p2p: peer state init too late and pex message too soon (#3634)

* fix peer state init to late

Peer does not have a state yet. We set it in AddPeer.
We need an new interface before mconnection is started

* pex message to soon

fix reconnection pex send too fast,
error is caused lastReceivedRequests is still
not deleted when a peer reconnected

* add test case for initpeer

* add prove case

* remove potentially infinite loop

* Update consensus/reactor.go

Co-Authored-By: guagualvcha <baifudong@lancai.cn>

* Update consensus/reactor_test.go

Co-Authored-By: guagualvcha <baifudong@lancai.cn>

* document Reactor interface better

* refactor TestReactorReceiveDoesNotPanicIfAddPeerHasntBeenCalledYet

* fix merge conflicts

* blockchain: remove peer's ID from the pool in InitPeer

Refs #3338

* pex: resetPeersRequestsInfo both upon InitPeer and RemovePeer

* ensure RemovePeer is always called before InitPeer

by removing the peer from the switch last (after we've stopped it and
removed from all reactors)

* add some comments for ConsensusReactor#InitPeer

* fix pex reactor

* format code

* fix spelling

* update changelog

* remove unused methods

* do not clear lastReceivedRequests upon error

only in RemovePeer

* call InitPeer before we start the peer!

* add a comment to InitPeer

* write a test

* use waitUntilSwitchHasAtLeastNPeers func

* bring back timeouts

* Test to ensure Receive panics if InitPeer has not been called

consensus/byzantine_test.go

@@ -270,3 +270,4 @@ func (br *ByzantineReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
 func (br *ByzantineReactor) Receive(chID byte, peer p2p.Peer, msgBytes []byte) {
 	br.reactor.Receive(chID, peer, msgBytes)
 }
+func (br *ByzantineReactor) InitPeer(peer p2p.Peer) p2p.Peer { return peer }

consensus/reactor.go

@@ -155,16 +155,24 @@ func (conR *ConsensusReactor) GetChannels() []*p2p.ChannelDescriptor {
 	}
 }
 
-// AddPeer implements Reactor
+// InitPeer implements Reactor by creating a state for the peer.
+func (conR *ConsensusReactor) InitPeer(peer p2p.Peer) p2p.Peer {
+	peerState := NewPeerState(peer).SetLogger(conR.Logger)
+	peer.Set(types.PeerStateKey, peerState)
+	return peer
+}
+
+// AddPeer implements Reactor by spawning multiple gossiping goroutines for the
+// peer.
 func (conR *ConsensusReactor) AddPeer(peer p2p.Peer) {
 	if !conR.IsRunning() {
 		return
 	}
 
-	// Create peerState for peer
-	peerState := NewPeerState(peer).SetLogger(conR.Logger)
-	peer.Set(types.PeerStateKey, peerState)
-
+	peerState, ok := peer.Get(types.PeerStateKey).(*PeerState)
+	if !ok {
+		panic(fmt.Sprintf("peer %v has no state", peer))
+	}
 	// Begin routines for this peer.
 	go conR.gossipDataRoutine(peer, peerState)
 	go conR.gossipVotesRoutine(peer, peerState)
@@ -177,7 +185,7 @@ func (conR *ConsensusReactor) AddPeer(peer p2p.Peer) {
 	}
 }
 
-// RemovePeer implements Reactor
+// RemovePeer is a noop.
 func (conR *ConsensusReactor) RemovePeer(peer p2p.Peer, reason interface{}) {
 	if !conR.IsRunning() {
 		return

consensus/reactor_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/tendermint/tendermint/libs/log"
 	mempl "github.com/tendermint/tendermint/mempool"
 	"github.com/tendermint/tendermint/p2p"
+	"github.com/tendermint/tendermint/p2p/mock"
 	sm "github.com/tendermint/tendermint/state"
 	"github.com/tendermint/tendermint/types"
 )
@@ -243,6 +244,49 @@ func TestReactorCreatesBlockWhenEmptyBlocksFalse(t *testing.T) {
 	}, css)
 }
 
+func TestReactorReceiveDoesNotPanicIfAddPeerHasntBeenCalledYet(t *testing.T) {
+	N := 1
+	css, cleanup := randConsensusNet(N, "consensus_reactor_test", newMockTickerFunc(true), newCounter)
+	defer cleanup()
+	reactors, _, eventBuses := startConsensusNet(t, css, N)
+	defer stopConsensusNet(log.TestingLogger(), reactors, eventBuses)
+
+	var (
+		reactor = reactors[0]
+		peer    = mock.NewPeer(nil)
+		msg     = cdc.MustMarshalBinaryBare(&HasVoteMessage{Height: 1, Round: 1, Index: 1, Type: types.PrevoteType})
+	)
+
+	reactor.InitPeer(peer)
+
+	// simulate switch calling Receive before AddPeer
+	assert.NotPanics(t, func() {
+		reactor.Receive(StateChannel, peer, msg)
+		reactor.AddPeer(peer)
+	})
+}
+
+func TestReactorReceivePanicsIfInitPeerHasntBeenCalledYet(t *testing.T) {
+	N := 1
+	css, cleanup := randConsensusNet(N, "consensus_reactor_test", newMockTickerFunc(true), newCounter)
+	defer cleanup()
+	reactors, _, eventBuses := startConsensusNet(t, css, N)
+	defer stopConsensusNet(log.TestingLogger(), reactors, eventBuses)
+
+	var (
+		reactor = reactors[0]
+		peer    = mock.NewPeer(nil)
+		msg     = cdc.MustMarshalBinaryBare(&HasVoteMessage{Height: 1, Round: 1, Index: 1, Type: types.PrevoteType})
+	)
+
+	// we should call InitPeer here
+
+	// simulate switch calling Receive before AddPeer
+	assert.Panics(t, func() {
+		reactor.Receive(StateChannel, peer, msg)
+	})
+}
+
 // Test we record stats about votes and block parts from other peers.
 func TestReactorRecordsVotesAndBlockParts(t *testing.T) {
 	N := 4