wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10
  11 #include "utils/common.h"
  12 #include "utils/eloop.h"
  13 #include "common/ieee802_11_defs.h"
  14 #include "config.h"
  15 #include "wpa_supplicant_i.h"
  16 #include "driver_i.h"
  17 #include "wps_supplicant.h"
  18 #include "p2p_supplicant.h"
  19 #include "p2p/p2p.h"
  20 #include "hs20_supplicant.h"
  21 #include "notify.h"
  22 #include "bss.h"
  23 #include "scan.h"
  24
  25
  26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  27 {
  28         struct wpa_ssid *ssid;
  29         union wpa_event_data data;
  30
  31         ssid = wpa_supplicant_get_ssid(wpa_s);
  32         if (ssid == NULL)
  33                 return;
  34
  35         if (wpa_s->current_ssid == NULL) {
  36                 wpa_s->current_ssid = ssid;
  37                 if (wpa_s->current_ssid != NULL)
  38                         wpas_notify_network_changed(wpa_s);
  39         }
  40         wpa_supplicant_initiate_eapol(wpa_s);
  41         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  42                 "network - generating associated event");
  43         os_memset(&data, 0, sizeof(data));
  44         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  45 }
  46
  47
  48 #ifdef CONFIG_WPS
  49 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  50                            enum wps_request_type *req_type)
  51 {
  52         struct wpa_ssid *ssid;
  53         int wps = 0;
  54
  55         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  56                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  57                         continue;
  58
  59                 wps = 1;
  60                 *req_type = wpas_wps_get_req_type(ssid);
  61                 if (!ssid->eap.phase1)
  62                         continue;
  63
  64                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  65                         return 2;
  66         }
  67
  68 #ifdef CONFIG_P2P
  69         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p) {
  70                 wpa_s->wps->dev.p2p = 1;
  71                 if (!wps) {
  72                         wps = 1;
  73                         *req_type = WPS_REQ_ENROLLEE_INFO;
  74                 }
  75         }
  76 #endif /* CONFIG_P2P */
  77
  78         return wps;
  79 }
  80 #endif /* CONFIG_WPS */
  81
  82
  83 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  84 {
  85         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  86         int count = 0;
  87         while (ssid) {
  88                 if (!wpas_network_disabled(wpa_s, ssid))
  89                         count++;
  90                 ssid = ssid->next;
  91         }
  92         return count;
  93 }
  94
  95
  96 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
  97                                      struct wpa_ssid *ssid)
  98 {
  99         while (ssid) {
 100                 if (!wpas_network_disabled(wpa_s, ssid))
 101                         break;
 102                 ssid = ssid->next;
 103         }
 104
 105         /* ap_scan=2 mode - try to associate with each SSID. */
 106         if (ssid == NULL) {
 107                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 108                         "end of scan list - go back to beginning");
 109                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 110                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 111                 return;
 112         }
 113         if (ssid->next) {
 114                 /* Continue from the next SSID on the next attempt. */
 115                 wpa_s->prev_scan_ssid = ssid;
 116         } else {
 117                 /* Start from the beginning of the SSID list. */
 118                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 119         }
 120         wpa_supplicant_associate(wpa_s, NULL, ssid);
 121 }
 122
 123
 124 static int int_array_len(const int *a)
 125 {
 126         int i;
 127         for (i = 0; a && a[i]; i++)
 128                 ;
 129         return i;
 130 }
 131
 132
 133 static void int_array_concat(int **res, const int *a)
 134 {
 135         int reslen, alen, i;
 136         int *n;
 137
 138         reslen = int_array_len(*res);
 139         alen = int_array_len(a);
 140
 141         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 142         if (n == NULL) {
 143                 os_free(*res);
 144                 *res = NULL;
 145                 return;
 146         }
 147         for (i = 0; i <= alen; i++)
 148                 n[reslen + i] = a[i];
 149         *res = n;
 150 }
 151
 152
 153 static int freq_cmp(const void *a, const void *b)
 154 {
 155         int _a = *(int *) a;
 156         int _b = *(int *) b;
 157
 158         if (_a == 0)
 159                 return 1;
 160         if (_b == 0)
 161                 return -1;
 162         return _a - _b;
 163 }
 164
 165
 166 static void int_array_sort_unique(int *a)
 167 {
 168         int alen;
 169         int i, j;
 170
 171         if (a == NULL)
 172                 return;
 173
 174         alen = int_array_len(a);
 175         qsort(a, alen, sizeof(int), freq_cmp);
 176
 177         i = 0;
 178         j = 1;
 179         while (a[i] && a[j]) {
 180                 if (a[i] == a[j]) {
