1 files changed, 11 insertions, 6 deletions
diff --git a/pkg/tcpip/config/config.go b/pkg/tcpip/config/config.go
index d021bf6a3..4eb0eacaf 100644
--- a/pkg/tcpip/config/config.go
+++ b/pkg/tcpip/config/config.go
@@ -62,6 +62,7 @@ type Tuntap struct {
 	Common `yaml:",inline"`
 	Mode string `yaml:"mode"`
 	Name string `yaml:"name"`
+	Fd int `yaml:"fd"`
 }
 
 type WireguardKey []byte
@@ -163,13 +164,17 @@ func addTunLink(s *stack.Stack, nic tcpip.NICID, id string, tap bool, addr tcpip
 	}
 
 	var fd int
-	if tap {
-		fd, err = tun.OpenTAP(tunName)
+	if tuntap.Fd != 0 {
+		fd = tuntap.Fd
 	} else {
-		fd, err = tun.Open(tunName)
-	}
-	if err != nil {
-		log.Fatalf("Open %s %b %s", err, tap, tunName)
+		if tap {
+			fd, err = tun.OpenTAP(tunName)
+		} else {
+			fd, err = tun.Open(tunName)
+		}
+		if err != nil {
+			log.Fatalf("Open %s %b %s", err, tap, tunName)
+		}
 	}
 
 	linkEP, err := fdbased.New(&fdbased.Options{