Add pre-authorized port system for internal dialers

firewall/dialer.go

@@ -0,0 +1,44 @@
+package firewall
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/Safing/portmaster/intel"
+)
+
+func init() {
+	intel.SetLocalAddrFactory(PermittedAddr)
+}
+
+// PermittedAddr returns an already permitted local address for the given network for reliable connectivity.
+// Returns nil in case of error.
+func PermittedAddr(network string) net.Addr {
+	switch network {
+	case "udp":
+		return PermittedUDPAddr()
+	case "tcp":
+		return PermittedTCPAddr()
+	}
+	return nil
+}
+
+// PermittedUDPAddr returns an already permitted local udp address for reliable connectivity.
+// Returns nil in case of error.
+func PermittedUDPAddr() *net.UDPAddr {
+	addr, err := net.ResolveUDPAddr("udp", fmt.Sprintf(":%d", GetPermittedPort()))
+	if err != nil {
+		return nil
+	}
+	return addr
+}
+
+// PermittedTCPAddr returns an already permitted local tcp address for reliable connectivity.
+// Returns nil in case of error.
+func PermittedTCPAddr() *net.TCPAddr {
+	addr, err := net.ResolveTCPAddr("tcp", fmt.Sprintf(":%d", GetPermittedPort()))
+	if err != nil {
+		return nil
+	}
+	return addr
+}