 181                         j++;
 182                         continue;
 183                 }
 184                 a[++i] = a[j++];
 185         }
 186         if (a[i])
 187                 i++;
 188         a[i] = 0;
 189 }
 190
 191
 192 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 193                                 struct wpa_driver_scan_params *params)
 194 {
 195         int ret;
 196
 197         wpa_supplicant_notify_scanning(wpa_s, 1);
 198
 199         ret = wpa_drv_scan(wpa_s, params);
 200         if (ret) {
 201                 wpa_supplicant_notify_scanning(wpa_s, 0);
 202                 wpas_notify_scan_done(wpa_s, 0);
 203         } else {
 204                 wpa_s->scan_runs++;
 205                 wpa_s->normal_scans++;
 206         }
 207
 208         return ret;
 209 }
 210
 211
 212 static void
 213 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 214 {
 215         struct wpa_supplicant *wpa_s = eloop_ctx;
 216
 217         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 218
 219         if (wpa_supplicant_req_sched_scan(wpa_s))
 220                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 221 }
 222
 223
 224 static void
 225 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 226 {
 227         struct wpa_supplicant *wpa_s = eloop_ctx;
 228
 229         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 230
 231         wpa_s->sched_scan_timed_out = 1;
 232         wpa_supplicant_cancel_sched_scan(wpa_s);
 233 }
 234
 235
 236 static int
 237 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 238                                 struct wpa_driver_scan_params *params,
 239                                 int interval)
 240 {
 241         int ret;
 242
 243         wpa_supplicant_notify_scanning(wpa_s, 1);
 244         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 245         if (ret)
 246                 wpa_supplicant_notify_scanning(wpa_s, 0);
 247         else
 248                 wpa_s->sched_scanning = 1;
 249
 250         return ret;
 251 }
 252
 253
 254 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 255 {
 256         int ret;
 257
 258         ret = wpa_drv_stop_sched_scan(wpa_s);
 259         if (ret) {
 260                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 261                 /* TODO: what to do if stopping fails? */
 262                 return -1;
 263         }
 264
 265         return ret;
 266 }
 267
 268
 269 static struct wpa_driver_scan_filter *
 270 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 271 {
 272         struct wpa_driver_scan_filter *ssids;
 273         struct wpa_ssid *ssid;
 274         size_t count;
 275
 276         *num_ssids = 0;
 277         if (!conf->filter_ssids)
 278                 return NULL;
 279
 280         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 281                 if (ssid->ssid && ssid->ssid_len)
 282                         count++;
 283         }
 284         if (count == 0)
 285                 return NULL;
 286         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 287         if (ssids == NULL)
 288                 return NULL;
 289
 290         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 291                 if (!ssid->ssid || !ssid->ssid_len)
 292                         continue;
 293                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 294                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 295                 (*num_ssids)++;
 296         }
 297
 298         return ssids;
 299 }
 300
 301
 302 static void wpa_supplicant_optimize_freqs(
 303         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 304 {
 305 #ifdef CONFIG_P2P
 306         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 307             wpa_s->go_params) {
 308                 /* Optimize provisioning state scan based on GO information */
 309                 if (wpa_s->p2p_in_provisioning < 5 &&
 310                     wpa_s->go_params->freq > 0) {
 311                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 312                                 "preferred frequency %d MHz",
 313                                 wpa_s->go_params->freq);
 314                         params->freqs = os_zalloc(2 * sizeof(int));
 315                         if (params->freqs)
 316                                 params->freqs[0] = wpa_s->go_params->freq;
 317                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 318                            wpa_s->go_params->freq_list[0]) {
 319                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 320                                 "channels");
 321                         int_array_concat(&params->freqs,
 322                                          wpa_s->go_params->freq_list);
 323                         if (params->freqs)
 324                                 int_array_sort_unique(params->freqs);
 325                 }
 326                 wpa_s->p2p_in_provisioning++;
 327         }
 328 #endif /* CONFIG_P2P */
 329
 330 #ifdef CONFIG_WPS
 331         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 332                 /*
 333                  * Optimize post-provisioning scan based on channel used
 334                  * during provisioning.
