add GREHeaderSize

2 files changed, 3 insertions, 1 deletions

diff --git a/pkg/tcpip/header/gre.go b/pkg/tcpip/header/gre.go
index 326d03ba8..f5c52cd1b 100644
--- a/pkg/tcpip/header/gre.go
+++ b/pkg/tcpip/header/gre.go
@@ -14,6 +14,8 @@ const (
 type GRE []byte
 
 const (
+        GREHeaderSize = 4
+
 	// GREProtocolNumber is GRE's transport protocol number.
 	GREProtocolNumber tcpip.TransportProtocolNumber = 47
 )
diff --git a/pkg/tcpip/header/parse/parse.go b/pkg/tcpip/header/parse/parse.go
index de3a91227..7ac5168c7 100644
--- a/pkg/tcpip/header/parse/parse.go
+++ b/pkg/tcpip/header/parse/parse.go
@@ -175,7 +175,7 @@ func TCP(pkt *stack.PacketBuffer) bool {
 //
 // Returns true if the header was successfully parsed.
 func GRE(pkt *stack.PacketBuffer) bool {
-	_, ok := pkt.TransportHeader().Consume(4)
+	_, ok := pkt.TransportHeader().Consume(header.GREHeaderSize)
 	pkt.TransportProtocolNumber = header.GREProtocolNumber
 	return ok
 }