stop peer if it sends invalid vote

consensus/state.go

@@ -63,6 +63,19 @@ func (ti *timeoutInfo) String() string {
 	return fmt.Sprintf("%v ; %d/%d %v", ti.Duration, ti.Height, ti.Round, ti.Step)
 }
 
+type peerError struct {
+	err    error
+	peerID p2p.ID
+}
+
+func (e peerError) Error() string {
+	return fmt.Sprintf("error with peer %v: %s", e.peerID, e.err.Error())
+}
+
+const (
+	peerErrorEvent = "cs.PeerError"
+)
+
 // ConsensusState handles execution of the consensus algorithm.
 // It processes votes and proposals, and upon reaching agreement,
 // commits blocks to the chain and executes them against the application.
@@ -582,7 +595,8 @@ func (cs *ConsensusState) handleMsg(mi msgInfo) {
 		// if the vote gives us a 2/3-any or 2/3-one, we transition
 		err := cs.tryAddVote(msg.Vote, peerID)
 		if err == ErrAddingVote {
-			// TODO: punish peer
+			// punish peer
+			cs.eventBus.Publish(peerErrorEvent, types.TMEventData{peerError{err, peerID}})
 		}
 
 		// NOTE: the vote is broadcast to peers by the reactor listening