v6: simplify GetTransactionID

Signed-off-by: Chris Koch <chrisko@google.com>

1 files changed, 4 insertions, 11 deletions

diff --git a/dhcpv6/dhcpv6.go b/dhcpv6/dhcpv6.go
index 41b4726..a8f7bdc 100644
--- a/dhcpv6/dhcpv6.go
+++ b/dhcpv6/dhcpv6.go
@@ -1,7 +1,6 @@
 package dhcpv6
 
 import (
-	"errors"
 	"fmt"
 	"net"
 	"strings"
@@ -223,15 +222,9 @@ func IsUsingUEFI(msg *Message) bool {
 // GetTransactionID returns a transactionID of a message or its inner message
 // in case of relay
 func GetTransactionID(packet DHCPv6) (TransactionID, error) {
-	if message, ok := packet.(*Message); ok {
-		return message.TransactionID, nil
-	}
-	if relay, ok := packet.(*RelayMessage); ok {
-		message, err := relay.GetInnerMessage()
-		if err != nil {
-			return TransactionID{0, 0, 0}, err
-		}
-		return GetTransactionID(message)
+	m, err := packet.GetInnerMessage()
+	if err != nil {
+		return TransactionID{0, 0, 0}, err
 	}
-	return TransactionID{0, 0, 0}, errors.New("Invalid DHCPv6 packet")
+	return m.TransactionID, nil
 }