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"
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, u8 *uuid)
48 struct wpa_ssid *ssid;
52 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
53 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
57 if (!ssid->eap.phase1)
60 pos = os_strstr(ssid->eap.phase1, "uuid=");
62 uuid_str2bin(pos + 5, uuid);
64 if (os_strstr(ssid->eap.phase1, "pbc=1"))
70 #endif /* CONFIG_WPS */
72 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
74 struct wpa_supplicant *wpa_s = eloop_ctx;
75 struct wpa_ssid *ssid;
76 int enabled, scan_req = 0, ret;
77 struct wpabuf *wps_ie = NULL;
78 const u8 *extra_ie = NULL;
79 size_t extra_ie_len = 0;
83 #endif /* CONFIG_WPS */
85 if (wpa_s->disconnected && !wpa_s->scan_req)
89 ssid = wpa_s->conf->ssid;
91 if (!ssid->disabled) {
97 if (!enabled && !wpa_s->scan_req) {
98 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
99 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
102 scan_req = wpa_s->scan_req;
105 if (wpa_s->conf->ap_scan != 0 &&
106 wpa_s->driver && IS_WIRED(wpa_s->driver)) {
107 wpa_printf(MSG_DEBUG, "Using wired authentication - "
108 "overriding ap_scan configuration");
109 wpa_s->conf->ap_scan = 0;
112 if (wpa_s->conf->ap_scan == 0) {
113 wpa_supplicant_gen_assoc_event(wpa_s);
117 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
118 wpa_s->wpa_state == WPA_INACTIVE)
119 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
121 ssid = wpa_s->conf->ssid;
122 if (wpa_s->prev_scan_ssid != BROADCAST_SSID_SCAN) {
124 if (ssid == wpa_s->prev_scan_ssid) {
132 if (!ssid->disabled &&
133 (ssid->scan_ssid || wpa_s->conf->ap_scan == 2))
138 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
140 * ap_scan=2 mode - try to associate with each SSID instead of
141 * scanning for each scan_ssid=1 network.
144 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
145 "end of scan list - go back to beginning");
146 wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
147 wpa_supplicant_req_scan(wpa_s, 0, 0);
151 /* Continue from the next SSID on the next attempt. */
152 wpa_s->prev_scan_ssid = ssid;
154 /* Start from the beginning of the SSID list. */
155 wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
157 wpa_supplicant_associate(wpa_s, NULL, ssid);
161 wpa_printf(MSG_DEBUG, "Starting AP scan (%s SSID)",
162 ssid ? "specific": "broadcast");
164 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
165 ssid->ssid, ssid->ssid_len);
166 wpa_s->prev_scan_ssid = ssid;
168 wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
171 wps = wpas_wps_in_use(wpa_s->conf, uuid);
172 #endif /* CONFIG_WPS */
174 if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
175 !wpa_s->use_client_mlme && wps != 2) {
176 wpa_s->scan_res_tried++;
177 wpa_s->scan_req = scan_req;
178 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
179 "first without requesting a new scan to speed up "
180 "initial association");
181 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
187 wps_ie = wps_enrollee_build_probe_req_ie(wps == 2, uuid);
189 extra_ie = wpabuf_head(wps_ie);
190 extra_ie_len = wpabuf_len(wps_ie);
193 #endif /* CONFIG_WPS */
195 if (wpa_s->use_client_mlme) {
196 ieee80211_sta_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
197 ret = ieee80211_sta_req_scan(wpa_s, ssid ? ssid->ssid : NULL,
198 ssid ? ssid->ssid_len : 0);
200 wpa_drv_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
201 ret = wpa_drv_scan(wpa_s, ssid ? ssid->ssid : NULL,
202 ssid ? ssid->ssid_len : 0);
208 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
209 wpa_supplicant_req_scan(wpa_s, 10, 0);
215 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
216 * @wpa_s: Pointer to wpa_supplicant data
217 * @sec: Number of seconds after which to scan
218 * @usec: Number of microseconds after which to scan
220 * This function is used to schedule a scan for neighboring access points after
221 * the specified time.
223 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
225 /* If there's at least one network that should be specifically scanned
226 * then don't cancel the scan and reschedule. Some drivers do
227 * background scanning which generates frequent scan results, and that
228 * causes the specific SSID scan to get continually pushed back and
229 * never happen, which causes hidden APs to never get probe-scanned.
231 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
232 wpa_s->conf->ap_scan == 1) {
233 struct wpa_ssid *ssid = wpa_s->conf->ssid;
236 if (!ssid->disabled && ssid->scan_ssid)
241 wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
242 "ensure that specific SSID scans occur");
247 wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
249 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
250 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
255 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
256 * @wpa_s: Pointer to wpa_supplicant data
258 * This function is used to cancel a scan request scheduled with
259 * wpa_supplicant_req_scan().
261 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
263 wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
264 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);