// Copyright 2018 The dexon-consensus-core Authors
// This file is part of the dexon-consensus-core library.
//
// The dexon-consensus-core library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus-core library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus-core library. If not, see
// <http://www.gnu.org/licenses/>.
package dex
import (
"bytes"
"fmt"
"math/big"
"sync"
"time"
coreCommon "github.com/dexon-foundation/dexon-consensus-core/common"
coreTypes "github.com/dexon-foundation/dexon-consensus-core/core/types"
"github.com/dexon-foundation/dexon/common"
"github.com/dexon-foundation/dexon/core"
"github.com/dexon-foundation/dexon/core/state"
"github.com/dexon-foundation/dexon/core/types"
"github.com/dexon-foundation/dexon/core/vm"
"github.com/dexon-foundation/dexon/ethdb"
"github.com/dexon-foundation/dexon/log"
"github.com/dexon-foundation/dexon/rlp"
)
// DexconApp implementes the DEXON consensus core application interface.
type DexconApp struct {
txPool *core.TxPool
blockchain *core.BlockChain
gov *DexconGovernance
chainDB ethdb.Database
config *Config
vmConfig vm.Config
notifyChan map[uint64]*notify
mutex *sync.Mutex
lastPendingHeight uint64
insertMu sync.Mutex
chainHeight map[uint32]uint64
}
type notify struct {
results []chan uint64
}
type witnessData struct {
Root common.Hash
TxHash common.Hash
ReceiptHash common.Hash
}
func NewDexconApp(txPool *core.TxPool, blockchain *core.BlockChain, gov *DexconGovernance, chainDB ethdb.Database, config *Config, vmConfig vm.Config) *DexconApp {
return &DexconApp{
txPool: txPool,
blockchain: blockchain,
gov: gov,
chainDB: chainDB,
config: config,
vmConfig: vmConfig,
notifyChan: make(map[uint64]*notify),
mutex: &sync.Mutex{},
chainHeight: make(map[uint32]uint64),
}
}
func (d *DexconApp) addNotify(height uint64) <-chan uint64 {
d.mutex.Lock()
defer d.mutex.Unlock()
result := make(chan uint64)
if n, exist := d.notifyChan[height]; exist {
n.results = append(n.results, result)
} else {
d.notifyChan[height] = ¬ify{}
d.notifyChan[height].results = append(d.notifyChan[height].results, result)
}
return result
}
func (d *DexconApp) notify(height uint64) {
d.mutex.Lock()
defer d.mutex.Unlock()
for h, n := range d.notifyChan {
if height >= h {
for _, ch := range n.results {
ch <- height
}
delete(d.notifyChan, h)
}
}
d.lastPendingHeight = height
}
func (d *DexconApp) checkChain(address common.Address, chainSize, chainID *big.Int) bool {
addrModChainSize := new(big.Int)
return addrModChainSize.Mod(address.Big(), chainSize).Cmp(chainID) == 0
}
// PreparePayload is called when consensus core is preparing payload for block.
func (d *DexconApp) PreparePayload(position coreTypes.Position) (payload []byte, err error) {
d.insertMu.Lock()
defer d.insertMu.Unlock()
if position.Height != 0 {
chainLastHeight, empty := d.blockchain.GetChainLastConfirmedHeight(position.ChainID)
if empty {
var exist bool
chainLastHeight, exist = d.chainHeight[position.ChainID]
if !exist {
log.Error("Something wrong")
return nil, fmt.Errorf("something wrong")
}
}
// check if chain block height is sequential
if chainLastHeight != position.Height-1 {
log.Error("Check confirmed block height fail", "chain", position.ChainID, "height", position.Height-1, "cache height", chainLastHeight)
return nil, fmt.Errorf("check confirmed block height fail")
}
}
// set state to the pending height
var latestState *state.StateDB
if d.lastPendingHeight == 0 {
latestState, err = d.blockchain.State()
if err != nil {
log.Error("Get current state", "error", err)
return nil, fmt.Errorf("get current state error %v", err)
}
} else {
latestState, err = d.blockchain.StateAt(d.blockchain.GetPendingBlockByHeight(d.lastPendingHeight).Root())
if err != nil {
log.Error("Get pending state", "error", err)
return nil, fmt.Errorf("get pending state error: %v", err)
}
}
txsMap, err := d.txPool.Pending()
if err != nil {
return
}
chainID := new(big.Int).SetUint64(uint64(position.ChainID))