 335                  */
 336                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 337                         "that was used during provisioning", wpa_s->wps_freq);
 338                 params->freqs = os_zalloc(2 * sizeof(int));
 339                 if (params->freqs)
 340                         params->freqs[0] = wpa_s->wps_freq;
 341                 wpa_s->after_wps--;
 342         }
 343
 344         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 345         {
 346                 /* Optimize provisioning scan based on already known channel */
 347                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 348                         wpa_s->wps_freq);
 349                 params->freqs = os_zalloc(2 * sizeof(int));
 350                 if (params->freqs)
 351                         params->freqs[0] = wpa_s->wps_freq;
 352                 wpa_s->known_wps_freq = 0; /* only do this once */
 353         }
 354 #endif /* CONFIG_WPS */
 355 }
 356
 357
 358 #ifdef CONFIG_INTERWORKING
 359 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 360                                            struct wpabuf *buf)
 361 {
 362         if (wpa_s->conf->interworking == 0)
 363                 return;
 364
 365         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 366         wpabuf_put_u8(buf, 4);
 367         wpabuf_put_u8(buf, 0x00);
 368         wpabuf_put_u8(buf, 0x00);
 369         wpabuf_put_u8(buf, 0x00);
 370         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 371
 372         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 373         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 374                       1 + ETH_ALEN);
 375         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 376         /* No Venue Info */
 377         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 378                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 379 }
 380 #endif /* CONFIG_INTERWORKING */
 381
 382
 383 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 384 {
 385         struct wpabuf *extra_ie = NULL;
 386 #ifdef CONFIG_WPS
 387         int wps = 0;
 388         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 389 #endif /* CONFIG_WPS */
 390
 391 #ifdef CONFIG_INTERWORKING
 392         if (wpa_s->conf->interworking &&
 393             wpabuf_resize(&extra_ie, 100) == 0)
 394                 wpas_add_interworking_elements(wpa_s, extra_ie);
 395 #endif /* CONFIG_INTERWORKING */
 396
 397 #ifdef CONFIG_WPS
 398         wps = wpas_wps_in_use(wpa_s, &req_type);
 399
 400         if (wps) {
 401                 struct wpabuf *wps_ie;
 402                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 403                                                 DEV_PW_DEFAULT,
 404                                                 &wpa_s->wps->dev,
 405                                                 wpa_s->wps->uuid, req_type,
 406                                                 0, NULL);
 407                 if (wps_ie) {
 408                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 409                                 wpabuf_put_buf(extra_ie, wps_ie);
 410                         wpabuf_free(wps_ie);
 411                 }
 412         }
 413
 414 #ifdef CONFIG_P2P
 415         if (wps) {
 416                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 417                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 418                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 419         }
 420 #endif /* CONFIG_P2P */
 421
 422 #endif /* CONFIG_WPS */
 423
 424         return extra_ie;
 425 }
 426
 427
 428 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 429 {
 430         struct wpa_supplicant *wpa_s = eloop_ctx;
 431         struct wpa_ssid *ssid;
 432         int scan_req = 0, ret;
 433         struct wpabuf *extra_ie = NULL;
 434         struct wpa_driver_scan_params params;
 435         struct wpa_driver_scan_params *scan_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) &&
 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->sta_scan_pending &&
 472                     wpas_p2p_in_progress(wpa_s) == 2 &&
 473                     wpa_s->p2p_cb_on_scan_complete) {
 474                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 475                                 "mode scan during P2P search");
 476                 } else {
 477                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 478                                 "while P2P operation is in progress");
 479                         wpa_s->sta_scan_pending = 1;
 480                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 481                         return;
 482                 }
 483         }
 484 #endif /* CONFIG_P2P */
 485
 486         if (wpa_s->conf->ap_scan == 2)
 487                 max_ssids = 1;
 488         else {
 489                 max_ssids = wpa_s->max_scan_ssids;
 490                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 491                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 492         }
 493
 494         scan_req = wpa_s->scan_req;
 495         wpa_s->scan_req = 0;
 496
 497         os_memset(&params, 0, sizeof(params));
 498
 499         prev_state = wpa_s->wpa_state;
 500         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 501             wpa_s->wpa_state == WPA_INACTIVE)
 502                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 503
 504         /*
 505          * If autoscan has set its own scanning parameters
 506          */
 507         if (wpa_s->autoscan_params != NULL) {
 508                 scan_params = wpa_s->autoscan_params;
 509                 goto scan;
 510         }
 511
 512         if (scan_req != 2 && wpa_s->connect_without_scan) {
 513                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 514                         if (ssid == wpa_s->connect_without_scan)
 515                                 break;
 516                 }
 517                 wpa_s->connect_without_scan = NULL;
 518                 if (ssid) {
 519                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 520                                    "without scan step");
 521                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 522                         return;
 523                 }
 524         }
 525
 526 #ifdef CONFIG_P2P
 527         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 528             wpa_s->go_params) {
 529                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 530                            "P2P group formation");
 531                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 532                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 533                 params.num_ssids = 1;
 534                 goto ssid_list_set;
 535         }
 536 #endif /* CONFIG_P2P */
 537
 538         /* Find the starting point from which to continue scanning */
 539         ssid = wpa_s->conf->ssid;
 540         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 541                 while (ssid) {
 542                         if (ssid == wpa_s->prev_scan_ssid) {
 543                                 ssid = ssid->next;
 544                                 break;
 545                         }
 546                         ssid = ssid->next;
 547                 }
 548         }
 549
 550         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 551                 wpa_s->connect_without_scan = NULL;
 552                 wpa_s->prev_scan_wildcard = 0;
 553                 wpa_supplicant_assoc_try(wpa_s, ssid);
 554                 return;
 555         } else if (wpa_s->conf->ap_scan == 2) {
 556                 /*
 557                  * User-initiated scan request in ap_scan == 2; scan with
 558                  * wildcard SSID.
