wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "utils/includes.h"
  16
  17 #include "utils/common.h"
  18 #include "utils/eloop.h"
  19 #include "common/ieee802_11_defs.h"
  20 #include "config.h"
  21 #include "wpa_supplicant_i.h"
  22 #include "driver_i.h"
  23 #include "mlme.h"
  24 #include "wps_supplicant.h"
  25 #include "p2p_supplicant.h"
  26 #include "p2p/p2p.h"
  27 #include "notify.h"
  28 #include "bss.h"
  29 #include "scan.h"
  30
  31
  32 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  33 {
  34         struct wpa_ssid *ssid;
  35         union wpa_event_data data;
  36
  37         ssid = wpa_supplicant_get_ssid(wpa_s);
  38         if (ssid == NULL)
  39                 return;
  40
  41         if (wpa_s->current_ssid == NULL) {
  42                 wpa_s->current_ssid = ssid;
  43                 if (wpa_s->current_ssid != NULL)
  44                         wpas_notify_network_changed(wpa_s);
  45         }
  46         wpa_supplicant_initiate_eapol(wpa_s);
  47         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  48                 "network - generating associated event");
  49         os_memset(&data, 0, sizeof(data));
  50         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  51 }
  52
  53
  54 #ifdef CONFIG_WPS
  55 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  56                            enum wps_request_type *req_type)
  57 {
  58         struct wpa_ssid *ssid;
  59         int wps = 0;
  60
  61         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  62                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  63                         continue;
  64
  65                 wps = 1;
  66                 *req_type = wpas_wps_get_req_type(ssid);
  67                 if (!ssid->eap.phase1)
  68                         continue;
  69
  70                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  71                         return 2;
  72         }
  73
  74 #ifdef CONFIG_P2P
  75         wpa_s->wps->dev.p2p = 1;
  76         if (!wps) {
  77                 wps = 1;
  78                 *req_type = WPS_REQ_ENROLLEE_INFO;
  79         }
  80 #endif /* CONFIG_P2P */
  81
  82         return wps;
  83 }
  84 #endif /* CONFIG_WPS */
  85
  86
  87 int wpa_supplicant_enabled_networks(struct wpa_config *conf)
  88 {
  89         struct wpa_ssid *ssid = conf->ssid;
  90         int count = 0;
  91         while (ssid) {
  92                 if (!ssid->disabled)
  93                         count++;
  94                 ssid = ssid->next;
  95         }
  96         return count;
  97 }
  98
  99
 100 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 101                                      struct wpa_ssid *ssid)
 102 {
 103         while (ssid) {
 104                 if (!ssid->disabled)
 105                         break;
 106                 ssid = ssid->next;
 107         }
 108
 109         /* ap_scan=2 mode - try to associate with each SSID. */
 110         if (ssid == NULL) {
 111                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 112                         "end of scan list - go back to beginning");
 113                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 114                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 115                 return;
 116         }
 117         if (ssid->next) {
 118                 /* Continue from the next SSID on the next attempt. */
 119                 wpa_s->prev_scan_ssid = ssid;
 120         } else {
 121                 /* Start from the beginning of the SSID list. */
 122                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 123         }
 124         wpa_supplicant_associate(wpa_s, NULL, ssid);
 125 }
 126
 127
 128 static int int_array_len(const int *a)
 129 {
 130         int i;
 131         for (i = 0; a && a[i]; i++)
 132                 ;
 133         return i;
 134 }
 135
 136
 137 static void int_array_concat(int **res, const int *a)
 138 {
 139         int reslen, alen, i;
 140         int *n;
 141
 142         reslen = int_array_len(*res);
 143         alen = int_array_len(a);
 144
 145         n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
 146         if (n == NULL) {
 147                 os_free(*res);
 148                 *res = NULL;
 149                 return;
 150         }
 151         for (i = 0; i <= alen; i++)
 152                 n[reslen + i] = a[i];
 153         *res = n;
 154 }
 155
 156
 157 static int freq_cmp(const void *a, const void *b)
 158 {
 159         int _a = *(int *) a;
 160         int _b = *(int *) b;
 161
 162         if (_a == 0)
 163                 return 1;
 164         if (_b == 0)
 165                 return -1;
 166         return _a - _b;
 167 }
 168
 169
 170 static void int_array_sort_unique(int *a)
 171 {
 172         int alen;
 173         int i, j;
 174
 175         if (a == NULL)
 176                 return;
 177
 178         alen = int_array_len(a);
 179         qsort(a, alen, sizeof(int), freq_cmp);
 180
 181         i = 0;
 182         j = 1;
 183         while (a[i] && a[j]) {
 184                 if (a[i] == a[j]) {
 185                         j++;
 186                         continue;
 187                 }
 188                 a[++i] = a[j++];
 189         }
 190         if (a[i])
