FIREWALL_VPN_INPUT_PORTS variable, fixes #196

internal/params/firewall.go

@@ -3,6 +3,7 @@ package params
 import (
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 
 	libparams "github.com/qdm12/golibs/params"
@@ -35,6 +36,30 @@ func (r *reader) GetExtraSubnets() (extraSubnets []net.IPNet, err error) {
 	return extraSubnets, nil
 }
 
+// GetAllowedVPNInputPorts obtains a list of input ports to allow from the
+// VPN server side in the firewall, from the environment variable FIREWALL_VPN_INPUT_PORTS
+func (r *reader) GetVPNInputPorts() (ports []uint16, err error) {
+	s, err := r.envParams.GetEnv("FIREWALL_VPN_INPUT_PORTS", libparams.Default(""))
+	if err != nil {
+		return nil, err
+	}
+	if len(s) == 0 {
+		return nil, nil
+	}
+	portsStr := strings.Split(s, ",")
+	ports = make([]uint16, len(portsStr))
+	for i := range portsStr {
+		portInt, err := strconv.Atoi(portsStr[i])
+		if err != nil {
+			return nil, fmt.Errorf("VPN input port %q is not valid (%s)", portInt, err)
+		} else if portInt <= 0 || portInt > 65535 {
+			return nil, fmt.Errorf("VPN input port %d must be between 1 and 65535", portInt)
+		}
+		ports[i] = uint16(portInt)
+	}
+	return ports, nil
+}
+
 // GetFirewallDebug obtains if the firewall should run in debug verbose mode from the environment variable FIREWALL_DEBUG
 func (r *reader) GetFirewallDebug() (debug bool, err error) {
 	return r.envParams.GetOnOff("FIREWALL_DEBUG", libparams.Default("off"))