 559                  */
 560                 ssid = NULL;
 561         } else {
 562                 struct wpa_ssid *start = ssid, *tssid;
 563                 int freqs_set = 0;
 564                 if (ssid == NULL && max_ssids > 1)
 565                         ssid = wpa_s->conf->ssid;
 566                 while (ssid) {
 567                         if (!wpas_network_disabled(wpa_s, ssid) &&
 568                             ssid->scan_ssid) {
 569                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 570                                                   ssid->ssid, ssid->ssid_len);
 571                                 params.ssids[params.num_ssids].ssid =
 572                                         ssid->ssid;
 573                                 params.ssids[params.num_ssids].ssid_len =
 574                                         ssid->ssid_len;
 575                                 params.num_ssids++;
 576                                 if (params.num_ssids + 1 >= max_ssids)
 577                                         break;
 578                         }
 579                         ssid = ssid->next;
 580                         if (ssid == start)
 581                                 break;
 582                         if (ssid == NULL && max_ssids > 1 &&
 583                             start != wpa_s->conf->ssid)
 584                                 ssid = wpa_s->conf->ssid;
 585                 }
 586
 587                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 588                         if (wpas_network_disabled(wpa_s, tssid))
 589                                 continue;
 590                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 591                                 int_array_concat(&params.freqs,
 592                                                  tssid->scan_freq);
 593                         } else {
 594                                 os_free(params.freqs);
 595                                 params.freqs = NULL;
 596                         }
 597                         freqs_set = 1;
 598                 }
 599                 int_array_sort_unique(params.freqs);
 600         }
 601
 602         if (ssid && max_ssids == 1) {
 603                 /*
 604                  * If the driver is limited to 1 SSID at a time interleave
 605                  * wildcard SSID scans with specific SSID scans to avoid
 606                  * waiting a long time for a wildcard scan.
 607                  */
 608                 if (!wpa_s->prev_scan_wildcard) {
 609                         params.ssids[0].ssid = NULL;
 610                         params.ssids[0].ssid_len = 0;
 611                         wpa_s->prev_scan_wildcard = 1;
 612                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 613                                 "wildcard SSID (Interleave with specific)");
 614                 } else {
 615                         wpa_s->prev_scan_ssid = ssid;
 616                         wpa_s->prev_scan_wildcard = 0;
 617                         wpa_dbg(wpa_s, MSG_DEBUG,
 618                                 "Starting AP scan for specific SSID: %s",
 619                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 620                 }
 621         } else if (ssid) {
 622                 /* max_ssids > 1 */
 623
 624                 wpa_s->prev_scan_ssid = ssid;
 625                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 626                         "the scan request");
 627                 params.num_ssids++;
 628         } else {
 629                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 630                 params.num_ssids++;
 631                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 632                         "SSID");
 633         }
 634 #ifdef CONFIG_P2P
 635 ssid_list_set:
 636 #endif /* CONFIG_P2P */
 637
 638         wpa_supplicant_optimize_freqs(wpa_s, &params);
 639         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 640
 641 #ifdef CONFIG_HS20
 642         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 643                 wpas_hs20_add_indication(extra_ie);
 644 #endif /* CONFIG_HS20 */
 645
 646         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 647                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 648                         "generated frequency list");
 649                 params.freqs = wpa_s->next_scan_freqs;
 650         } else
 651                 os_free(wpa_s->next_scan_freqs);
 652         wpa_s->next_scan_freqs = NULL;
 653
 654         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 655                 wpa_s->conf, &params.num_filter_ssids);
 656         if (extra_ie) {
 657                 params.extra_ies = wpabuf_head(extra_ie);
 658                 params.extra_ies_len = wpabuf_len(extra_ie);
 659         }
 660
 661 #ifdef CONFIG_P2P
 662         if (wpa_s->p2p_in_provisioning ||
 663             (wpa_s->show_group_started && wpa_s->go_params)) {
 664                 /*
 665                  * The interface may not yet be in P2P mode, so we have to
 666                  * explicitly request P2P probe to disable CCK rates.
 667                  */
 668                 params.p2p_probe = 1;
 669         }
 670 #endif /* CONFIG_P2P */
 671
 672         scan_params = &params;
 673
 674 scan:
 675         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 676
 677         wpabuf_free(extra_ie);
 678         os_free(params.freqs);
 679         os_free(params.filter_ssids);
 680
 681         if (ret) {
 682                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 683                 if (prev_state != wpa_s->wpa_state)
 684                         wpa_supplicant_set_state(wpa_s, prev_state);
 685                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 686         }
 687 }
 688
 689
 690 /**
 691  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 692  * @wpa_s: Pointer to wpa_supplicant data
 693  * @sec: Number of seconds after which to scan
 694  * @usec: Number of microseconds after which to scan
 695  *
 696  * This function is used to schedule a scan for neighboring access points after
 697  * the specified time.
 698  */
 699 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 700 {
 701         /* If there's at least one network that should be specifically scanned
 702          * then don't cancel the scan and reschedule.  Some drivers do
 703          * background scanning which generates frequent scan results, and that
 704          * causes the specific SSID scan to get continually pushed back and
 705          * never happen, which causes hidden APs to never get probe-scanned.