 191                 i++;
 192         a[i] = 0;
 193 }
 194
 195
 196 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 197                                 struct wpa_driver_scan_params *params)
 198 {
 199         int ret;
 200
 201         wpa_supplicant_notify_scanning(wpa_s, 1);
 202
 203         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 204                 ret = ieee80211_sta_req_scan(wpa_s, params);
 205         else
 206                 ret = wpa_drv_scan(wpa_s, params);
 207
 208         if (ret) {
 209                 wpa_supplicant_notify_scanning(wpa_s, 0);
 210                 wpas_notify_scan_done(wpa_s, 0);
 211         } else
 212                 wpa_s->scan_runs++;
 213
 214         return ret;
 215 }
 216
 217
 218 static void
 219 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 220 {
 221         struct wpa_supplicant *wpa_s = eloop_ctx;
 222
 223         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 224
 225         if (wpa_supplicant_req_sched_scan(wpa_s))
 226                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 227 }
 228
 229
 230 static void
 231 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 232 {
 233         struct wpa_supplicant *wpa_s = eloop_ctx;
 234
 235         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 236
 237         wpa_s->sched_scan_timed_out = 1;
 238         wpa_supplicant_cancel_sched_scan(wpa_s);
 239 }
 240
 241
 242 static int
 243 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 244                                 struct wpa_driver_scan_params *params,
 245                                 int interval)
 246 {
 247         int ret;
 248
 249         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 250                 return -1;
 251
 252         wpa_supplicant_notify_scanning(wpa_s, 1);
 253         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 254         if (ret)
 255                 wpa_supplicant_notify_scanning(wpa_s, 0);
 256         else
 257                 wpa_s->sched_scanning = 1;
 258
 259         return ret;
 260 }
 261
 262
 263 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 264 {
 265         int ret;
 266
 267         ret = wpa_drv_stop_sched_scan(wpa_s);
 268         if (ret) {
 269                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 270                 /* TODO: what to do if stopping fails? */
 271                 return -1;
 272         }
 273
 274         return ret;
 275 }
 276
 277
 278 static struct wpa_driver_scan_filter *
 279 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 280 {
 281         struct wpa_driver_scan_filter *ssids;
 282         struct wpa_ssid *ssid;
 283         size_t count;
 284
 285         *num_ssids = 0;
 286         if (!conf->filter_ssids)
 287                 return NULL;
 288
 289         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 290                 if (ssid->ssid && ssid->ssid_len)
 291                         count++;
 292         }
 293         if (count == 0)
 294                 return NULL;
 295         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 296         if (ssids == NULL)
 297                 return NULL;
 298
 299         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 300                 if (!ssid->ssid || !ssid->ssid_len)
 301                         continue;
 302                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 303                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 304                 (*num_ssids)++;
 305         }
 306
 307         return ssids;
 308 }
 309
 310
 311 static void wpa_supplicant_optimize_freqs(
 312         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 313 {
 314 #ifdef CONFIG_P2P
 315         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 316             wpa_s->go_params) {
 317                 /* Optimize provisioning state scan based on GO information */
 318                 if (wpa_s->p2p_in_provisioning < 5 &&
 319                     wpa_s->go_params->freq > 0) {
 320                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 321                                 "preferred frequency %d MHz",
 322                                 wpa_s->go_params->freq);
 323                         params->freqs = os_zalloc(2 * sizeof(int));
 324                         if (params->freqs)
 325                                 params->freqs[0] = wpa_s->go_params->freq;
 326                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 327                            wpa_s->go_params->freq_list[0]) {
 328                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 329                                 "channels");
 330                         int_array_concat(&params->freqs,
 331                                          wpa_s->go_params->freq_list);
 332                         if (params->freqs)
 333                                 int_array_sort_unique(params->freqs);
 334                 }
 335                 wpa_s->p2p_in_provisioning++;
 336         }
 337 #endif /* CONFIG_P2P */
 338
 339 #ifdef CONFIG_WPS
 340         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 341                 /*
 342                  * Optimize post-provisioning scan based on channel used
 343                  * during provisioning.
