Chore: Three small fixes (#4922)

proxy/shadowsocks/server.go

@@ -128,6 +128,7 @@ func (s *Server) handleUDPPayload(ctx context.Context, conn stat.Connection, dis
 
 		conn.Write(data.Bytes())
 	})
+	defer udpServer.RemoveRay()
 
 	inbound := session.InboundFromContext(ctx)
 	var dest *net.Destination

proxy/socks/server.go

@@ -245,13 +245,15 @@ func (s *Server) handleUDPPayload(ctx context.Context, conn stat.Connection, dis
 		udpMessage, err := EncodeUDPPacket(request, payload.Bytes())
 		payload.Release()
 
-		defer udpMessage.Release()
 		if err != nil {
 			errors.LogWarningInner(ctx, err, "failed to write UDP response")
+			return
 		}
+		defer udpMessage.Release()
 
 		conn.Write(udpMessage.Bytes())
 	})
+	defer udpServer.RemoveRay()
 
 	inbound := session.InboundFromContext(ctx)
 	if inbound != nil && inbound.Source.IsValid() {

proxy/trojan/server.go

@@ -259,6 +259,7 @@ func (s *Server) handleUDPPayload(ctx context.Context, clientReader *PacketReade
 			errors.LogWarningInner(ctx, err, "failed to write response")
 		}
 	})
+	defer udpServer.RemoveRay()
 
 	inbound := session.InboundFromContext(ctx)
 	user := inbound.User

proxy/vless/inbound/inbound.go

@@ -206,7 +206,10 @@ func (h *Handler) Process(ctx context.Context, network net.Network, connection s
 
 	first := buf.FromBytes(make([]byte, buf.Size))
 	first.Clear()
-	firstLen, _ := first.ReadFrom(connection)
+	firstLen, errR := first.ReadFrom(connection)
+	if errR != nil {
+		return errR
+	}
 	errors.LogInfo(ctx, "firstLen = ", firstLen)
 
 	reader := &buf.BufferedReader{