 706          */
 707         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 708             wpa_s->conf->ap_scan == 1) {
 709                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 710
 711                 while (ssid) {
 712                         if (!wpas_network_disabled(wpa_s, ssid) &&
 713                             ssid->scan_ssid)
 714                                 break;
 715                         ssid = ssid->next;
 716                 }
 717                 if (ssid) {
 718                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 719                                 "ensure that specific SSID scans occur");
 720                         return;
 721                 }
 722         }
 723
 724         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 725                 sec, usec);
 726         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 727         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 728 }
 729
 730
 731 /**
 732  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 733  * @wpa_s: Pointer to wpa_supplicant data
 734  * @sec: Number of seconds after which to scan
 735  * @usec: Number of microseconds after which to scan
 736  *
 737  * This function is used to schedule periodic scans for neighboring
 738  * access points after the specified time.
 739  */
 740 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 741                                       int sec, int usec)
 742 {
 743         if (!wpa_s->sched_scan_supported)
 744                 return -1;
 745
 746         eloop_register_timeout(sec, usec,
 747                                wpa_supplicant_delayed_sched_scan_timeout,
 748                                wpa_s, NULL);
 749
 750         return 0;
 751 }
 752
 753
 754 /**
 755  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 756  * @wpa_s: Pointer to wpa_supplicant data
 757  *
 758  * This function is used to schedule periodic scans for neighboring
 759  * access points repeating the scan continuously.
 760  */
 761 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 762 {
 763         struct wpa_driver_scan_params params;
 764         struct wpa_driver_scan_params *scan_params;
 765         enum wpa_states prev_state;
 766         struct wpa_ssid *ssid = NULL;
 767         struct wpabuf *extra_ie = NULL;
 768         int ret;
 769         unsigned int max_sched_scan_ssids;
 770         int wildcard = 0;
 771         int need_ssids;
 772
 773         if (!wpa_s->sched_scan_supported)
 774                 return -1;
 775
 776         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 777                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 778         else
 779                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 780         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 781                 return -1;
 782
 783         if (wpa_s->sched_scanning) {
 784                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 785                 return 0;
 786         }
 787
 788         need_ssids = 0;
 789         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 790                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 791                         /* Use wildcard SSID to find this network */
 792                         wildcard = 1;
 793                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 794                            ssid->ssid_len)
 795                         need_ssids++;
 796
 797 #ifdef CONFIG_WPS
 798                 if (!wpas_network_disabled(wpa_s, ssid) &&
 799                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 800                         /*
 801                          * Normal scan is more reliable and faster for WPS
 802                          * operations and since these are for short periods of
 803                          * time, the benefit of trying to use sched_scan would
 804                          * be limited.
 805                          */
 806                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 807                                 "sched_scan for WPS");
 808                         return -1;
 809                 }
 810 #endif /* CONFIG_WPS */
 811         }
 812         if (wildcard)
 813                 need_ssids++;
 814
 815         if (wpa_s->normal_scans < 3 &&
 816             (need_ssids <= wpa_s->max_scan_ssids ||
 817              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 818                 /*
 819                  * When normal scan can speed up operations, use that for the
 820                  * first operations before starting the sched_scan to allow
 821                  * user space sleep more. We do this only if the normal scan
 822                  * has functionality that is suitable for this or if the
 823                  * sched_scan does not have better support for multiple SSIDs.
 824                  */
 825                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 826                         "sched_scan for initial scans (normal_scans=%d)",
 827                         wpa_s->normal_scans);
 828                 return -1;
 829         }
 830
 831         os_memset(&params, 0, sizeof(params));
 832
 833         /* If we can't allocate space for the filters, we just don't filter */
 834         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 835                                         sizeof(struct wpa_driver_scan_filter));
 836
 837         prev_state = wpa_s->wpa_state;
 838         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 839             wpa_s->wpa_state == WPA_INACTIVE)
 840                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 841
 842         if (wpa_s->autoscan_params != NULL) {
 843                 scan_params = wpa_s->autoscan_params;
 844                 goto scan;
 845         }
 846
 847         /* Find the starting point from which to continue scanning */
 848         ssid = wpa_s->conf->ssid;
 849         if (wpa_s->prev_sched_ssid) {
 850                 while (ssid) {
 851                         if (ssid == wpa_s->prev_sched_ssid) {
 852                                 ssid = ssid->next;
 853                                 break;
 854                         }
 855                         ssid = ssid->next;
 856                 }
 857         }
 858
 859         if (!ssid || !wpa_s->prev_sched_ssid) {
 860                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 861
 862                 if (wpa_s->sched_scan_interval == 0)
 863                         wpa_s->sched_scan_interval = 10;
 864                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 865                 wpa_s->first_sched_scan = 1;
 866                 ssid = wpa_s->conf->ssid;
 867                 wpa_s->prev_sched_ssid = ssid;
 868         }
 869
 870         if (wildcard) {
 871                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 872                 params.num_ssids++;
 873         }
 874
 875         while (ssid) {
 876                 if (wpas_network_disabled(wpa_s, ssid))
 877                         goto next;
 878
