package consensus import ( "encoding/hex" "errors" "fmt" "math/big" "sort" "time" "github.com/Secured-Finance/dione/ethclient" "github.com/libp2p/go-libp2p-core/host" drand2 "github.com/Secured-Finance/dione/beacon/drand" "github.com/libp2p/go-libp2p-core/peer" "github.com/fxamacker/cbor/v2" "github.com/asaskevich/EventBus" "github.com/Secured-Finance/dione/blockchain" types3 "github.com/Secured-Finance/dione/blockchain/types" "github.com/libp2p/go-libp2p-core/crypto" "github.com/Secured-Finance/dione/blockchain/pool" "github.com/Secured-Finance/dione/consensus/types" types2 "github.com/Secured-Finance/dione/types" "github.com/sirupsen/logrus" "github.com/Secured-Finance/dione/pubsub" ) var ( ErrNoAcceptedBlocks = errors.New("there is no accepted blocks") ) type ConsensusHandler struct { bus EventBus.Bus psb *pubsub.PubSubRouter privKey crypto.PrivKey validator *ConsensusValidator ethereumClient ethclient.EthereumSideAPI miner *blockchain.Miner consensus *ConsensusManager mempool *pool.Mempool blockchain *blockchain.BlockChain address peer.ID } func NewConsensusHandler( bus EventBus.Bus, psb *pubsub.PubSubRouter, privKey crypto.PrivKey, ethereumClient ethclient.EthereumSideAPI, miner *blockchain.Miner, bc *blockchain.BlockChain, bp *ConsensusManager, db *drand2.DrandBeacon, mempool *pool.Mempool, h host.Host, ) *ConsensusHandler { pcm := &ConsensusHandler{ psb: psb, miner: miner, validator: NewConsensusValidator(miner, bc, db), privKey: privKey, ethereumClient: ethereumClient, bus: bus, consensus: bp, mempool: mempool, blockchain: bc, address: h.ID(), } pcm.psb.Hook(pubsub.PrePrepareMessageType, pcm.handlePrePrepare) pcm.psb.Hook(pubsub.PrepareMessageType, pcm.handlePrepare) pcm.psb.Hook(pubsub.CommitMessageType, pcm.handleCommit) pcm.bus.SubscribeAsync("beacon:newEntry", func(entry types2.BeaconEntry) { pcm.onNewBeaconEntry(entry) }, true) pcm.bus.SubscribeAsync("consensus:newState", func(block *types3.Block, newStateNumber int) { newState := State(newStateNumber) // hacky, because reflection panics if we pass int to a handler which has type-alias for int consensusMessageType := types.ConsensusMessageTypeUnknown switch newState { case StateStatusPrePrepared: { logrus.WithField("blockHash", fmt.Sprintf("%x", block.Header.Hash)).Debugf("Entered into PREPREPARED state") if *block.Header.Proposer == pcm.address { return } consensusMessageType = types.ConsensusMessageTypePrepare break } case StateStatusPrepared: { consensusMessageType = types.ConsensusMessageTypeCommit logrus.WithField("blockHash", fmt.Sprintf("%x", block.Header.Hash)).Debugf("Entered into PREPARED state") break } case StateStatusCommited: { logrus.WithField("blockHash", fmt.Sprintf("%x", block.Header.Hash)).Debugf("Entered into COMMITTED state") break } } if consensusMessageType == types.ConsensusMessageTypeUnknown { return } message, err := NewMessage(&types.ConsensusMessage{ Type: consensusMessageType, Blockhash: block.Header.Hash, }, pcm.privKey) if err != nil { logrus.Errorf("Failed to create consensus message: %v", err) return } if err = pcm.psb.BroadcastToServiceTopic(message); err != nil { logrus.Errorf("Failed to send consensus message: %s", err.Error()) return } }, true) logrus.Info("Consensus handler has been initialized!") return pcm } func (pcm *ConsensusHandler) propose(blk *types3.Block) error { cmsg := &types.ConsensusMessage{ Type: StateStatusPrePrepared, Block: blk, Blockhash: blk.Header.Hash, From: pcm.address, } prePrepareMsg, err := NewMessage(cmsg, pcm.privKey) if err != nil { return err } time.Sleep(1 * time.Second) // wait