 344                  */
 345                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 346                         "that was used during provisioning", wpa_s->wps_freq);
 347                 params->freqs = os_zalloc(2 * sizeof(int));
 348                 if (params->freqs)
 349                         params->freqs[0] = wpa_s->wps_freq;
 350                 wpa_s->after_wps--;
 351         }
 352
 353 #endif /* CONFIG_WPS */
 354 }
 355
 356
 357 static struct wpabuf *
 358 wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s,
 359                          struct wpa_driver_scan_params *params)
 360 {
 361         struct wpabuf *wps_ie = NULL;
 362 #ifdef CONFIG_WPS
 363         int wps = 0;
 364         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 365
 366         wps = wpas_wps_in_use(wpa_s, &req_type);
 367
 368         if (wps) {
 369                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 370                                                 wpa_s->wps->uuid, req_type,
 371                                                 0, NULL);
 372                 if (wps_ie) {
 373                         params->extra_ies = wpabuf_head(wps_ie);
 374                         params->extra_ies_len = wpabuf_len(wps_ie);
 375                 }
 376         }
 377
 378 #ifdef CONFIG_P2P
 379         if (wps_ie) {
 380                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 381                 if (wpabuf_resize(&wps_ie, ielen) == 0) {
 382                         wpas_p2p_scan_ie(wpa_s, wps_ie);
 383                         params->extra_ies = wpabuf_head(wps_ie);
 384                         params->extra_ies_len = wpabuf_len(wps_ie);
 385                 }
 386         }
 387 #endif /* CONFIG_P2P */
 388
 389 #endif /* CONFIG_WPS */
 390
 391         return wps_ie;
 392 }
 393
 394
 395 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 396 {
 397         struct wpa_supplicant *wpa_s = eloop_ctx;
 398         struct wpa_ssid *ssid;
 399         int scan_req = 0, ret;
 400         struct wpabuf *wps_ie;
 401         struct wpa_driver_scan_params params;
 402         size_t max_ssids;
 403         enum wpa_states prev_state;
 404
 405         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 406                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 407                 return;
 408         }
 409
 410         if (wpa_s->disconnected && !wpa_s->scan_req) {
 411                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 412                 return;
 413         }
 414
 415         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 416             !wpa_s->scan_req) {
 417                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 418                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 419                 return;
 420         }
 421
 422         if (wpa_s->conf->ap_scan != 0 &&
 423             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 424                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 425                         "overriding ap_scan configuration");
 426                 wpa_s->conf->ap_scan = 0;
 427                 wpas_notify_ap_scan_changed(wpa_s);
 428         }
 429
 430         if (wpa_s->conf->ap_scan == 0) {
 431                 wpa_supplicant_gen_assoc_event(wpa_s);
 432                 return;
 433         }
 434
 435 #ifdef CONFIG_P2P
 436         if (wpas_p2p_in_progress(wpa_s)) {
 437                 if (wpa_s->wpa_state == WPA_SCANNING) {
 438                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 439                                 "while P2P operation is in progress");
 440                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 441                 } else {
 442                         wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
 443                                 "P2P operation is in progress");
 444                 }
 445                 return;
 446         }
 447 #endif /* CONFIG_P2P */
 448
 449         if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 450             wpa_s->conf->ap_scan == 2)
 451                 max_ssids = 1;
 452         else {
 453                 max_ssids = wpa_s->max_scan_ssids;
 454                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 455                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 456         }
 457
 458         scan_req = wpa_s->scan_req;
 459         wpa_s->scan_req = 0;
 460
 461         os_memset(&params, 0, sizeof(params));
 462
 463         prev_state = wpa_s->wpa_state;
 464         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 465             wpa_s->wpa_state == WPA_INACTIVE)
 466                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 467
 468         if (scan_req != 2 && wpa_s->connect_without_scan) {
 469                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 470                         if (ssid == wpa_s->connect_without_scan)
 471                                 break;
 472                 }
 473                 wpa_s->connect_without_scan = NULL;
 474                 if (ssid) {
 475                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 476                                    "without scan step");