 879                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 880                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 881                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 882                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 883                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 884                                   ssid->ssid, ssid->ssid_len);
 885                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 886                                 ssid->ssid_len;
 887                         params.num_filter_ssids++;
 888                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
 889                 {
 890                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
 891                                 "filter for sched_scan - drop filter");
 892                         os_free(params.filter_ssids);
 893                         params.filter_ssids = NULL;
 894                         params.num_filter_ssids = 0;
 895                 }
 896
 897                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
 898                         if (params.num_ssids == max_sched_scan_ssids)
 899                                 break; /* only room for broadcast SSID */
 900                         wpa_dbg(wpa_s, MSG_DEBUG,
 901                                 "add to active scan ssid: %s",
 902                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 903                         params.ssids[params.num_ssids].ssid =
 904                                 ssid->ssid;
 905                         params.ssids[params.num_ssids].ssid_len =
 906                                 ssid->ssid_len;
 907                         params.num_ssids++;
 908                         if (params.num_ssids >= max_sched_scan_ssids) {
 909                                 wpa_s->prev_sched_ssid = ssid;
 910                                 do {
 911                                         ssid = ssid->next;
 912                                 } while (ssid &&
 913                                          (wpas_network_disabled(wpa_s, ssid) ||
 914                                           !ssid->scan_ssid));
 915                                 break;
 916                         }
 917                 }
 918
 919         next:
 920                 wpa_s->prev_sched_ssid = ssid;
 921                 ssid = ssid->next;
 922         }
 923
 924         if (params.num_filter_ssids == 0) {
 925                 os_free(params.filter_ssids);
 926                 params.filter_ssids = NULL;
 927         }
 928
 929         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 930         if (extra_ie) {
 931                 params.extra_ies = wpabuf_head(extra_ie);
 932                 params.extra_ies_len = wpabuf_len(extra_ie);
 933         }
 934
 935         scan_params = &params;
 936
 937 scan:
 938         if (ssid || !wpa_s->first_sched_scan) {
 939                 wpa_dbg(wpa_s, MSG_DEBUG,
 940                         "Starting sched scan: interval %d timeout %d",
 941                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 942         } else {
 943                 wpa_dbg(wpa_s, MSG_DEBUG,
 944                         "Starting sched scan: interval %d (no timeout)",
 945                         wpa_s->sched_scan_interval);
 946         }
 947
 948         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
 949                                               wpa_s->sched_scan_interval);
 950         wpabuf_free(extra_ie);
 951         os_free(params.filter_ssids);
 952         if (ret) {
 953                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 954                 if (prev_state != wpa_s->wpa_state)
 955                         wpa_supplicant_set_state(wpa_s, prev_state);
 956                 return ret;
 957         }
 958
 959         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 960         if (ssid || !wpa_s->first_sched_scan) {
 961                 wpa_s->sched_scan_timed_out = 0;
 962                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 963                                        wpa_supplicant_sched_scan_timeout,
 964                                        wpa_s, NULL);
 965                 wpa_s->first_sched_scan = 0;
 966                 wpa_s->sched_scan_timeout /= 2;
 967                 wpa_s->sched_scan_interval *= 2;
 968         }
 969
 970         return 0;
 971 }
 972
 973
 974 /**
 975  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 976  * @wpa_s: Pointer to wpa_supplicant data
 977  *
 978  * This function is used to cancel a scan request scheduled with
 979  * wpa_supplicant_req_scan().
 980  */
 981 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 982 {
 983         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 984         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 985 }
 986
 987
 988 /**
 989  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
 990  * @wpa_s: Pointer to wpa_supplicant data
 991  *
 992  * This function is used to stop a periodic scheduled scan.
 993  */
 994 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
 995 {
 996         if (!wpa_s->sched_scanning)
 997                 return;
 998
 999         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1000         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1001         wpa_supplicant_stop_sched_scan(wpa_s);
1002 }
1003
1004
1005 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1006                                     int scanning)
1007 {
1008         if (wpa_s->scanning != scanning) {
1009                 wpa_s->scanning = scanning;
1010                 wpas_notify_scanning(wpa_s);
1011         }
1012 }
1013
1014
1015 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1016 {
1017         int rate = 0;
1018         const u8 *ie;
1019         int i;
1020
1021         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1022         for (i = 0; ie && i < ie[1]; i++) {
1023                 if ((ie[i + 2] & 0x7f) > rate)
1024                         rate = ie[i + 2] & 0x7f;
1025         }
1026
1027         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1028         for (i = 0; ie && i < ie[1]; i++) {
1029                 if ((ie[i + 2] & 0x7f) > rate)
1030                         rate = ie[i + 2] & 0x7f;
1031         }
1032
1033         return rate;
1034 }
1035
1036
1037 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1038 {
1039         const u8 *end, *pos;
1040
1041         pos = (const u8 *) (res + 1);
1042         end = pos + res->ie_len;
1043
1044         while (pos + 1 < end) {
1045                 if (pos + 2 + pos[1] > end)
1046                         break;
1047                 if (pos[0] == ie)
1048                         return pos;
1049                 pos += 2 + pos[1];
1050         }
1051
1052         return NULL;
1053 }
1054
1055
1056 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1057                                   u32 vendor_type)
1058 {
1059         const u8 *end, *pos;
1060
1061         pos = (const u8 *) (res + 1);
1062         end = pos + res->ie_len;
1063
1064         while (pos + 1 < end) {
1065                 if (pos + 2 + pos[1] > end)
