2 * WPA Supplicant - Scanning
3 * Copyright (c) 2003-2008, Jouni Malinen <j@w1.fi>
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.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
20 #include "wpa_supplicant_i.h"
23 #include "wps_supplicant.h"
27 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
29 struct wpa_ssid *ssid;
30 union wpa_event_data data;
32 ssid = wpa_supplicant_get_ssid(wpa_s);
36 if (wpa_s->current_ssid == NULL) {
37 wpa_s->current_ssid = ssid;
38 if (wpa_s->current_ssid != NULL)
39 wpas_notify_network_changed(wpa_s);
41 wpa_supplicant_initiate_eapol(wpa_s);
42 wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
43 "generating associated event");
44 os_memset(&data, 0, sizeof(data));
45 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
50 static int wpas_wps_in_use(struct wpa_config *conf,
51 enum wps_request_type *req_type)
53 struct wpa_ssid *ssid;
56 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
57 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
61 *req_type = wpas_wps_get_req_type(ssid);
62 if (!ssid->eap.phase1)
65 if (os_strstr(ssid->eap.phase1, "pbc=1"))
71 #endif /* CONFIG_WPS */
74 int wpa_supplicant_enabled_networks(struct wpa_config *conf)
76 struct wpa_ssid *ssid = conf->ssid;
86 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
87 struct wpa_ssid *ssid)
95 /* ap_scan=2 mode - try to associate with each SSID. */
97 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
98 "end of scan list - go back to beginning");
99 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
100 wpa_supplicant_req_scan(wpa_s, 0, 0);
104 /* Continue from the next SSID on the next attempt. */
105 wpa_s->prev_scan_ssid = ssid;
107 /* Start from the beginning of the SSID list. */
108 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
110 wpa_supplicant_associate(wpa_s, NULL, ssid);
114 static int int_array_len(const int *a)
117 for (i = 0; a && a[i]; i++)
123 static void int_array_concat(int **res, const int *a)
128 reslen = int_array_len(*res);
129 alen = int_array_len(a);
131 n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
136 for (i = 0; i <= alen; i++)
137 n[reslen + i] = a[i];
142 static int freq_cmp(const void *a, const void *b)
155 static void int_array_sort_unique(int *a)
163 alen = int_array_len(a);
164 qsort(a, alen, sizeof(int), freq_cmp);
168 while (a[i] && a[j]) {
181 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
182 struct wpa_driver_scan_params *params)
186 wpa_supplicant_notify_scanning(wpa_s, 1);
188 if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) {
189 ieee80211_sta_set_probe_req_ie(wpa_s, params->extra_ies,
190 params->extra_ies_len);
191 ret = ieee80211_sta_req_scan(wpa_s, params->ssids[0].ssid,
192 params->ssids[0].ssid_len);
194 wpa_drv_set_probe_req_ie(wpa_s, params->extra_ies,
195 params->extra_ies_len);
196 ret = wpa_drv_scan(wpa_s, params);
200 wpa_supplicant_notify_scanning(wpa_s, 0);
201 wpas_notify_scan_done(wpa_s, 0);
209 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
211 struct wpa_supplicant *wpa_s = eloop_ctx;
212 struct wpa_ssid *ssid;
213 int scan_req = 0, ret;
214 struct wpabuf *wps_ie = NULL;
217 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
218 #endif /* CONFIG_WPS */
219 struct wpa_driver_scan_params params;
222 if (wpa_s->disconnected && !wpa_s->scan_req) {
223 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
227 if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
229 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
230 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
234 if (wpa_s->conf->ap_scan != 0 &&
235 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
236 wpa_printf(MSG_DEBUG, "Using wired authentication - "
237 "overriding ap_scan configuration");
238 wpa_s->conf->ap_scan = 0;
239 wpas_notify_ap_scan_changed(wpa_s);
242 if (wpa_s->conf->ap_scan == 0) {
243 wpa_supplicant_gen_assoc_event(wpa_s);
247 if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
248 wpa_s->conf->ap_scan == 2)
251 max_ssids = wpa_s->max_scan_ssids;
252 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
253 max_ssids = WPAS_MAX_SCAN_SSIDS;
257 wps = wpas_wps_in_use(wpa_s->conf, &req_type);
258 #endif /* CONFIG_WPS */
260 if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
261 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) &&
263 wpa_s->scan_res_tried++;
264 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
265 "first without requesting a new scan to speed up "
266 "initial association");
267 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
271 scan_req = wpa_s->scan_req;
274 os_memset(¶ms, 0, sizeof(params));
276 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
277 wpa_s->wpa_state == WPA_INACTIVE)
278 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
280 /* Find the starting point from which to continue scanning */
281 ssid = wpa_s->conf->ssid;
282 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
284 if (ssid == wpa_s->prev_scan_ssid) {
292 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
293 wpa_supplicant_assoc_try(wpa_s, ssid);
295 } else if (wpa_s->conf->ap_scan == 2) {
297 * User-initiated scan request in ap_scan == 2; scan with
302 struct wpa_ssid *start = ssid;
304 if (ssid == NULL && max_ssids > 1)
305 ssid = wpa_s->conf->ssid;
307 if (!ssid->disabled && ssid->scan_ssid) {
308 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
309 ssid->ssid, ssid->ssid_len);
310 params.ssids[params.num_ssids].ssid =
312 params.ssids[params.num_ssids].ssid_len =
315 if (params.num_ssids + 1 >= max_ssids)
321 if (ssid == NULL && max_ssids > 1 &&
322 start != wpa_s->conf->ssid)
323 ssid = wpa_s->conf->ssid;
326 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
329 if ((params.freqs || !freqs_set) && ssid->scan_freq) {
330 int_array_concat(¶ms.freqs,
333 os_free(params.freqs);
338 int_array_sort_unique(params.freqs);
342 wpa_s->prev_scan_ssid = ssid;
344 wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
348 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
350 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
352 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
357 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
358 wpa_s->wps->uuid, req_type);
360 params.extra_ies = wpabuf_head(wps_ie);
361 params.extra_ies_len = wpabuf_len(wps_ie);
364 #endif /* CONFIG_WPS */
366 ret = wpa_supplicant_trigger_scan(wpa_s, ¶ms);
369 os_free(params.freqs);
372 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
373 wpa_supplicant_req_scan(wpa_s, 10, 0);
380 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
381 * @wpa_s: Pointer to wpa_supplicant data
382 * @sec: Number of seconds after which to scan
383 * @usec: Number of microseconds after which to scan
385 * This function is used to schedule a scan for neighboring access points after
386 * the specified time.
388 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
390 /* If there's at least one network that should be specifically scanned
391 * then don't cancel the scan and reschedule. Some drivers do
392 * background scanning which generates frequent scan results, and that
393 * causes the specific SSID scan to get continually pushed back and
394 * never happen, which causes hidden APs to never get probe-scanned.
396 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
397 wpa_s->conf->ap_scan == 1) {
398 struct wpa_ssid *ssid = wpa_s->conf->ssid;
401 if (!ssid->disabled && ssid->scan_ssid)
406 wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
407 "ensure that specific SSID scans occur");
412 wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
414 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
415 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
420 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
421 * @wpa_s: Pointer to wpa_supplicant data
423 * This function is used to cancel a scan request scheduled with
424 * wpa_supplicant_req_scan().
426 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
428 wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
429 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
433 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
436 if (wpa_s->scanning != scanning) {
437 wpa_s->scanning = scanning;
438 wpas_notify_scanning(wpa_s);