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));
137 for (i = 0; i <= alen; i++)
138 n[reslen + i] = a[i];
143 static int freq_cmp(const void *a, const void *b)
156 static void int_array_sort_unique(int *a)
164 alen = int_array_len(a);
165 qsort(a, alen, sizeof(int), freq_cmp);
169 while (a[i] && a[j]) {
182 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
183 struct wpa_driver_scan_params *params)
187 wpa_supplicant_notify_scanning(wpa_s, 1);
189 if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
190 ret = ieee80211_sta_req_scan(wpa_s, params);
192 ret = wpa_drv_scan(wpa_s, params);
195 wpa_supplicant_notify_scanning(wpa_s, 0);
196 wpas_notify_scan_done(wpa_s, 0);
204 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
206 struct wpa_supplicant *wpa_s = eloop_ctx;
207 struct wpa_ssid *ssid;
208 int scan_req = 0, ret;
209 struct wpabuf *wps_ie = NULL;
212 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
213 #endif /* CONFIG_WPS */
214 struct wpa_driver_scan_params params;
217 if (wpa_s->disconnected && !wpa_s->scan_req) {
218 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
222 if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
224 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
225 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
229 if (wpa_s->conf->ap_scan != 0 &&
230 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
231 wpa_printf(MSG_DEBUG, "Using wired authentication - "
232 "overriding ap_scan configuration");
233 wpa_s->conf->ap_scan = 0;
234 wpas_notify_ap_scan_changed(wpa_s);
237 if (wpa_s->conf->ap_scan == 0) {
238 wpa_supplicant_gen_assoc_event(wpa_s);
242 if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
243 wpa_s->conf->ap_scan == 2)
246 max_ssids = wpa_s->max_scan_ssids;
247 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
248 max_ssids = WPAS_MAX_SCAN_SSIDS;
252 wps = wpas_wps_in_use(wpa_s->conf, &req_type);
253 #endif /* CONFIG_WPS */
255 if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
256 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) &&
258 wpa_s->scan_res_tried++;
259 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
260 "first without requesting a new scan to speed up "
261 "initial association");
262 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
266 scan_req = wpa_s->scan_req;
269 os_memset(¶ms, 0, sizeof(params));
271 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
272 wpa_s->wpa_state == WPA_INACTIVE)
273 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
275 /* Find the starting point from which to continue scanning */
276 ssid = wpa_s->conf->ssid;
277 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
279 if (ssid == wpa_s->prev_scan_ssid) {
287 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
288 wpa_supplicant_assoc_try(wpa_s, ssid);
290 } else if (wpa_s->conf->ap_scan == 2) {
292 * User-initiated scan request in ap_scan == 2; scan with
297 struct wpa_ssid *start = ssid, *tssid;
299 if (ssid == NULL && max_ssids > 1)
300 ssid = wpa_s->conf->ssid;
302 if (!ssid->disabled && ssid->scan_ssid) {
303 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
304 ssid->ssid, ssid->ssid_len);
305 params.ssids[params.num_ssids].ssid =
307 params.ssids[params.num_ssids].ssid_len =
310 if (params.num_ssids + 1 >= max_ssids)
316 if (ssid == NULL && max_ssids > 1 &&
317 start != wpa_s->conf->ssid)
318 ssid = wpa_s->conf->ssid;
321 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
324 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
325 int_array_concat(¶ms.freqs,
328 os_free(params.freqs);
333 int_array_sort_unique(params.freqs);
337 wpa_s->prev_scan_ssid = ssid;
339 wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
343 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
345 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
347 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
352 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
353 wpa_s->wps->uuid, req_type);
355 params.extra_ies = wpabuf_head(wps_ie);
356 params.extra_ies_len = wpabuf_len(wps_ie);
359 #endif /* CONFIG_WPS */
361 ret = wpa_supplicant_trigger_scan(wpa_s, ¶ms);
364 os_free(params.freqs);
367 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
368 wpa_supplicant_req_scan(wpa_s, 10, 0);
375 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
376 * @wpa_s: Pointer to wpa_supplicant data
377 * @sec: Number of seconds after which to scan
378 * @usec: Number of microseconds after which to scan
380 * This function is used to schedule a scan for neighboring access points after
381 * the specified time.
383 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
385 /* If there's at least one network that should be specifically scanned
386 * then don't cancel the scan and reschedule. Some drivers do
387 * background scanning which generates frequent scan results, and that
388 * causes the specific SSID scan to get continually pushed back and
389 * never happen, which causes hidden APs to never get probe-scanned.
391 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
392 wpa_s->conf->ap_scan == 1) {
393 struct wpa_ssid *ssid = wpa_s->conf->ssid;
396 if (!ssid->disabled && ssid->scan_ssid)
401 wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
402 "ensure that specific SSID scans occur");
407 wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
409 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
410 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
415 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
416 * @wpa_s: Pointer to wpa_supplicant data
418 * This function is used to cancel a scan request scheduled with
419 * wpa_supplicant_req_scan().
421 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
423 wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
424 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
428 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
431 if (wpa_s->scanning != scanning) {
432 wpa_s->scanning = scanning;
433 wpas_notify_scanning(wpa_s);