until all nodes will commit previous blocks if err = pcm.consensus.InsertMessageIntoLog(cmsg); err != nil { return err } if err = pcm.psb.BroadcastToServiceTopic(prePrepareMsg); err != nil { return err } logrus.WithField("blockHash", fmt.Sprintf("%x", blk.Header.Hash)).Debugf("Entered into PREPREPARED state") return nil } func (pcm *ConsensusHandler) handlePrePrepare(message *pubsub.PubSubMessage) { var prePrepare types.PrePrepareMessage err := cbor.Unmarshal(message.Payload, &prePrepare) if err != nil { logrus.Errorf("failed to convert payload to PrePrepare message: %s", err.Error()) return } if *prePrepare.Block.Header.Proposer == pcm.address { return } cmsg := &types.ConsensusMessage{ Type: types.ConsensusMessageTypePrePrepare, From: message.From, Block: prePrepare.Block, Blockhash: prePrepare.Block.Header.Hash, } if !pcm.validator.Valid(cmsg) { logrus.WithField("blockHash", hex.EncodeToString(cmsg.Block.Header.Hash)).Warn("Received invalid PREPREPARE for block") return } err = pcm.consensus.InsertMessageIntoLog(cmsg) if err != nil { logrus.WithField("err", err.Error()).Warn("Failed to add PREPARE message to log") return } logrus.WithFields(logrus.Fields{ "blockHash": fmt.Sprintf("%x", cmsg.Block.Header.Hash), "from": message.From.String(), }).Debug("Received PREPREPARE message") } func (pcm *ConsensusHandler) handlePrepare(message *pubsub.PubSubMessage) { var prepare types.PrepareMessage err := cbor.Unmarshal(message.Payload, &prepare) if err != nil { logrus.Errorf("failed to convert payload to Prepare message: %s", err.Error()) return } cmsg := &types.ConsensusMessage{ Type: types.ConsensusMessageTypePrepare, From: message.From, Blockhash: prepare.Blockhash, Signature: prepare.Signature, } if !pcm.validator.Valid(cmsg) { logrus.Warnf("received invalid prepare msg for block %x", cmsg.Blockhash) return } err = pcm.consensus.InsertMessageIntoLog(cmsg) if err != nil { logrus.WithField("err", err.Error()).Warn("Failed to add PREPARE message to log") return } logrus.WithFields(logrus.Fields{ "blockHash": fmt.Sprintf("%x", cmsg.Blockhash), "from": message.From.String(), }).Debug("Received PREPARE message") } func (pcm *ConsensusHandler) handleCommit(message *pubsub.PubSubMessage) { var commit types.CommitMessage err := cbor.Unmarshal(message.Payload, &commit) if err != nil { logrus.Errorf("failed to convert payload to Commit message: %s", err.Error()) return } cmsg := &types.ConsensusMessage{ Type: types.ConsensusMessageTypeCommit, From: message.From, Blockhash: commit.Blockhash, Signature: commit.Signature, } if !pcm.validator.Valid(cmsg) { logrus.Warnf("received invalid commit msg for block %x", cmsg.Blockhash) return } err = pcm.consensus.InsertMessageIntoLog(cmsg) if err != nil { logrus.WithField("err", err.Error()).Warn("Failed to add COMMIT message to log") return } logrus.WithFields(logrus.Fields{ "blockHash": fmt.Sprintf("%x", cmsg.Blockhash), "from": message.From.String(), }).Debug("Received COMMIT message") } func (pcm *ConsensusHandler) onNewBeaconEntry(entry types2.BeaconEntry) { block, err := pcm.commitAcceptedBlocks() height, _ := pcm.blockchain.GetLatestBlockHeight() if err != nil { if errors.Is(err, ErrNoAcceptedBlocks) { logrus.WithFields(logrus.Fields{ "height": height + 1, }).Infof("No accepted blocks in the current consensus round") } else { logrus.WithFields(logrus.Fields{ "height": height + 1, "err": err.Error(), }).Errorf("Failed to select the block in the current consensus round") return } } if block != nil { // broadcast new block var newBlockMessage pubsub.PubSubMessage