2  * WPA Supplicant - background scan and roaming module: simple
3  * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
17 #include "scan.h"
30 	int short_scan_count; /* counter for scans using short scan interval */
31 	int max_short_scans; /* maximum times we short-scan before back-off */
46 	if (!data->use_btm_query || wpa_s->conf->disable_btm ||  in bgscan_simple_btm_query()
47 	    !wpa_s->current_bss ||  in bgscan_simple_btm_query()
48 	    !wpa_bss_ext_capab(wpa_s->current_bss,  in bgscan_simple_btm_query()
52 	/* Try BTM x times, scan on x + 1 */  in bgscan_simple_btm_query()
53 	data->scan_action_count++;  in bgscan_simple_btm_query()
54 	mod = data->scan_action_count % (data->use_btm_query + 1);  in bgscan_simple_btm_query()
55 	if (mod >= data->use_btm_query)  in bgscan_simple_btm_query()
60 		   mod, data->use_btm_query);  in bgscan_simple_btm_query()
65 		/* Fall through and do regular scan */  in bgscan_simple_btm_query()
69 	/* Start a new timeout for the next one. We don't have scan callback to  in bgscan_simple_btm_query()
71 	eloop_register_timeout(data->scan_interval, 0,  in bgscan_simple_btm_query()
80 	struct wpa_supplicant *wpa_s = data->wpa_s;  in bgscan_simple_timeout()
88 	params.ssids[0].ssid = data->ssid->ssid;  in bgscan_simple_timeout()
89 	params.ssids[0].ssid_len = data->ssid->ssid_len;  in bgscan_simple_timeout()
90 	params.freqs = data->ssid->scan_freq;  in bgscan_simple_timeout()
98 	wpa_printf(MSG_DEBUG, "bgscan simple: Request a background scan");  in bgscan_simple_timeout()
100 		wpa_printf(MSG_DEBUG, "bgscan simple: Failed to trigger scan");  in bgscan_simple_timeout()
101 		eloop_register_timeout(data->scan_interval, 0,  in bgscan_simple_timeout()
105 		if (data->scan_interval == data->short_interval) {  in bgscan_simple_timeout()
106 			data->short_scan_count++;  in bgscan_simple_timeout()
107 			if (data->short_scan_count >= data->max_short_scans) {  in bgscan_simple_timeout()
108 				data->scan_interval = data->long_interval;  in bgscan_simple_timeout()
110 					   "off to long scan interval");  in bgscan_simple_timeout()
112 		} else if (data->short_scan_count > 0) {  in bgscan_simple_timeout()
114 			 * If we lasted a long scan interval without any  in bgscan_simple_timeout()
115 			 * CQM triggers, decrease the short-scan count,  in bgscan_simple_timeout()
116 			 * which allows 1 more short-scan interval to  in bgscan_simple_timeout()
119 			data->short_scan_count--;  in bgscan_simple_timeout()
121 		os_get_reltime(&data->last_bgscan);  in bgscan_simple_timeout()
131 	data->use_btm_query = 0;  in bgscan_simple_get_params()
133 	data->short_interval = atoi(params);  in bgscan_simple_get_params()
139 	data->signal_threshold = atoi(pos);  in bgscan_simple_get_params()
142 		wpa_printf(MSG_ERROR, "bgscan simple: Missing scan interval "  in bgscan_simple_get_params()
144 		return -1;  in bgscan_simple_get_params()
147 	data->long_interval = atoi(pos);  in bgscan_simple_get_params()
151 		data->use_btm_query = atoi(pos);  in bgscan_simple_get_params()
167 	data->wpa_s = wpa_s;  in bgscan_simple_init()
168 	data->ssid = ssid;  in bgscan_simple_init()
173 	if (data->short_interval <= 0)  in bgscan_simple_init()
174 		data->short_interval = 30;  in bgscan_simple_init()
175 	if (data->long_interval <= 0)  in bgscan_simple_init()
176 		data->long_interval = 30;  in bgscan_simple_init()
179 		   "Short bgscan interval %d  Long bgscan interval %d",  in bgscan_simple_init()
180 		   data->signal_threshold, data->short_interval,  in bgscan_simple_init()
181 		   data->long_interval);  in bgscan_simple_init()
183 	if (data->signal_threshold &&  in bgscan_simple_init()
184 	    wpa_drv_signal_monitor(wpa_s, data->signal_threshold, 4) < 0) {  in bgscan_simple_init()
