p2p: define DiscReason as uint8.

ref:ethereum/go-ethereum#24507

Author: ken0x4b656e

p2p/peer.go

@@ -324,11 +324,11 @@ func (p *Peer) handle(msg Msg) error {
 		msg.Discard()
 		go SendItems(p.rw, pongMsg)
 	case msg.Code == discMsg:
-		var reason [1]DiscReason
 		// This is the last message. We don't need to discard or
 		// check errors because, the connection will be closed after it.
-		rlp.Decode(msg.Payload, &reason)
-		return reason[0]
+		var m struct{ R DiscReason }
+		rlp.Decode(msg.Payload, &m)
+		return m.R
 	case msg.Code < baseProtocolLength:
 		// ignore other base protocol messages
 		return msg.Discard()

p2p/peer_error.go

@@ -54,7 +54,7 @@ func (pe *peerError) Error() string {
 
 var errProtocolReturned = errors.New("protocol returned")
 
-type DiscReason uint
+type DiscReason uint8
 
 const (
 	DiscRequested DiscReason = iota
@@ -69,7 +69,7 @@ const (
 	DiscUnexpectedIdentity
 	DiscSelf
 	DiscReadTimeout
-	DiscSubprotocolError = 0x10
+	DiscSubprotocolError = DiscReason(0x10)
 )
 
 var discReasonToString = [...]string{