1066                         break;
1067                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1068                     vendor_type == WPA_GET_BE32(&pos[2]))
1069                         return pos;
1070                 pos += 2 + pos[1];
1071         }
1072
1073         return NULL;
1074 }
1075
1076
1077 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1078                                              u32 vendor_type)
1079 {
1080         struct wpabuf *buf;
1081         const u8 *end, *pos;
1082
1083         buf = wpabuf_alloc(res->ie_len);
1084         if (buf == NULL)
1085                 return NULL;
1086
1087         pos = (const u8 *) (res + 1);
1088         end = pos + res->ie_len;
1089
1090         while (pos + 1 < end) {
1091                 if (pos + 2 + pos[1] > end)
1092                         break;
1093                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1094                     vendor_type == WPA_GET_BE32(&pos[2]))
1095                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1096                 pos += 2 + pos[1];
1097         }
1098
1099         if (wpabuf_len(buf) == 0) {
1100                 wpabuf_free(buf);
1101                 buf = NULL;
1102         }
1103
1104         return buf;
1105 }
1106
1107
1108 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1109         const struct wpa_scan_res *res, u32 vendor_type)
1110 {
1111         struct wpabuf *buf;
1112         const u8 *end, *pos;
1113
1114         if (res->beacon_ie_len == 0)
1115                 return NULL;
1116         buf = wpabuf_alloc(res->beacon_ie_len);
1117         if (buf == NULL)
1118                 return NULL;
1119
1120         pos = (const u8 *) (res + 1);
1121         pos += res->ie_len;
1122         end = pos + res->beacon_ie_len;
1123
1124         while (pos + 1 < end) {
1125                 if (pos + 2 + pos[1] > end)
1126                         break;
1127                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1128                     vendor_type == WPA_GET_BE32(&pos[2]))
1129                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1130                 pos += 2 + pos[1];
1131         }
1132
1133         if (wpabuf_len(buf) == 0) {
1134                 wpabuf_free(buf);
1135                 buf = NULL;
1136         }
1137
1138         return buf;
1139 }
1140
1141
1142 /*
1143  * Channels with a great SNR can operate at full rate. What is a great SNR?
1144  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1145  * rule of thumb is that any SNR above 20 is good." This one
1146  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1147  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1148  * conservative value.
1149  */
1150 #define GREAT_SNR 30
1151
1152 /* Compare function for sorting scan results. Return >0 if @b is considered
1153  * better. */
1154 static int wpa_scan_result_compar(const void *a, const void *b)
1155 {
1156 #define IS_5GHZ(n) (n > 4000)
1157 #define MIN(a,b) a < b ? a : b
1158         struct wpa_scan_res **_wa = (void *) a;
1159         struct wpa_scan_res **_wb = (void *) b;
1160         struct wpa_scan_res *wa = *_wa;
1161         struct wpa_scan_res *wb = *_wb;
1162         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1163         int snr_a, snr_b;
1164
1165         /* WPA/WPA2 support preferred */
1166         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1167                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1168         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1169                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1170
1171         if (wpa_b && !wpa_a)
1172                 return 1;
1173         if (!wpa_b && wpa_a)
1174                 return -1;
1175
1176         /* privacy support preferred */
1177         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1178             (wb->caps & IEEE80211_CAP_PRIVACY))
1179                 return 1;
1180         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1181             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1182                 return -1;
1183
1184         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1185             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1186                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1187                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1188         } else {
1189                 /* Not suitable information to calculate SNR, so use level */
1190                 snr_a = wa->level;
1191                 snr_b = wb->level;
1192         }
1193
1194         /* best/max rate preferred if SNR close enough */
1195         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1196             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1197                 maxrate_a = wpa_scan_get_max_rate(wa);
1198                 maxrate_b = wpa_scan_get_max_rate(wb);
1199                 if (maxrate_a != maxrate_b)
1200                         return maxrate_b - maxrate_a;
1201                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1202                         return IS_5GHZ(wa->freq) ? -1 : 1;
1203         }
1204
1205         /* use freq for channel preference */
1206
1207         /* all things being equal, use SNR; if SNRs are
1208          * identical, use quality values since some drivers may only report
1209          * that value and leave the signal level zero */
1210         if (snr_b == snr_a)
1211                 return wb->qual - wa->qual;
1212         return snr_b - snr_a;
1213 #undef MIN
1214 #undef IS_5GHZ
1215 }
1216
1217
1218 #ifdef CONFIG_WPS
1219 /* Compare function for sorting scan results when searching a WPS AP for
1220  * provisioning. Return >0 if @b is considered better. */
1221 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1222 {
1223         struct wpa_scan_res **_wa = (void *) a;
1224         struct wpa_scan_res **_wb = (void *) b;
1225         struct wpa_scan_res *wa = *_wa;
1226         struct wpa_scan_res *wb = *_wb;
1227         int uses_wps_a, uses_wps_b;
1228         struct wpabuf *wps_a, *wps_b;
1229         int res;
1230
1231         /* Optimization - check WPS IE existence before allocated memory and
1232          * doing full reassembly. */
1233         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1234         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1235         if (uses_wps_a && !uses_wps_b)
1236                 return -1;
1237         if (!uses_wps_a && uses_wps_b)
1238                 return 1;
1239
1240         if (uses_wps_a && uses_wps_b) {
1241                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1242                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1243                 res = wps_ap_priority_compar(wps_a, wps_b);
1244                 wpabuf_free(wps_a);
1245                 wpabuf_free(wps_b);
1246                 if (res)
1247                         return res;
1248         }
1249
1250         /*
1251          * Do not use current AP security policy as a sorting criteria during
1252          * WPS provisioning step since the AP may get reconfigured at the
1253          * completion of provisioning.
