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 ieee80211_sta_set_probe_req_ie(wpa_s, params->extra_ies,
191 params->extra_ies_len);
192 ret = ieee80211_sta_req_scan(wpa_s, params->ssids[0].ssid,
193 params->ssids[0].ssid_len);
195 wpa_drv_set_probe_req_ie(wpa_s, params->extra_ies,
196 params->extra_ies_len);
197 ret = wpa_drv_scan(wpa_s, params);
201 wpa_supplicant_notify_scanning(wpa_s, 0);
202 wpas_notify_scan_done(wpa_s, 0);
210 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
212 struct wpa_supplicant *wpa_s = eloop_ctx;
213 struct wpa_ssid *ssid;
214 int scan_req = 0, ret;
215 struct wpabuf *wps_ie = NULL;
218 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
219 #endif /* CONFIG_WPS */
220 struct wpa_driver_scan_params params;
223 if (wpa_s->disconnected && !wpa_s->scan_req) {
224 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
228 if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
230 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
231 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
235 if (wpa_s->conf->ap_scan != 0 &&
236 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
237 wpa_printf(MSG_DEBUG, "Using wired authentication - "
238 "overriding ap_scan configuration");
239 wpa_s->conf->ap_scan = 0;
240 wpas_notify_ap_scan_changed(wpa_s);
243 if (wpa_s->conf->ap_scan == 0) {
244 wpa_supplicant_gen_assoc_event(wpa_s);
248 if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
249 wpa_s->conf->ap_scan == 2)
252 max_ssids = wpa_s->max_scan_ssids;
253 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
254 max_ssids = WPAS_MAX_SCAN_SSIDS;
258 wps = wpas_wps_in_use(wpa_s->conf, &req_type);
259 #endif /* CONFIG_WPS */
261 if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
262 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) &&
264 wpa_s->scan_res_tried++;
265 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
266 "first without requesting a new scan to speed up "
267 "initial association");
268 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
272 scan_req = wpa_s->scan_req;
275 os_memset(¶ms, 0, sizeof(params));
277 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
278 wpa_s->wpa_state == WPA_INACTIVE)
279 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
281 /* Find the starting point from which to continue scanning */
282 ssid = wpa_s->conf->ssid;
283 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
285 if (ssid == wpa_s->prev_scan_ssid) {
293 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
294 wpa_supplicant_assoc_try(wpa_s, ssid);
296 } else if (wpa_s->conf->ap_scan == 2) {
298 * User-initiated scan request in ap_scan == 2; scan with
303 struct wpa_ssid *start = ssid, *tssid;
305 if (ssid == NULL && max_ssids > 1)
306 ssid = wpa_s->conf->ssid;
308 if (!ssid->disabled && ssid->scan_ssid) {
309 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
310 ssid->ssid, ssid->ssid_len);
311 params.ssids[params.num_ssids].ssid =
313 params.ssids[params.num_ssids].ssid_len =
316 if (params.num_ssids + 1 >= max_ssids)
322 if (ssid == NULL && max_ssids > 1 &&
323 start != wpa_s->conf->ssid)
324 ssid = wpa_s->conf->ssid;
327 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
330 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
331 int_array_concat(¶ms.freqs,
334 os_free(params.freqs);
339 int_array_sort_unique(params.freqs);
343 wpa_s->prev_scan_ssid = ssid;
345 wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
349 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
351 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
353 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
358 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
359 wpa_s->wps->uuid, req_type);
361 params.extra_ies = wpabuf_head(wps_ie);
362 params.extra_ies_len = wpabuf_len(wps_ie);
365 #endif /* CONFIG_WPS */
367 ret = wpa_supplicant_trigger_scan(wpa_s, ¶ms);
370 os_free(params.freqs);
373 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
374 wpa_supplicant_req_scan(wpa_s, 10, 0);
381 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
382 * @wpa_s: Pointer to wpa_supplicant data
383 * @sec: Number of seconds after which to scan
384 * @usec: Number of microseconds after which to scan
386 * This function is used to schedule a scan for neighboring access points after
387 * the specified time.
389 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
391 /* If there's at least one network that should be specifically scanned
392 * then don't cancel the scan and reschedule. Some drivers do
393 * background scanning which generates frequent scan results, and that
394 * causes the specific SSID scan to get continually pushed back and
395 * never happen, which causes hidden APs to never get probe-scanned.
397 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
398 wpa_s->conf->ap_scan == 1) {
399 struct wpa_ssid *ssid = wpa_s->conf->ssid;
402 if (!ssid->disabled && ssid->scan_ssid)
407 wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
408 "ensure that specific SSID scans occur");
413 wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
415 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
416 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
421 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
422 * @wpa_s: Pointer to wpa_supplicant data
424 * This function is used to cancel a scan request scheduled with
425 * wpa_supplicant_req_scan().
427 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
429 wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
430 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
434 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
437 if (wpa_s->scanning != scanning) {
438 wpa_s->scanning = scanning;
439 wpas_notify_scanning(wpa_s);