 477                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 478                         return;
 479                 }
 480         }
 481
 482         /* Find the starting point from which to continue scanning */
 483         ssid = wpa_s->conf->ssid;
 484         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 485                 while (ssid) {
 486                         if (ssid == wpa_s->prev_scan_ssid) {
 487                                 ssid = ssid->next;
 488                                 break;
 489                         }
 490                         ssid = ssid->next;
 491                 }
 492         }
 493
 494         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 495                 wpa_s->connect_without_scan = NULL;
 496                 wpa_supplicant_assoc_try(wpa_s, ssid);
 497                 return;
 498         } else if (wpa_s->conf->ap_scan == 2) {
 499                 /*
 500                  * User-initiated scan request in ap_scan == 2; scan with
 501                  * wildcard SSID.
 502                  */
 503                 ssid = NULL;
 504         } else {
 505                 struct wpa_ssid *start = ssid, *tssid;
 506                 int freqs_set = 0;
 507                 if (ssid == NULL && max_ssids > 1)
 508                         ssid = wpa_s->conf->ssid;
 509                 while (ssid) {
 510                         if (!ssid->disabled && ssid->scan_ssid) {
 511                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 512                                                   ssid->ssid, ssid->ssid_len);
 513                                 params.ssids[params.num_ssids].ssid =
 514                                         ssid->ssid;
 515                                 params.ssids[params.num_ssids].ssid_len =
 516                                         ssid->ssid_len;
 517                                 params.num_ssids++;
 518                                 if (params.num_ssids + 1 >= max_ssids)
 519                                         break;
 520                         }
 521                         ssid = ssid->next;
 522                         if (ssid == start)
 523                                 break;
 524                         if (ssid == NULL && max_ssids > 1 &&
 525                             start != wpa_s->conf->ssid)
 526                                 ssid = wpa_s->conf->ssid;
 527                 }
 528
 529                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 530                         if (tssid->disabled)
 531                                 continue;
 532                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 533                                 int_array_concat(&params.freqs,
 534                                                  tssid->scan_freq);
 535                         } else {
 536                                 os_free(params.freqs);
 537                                 params.freqs = NULL;
 538                         }
 539                         freqs_set = 1;
 540                 }
 541                 int_array_sort_unique(params.freqs);
 542         }
 543
 544         if (ssid) {
 545                 wpa_s->prev_scan_ssid = ssid;
 546                 if (max_ssids > 1) {
 547                         wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 548                                 "the scan request");
 549                         params.num_ssids++;
 550                 }
 551                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific "
 552                         "SSID(s)");
 553         } else {
 554                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 555                 params.num_ssids++;
 556                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 557                         "SSID");
 558         }
 559
 560         wpa_supplicant_optimize_freqs(wpa_s, &params);
 561         wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 562
 563         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 564                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 565                         "generated frequency list");
 566                 params.freqs = wpa_s->next_scan_freqs;
 567         } else
 568                 os_free(wpa_s->next_scan_freqs);
 569         wpa_s->next_scan_freqs = NULL;
 570
 571         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 572                 wpa_s->conf, &params.num_filter_ssids);
 573
 574         ret = wpa_supplicant_trigger_scan(wpa_s, &params);
 575
 576         wpabuf_free(wps_ie);
 577         os_free(params.freqs);
 578         os_free(params.filter_ssids);
 579
 580         if (ret) {
 581                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 582                 if (prev_state != wpa_s->wpa_state)
 583                         wpa_supplicant_set_state(wpa_s, prev_state);
 584                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 585         }
 586 }
 587
 588
 589 /**
 590  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 591  * @wpa_s: Pointer to wpa_supplicant data
 592  * @sec: Number of seconds after which to scan
 593  * @usec: Number of microseconds after which to scan
 594  *
 595  * This function is used to schedule a scan for neighboring access points after
 596  * the specified time.
