Start scan for wifi roaming when SNR and signal are weakened

If SNR is less than 20 or RSSI level is less than 3,
scan for BSS transition is started.

Change-Id: I69c1e3e9a42ddb5f6087d580ff2c15c7086317d2
Signed-off-by: Jaehyun Kim <jeik01.kim@samsung.com>

5 files changed, 48 insertions, 5 deletions

diff --git a/gsupplicant/gsupplicant.h b/gsupplicant/gsupplicant.h
index 05af5de1..6f4dca4a 100755
--- a/gsupplicant/gsupplicant.h
+++ b/gsupplicant/gsupplicant.h
@@ -305,7 +305,7 @@ typedef void (*GSupplicantInterfaceCallback) (int result,
 
 #if defined TIZEN_EXT
 typedef void (*GSupplicantMaxSpeedCallback) (int result, int maxspeed,
-					     int strength, void *user_data);
+					     int strength, int snr, void *user_data);
 #endif
 
 void g_supplicant_interface_cancel(GSupplicantInterface *interface);
diff --git a/gsupplicant/supplicant.c b/gsupplicant/supplicant.c
index 906f0ea7..17ea4502 100755
--- a/gsupplicant/supplicant.c
+++ b/gsupplicant/supplicant.c
@@ -6425,6 +6425,7 @@ static void interface_signalpoll_result(const char *error,
 	int err = 0;
 	dbus_int32_t maxspeed = 0;
 	dbus_int32_t strength = 0;
+	dbus_int32_t snr = 0;
 	DBusMessageIter sub_iter, dict;
 
 	if (error) {
@@ -6461,6 +6462,10 @@ static void interface_signalpoll_result(const char *error,
 				dbus_message_iter_get_basic(&value, &strength);
 				SUPPLICANT_DBG("Strength = %d", strength);
 				break;
+			} else if (g_strcmp0(key, "SNR") == 0) {
+				dbus_message_iter_get_basic(&value, &snr);
+				SUPPLICANT_DBG("SNR = %d", snr);
+				break;
 			}
 		}
 		dbus_message_iter_next(&dict);
@@ -6468,7 +6473,7 @@ static void interface_signalpoll_result(const char *error,
 
 out:
 	if(data->callback)
-		data->callback(err, maxspeed, strength, data->user_data);
+		data->callback(err, maxspeed, strength, snr, data->user_data);
 
 	g_free(data->path);
 	dbus_free(data);
diff --git a/plugins/wifi.c b/plugins/wifi.c
index 82168162..11f7007e 100755
--- a/plugins/wifi.c
+++ b/plugins/wifi.c
@@ -83,6 +83,8 @@
 
 #if defined TIZEN_EXT
 #define WIFI_EAP_FAST_PAC_FILE		"/var/lib/wifi/wifi.pac"	/* path of Pac file for EAP-FAST */
+#define RSSI_LEVEL_2_5G  -77
+#define RSSI_LEVEL_2_24G -75
 #endif
 
 static struct connman_technology *wifi_technology = NULL;
@@ -2178,7 +2180,8 @@ static void scan_callback(int result, GSupplicantInterface *interface,
 			/* On error, let's recall scan_callback, which will cleanup */
 			return scan_callback(ret, interface, user_data);
 		}
-	}
+	} else
+		wifi->allow_full_scan = false;
 #endif
 
 	scanning = connman_device_get_scanning(device, CONNMAN_SERVICE_TYPE_WIFI);
@@ -3964,9 +3967,10 @@ static void set_connection_mode(struct connman_network *network,
 }
 
 static void signalpoll_callback(int result, int maxspeed, int strength,
-				void *user_data)
+				int snr, void *user_data)
 {
 	struct connman_network *network = user_data;
+	uint16_t freq = connman_network_get_frequency(network);
 
 	if (result != 0) {
 		DBG("Failed to get maxspeed from signalpoll !");
@@ -3978,13 +3982,31 @@ static void signalpoll_callback(int result, int maxspeed, int strength,
 	if (strength > 100)
 		strength = 100;
 
