new: new wifi.region and wifi.txpower parameters

modules/wifi/wifi.go

@@ -28,6 +28,8 @@ type WiFiModule struct {
 
 	handle              *pcap.Handle
 	source              string
+	region              string
+	txPower             int
 	minRSSI             int
 	channel             int
 	hopPeriod           time.Duration
@@ -169,6 +171,15 @@ func NewWiFiModule(s *session.Session) *WiFiModule {
 
 	mod.AddHandler(assoc)
 
+	mod.AddParam(session.NewStringParameter("wifi.region",
+		"BO",
+		"",
+		"Set the WiFi region to this value before activating the interface."))
+
+	mod.AddParam(session.NewIntParameter("wifi.txpower",
+		"30",
+		"Set WiFi transmission power to this value before activating the interface."))
+
 	mod.AddParam(session.NewStringParameter("wifi.assoc.skip",
 		"",
 		"",
@@ -310,7 +321,13 @@ func (mod *WiFiModule) Configure() error {
 	var hopPeriod int
 	var err error
 
-	if err, mod.source = mod.StringParam("wifi.source.file"); err != nil {
+	if err, mod.region = mod.StringParam("wifi.region"); err != nil {
+		return err
+	} else if err, mod.txPower = mod.IntParam("wifi.txpower"); err != nil {
+		return err
+	} else if err, mod.source = mod.StringParam("wifi.source.file"); err != nil {
+		return err
+	} else if err, mod.minRSSI = mod.IntParam("wifi.rssi.min"); err != nil {
 		return err
 	}
 
@@ -322,17 +339,28 @@ func (mod *WiFiModule) Configure() error {
 		}
 	}
 
-	if err, mod.minRSSI = mod.IntParam("wifi.rssi.min"); err != nil {
-		return err
-	}
-
 	ifName := mod.Session.Interface.Name()
-
 	if mod.source != "" {
 		if mod.handle, err = pcap.OpenOffline(mod.source); err != nil {
 			return fmt.Errorf("error while opening file %s: %s", mod.source, err)
 		}
 	} else {
+		if mod.region != "" {
+			if err := network.SetWiFiRegion(mod.region); err != nil {
+				return err
+			} else {
+				mod.Info("WiFi region set to '%s'", mod.region)
+			}
+		}
+
+		if mod.txPower > 0 {
+			if err := network.SetInterfaceTxPower(ifName, mod.txPower); err != nil {
+				mod.Warning("could not set interface %s txpower to %d, 'Set Tx Power' requests not supported", ifName, mod.txPower)
+			} else {
+				mod.Info("interface %s txpower set to %d", ifName, mod.txPower)
+			}
+		}
+
 		for retry := 0; ; retry++ {
 			ihandle, err := pcap.NewInactiveHandle(ifName)
 			if err != nil {

network/net.go

@@ -264,6 +264,15 @@ func FindInterface(name string) (*Endpoint, error) {
 	return nil, ErrNoIfaces
 }
 
+func SetWiFiRegion(region string) error {
+	if out, err := core.Exec("iw", []string{"reg", "set", region}); err != nil {
+		return err
+	} else if out != "" {
+		return fmt.Errorf("unexpected output while setting WiFi region %s: %s", region, out)
+	}
+	return nil
+}
+
 func ActivateInterface(name string) error {
 	if out, err := core.Exec("ifconfig", []string{name, "up"}); err != nil {
 		return err
@@ -273,6 +282,15 @@ func ActivateInterface(name string) error {
 	return nil
 }
 
+func SetInterfaceTxPower(name string, txpower int) error {
+	if out, err := core.ExecSilent("iwconfig", []string{name, "txpower", fmt.Sprintf("%d", txpower)}); err != nil {
+		return err
+	} else if out != "" {
+		return fmt.Errorf("unexpected output while setting txpower to %d for interface %s: %s", txpower, name, out)
+	}
+	return nil
+}
+
 func GatewayProvidedByUser(iface *Endpoint, gateway string) (*Endpoint, error) {
 	Debug("GatewayProvidedByUser(%s) [cmd=%v opts=%v parser=%v]", gateway, IPv4RouteCmd, IPv4RouteCmdOpts, IPv4RouteParser)
 	if IPv4Validator.MatchString(gateway) {