 597  */
 598 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 599 {
 600         /* If there's at least one network that should be specifically scanned
 601          * then don't cancel the scan and reschedule.  Some drivers do
 602          * background scanning which generates frequent scan results, and that
 603          * causes the specific SSID scan to get continually pushed back and
 604          * never happen, which causes hidden APs to never get probe-scanned.
 605          */
 606         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 607             wpa_s->conf->ap_scan == 1) {
 608                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 609
 610                 while (ssid) {
 611                         if (!ssid->disabled && ssid->scan_ssid)
 612                                 break;
 613                         ssid = ssid->next;
 614                 }
 615                 if (ssid) {
 616                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 617                                 "ensure that specific SSID scans occur");
 618                         return;
 619                 }
 620         }
 621
 622         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 623                 sec, usec);
 624         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 625         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 626 }
 627
 628
 629 /**
 630  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 631  * @wpa_s: Pointer to wpa_supplicant data
 632  * @sec: Number of seconds after which to scan
 633  * @usec: Number of microseconds after which to scan
 634  *
 635  * This function is used to schedule periodic scans for neighboring
 636  * access points after the specified time.
 637  */
 638 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 639                                       int sec, int usec)
 640 {
 641         if (!wpa_s->sched_scan_supported)
 642                 return -1;
 643
 644         eloop_register_timeout(sec, usec,
 645                                wpa_supplicant_delayed_sched_scan_timeout,
 646                                wpa_s, NULL);
 647
 648         return 0;
 649 }
 650
 651
 652 /**
 653  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 654  * @wpa_s: Pointer to wpa_supplicant data
 655  *
 656  * This function is used to schedule periodic scans for neighboring
 657  * access points repeating the scan continuously.
 658  */
 659 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 660 {
 661         struct wpa_driver_scan_params params;
 662         enum wpa_states prev_state;
 663         struct wpa_ssid *ssid;
 664         struct wpabuf *wps_ie = NULL;
 665         int ret;
 666         unsigned int max_sched_scan_ssids;
 667
 668         if (!wpa_s->sched_scan_supported)
 669                 return -1;
 670
 671         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 672                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 673         else
 674                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 675
 676         if (wpa_s->sched_scanning)
 677                 return 0;
 678
 679         os_memset(&params, 0, sizeof(params));
 680
 681         /* If we can't allocate space for the filters, we just don't filter */
 682         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 683                                         sizeof(struct wpa_driver_scan_filter));
 684
 685         prev_state = wpa_s->wpa_state;
 686         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 687             wpa_s->wpa_state == WPA_INACTIVE)
 688                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 689
 690         /* Find the starting point from which to continue scanning */
 691         ssid = wpa_s->conf->ssid;
 692         if (wpa_s->prev_sched_ssid) {
 693                 while (ssid) {
 694                         if (ssid == wpa_s->prev_sched_ssid) {
 695                                 ssid = ssid->next;
 696                                 break;
 697                         }
 698                         ssid = ssid->next;
 699                 }
 700         }
 701
 702         if (!ssid || !wpa_s->prev_sched_ssid) {
 703                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 704
 705                 wpa_s->sched_scan_interval = 2;
 706                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 707                 wpa_s->first_sched_scan = 1;
 708                 ssid = wpa_s->conf->ssid;
 709                 wpa_s->prev_sched_ssid = ssid;
 710         }
 711
 712         while (ssid) {
 713                 if (ssid->disabled) {
 714                         wpa_s->prev_sched_ssid = ssid;
 715                         ssid = ssid->next;
 716                         continue;
 717                 }
 718
