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"
26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
28 struct wpa_ssid *ssid;
29 union wpa_event_data data;
31 ssid = wpa_supplicant_get_ssid(wpa_s);
35 if (wpa_s->current_ssid == NULL)
36 wpa_s->current_ssid = ssid;
37 wpa_supplicant_initiate_eapol(wpa_s);
38 wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
39 "generating associated event");
40 os_memset(&data, 0, sizeof(data));
41 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
46 static int wpas_wps_in_use(struct wpa_config *conf,
47 enum wps_request_type *req_type)
49 struct wpa_ssid *ssid;
52 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
53 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
57 *req_type = wpas_wps_get_req_type(ssid);
58 if (!ssid->eap.phase1)
61 if (os_strstr(ssid->eap.phase1, "pbc=1"))
67 #endif /* CONFIG_WPS */
70 static int wpa_supplicant_enabled_networks(struct wpa_config *conf)
72 struct wpa_ssid *ssid = conf->ssid;
82 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
83 struct wpa_ssid *ssid)
91 /* ap_scan=2 mode - try to associate with each SSID. */
93 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
94 "end of scan list - go back to beginning");
95 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
96 wpa_supplicant_req_scan(wpa_s, 0, 0);
100 /* Continue from the next SSID on the next attempt. */
101 wpa_s->prev_scan_ssid = ssid;
103 /* Start from the beginning of the SSID list. */
104 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
106 wpa_supplicant_associate(wpa_s, NULL, ssid);
110 static int int_array_len(const int *a)
113 for (i = 0; a && a[i]; i++)
119 static void int_array_concat(int **res, const int *a)
124 reslen = int_array_len(*res);
125 alen = int_array_len(a);
127 n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
132 for (i = 0; i <= alen; i++)
133 n[reslen + i] = a[i];
138 static int freq_cmp(const void *a, const void *b)
151 static void int_array_sort_unique(int *a)
159 alen = int_array_len(a);
160 qsort(a, alen, sizeof(int), freq_cmp);
164 while (a[i] && a[j]) {
177 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
179 struct wpa_supplicant *wpa_s = eloop_ctx;
180 struct wpa_ssid *ssid;
181 int scan_req = 0, ret;
182 struct wpabuf *wps_ie = NULL;
185 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
186 #endif /* CONFIG_WPS */
187 struct wpa_driver_scan_params params;
190 if (wpa_s->disconnected && !wpa_s->scan_req)
193 if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
195 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
196 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
200 if (wpa_s->conf->ap_scan != 0 &&
201 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
202 wpa_printf(MSG_DEBUG, "Using wired authentication - "
203 "overriding ap_scan configuration");
204 wpa_s->conf->ap_scan = 0;
207 if (wpa_s->conf->ap_scan == 0) {
208 wpa_supplicant_gen_assoc_event(wpa_s);
212 if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
213 wpa_s->conf->ap_scan == 2)
216 max_ssids = wpa_s->max_scan_ssids;
217 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
218 max_ssids = WPAS_MAX_SCAN_SSIDS;
222 wps = wpas_wps_in_use(wpa_s->conf, &req_type);
223 #endif /* CONFIG_WPS */
225 if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
226 !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) &&
228 wpa_s->scan_res_tried++;
229 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
230 "first without requesting a new scan to speed up "
231 "initial association");
232 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
236 scan_req = wpa_s->scan_req;
239 os_memset(¶ms, 0, sizeof(params));
241 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
242 wpa_s->wpa_state == WPA_INACTIVE)
243 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
245 /* Find the starting point from which to continue scanning */
246 ssid = wpa_s->conf->ssid;
247 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
249 if (ssid == wpa_s->prev_scan_ssid) {
257 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
258 wpa_supplicant_assoc_try(wpa_s, ssid);
260 } else if (wpa_s->conf->ap_scan == 2) {
262 * User-initiated scan request in ap_scan == 2; scan with
267 struct wpa_ssid *start = ssid;
269 if (ssid == NULL && max_ssids > 1)
270 ssid = wpa_s->conf->ssid;
272 if (!ssid->disabled && ssid->scan_ssid) {
273 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
274 ssid->ssid, ssid->ssid_len);
275 params.ssids[params.num_ssids].ssid =
277 params.ssids[params.num_ssids].ssid_len =
280 if (params.num_ssids + 1 >= max_ssids)
286 if (ssid == NULL && max_ssids > 1 &&
287 start != wpa_s->conf->ssid)
288 ssid = wpa_s->conf->ssid;
291 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
294 if ((params.freqs || !freqs_set) && ssid->scan_freq) {
295 int_array_concat(¶ms.freqs,
298 os_free(params.freqs);
303 int_array_sort_unique(params.freqs);
307 wpa_s->prev_scan_ssid = ssid;
309 wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
313 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
315 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
317 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
322 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
323 wpa_s->wps->uuid, req_type);
325 params.extra_ies = wpabuf_head(wps_ie);
326 params.extra_ies_len = wpabuf_len(wps_ie);
329 #endif /* CONFIG_WPS */
331 if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) {
332 ieee80211_sta_set_probe_req_ie(wpa_s, params.extra_ies,
333 params.extra_ies_len);
334 ret = ieee80211_sta_req_scan(wpa_s, params.ssids[0].ssid,
335 params.ssids[0].ssid_len);
337 wpa_drv_set_probe_req_ie(wpa_s, params.extra_ies,
338 params.extra_ies_len);
339 ret = wpa_drv_scan(wpa_s, ¶ms);
343 os_free(params.freqs);
346 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
347 wpa_supplicant_req_scan(wpa_s, 10, 0);
354 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
355 * @wpa_s: Pointer to wpa_supplicant data
356 * @sec: Number of seconds after which to scan
357 * @usec: Number of microseconds after which to scan
359 * This function is used to schedule a scan for neighboring access points after
360 * the specified time.
362 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
364 /* If there's at least one network that should be specifically scanned
365 * then don't cancel the scan and reschedule. Some drivers do
366 * background scanning which generates frequent scan results, and that
367 * causes the specific SSID scan to get continually pushed back and
368 * never happen, which causes hidden APs to never get probe-scanned.
370 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
371 wpa_s->conf->ap_scan == 1) {
372 struct wpa_ssid *ssid = wpa_s->conf->ssid;
375 if (!ssid->disabled && ssid->scan_ssid)
380 wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
381 "ensure that specific SSID scans occur");
386 wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
388 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
389 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
394 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
395 * @wpa_s: Pointer to wpa_supplicant data
397 * This function is used to cancel a scan request scheduled with
398 * wpa_supplicant_req_scan().
400 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
402 wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
403 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);