1254          */
1255
1256         /* all things being equal, use signal level; if signal levels are
1257          * identical, use quality values since some drivers may only report
1258          * that value and leave the signal level zero */
1259         if (wb->level == wa->level)
1260                 return wb->qual - wa->qual;
1261         return wb->level - wa->level;
1262 }
1263 #endif /* CONFIG_WPS */
1264
1265
1266 static void dump_scan_res(struct wpa_scan_results *scan_res)
1267 {
1268 #ifndef CONFIG_NO_STDOUT_DEBUG
1269         size_t i;
1270
1271         if (scan_res->res == NULL || scan_res->num == 0)
1272                 return;
1273
1274         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1275
1276         for (i = 0; i < scan_res->num; i++) {
1277                 struct wpa_scan_res *r = scan_res->res[i];
1278                 u8 *pos;
1279                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1280                     == WPA_SCAN_LEVEL_DBM) {
1281                         int snr = r->level - r->noise;
1282                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1283                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1284                                    MAC2STR(r->bssid), r->freq, r->qual,
1285                                    r->noise, r->level, snr,
1286                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1287                 } else {
1288                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1289                                    "noise=%d level=%d flags=0x%x",
1290                                    MAC2STR(r->bssid), r->freq, r->qual,
1291                                    r->noise, r->level, r->flags);
1292                 }
1293                 pos = (u8 *) (r + 1);
1294                 if (r->ie_len)
1295                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1296                 pos += r->ie_len;
1297                 if (r->beacon_ie_len)
1298                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1299                                     pos, r->beacon_ie_len);
1300         }
1301 #endif /* CONFIG_NO_STDOUT_DEBUG */
1302 }
1303
1304
1305 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1306                                       const u8 *bssid)
1307 {
1308         size_t i;
1309
1310         if (wpa_s->bssid_filter == NULL)
1311                 return 1;
1312
1313         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1314                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1315                               ETH_ALEN) == 0)
1316                         return 1;
1317         }
1318
1319         return 0;
1320 }
1321
1322
1323 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1324                             struct wpa_scan_results *res)
1325 {
1326         size_t i, j;
1327
1328         if (wpa_s->bssid_filter == NULL)
1329                 return;
1330
1331         for (i = 0, j = 0; i < res->num; i++) {
1332                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1333                                                       res->res[i]->bssid)) {
1334                         res->res[j++] = res->res[i];
1335                 } else {
1336                         os_free(res->res[i]);
1337                         res->res[i] = NULL;
1338                 }
1339         }
1340
1341         if (res->num != j) {
1342                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1343                            (int) (res->num - j));
1344                 res->num = j;
1345         }
1346 }
1347
1348
1349 /**
1350  * wpa_supplicant_get_scan_results - Get scan results
1351  * @wpa_s: Pointer to wpa_supplicant data
1352  * @info: Information about what was scanned or %NULL if not available
1353  * @new_scan: Whether a new scan was performed
1354  * Returns: Scan results, %NULL on failure
1355  *
1356  * This function request the current scan results from the driver and updates
1357  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1358  * results with wpa_scan_results_free().
1359  */
1360 struct wpa_scan_results *
1361 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1362                                 struct scan_info *info, int new_scan)
1363 {
1364         struct wpa_scan_results *scan_res;
1365         size_t i;
1366         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1367
1368         scan_res = wpa_drv_get_scan_results2(wpa_s);
1369         if (scan_res == NULL) {
1370                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1371                 return NULL;
1372         }
1373         filter_scan_res(wpa_s, scan_res);
1374
1375 #ifdef CONFIG_WPS
1376         if (wpas_wps_in_progress(wpa_s)) {
1377                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1378                         "provisioning rules");
1379                 compar = wpa_scan_result_wps_compar;
1380         }
1381 #endif /* CONFIG_WPS */
1382
1383         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1384               compar);
1385         dump_scan_res(scan_res);
1386
1387         wpa_bss_update_start(wpa_s);
1388         for (i = 0; i < scan_res->num; i++)
1389                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1390         wpa_bss_update_end(wpa_s, info, new_scan);
1391
1392         return scan_res;
1393 }
1394
1395
1396 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1397 {
1398         struct wpa_scan_results *scan_res;
1399         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1400         if (scan_res == NULL)
1401                 return -1;
1402         wpa_scan_results_free(scan_res);
1403
1404         return 0;
1405 }