1390         wpa_bss_update_start(wpa_s);
1391         for (i = 0; i < scan_res->num; i++)
1392                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1393         wpa_bss_update_end(wpa_s, info, new_scan);
1394
1395         return scan_res;
1396 }
1397
1398
1399 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1400 {
1401         struct wpa_scan_results *scan_res;
1402         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1403         if (scan_res == NULL)
1404                 return -1;
1405         wpa_scan_results_free(scan_res);
1406
1407         return 0;
1408 }