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"
22 #include "wps_supplicant.h"
25 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
27 struct wpa_ssid *ssid;
28 union wpa_event_data data;
30 ssid = wpa_supplicant_get_ssid(wpa_s);
34 if (wpa_s->current_ssid == NULL)
35 wpa_s->current_ssid = ssid;
36 wpa_supplicant_initiate_eapol(wpa_s);
37 wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
38 "generating associated event");
39 os_memset(&data, 0, sizeof(data));
40 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
45 static int wpas_wps_in_use(struct wpa_config *conf,
46 enum wps_request_type *req_type)
48 struct wpa_ssid *ssid;
51 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
52 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
56 *req_type = wpas_wps_get_req_type(ssid);
57 if (!ssid->eap.phase1)
60 if (os_strstr(ssid->eap.phase1, "pbc=1"))
66 #endif /* CONFIG_WPS */
69 static int wpa_supplicant_enabled_networks(struct wpa_config *conf)
71 struct wpa_ssid *ssid = conf->ssid;
81 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
82 struct wpa_ssid *ssid)
90 /* ap_scan=2 mode - try to associate with each SSID. */
92 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
93 "end of scan list - go back to beginning");
94 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
95 wpa_supplicant_req_scan(wpa_s, 0, 0);
99 /* Continue from the next SSID on the next attempt. */
100 wpa_s->prev_scan_ssid = ssid;
102 /* Start from the beginning of the SSID list. */
103 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
105 wpa_supplicant_associate(wpa_s, NULL, ssid);
109 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
111 struct wpa_supplicant *wpa_s = eloop_ctx;
112 struct wpa_ssid *ssid;
113 int scan_req = 0, ret;
114 struct wpabuf *wps_ie = NULL;
117 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
118 #endif /* CONFIG_WPS */
119 struct wpa_driver_scan_params params;
122 if (wpa_s->disconnected && !wpa_s->scan_req)
125 if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
127 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
128 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
132 if (wpa_s->conf->ap_scan != 0 && wpa_s->drv_wired) {
133 wpa_printf(MSG_DEBUG, "Using wired authentication - "
134 "overriding ap_scan configuration");
135 wpa_s->conf->ap_scan = 0;
138 if (wpa_s->conf->ap_scan == 0) {
139 wpa_supplicant_gen_assoc_event(wpa_s);
143 if (wpa_s->use_client_mlme || wpa_s->conf->ap_scan == 2)
146 max_ssids = wpa_s->max_scan_ssids;
147 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
148 max_ssids = WPAS_MAX_SCAN_SSIDS;
152 wps = wpas_wps_in_use(wpa_s->conf, &req_type);
153 #endif /* CONFIG_WPS */
155 if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
156 !wpa_s->use_client_mlme && wps != 2) {
157 wpa_s->scan_res_tried++;
158 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
159 "first without requesting a new scan to speed up "
160 "initial association");
161 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
165 scan_req = wpa_s->scan_req;
168 os_memset(¶ms, 0, sizeof(params));
170 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
171 wpa_s->wpa_state == WPA_INACTIVE)
172 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
174 /* Find the starting point from which to continue scanning */
175 ssid = wpa_s->conf->ssid;
176 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
178 if (ssid == wpa_s->prev_scan_ssid) {
186 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
187 wpa_supplicant_assoc_try(wpa_s, ssid);
189 } else if (wpa_s->conf->ap_scan == 2) {
191 * User-initiated scan request in ap_scan == 2; scan with
196 struct wpa_ssid *start = ssid;
197 if (ssid == NULL && max_ssids > 1)
198 ssid = wpa_s->conf->ssid;
200 if (!ssid->disabled && ssid->scan_ssid) {
201 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
202 ssid->ssid, ssid->ssid_len);
203 params.ssids[params.num_ssids].ssid =
205 params.ssids[params.num_ssids].ssid_len =
208 if (params.num_ssids + 1 >= max_ssids)
214 if (ssid == NULL && max_ssids > 1 &&
215 start != wpa_s->conf->ssid)
216 ssid = wpa_s->conf->ssid;
221 wpa_s->prev_scan_ssid = ssid;
223 wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
227 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
229 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
231 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
236 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
237 wpa_s->wps->uuid, req_type);
239 params.extra_ies = wpabuf_head(wps_ie);
240 params.extra_ies_len = wpabuf_len(wps_ie);
243 #endif /* CONFIG_WPS */
245 if (wpa_s->use_client_mlme) {
246 ieee80211_sta_set_probe_req_ie(wpa_s, params.extra_ies,
247 params.extra_ies_len);
248 ret = ieee80211_sta_req_scan(wpa_s, params.ssids[0].ssid,
249 params.ssids[0].ssid_len);
251 wpa_drv_set_probe_req_ie(wpa_s, params.extra_ies,
252 params.extra_ies_len);
253 ret = wpa_drv_scan(wpa_s, ¶ms);
259 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
260 wpa_supplicant_req_scan(wpa_s, 10, 0);
267 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
268 * @wpa_s: Pointer to wpa_supplicant data
269 * @sec: Number of seconds after which to scan
270 * @usec: Number of microseconds after which to scan
272 * This function is used to schedule a scan for neighboring access points after
273 * the specified time.
275 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
277 /* If there's at least one network that should be specifically scanned
278 * then don't cancel the scan and reschedule. Some drivers do
279 * background scanning which generates frequent scan results, and that
280 * causes the specific SSID scan to get continually pushed back and
281 * never happen, which causes hidden APs to never get probe-scanned.
283 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
284 wpa_s->conf->ap_scan == 1) {
285 struct wpa_ssid *ssid = wpa_s->conf->ssid;
288 if (!ssid->disabled && ssid->scan_ssid)
293 wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
294 "ensure that specific SSID scans occur");
299 wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
301 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
302 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
307 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
308 * @wpa_s: Pointer to wpa_supplicant data
310 * This function is used to cancel a scan request scheduled with
311 * wpa_supplicant_req_scan().
313 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
315 wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
316 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);