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 */
68 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
70 struct wpa_supplicant *wpa_s = eloop_ctx;
71 struct wpa_ssid *ssid;
72 int enabled, scan_req = 0, ret;
73 struct wpabuf *wps_ie = NULL;
74 const u8 *extra_ie = NULL;
75 size_t extra_ie_len = 0;
78 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
79 #endif /* CONFIG_WPS */
81 if (wpa_s->disconnected && !wpa_s->scan_req)
85 ssid = wpa_s->conf->ssid;
87 if (!ssid->disabled) {
93 if (!enabled && !wpa_s->scan_req) {
94 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
95 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
98 scan_req = wpa_s->scan_req;
101 if (wpa_s->conf->ap_scan != 0 &&
102 wpa_s->driver && IS_WIRED(wpa_s->driver)) {
103 wpa_printf(MSG_DEBUG, "Using wired authentication - "
104 "overriding ap_scan configuration");
105 wpa_s->conf->ap_scan = 0;
108 if (wpa_s->conf->ap_scan == 0) {
109 wpa_supplicant_gen_assoc_event(wpa_s);
113 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
114 wpa_s->wpa_state == WPA_INACTIVE)
115 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
117 ssid = wpa_s->conf->ssid;
118 if (wpa_s->prev_scan_ssid != BROADCAST_SSID_SCAN) {
120 if (ssid == wpa_s->prev_scan_ssid) {
128 if (!ssid->disabled &&
129 (ssid->scan_ssid || wpa_s->conf->ap_scan == 2))
134 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
136 * ap_scan=2 mode - try to associate with each SSID instead of
137 * scanning for each scan_ssid=1 network.
140 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
141 "end of scan list - go back to beginning");
142 wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
143 wpa_supplicant_req_scan(wpa_s, 0, 0);
147 /* Continue from the next SSID on the next attempt. */
148 wpa_s->prev_scan_ssid = ssid;
150 /* Start from the beginning of the SSID list. */
151 wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
153 wpa_supplicant_associate(wpa_s, NULL, ssid);
157 wpa_printf(MSG_DEBUG, "Starting AP scan (%s SSID)",
158 ssid ? "specific": "broadcast");
160 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
161 ssid->ssid, ssid->ssid_len);
162 wpa_s->prev_scan_ssid = ssid;
164 wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
167 wps = wpas_wps_in_use(wpa_s->conf, &req_type);
168 #endif /* CONFIG_WPS */
170 if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
171 !wpa_s->use_client_mlme && wps != 2) {
172 wpa_s->scan_res_tried++;
173 wpa_s->scan_req = scan_req;
174 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
175 "first without requesting a new scan to speed up "
176 "initial association");
177 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
183 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
184 wpa_s->wps->uuid, req_type);
186 extra_ie = wpabuf_head(wps_ie);
187 extra_ie_len = wpabuf_len(wps_ie);
190 #endif /* CONFIG_WPS */
192 if (wpa_s->use_client_mlme) {
193 ieee80211_sta_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
194 ret = ieee80211_sta_req_scan(wpa_s, ssid ? ssid->ssid : NULL,
195 ssid ? ssid->ssid_len : 0);
197 wpa_drv_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
198 ret = wpa_drv_scan(wpa_s, ssid ? ssid->ssid : NULL,
199 ssid ? ssid->ssid_len : 0);
205 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
206 wpa_supplicant_req_scan(wpa_s, 10, 0);
213 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
214 * @wpa_s: Pointer to wpa_supplicant data
215 * @sec: Number of seconds after which to scan
216 * @usec: Number of microseconds after which to scan
218 * This function is used to schedule a scan for neighboring access points after
219 * the specified time.
221 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
223 /* If there's at least one network that should be specifically scanned
224 * then don't cancel the scan and reschedule. Some drivers do
225 * background scanning which generates frequent scan results, and that
226 * causes the specific SSID scan to get continually pushed back and
227 * never happen, which causes hidden APs to never get probe-scanned.
229 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
230 wpa_s->conf->ap_scan == 1) {
231 struct wpa_ssid *ssid = wpa_s->conf->ssid;
234 if (!ssid->disabled && ssid->scan_ssid)
239 wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
240 "ensure that specific SSID scans occur");
245 wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
247 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
248 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
253 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
254 * @wpa_s: Pointer to wpa_supplicant data
256 * This function is used to cancel a scan request scheduled with
257 * wpa_supplicant_req_scan().
259 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
261 wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
262 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);