Maint: dynamically set allowed VPN input ports

- Feat: allow to change VPN type at runtime
- Feat: allow to change interface name at runtime
- Maint: Add cleanup method to cleanup VPN loop on a vpn shutdown
- Change: allow VPN inputs ports only when tunnel is up

cmd/gluetun/main.go

@@ -292,14 +292,6 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		}
 	}
 
-	for _, vpnPort := range allSettings.Firewall.VPNInputPorts {
-		vpnIntf := allSettings.VPN.VPNInterface()
-		err = firewallConf.SetAllowedPort(ctx, vpnPort, vpnIntf)
-		if err != nil {
-			return err
-		}
-	}
-
 	for _, port := range allSettings.Firewall.InputPorts {
 		err = firewallConf.SetAllowedPort(ctx, port, defaultInterface)
 		if err != nil {
@@ -360,7 +352,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	tickersGroupHandler.Add(pubIPTickerHandler)
 
 	vpnLogger := logger.NewChild(logging.Settings{Prefix: "vpn: "})
-	vpnLooper := vpn.NewLoop(allSettings.VPN,
+	vpnLooper := vpn.NewLoop(allSettings.VPN, allSettings.Firewall.VPNInputPorts,
 		allServers, ovpnConf, netLinker, firewallConf, routingConf, portForwardLooper,
 		cmder, publicIPLooper, unboundLooper, vpnLogger, httpClient,
 		buildInfo, allSettings.VersionInformation)

internal/vpn/cleanup.go

@@ -0,0 +1,27 @@
+package vpn
+
+import (
+	"context"
+	"time"
+
+	"github.com/qdm12/gluetun/internal/publicip/models"
+)
+
+func (l *Loop) cleanup(ctx context.Context, pfEnabled bool) {
+	for _, vpnPort := range l.vpnInputPorts {
+		err := l.fw.RemoveAllowedPort(ctx, vpnPort)
+		if err != nil {
+			l.logger.Error("cannot remove allowed input port from firewall: " + err.Error())
+		}
+	}
+
+	l.publicip.SetData(models.IPInfoData{}) // clear public IP address data
+
+	if pfEnabled {
+		const pfTimeout = 100 * time.Millisecond
+		err := l.stopPortForwarding(ctx, pfTimeout)
+		if err != nil {
+			l.logger.Error("cannot stop port forwarding: " + err.Error())
+		}
+	}
+}

internal/vpn/loop.go

@@ -36,6 +36,7 @@ type Loop struct {
 	// Fixed parameters
 	buildInfo     models.BuildInformation
 	versionInfo   bool
+	vpnInputPorts []uint16 // TODO make changeable through stateful firewall
 	// Configurators
 	openvpnConf openvpn.Interface
 	netLinker   netlink.NetLinker
@@ -67,7 +68,7 @@ const (
 	defaultBackoffTime = 15 * time.Second
 )
 
-func NewLoop(vpnSettings configuration.VPN,
+func NewLoop(vpnSettings configuration.VPN, vpnInputPorts []uint16,
 	allServers models.AllServers, openvpnConf openvpn.Interface,
 	netLinker netlink.NetLinker, fw firewallConfigurer, routing routing.VPNGetter,
 	portForward portforward.StartStopper, starter command.Starter,
@@ -87,6 +88,7 @@ func NewLoop(vpnSettings configuration.VPN,
 		state:         state,
 		buildInfo:     buildInfo,
 		versionInfo:   versionInfo,
+		vpnInputPorts: vpnInputPorts,
 		openvpnConf:   openvpnConf,
 		netLinker:     netLinker,
 		fw:            fw,

internal/vpn/portforward.go

@@ -40,20 +40,14 @@ func (l *Loop) startPortForwarding(ctx context.Context, data tunnelUpData) (err
 	return nil
 }
 
-func (l *Loop) stopPortForwarding(ctx context.Context, enabled bool,
-	timeout time.Duration) {
-	if !enabled {
-		return // nothing to stop
-	}
-
+func (l *Loop) stopPortForwarding(ctx context.Context,
+	timeout time.Duration) (err error) {
 	if timeout > 0 {
 		var cancel context.CancelFunc
 		ctx, cancel = context.WithTimeout(ctx, timeout)
 		defer cancel()
 	}
 
-	_, err := l.portForward.Stop(ctx)
-	if err != nil {
-		l.logger.Error("cannot stop port forwarding: " + err.Error())
-	}
+	_, err = l.portForward.Stop(ctx)
+	return err
 }

internal/vpn/run.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/qdm12/gluetun/internal/constants"
 	"github.com/qdm12/gluetun/internal/provider"
-	"github.com/qdm12/gluetun/internal/publicip/models"
 	"github.com/qdm12/golibs/logging"
 )
 
@@ -32,6 +31,7 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 
 		providerConf := provider.New(settings.Provider.Name, allServers, time.Now)
 
+		portForwarding := settings.Provider.PortForwarding.Enabled
 		var vpnRunner vpnRunner
 		var serverName, vpnInterface string
 		var err error
@@ -49,7 +49,7 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 			continue
 		}
 		tunnelUpData := tunnelUpData{
-			portForwarding: settings.Provider.PortForwarding.Enabled,
+			portForwarding: portForwarding,
 			serverName:     serverName,
 			portForwarder:  providerConf,
 			vpnIntf:        vpnInterface,
@@ -76,9 +76,7 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 			case <-tunnelReady:
 				go l.onTunnelUp(openvpnCtx, tunnelUpData)
 			case <-ctx.Done():
-				const pfTimeout = 100 * time.Millisecond
-				l.stopPortForwarding(context.Background(),
-					settings.Provider.PortForwarding.Enabled, pfTimeout)
+				l.cleanup(context.Background(), portForwarding)
 				openvpnCancel()
 				<-waitError
 				close(waitError)
@@ -86,8 +84,7 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 			case <-l.stop:
 				l.userTrigger = true
 				l.logger.Info("stopping")
-				l.publicip.SetData(models.IPInfoData{}) // clear public IP address data
-				l.stopPortForwarding(ctx, settings.Provider.PortForwarding.Enabled, 0)
+				l.cleanup(context.Background(), portForwarding)
 				openvpnCancel()
 				<-waitError
 				// do not close waitError or the waitError
@@ -102,7 +99,7 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 
 				l.statusManager.Lock() // prevent SetStatus from running in parallel
 
-				l.stopPortForwarding(ctx, settings.Provider.PortForwarding.Enabled, 0)
+				l.cleanup(context.Background(), portForwarding)
 				openvpnCancel()
 				l.statusManager.SetStatus(constants.Crashed)
 				l.logAndWait(ctx, err)

internal/vpn/tunnelup.go

@@ -19,6 +19,13 @@ type tunnelUpData struct {
 func (l *Loop) onTunnelUp(ctx context.Context, data tunnelUpData) {
 	l.client.CloseIdleConnections()
 
+	for _, vpnPort := range l.vpnInputPorts {
+		err := l.fw.SetAllowedPort(ctx, vpnPort, data.vpnIntf)
+		if err != nil {
+			l.logger.Error("cannot allow input port through firewall: " + err.Error())
+		}
+	}
+
 	if l.dnsLooper.GetSettings().Enabled {
 		_, _ = l.dnsLooper.ApplyStatus(ctx, constants.Running)
 	}