newBlockMessage.Type = pubsub.NewBlockMessageType blockSerialized, err := cbor.Marshal(block) if err != nil { logrus.Errorf("Failed to serialize block %x for broadcasting!", block.Header.Hash) } else { newBlockMessage.Payload = blockSerialized pcm.psb.BroadcastToServiceTopic(&newBlockMessage) } // if we are miner of this block // then post dione tasks to target chains (currently, only Ethereum) if block.Header.Proposer.String() == pcm.address.String() { pcm.submitTasksFromBlock(block) } } minedBlock, err := pcm.miner.MineBlock(entry.Data, entry.Round) if err != nil { if errors.Is(err, blockchain.ErrNoTxForBlock) { logrus.Info("Sealing skipped, no transactions in mempool") } else { logrus.Errorf("Failed to mine the block: %s", err.Error()) } return } // if we are round winner if minedBlock != nil { err = pcm.propose(minedBlock) if err != nil { logrus.Errorf("Failed to propose the block: %s", err.Error()) return } } } func (pcm *ConsensusHandler) submitTasksFromBlock(block *types3.Block) { for _, tx := range block.Data { var task types2.DioneTask err := cbor.Unmarshal(tx.Data, &task) if err != nil { logrus.WithFields(logrus.Fields{ "err": err.Error(), "txHash": hex.EncodeToString(tx.Hash), }).Error("Failed to unmarshal transaction payload") continue // FIXME } reqIDNumber, ok := big.NewInt(0).SetString(task.RequestID, 10) if !ok { logrus.WithFields(logrus.Fields{ "txHash": hex.EncodeToString(tx.Hash), }).Error("Failed to parse request id number in Dione task") continue // FIXME } err = pcm.ethereumClient.SubmitRequestAnswer(reqIDNumber, task.Payload) if err != nil { logrus.WithFields(logrus.Fields{ "err": err.Error(), "txHash": hex.EncodeToString(tx.Hash), "reqID": reqIDNumber.String(), }).Error("Failed to submit task to ETH chain") continue // FIXME } logrus.WithFields(logrus.Fields{ "txHash": hex.EncodeToString(tx.Hash), "reqID": reqIDNumber.String(), }).Debug("Dione task has been sucessfully submitted to ETH chain (DioneOracle contract)") } } func (pcm *ConsensusHandler) commitAcceptedBlocks() (*types3.Block, error) { blocks := pcm.consensus.GetAllBlocksWithCommit() if blocks == nil { return nil, ErrNoAcceptedBlocks } var selectedBlock *types3.Block sort.Slice(blocks, func(i, j int) bool { iStake, err := pcm.ethereumClient.GetMinerStake(blocks[i].Block.Header.ProposerEth) if err != nil { logrus.Error(err) return false } jStake, err := pcm.ethereumClient.GetMinerStake(blocks[j].Block.Header.ProposerEth) if err != nil { logrus.Error(err) return false } if iStake.Cmp(jStake) == -1 { return false } else if iStake.Cmp(jStake) == 1 { return true } else { return blocks[i].Block.Header.Timestamp > blocks[j].Block.Header.Timestamp } }) selectedBlock = blocks[0].Block stake, err := pcm.ethereumClient.GetMinerStake(selectedBlock.Header.ProposerEth) if err != nil { logrus.Error(err) return nil, err } logrus.WithFields(logrus.Fields{ "winCount": selectedBlock.Header.ElectionProof.WinCount, "proposerStake": stake.String(), }).Debug("Selected the block with maximal win count and proposer's stake.") logrus.WithFields(logrus.Fields{ "hash": hex.EncodeToString(selectedBlock.Header.Hash), "height": selectedBlock.Header.Height, "miner": selectedBlock.Header.Proposer.String(), }).Info("Committed new block") pcm.consensus.Prune() for _, v := range selectedBlock.Data { err := pcm.mempool.DeleteTx(v.Hash) if err != nil { logrus.WithFields(logrus.Fields{ "err": err.Error(), "tx": hex.EncodeToString(v.Hash), }).Errorf("Failed to delete committed tx from mempool") continue } } return selectedBlock, pcm.blockchain.StoreBlock(selectedBlock) }