 719                 if (params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 720                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 721                                   ssid->ssid, ssid->ssid_len);
 722                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 723                                 ssid->ssid_len;
 724                         params.num_filter_ssids++;
 725                 }
 726
 727                 if (ssid->scan_ssid) {
 728                         params.ssids[params.num_ssids].ssid =
 729                                 ssid->ssid;
 730                         params.ssids[params.num_ssids].ssid_len =
 731                                 ssid->ssid_len;
 732                         params.num_ssids++;
 733                         if (params.num_ssids >= max_sched_scan_ssids) {
 734                                 wpa_s->prev_sched_ssid = ssid;
 735                                 break;
 736                         }
 737                 }
 738
 739                 if (params.num_filter_ssids >= wpa_s->max_match_sets)
 740                         break;
 741                 wpa_s->prev_sched_ssid = ssid;
 742                 ssid = ssid->next;
 743         }
 744
 745         if (!params.num_ssids) {
 746                 os_free(params.filter_ssids);
 747                 return 0;
 748         }
 749
 750         if (wpa_s->wps)
 751                 wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 752
 753         wpa_dbg(wpa_s, MSG_DEBUG,
 754                 "Starting sched scan: interval %d timeout %d",
 755                 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 756
 757         ret = wpa_supplicant_start_sched_scan(wpa_s, &params,
 758                                               wpa_s->sched_scan_interval);
 759         wpabuf_free(wps_ie);
 760         os_free(params.filter_ssids);
 761         if (ret) {
 762                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 763                 if (prev_state != wpa_s->wpa_state)
 764                         wpa_supplicant_set_state(wpa_s, prev_state);
 765                 return ret;
 766         }
 767
 768         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 769         if (ssid || !wpa_s->first_sched_scan) {
 770                 wpa_s->sched_scan_timed_out = 0;
 771                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 772                                        wpa_supplicant_sched_scan_timeout,
 773                                        wpa_s, NULL);
 774                 wpa_s->first_sched_scan = 0;
 775                 wpa_s->sched_scan_timeout /= 2;
 776                 wpa_s->sched_scan_interval *= 2;
 777         }
 778
 779         return 0;
 780 }
 781
 782
 783 /**
 784  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 785  * @wpa_s: Pointer to wpa_supplicant data
 786  *
 787  * This function is used to cancel a scan request scheduled with
 788  * wpa_supplicant_req_scan().
 789  */
 790 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 791 {
 792         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 793         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 794 }
 795
 796
 797 /**
 798  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
 799  * @wpa_s: Pointer to wpa_supplicant data
 800  *
 801  * This function is used to stop a periodic scheduled scan.
 802  */
 803 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
 804 {
 805         if (!wpa_s->sched_scanning)
 806                 return;
 807
 808         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
 809         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
 810         wpa_supplicant_stop_sched_scan(wpa_s);
 811 }
 812
 813
 814 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 815                                     int scanning)
 816 {
 817         if (wpa_s->scanning != scanning) {
 818                 wpa_s->scanning = scanning;
 819                 wpas_notify_scanning(wpa_s);
 820         }
 821 }
 822
 823
 824 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
 825 {
 826         int rate = 0;
 827         const u8 *ie;
 828         int i;
 829
 830         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
 831         for (i = 0; ie && i < ie[1]; i++) {
 832                 if ((ie[i + 2] & 0x7f) > rate)
 833                         rate = ie[i + 2] & 0x7f;
 834         }
 835
 836         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
 837         for (i = 0; ie && i < ie[1]; i++) {
 838                 if ((ie[i + 2] & 0x7f) > rate)
 839                         rate = ie[i + 2] & 0x7f;
 840         }
 841
 842         return rate;
 843 }
 844
 845
 846 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
 847 {
 848         const u8 *end, *pos;
 849
 850         pos = (const u8 *) (res + 1);
