Maint: internal/routing/inbound.go file

internal/routing/inbound.go

@@ -0,0 +1,74 @@
+package routing
+
+import (
+	"errors"
+	"fmt"
+	"net"
+)
+
+const (
+	inboundTable    = 200
+	inboundPriority = 100
+)
+
+var (
+	errDefaultIP   = errors.New("cannot get default IP address")
+	errRuleAdd     = errors.New("cannot add rule")
+	errRouteAdd    = errors.New("cannot add route")
+	errRuleDelete  = errors.New("cannot delete rule")
+	errRouteDelete = errors.New("cannot delete route")
+)
+
+func (r *Routing) routeInboundFromDefault(defaultGateway net.IP,
+	defaultInterface string) (err error) {
+	if err := r.addRuleInboundFromDefault(inboundTable); err != nil {
+		return fmt.Errorf("%w: %s", errRuleAdd, err)
+	}
+
+	defaultDestination := net.IPNet{IP: net.IPv4(0, 0, 0, 0), Mask: net.IPv4Mask(0, 0, 0, 0)}
+	if err := r.addRouteVia(defaultDestination, defaultGateway, defaultInterface, inboundTable); err != nil {
+		return fmt.Errorf("%w: %s", errRouteAdd, err)
+	}
+
+	return nil
+}
+
+func (r *Routing) unrouteInboundFromDefault(defaultGateway net.IP,
+	defaultInterface string) (err error) {
+	defaultDestination := net.IPNet{IP: net.IPv4(0, 0, 0, 0), Mask: net.IPv4Mask(0, 0, 0, 0)}
+	if err := r.deleteRouteVia(defaultDestination, defaultGateway, defaultInterface, inboundTable); err != nil {
+		return fmt.Errorf("%w: %s", errRouteDelete, err)
+	}
+
+	if err := r.delRuleInboundFromDefault(inboundTable); err != nil {
+		return fmt.Errorf("%w: %s", errRuleDelete, err)
+	}
+
+	return nil
+}
+
+func (r *Routing) addRuleInboundFromDefault(table int) (err error) {
+	defaultIP, err := r.DefaultIP()
+	if err != nil {
+		return fmt.Errorf("%w: %s", errDefaultIP, err)
+	}
+
+	if err := r.addIPRule(defaultIP, table, inboundPriority); err != nil {
+		return fmt.Errorf("%w: %s", errIPRuleAdd, err)
+	}
+
+	return nil
+}
+
+func (r *Routing) delRuleInboundFromDefault(table int) (err error) {
+	defaultIP, err := r.DefaultIP()
+	if err != nil {
+		return fmt.Errorf("%w: %s", errDefaultIP, err)
+	}
+
+	if err := r.deleteIPRule(defaultIP, table, inboundPriority); err != nil {
+		return fmt.Errorf("%w: %s", errIPRuleAdd, err)
+	}
+
+	return nil
+}