add

src/pingtunnel/pingtunnel.go

@@ -6,7 +6,6 @@ import (
 	"encoding/base64"
 	"encoding/binary"
 	"encoding/hex"
-	"golang.org/x/net/ipv4"
 	"io"
 )
 
@@ -20,14 +19,6 @@ const (
 	protocolICMP     = 1
 )
 
-func ipv4Payload(b []byte) []byte {
-	if len(b) < ipv4.HeaderLen {
-		return b
-	}
-	hdrlen := int(b[0]&0x0f) << 2
-	return b[hdrlen:]
-}
-
 type Msg struct {
 	TYPE int
 	ID   string // identifier

src/pingtunnel/server.go

@@ -65,10 +65,8 @@ func (p *Server) Recv() error {
 			}
 		}
 
-		bytes1 := ipv4Payload(bytes)
-
 		var m *icmp.Message
-		if m, err = icmp.ParseMessage(protocolICMP, bytes1[:n]); err != nil {
+		if m, err = icmp.ParseMessage(protocolICMP, bytes[:n]); err != nil {
 			fmt.Println("Error parsing icmp message")
 			return err
 		}