 851         end = pos + res->ie_len;
 852
 853         while (pos + 1 < end) {
 854                 if (pos + 2 + pos[1] > end)
 855                         break;
 856                 if (pos[0] == ie)
 857                         return pos;
 858                 pos += 2 + pos[1];
 859         }
 860
 861         return NULL;
 862 }
 863
 864
 865 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
 866                                   u32 vendor_type)
 867 {
 868         const u8 *end, *pos;
 869
 870         pos = (const u8 *) (res + 1);
 871         end = pos + res->ie_len;
 872
 873         while (pos + 1 < end) {
 874                 if (pos + 2 + pos[1] > end)
 875                         break;
 876                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 877                     vendor_type == WPA_GET_BE32(&pos[2]))
 878                         return pos;
 879                 pos += 2 + pos[1];
 880         }
 881
 882         return NULL;
 883 }
 884
 885
 886 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 887                                              u32 vendor_type)
 888 {
 889         struct wpabuf *buf;
 890         const u8 *end, *pos;
 891
 892         buf = wpabuf_alloc(res->ie_len);
 893         if (buf == NULL)
 894                 return NULL;
 895
 896         pos = (const u8 *) (res + 1);
 897         end = pos + res->ie_len;
 898
 899         while (pos + 1 < end) {
 900                 if (pos + 2 + pos[1] > end)
 901                         break;
 902                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 903                     vendor_type == WPA_GET_BE32(&pos[2]))
 904                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 905                 pos += 2 + pos[1];
 906         }
 907
 908         if (wpabuf_len(buf) == 0) {
 909                 wpabuf_free(buf);
 910                 buf = NULL;
 911         }
 912
 913         return buf;
 914 }
 915
 916
 917 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
 918         const struct wpa_scan_res *res, u32 vendor_type)
 919 {
 920         struct wpabuf *buf;
 921         const u8 *end, *pos;
 922
 923         if (res->beacon_ie_len == 0)
 924                 return NULL;
 925         buf = wpabuf_alloc(res->beacon_ie_len);
 926         if (buf == NULL)
 927                 return NULL;
 928
 929         pos = (const u8 *) (res + 1);
 930         pos += res->ie_len;
 931         end = pos + res->beacon_ie_len;
 932
 933         while (pos + 1 < end) {
 934                 if (pos + 2 + pos[1] > end)
 935                         break;
 936                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 937                     vendor_type == WPA_GET_BE32(&pos[2]))
 938                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 939                 pos += 2 + pos[1];
 940         }
 941
 942         if (wpabuf_len(buf) == 0) {
 943                 wpabuf_free(buf);
 944                 buf = NULL;
 945         }
 946
 947         return buf;
 948 }
 949
 950
 951 /* Compare function for sorting scan results. Return >0 if @b is considered
 952  * better. */
 953 static int wpa_scan_result_compar(const void *a, const void *b)
 954 {
 955         struct wpa_scan_res **_wa = (void *) a;
 956         struct wpa_scan_res **_wb = (void *) b;
 957         struct wpa_scan_res *wa = *_wa;
 958         struct wpa_scan_res *wb = *_wb;
 959         int wpa_a, wpa_b, maxrate_a, maxrate_b;
 960
 961         /* WPA/WPA2 support preferred */
 962         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
 963                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
 964         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
 965                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
 966
 967         if (wpa_b && !wpa_a)
 968                 return 1;
 969         if (!wpa_b && wpa_a)
 970                 return -1;
 971
 972         /* privacy support preferred */
 973         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
 974             (wb->caps & IEEE80211_CAP_PRIVACY))
 975                 return 1;
 976         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
 977             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
 978                 return -1;
 979
 980         /* best/max rate preferred if signal level close enough XXX */
 981         if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) ||
 982             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
 983                 maxrate_a = wpa_scan_get_max_rate(wa);
 984                 maxrate_b = wpa_scan_get_max_rate(wb);
 985                 if (maxrate_a != maxrate_b)
 986                         return maxrate_b - maxrate_a;
 987         }
 988
 989         /* use freq for channel preference */
 990