189 	data->scan_interval = data->short_interval;  in bgscan_simple_init()
190 	data->max_short_scans = data->long_interval / data->short_interval + 1;  in bgscan_simple_init()
191 	if (data->signal_threshold) {  in bgscan_simple_init()
192 		wpa_s->signal_threshold = data->signal_threshold;  in bgscan_simple_init()
193 		/* Poll for signal info to set initial scan interval */  in bgscan_simple_init()
196 		    siginfo.data.signal >= data->signal_threshold)  in bgscan_simple_init()
197 			data->scan_interval = data->long_interval;  in bgscan_simple_init()
199 	wpa_printf(MSG_DEBUG, "bgscan simple: Init scan interval: %d",  in bgscan_simple_init()
200 		   data->scan_interval);  in bgscan_simple_init()
201 	eloop_register_timeout(data->scan_interval, 0, bgscan_simple_timeout,  in bgscan_simple_init()
206 	 * reasonable to assume that a scan was completed recently. This makes  in bgscan_simple_init()
207 	 * us skip an immediate new scan in cases where the current signal  in bgscan_simple_init()
210 	os_get_reltime(&data->last_bgscan);  in bgscan_simple_init()
220 	if (data->signal_threshold) {  in bgscan_simple_deinit()
221 		data->wpa_s->signal_threshold = 0;  in bgscan_simple_deinit()
222 		wpa_drv_signal_monitor(data->wpa_s, 0, 0);  in bgscan_simple_deinit()
233 	wpa_printf(MSG_DEBUG, "bgscan simple: scan result notification");  in bgscan_simple_notify_scan()
236 	eloop_register_timeout(data->scan_interval, 0, bgscan_simple_timeout,  in bgscan_simple_notify_scan()
240 	 * A more advanced bgscan could process scan results internally, select  in bgscan_simple_notify_scan()
263 	int scan = 0;  in bgscan_simple_notify_signal_change()  local
266 	if (data->short_interval == data->long_interval ||  in bgscan_simple_notify_signal_change()
267 	    data->signal_threshold == 0)  in bgscan_simple_notify_signal_change()
274 	if (data->scan_interval == data->long_interval && !above) {  in bgscan_simple_notify_signal_change()
276 			   "bgscan interval");  in bgscan_simple_notify_signal_change()
277 		data->scan_interval = data->short_interval;  in bgscan_simple_notify_signal_change()
279 		if (now.sec > data->last_bgscan.sec + 1 &&  in bgscan_simple_notify_signal_change()
280 		    data->short_scan_count <= data->max_short_scans)  in bgscan_simple_notify_signal_change()
283 			 * performed a scan, and we haven't depleted our  in bgscan_simple_notify_signal_change()
284 			 * budget for short-scans, perform a scan  in bgscan_simple_notify_signal_change()
287 			scan = 1;  in bgscan_simple_notify_signal_change()
288 		else if (data->last_bgscan.sec + data->long_interval >  in bgscan_simple_notify_signal_change()
289 			 now.sec + data->scan_interval) {  in bgscan_simple_notify_signal_change()
291 			 * Restart scan interval timer if currently scheduled  in bgscan_simple_notify_signal_change()
292 			 * scan is too far in the future.  in bgscan_simple_notify_signal_change()
296 			eloop_register_timeout(data->scan_interval, 0,  in bgscan_simple_notify_signal_change()
300 	} else if (data->scan_interval == data->short_interval && above) {  in bgscan_simple_notify_signal_change()
302 			   "interval");  in bgscan_simple_notify_signal_change()
303 		data->scan_interval = data->long_interval;  in bgscan_simple_notify_signal_change()
305 		eloop_register_timeout(data->scan_interval, 0,  in bgscan_simple_notify_signal_change()
309 		 * Signal dropped further 4 dB. Request a new scan if we have  in bgscan_simple_notify_signal_change()
313 		if (now.sec > data->last_bgscan.sec + 10)  in bgscan_simple_notify_signal_change()
314 			scan = 1;  in bgscan_simple_notify_signal_change()
317 	if (scan) {  in bgscan_simple_notify_signal_change()
318 		wpa_printf(MSG_DEBUG, "bgscan simple: Trigger immediate scan");  in bgscan_simple_notify_signal_change()