eth, eth/downloader: fix #1231, DOS vulnerability in hash queueing

eth/handler.go

@@ -164,7 +164,7 @@ func (pm *ProtocolManager) newPeer(pv, nv int, p *p2p.Peer, rw p2p.MsgReadWriter
 // handle is the callback invoked to manage the life cycle of an eth peer. When
 // this function terminates, the peer is disconnected.
 func (pm *ProtocolManager) handle(p *peer) error {
-	glog.V(logger.Debug).Infof("%v: peer connected", p)
+	glog.V(logger.Debug).Infof("%v: peer connected [%s]", p, p.Name())
 
 	// Execute the Ethereum handshake
 	td, head, genesis := pm.chainman.Status()