-	DBG("maxspeed = %d, strength = %d", maxspeed, strength);
+	DBG("maxspeed = %d, strength = %d, snr = %d", maxspeed, strength, snr);
 
 	connman_network_set_strength(network, (uint8_t)strength);
 	connman_network_set_maxspeed(network, maxspeed);
 	set_connection_mode(network, maxspeed);
 
 	connman_network_unref(network);
+
+	/* If SNR is less than 20 or RSSI level is less than 3,
+	 * scan for BSS transition is started.
+	 * */
+	if (connman_setting_get_bool("WifiRoamingScan") == false)
+		return;
+
+	if (snr < 20 && snr != 0)
+		goto scan;
+	else if (freq > 4900 && strength <= RSSI_LEVEL_2_5G)
+		goto scan;
+	else if (freq <= 4900 && strength <= RSSI_LEVEL_2_24G)
+		goto scan;
+
+	return;
+
+scan:
+	throw_wifi_scan(connman_network_get_device(network), scan_callback);
 }
 
 static int network_signalpoll(struct wifi_data *wifi)
diff --git a/src/main.c b/src/main.c
index cc104d50..7b73a0b8 100755
--- a/src/main.c
+++ b/src/main.c
@@ -107,6 +107,7 @@ static struct {
 	bool file_log;
 	bool dlog_log;
 	bool simple_log;
+	bool wifi_roam_scan;
 #endif
 } connman_settings  = {
 	.bg_scan = true,
@@ -140,6 +141,7 @@ static struct {
 	.file_log = true,
 	.dlog_log = true,
 	.simple_log = true,
+	.wifi_roam_scan = true,
 #endif
 };
 
@@ -230,6 +232,7 @@ static struct {
 #define CONF_CONNMAN_FILE_LOG           "FileLogging"
 #define CONF_CONNMAN_DLOG_LOG           "DlogLogging"
 #define CONF_CONNMAN_SIMPLIFIED_LOG     "SimplifiedLog"
+#define CONF_CONNMAN_WIFI_ROAM_SCAN     "WifiRoamingScan"
 #endif
 
 #if defined TIZEN_EXT
@@ -291,6 +294,7 @@ static const char *supported_options[] = {
 	CONF_CONNMAN_FILE_LOG,
 	CONF_CONNMAN_DLOG_LOG,
 	CONF_CONNMAN_SIMPLIFIED_LOG,
+	CONF_CONNMAN_WIFI_ROAM_SCAN,
 #endif
 	NULL
 };
@@ -697,6 +701,11 @@ static void check_Tizen_configuration(GKeyFile *config)
 	if (!error)
 		connman_settings.simple_log = boolean;
 
+	boolean = __connman_config_get_bool(config, "General",
+			CONF_CONNMAN_WIFI_ROAM_SCAN, &error);
+	if (!error)
+		connman_settings.wifi_roam_scan = boolean;
+
 	g_clear_error(&error);
 
 	check_Tizen_INS_configuration(config);
@@ -1183,6 +1192,9 @@ bool connman_setting_get_bool(const char *key)
 
 	if (g_str_equal(key, CONF_CONNMAN_SIMPLIFIED_LOG))
 		return connman_settings.simple_log;
+
+	if (g_str_equal(key, CONF_CONNMAN_WIFI_ROAM_SCAN))
+		return connman_settings.wifi_roam_scan;
 #endif
 
 #if defined TIZEN_EXT
diff --git a/src/main.conf b/src/main.conf
index 555225f0..6763d71b 100755
--- a/src/main.conf
+++ b/src/main.conf
@@ -185,6 +185,10 @@ SimplifiedLog = true
 # Default value is wlan0.
 DefaultWifiInterface = wlan0
 
+# Allow ConnMan to start scan for wifi roaming when SNR and signal are weakened
+# Default value is true.
+WifiRoamingScan = true
+
 [INS]
 # INS(Intelligent Network Selection) configuration: BSSID Selection.
 INSPreferredFreqBSSID = 5GHz