Might fix #82

- Allow any input traffic on Shadowsocks port if Shadowsocks is enabled
- Allow any input traffic on TinyProxy port if TinyProxy is enabled

internal/firewall/firewall.go

@@ -24,6 +24,7 @@ type Configurator interface {
 	AddRoutesVia(subnets []net.IPNet, defaultGateway net.IP, defaultInterface string) error
 	GetDefaultRoute() (defaultInterface string, defaultGateway net.IP, defaultSubnet net.IPNet, err error)
 	AllowInputTrafficOnPort(device models.VPNDevice, port uint16) error
+	AllowAnyIncomingOnPort(port uint16) error
 }
 
 type configurator struct {

internal/firewall/iptables.go

@@ -128,3 +128,11 @@ func (c *configurator) AllowInputTrafficOnPort(device models.VPNDevice, port uin
 		fmt.Sprintf("-A INPUT -i %s -p udp --dport %d -j ACCEPT", device, port),
 	})
 }
+
+func (c *configurator) AllowAnyIncomingOnPort(port uint16) error {
+	c.logger.Info("%s: accepting any input traffic on port %d", logPrefix, port)
+	return c.runIptablesInstructions([]string{
+		fmt.Sprintf("-A INPUT -p tcp --dport %d -j ACCEPT", port),
+		fmt.Sprintf("-A INPUT -p udp --dport %d -j ACCEPT", port),
+	})
+}