package consensus import ( "sync" "testing" "time" "github.com/tendermint/tendermint/p2p" "github.com/tendermint/tendermint/types" . "github.com/tendermint/tmlibs/common" "github.com/tendermint/tmlibs/events" ) func init() { config = ResetConfig("consensus_byzantine_test") } //---------------------------------------------- // byzantine failures // 4 validators. 1 is byzantine. The other three are partitioned into A (1 val) and B (2 vals). // byzantine validator sends conflicting proposals into A and B, // and prevotes/precommits on both of them. // B sees a commit, A doesn't. // Byzantine validator refuses to prevote. // Heal partition and ensure A sees the commit func TestByzantine(t *testing.T) { N := 4 css := randConsensusNet(N, "consensus_byzantine_test", newMockTickerFunc(false), newCounter) // give the byzantine validator a normal ticker css[0].SetTimeoutTicker(NewTimeoutTicker()) switches := make([]*p2p.Switch, N) for i := 0; i < N; i++ { switches[i] = p2p.NewSwitch(config.P2P) } reactors := make([]p2p.Reactor, N) defer func() { for _, r := range reactors { if rr, ok := r.(*ByzantineReactor); ok { rr.reactor.Switch.Stop() } else { r.(*ConsensusReactor).Switch.Stop() } } }() eventChans := make([]chan interface{}, N) for i := 0; i < N; i++ { if i == 0 { css[i].privValidator = NewByzantinePrivValidator(css[i].privValidator.(*types.PrivValidator)) // make byzantine css[i].decideProposal = func(j int) func(int, int) { return func(height, round int) { byzantineDecideProposalFunc(height, round, css[j], switches[j]) } }(i) css[i].doPrevote = func(height, round int) {} } eventSwitch := events.NewEventSwitch() _, err := eventSwitch.Start() if err != nil { t.Fatalf("Failed to start switch: %v", err) } eventChans[i] = subscribeToEvent(eventSwitch, "tester", types.EventStringNewBlock(), 1) conR := NewConsensusReactor(css[i], true) // so we dont start the consensus states conR.SetEventSwitch(eventSwitch) var conRI p2p.Reactor conRI = conR if i == 0 { conRI = NewByzantineReactor(conR) } reactors[i] = conRI } p2p.MakeConnectedSwitches(config.P2P, N, func(i int, s *p2p.Switch) *p2p.Switch { // ignore new switch s, we already made ours switches[i].AddReactor("CONSENSUS", reactors[i]) return switches[i] }, func(sws []*p2p.Switch, i, j int) { // the network starts partitioned with globally active adversary if i != 0 { return } p2p.Connect2Switches(sws, i, j) }) // start the state machines byzR := reactors[0].(*ByzantineReactor) s := byzR.reactor.conS.GetState() byzR.reactor.SwitchToConsensus(s) for i := 1; i < N; i++ { cr := reactors[i].(*ConsensusReactor) cr.SwitchToConsensus(cr.conS.GetState()) } // byz proposer sends one block to peers[0] // and the other block to peers[1] and peers[2]. // note peers and switches order don't match. peers := switches[0].Peers().List() ind0 := getSwitchIndex(switches, peers[0]) ind1 := getSwitchIndex(switches, peers[1]) ind2 := getSwitchIndex(switches, peers[2]) // connect the 2 peers in the larger partition p2p.Connect2Switches(switches, ind1, ind2) // wait for someone in the big partition to make a block select { case <-eventChans[ind2]: } log.Notice("A block has been committed. Healing partition") // connect the partitions p2p.Connect2Switches(switches, ind0, ind1) p2p.Connect2Switches(switches, ind0, ind2) // wait till everyone makes the first new block // (one of them already has) wg := new(sync.WaitGroup) wg.Add(2) for i := 1; i < N-1; i++ { go func(j int) { <-eventChans[j] wg.Done() }(i) } done := make(chan struct{}) go func() { wg.Wait() close(done) }() tick := time.NewTicker(time.Second * 10) select { case <-done: case <-tick.C: for i, reactor := range reactors { t.Log(Fmt("Consensus Reactor %v", i)) t.Log(Fmt("%v", reactor)) } t.Fatalf("Timed out waiting for all validators to commit first block") } } //------------------------------- // byzantine consensus functions func byzantineDecideProposalFunc(height, round int, cs *ConsensusState, sw *p2p.Switch) { // byzantine user should create two proposals and try to split the vote. // Avoid sending on internalMsgQueue and running consensus state. // Create a new