Configuration package (#369)

internal/configuration/firewall.go

@@ -0,0 +1,93 @@
+package configuration
+
+import (
+	"net"
+	"strings"
+
+	"github.com/qdm12/golibs/params"
+)
+
+// Firewall contains settings to customize the firewall operation.
+type Firewall struct {
+	VPNInputPorts   []uint16
+	InputPorts      []uint16
+	OutboundSubnets []net.IPNet
+	Enabled         bool
+	Debug           bool
+}
+
+func (settings *Firewall) String() string {
+	return strings.Join(settings.lines(), "\n")
+}
+
+func (settings *Firewall) lines() (lines []string) {
+	if !settings.Enabled {
+		lines = append(lines, lastIndent+"Firewall: disabled ⚠️")
+		return lines
+	}
+
+	lines = append(lines, lastIndent+"Firewall:")
+
+	if settings.Debug {
+		lines = append(lines, indent+lastIndent+"Debug: on")
+	}
+
+	if len(settings.VPNInputPorts) > 0 {
+		lines = append(lines, indent+lastIndent+"VPN input ports: "+
+			strings.Join(uint16sToStrings(settings.VPNInputPorts), ", "))
+	}
+
+	if len(settings.InputPorts) > 0 {
+		lines = append(lines, indent+lastIndent+"Input ports: "+
+			strings.Join(uint16sToStrings(settings.InputPorts), ", "))
+	}
+
+	if len(settings.OutboundSubnets) > 0 {
+		lines = append(lines, indent+lastIndent+"Outbound subnets: "+
+			strings.Join(ipNetsToStrings(settings.OutboundSubnets), ", "))
+	}
+
+	return lines
+}
+
+func (settings *Firewall) read(r reader) (err error) {
+	settings.Enabled, err = r.env.OnOff("FIREWALL", params.Default("on"))
+	if err != nil {
+		return err
+	}
+
+	settings.Debug, err = r.env.OnOff("FIREWALL_DEBUG", params.Default("off"))
+	if err != nil {
+		return err
+	}
+
+	if err := settings.readVPNInputPorts(r.env); err != nil {
+		return err
+	}
+
+	if err := settings.readInputPorts(r.env); err != nil {
+		return err
+	}
+
+	if err := settings.readOutboundSubnets(r); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (settings *Firewall) readVPNInputPorts(env params.Env) (err error) {
+	settings.VPNInputPorts, err = readCSVPorts(env, "FIREWALL_VPN_INPUT_PORTS")
+	return err
+}
+
+func (settings *Firewall) readInputPorts(env params.Env) (err error) {
+	settings.VPNInputPorts, err = readCSVPorts(env, "FIREWALL_INPUT_PORTS")
+	return err
+}
+
+func (settings *Firewall) readOutboundSubnets(r reader) (err error) {
+	retroOption := params.RetroKeys([]string{"EXTRA_SUBNETS"}, r.onRetroActive)
+	settings.OutboundSubnets, err = readCSVIPNets(r.env, "FIREWALL_OUTBOUND_SUBNETS", retroOption)
+	return err
+}