 991         /* all things being equal, use signal level; if signal levels are
 992          * identical, use quality values since some drivers may only report
 993          * that value and leave the signal level zero */
 994         if (wb->level == wa->level)
 995                 return wb->qual - wa->qual;
 996         return wb->level - wa->level;
 997 }
 998
 999
1000 #ifdef CONFIG_WPS
1001 /* Compare function for sorting scan results when searching a WPS AP for
1002  * provisioning. Return >0 if @b is considered better. */
1003 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1004 {
1005         struct wpa_scan_res **_wa = (void *) a;
1006         struct wpa_scan_res **_wb = (void *) b;
1007         struct wpa_scan_res *wa = *_wa;
1008         struct wpa_scan_res *wb = *_wb;
1009         int uses_wps_a, uses_wps_b;
1010         struct wpabuf *wps_a, *wps_b;
1011         int res;
1012
1013         /* Optimization - check WPS IE existence before allocated memory and
1014          * doing full reassembly. */
1015         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1016         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1017         if (uses_wps_a && !uses_wps_b)
1018                 return -1;
1019         if (!uses_wps_a && uses_wps_b)
1020                 return 1;
1021
1022         if (uses_wps_a && uses_wps_b) {
1023                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1024                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1025                 res = wps_ap_priority_compar(wps_a, wps_b);
1026                 wpabuf_free(wps_a);
1027                 wpabuf_free(wps_b);
1028                 if (res)
1029                         return res;
1030         }
1031
1032         /*
1033          * Do not use current AP security policy as a sorting criteria during
1034          * WPS provisioning step since the AP may get reconfigured at the
1035          * completion of provisioning.
1036          */
1037
1038         /* all things being equal, use signal level; if signal levels are
1039          * identical, use quality values since some drivers may only report
1040          * that value and leave the signal level zero */
1041         if (wb->level == wa->level)
1042                 return wb->qual - wa->qual;
1043         return wb->level - wa->level;
1044 }
1045 #endif /* CONFIG_WPS */
1046
1047
1048 /**
1049  * wpa_supplicant_get_scan_results - Get scan results
1050  * @wpa_s: Pointer to wpa_supplicant data
1051  * @info: Information about what was scanned or %NULL if not available
1052  * @new_scan: Whether a new scan was performed
1053  * Returns: Scan results, %NULL on failure
1054  *
1055  * This function request the current scan results from the driver and updates
1056  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1057  * results with wpa_scan_results_free().
1058  */
1059 struct wpa_scan_results *
1060 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1061                                 struct scan_info *info, int new_scan)
1062 {
1063         struct wpa_scan_results *scan_res;
1064         size_t i;
1065         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1066
1067         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
1068                 scan_res = ieee80211_sta_get_scan_results(wpa_s);
1069         else
1070                 scan_res = wpa_drv_get_scan_results2(wpa_s);
1071         if (scan_res == NULL) {
1072                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1073                 return NULL;
1074         }
1075
1076 #ifdef CONFIG_WPS
1077         if (wpas_wps_in_progress(wpa_s)) {
1078                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1079                         "provisioning rules");
1080                 compar = wpa_scan_result_wps_compar;
1081         }
1082 #endif /* CONFIG_WPS */
1083
1084         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1085               compar);
1086
1087         wpa_bss_update_start(wpa_s);
1088         for (i = 0; i < scan_res->num; i++)
1089                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1090         wpa_bss_update_end(wpa_s, info, new_scan);
1091
1092         return scan_res;
1093 }
1094
1095
1096 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1097 {
1098         struct wpa_scan_results *scan_res;
1099         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1100         if (scan_res == NULL)
1101                 return -1;
1102         wpa_scan_results_free(scan_res);
1103
1104         return 0;
1105 }
1106
1107
1108 void wpa_scan_results_free(struct wpa_scan_results *res)
1109 {
1110         size_t i;
1111
1112         if (res == NULL)
1113                 return;
1114
1115         for (i = 0; i < res->num; i++)
1116                 os_free(res->res[i]);
1117         os_free(res->res);
1118         os_free(res);
1119 }