proposal block from state/txs from the mempool. block1, blockParts1 := cs.createProposalBlock() polRound, polBlockID := cs.Votes.POLInfo() proposal1 := types.NewProposal(height, round, blockParts1.Header(), polRound, polBlockID) cs.privValidator.SignProposal(cs.state.ChainID, proposal1) // byzantine doesnt err // Create a new proposal block from state/txs from the mempool. block2, blockParts2 := cs.createProposalBlock() polRound, polBlockID = cs.Votes.POLInfo() proposal2 := types.NewProposal(height, round, blockParts2.Header(), polRound, polBlockID) cs.privValidator.SignProposal(cs.state.ChainID, proposal2) // byzantine doesnt err block1Hash := block1.Hash() block2Hash := block2.Hash() // broadcast conflicting proposals/block parts to peers peers := sw.Peers().List() log.Notice("Byzantine: broadcasting conflicting proposals", "peers", len(peers)) for i, peer := range peers { if i < len(peers)/2 { go sendProposalAndParts(height, round, cs, peer, proposal1, block1Hash, blockParts1) } else { go sendProposalAndParts(height, round, cs, peer, proposal2, block2Hash, blockParts2) } } } func sendProposalAndParts(height, round int, cs *ConsensusState, peer *p2p.Peer, proposal *types.Proposal, blockHash []byte, parts *types.PartSet) { // proposal msg := &ProposalMessage{Proposal: proposal} peer.Send(DataChannel, struct{ ConsensusMessage }{msg}) // parts for i := 0; i < parts.Total(); i++ { part := parts.GetPart(i) msg := &BlockPartMessage{ Height: height, // This tells peer that this part applies to us. Round: round, // This tells peer that this part applies to us. Part: part, } peer.Send(DataChannel, struct{ ConsensusMessage }{msg}) } // votes cs.mtx.Lock() prevote, _ := cs.signVote(types.VoteTypePrevote, blockHash, parts.Header()) precommit, _ := cs.signVote(types.VoteTypePrecommit, blockHash, parts.Header()) cs.mtx.Unlock() peer.Send(VoteChannel, struct{ ConsensusMessage }{&VoteMessage{prevote}}) peer.Send(VoteChannel, struct{ ConsensusMessage }{&VoteMessage{precommit}}) } //---------------------------------------- // byzantine consensus reactor type ByzantineReactor struct { Service reactor *ConsensusReactor } func NewByzantineReactor(conR *ConsensusReactor) *ByzantineReactor { return &ByzantineReactor{ Service: conR, reactor: conR, } } func (br *ByzantineReactor) SetSwitch(s *p2p.Switch) { br.reactor.SetSwitch(s) } func (br *ByzantineReactor) GetChannels() []*p2p.ChannelDescriptor { return br.reactor.GetChannels() } func (br *ByzantineReactor) AddPeer(peer *p2p.Peer) { if !br.reactor.IsRunning() { return } // Create peerState for peer peerState := NewPeerState(peer) peer.Data.Set(types.PeerStateKey, peerState) // Send our state to peer. // If we're fast_syncing, broadcast a RoundStepMessage later upon SwitchToConsensus(). if !br.reactor.fastSync { br.reactor.sendNewRoundStepMessages(peer) } } func (br *ByzantineReactor) RemovePeer(peer *p2p.Peer, reason interface{}) { br.reactor.RemovePeer(peer, reason) } func (br *ByzantineReactor) Receive(chID byte, peer *p2p.Peer, msgBytes []byte) { br.reactor.Receive(chID, peer, msgBytes) } //---------------------------------------- // byzantine privValidator type ByzantinePrivValidator struct { Address []byte `json:"address"` types.Signer `json:"-"` mtx sync.Mutex } // Return a priv validator that will sign anything func NewByzantinePrivValidator(pv *types.PrivValidator) *ByzantinePrivValidator { return &ByzantinePrivValidator{ Address: pv.Address, Signer: pv.Signer, } } func (privVal *ByzantinePrivValidator) GetAddress() []byte { return privVal.Address } func (privVal *ByzantinePrivValidator) SignVote(chainID string, vote *types.Vote) error { privVal.mtx.Lock() defer privVal.mtx.Unlock() // Sign vote.Signature = privVal.Sign(types.SignBytes(chainID, vote)) return nil } func (privVal *ByzantinePrivValidator) SignProposal(chainID string, proposal *types.Proposal) error { privVal.mtx.Lock() defer privVal.mtx.Unlock() // Sign proposal.Signature = privVal.Sign(types.SignBytes(chainID, proposal)) return nil } func (privVal *ByzantinePrivValidator) String() string { return Fmt("PrivValidator{%X}", privVal.Address) }