chainNums := new(big.Int).SetUint64(uint64(d.gov.GetNumChains(position.Round)))
blockGasLimit := new(big.Int).SetUint64(core.CalcGasLimit(d.blockchain.CurrentBlock(), d.config.GasFloor, d.config.GasCeil))
blockGasUsed := new(big.Int)
var allTxs types.Transactions
addressMap:
for address, txs := range txsMap {
// every address's transactions will appear in fixed chain
if !d.checkChain(address, chainNums, chainID) {
continue
}
var expectNonce uint64
// get last nonce from confirmed blocks
lastConfirmedNonce, empty, err := d.blockchain.GetLastNonceFromConfirmedBlocks(position.ChainID, address)
if err != nil {
log.Error("Get last nonce from confirmed blocks", "error", err)
return nil, fmt.Errorf("get last nonce from confirmed blocks error: %v", err)
} else if empty {
// get expect nonce from latest state when confirmed block is empty
expectNonce = latestState.GetNonce(address)
} else {
expectNonce = lastConfirmedNonce + 1
}
if expectNonce != txs[0].Nonce() {
log.Warn("Nonce check error", "expect", expectNonce, "nonce", txs[0].Nonce())
continue
}
balance := latestState.GetBalance(address)
confirmedTxs, err := d.blockchain.GetConfirmedTxsByAddress(position.ChainID, address)
if err != nil {
return nil, fmt.Errorf("get confirmed txs error: %v", err)
}
for _, tx := range confirmedTxs {
maxGasUsed := new(big.Int).Mul(new(big.Int).SetUint64(tx.Gas()), tx.GasPrice())
balance = new(big.Int).Sub(balance, maxGasUsed)
balance = new(big.Int).Sub(balance, tx.Value())
}
for _, tx := range txs {
maxGasUsed := new(big.Int).Mul(new(big.Int).SetUint64(tx.Gas()), tx.GasPrice())
intrinsicGas, err := core.IntrinsicGas(tx.Data(), tx.To() == nil, true)
if err != nil {
log.Error("Calculate intrinsic gas fail", "err", err)
return nil, fmt.Errorf("calculate intrinsic gas error: %v", err)
}
if big.NewInt(int64(intrinsicGas)).Cmp(maxGasUsed) > 0 {
log.Warn("Intrinsic gas is larger than (gas limit * gas price)", "intrinsic", intrinsicGas, "maxGasUsed", maxGasUsed)
break
}
balance = new(big.Int).Sub(balance, maxGasUsed)
balance = new(big.Int).Sub(balance, tx.Value())
if balance.Cmp(big.NewInt(0)) < 0 {
log.Error("Tx fail", "reason", "not enough balance")
break
}
blockGasUsed = new(big.Int).Add(blockGasUsed, new(big.Int).SetUint64(tx.Gas()))
if blockGasLimit.Cmp(blockGasUsed) < 0 {
break addressMap
}
allTxs = append(allTxs, tx)
}
}
payload, err = rlp.EncodeToBytes(&allTxs)
if err != nil {
return
}
return
}
// PrepareWitness will return the witness data no lower than consensusHeight.
func (d *DexconApp) PrepareWitness(consensusHeight uint64) (witness coreTypes.Witness, err error) {
var witnessBlock *types.Block
if d.lastPendingHeight == 0 && consensusHeight == 0 {
witnessBlock = d.blockchain.CurrentBlock()
} else if d.lastPendingHeight >= consensusHeight {
d.insertMu.Lock()
witnessBlock = d.blockchain.GetPendingBlockByHeight(d.lastPendingHeight)
d.insertMu.Unlock()
} else if h := <-d.addNotify(consensusHeight); h >= consensusHeight {
d.insertMu.Lock()
witnessBlock = d.blockchain.GetPendingBlockByHeight(h)
d.insertMu.Unlock()
} else {
log.Error("need pending block")
return witness, fmt.Errorf("need pending block")
}
witnessData, err := rlp.EncodeToBytes(&witnessData{
Root: witnessBlock.Root(),
TxHash: witnessBlock.TxHash(),
ReceiptHash: witnessBlock.ReceiptHash(),
})
if err != nil {
return
}
return coreTypes.Witness{
Height: witnessBlock.NumberU64(),
Data: witnessData,
}, nil
}
// VerifyBlock verifies if the payloads are valid.
func (d *DexconApp) VerifyBlock(block *coreTypes.Block) coreTypes.BlockVerifyStatus {
var witnessData witnessData
err := rlp.Decode(bytes.NewReader(block.Witness.Data), &witnessData)
if err != nil {
log.Error("Witness rlp decode", "error", err)
return coreTypes.VerifyInvalidBlock
}
log.Info("Ready to verify witness block", "height", block.Witness.Height)
for i := 0; i < 3 && err != nil; i++ {
// check witness root exist
err = nil
_, err = d.blockchain.StateAt(witnessData.Root)
if err != nil {
log.Warn("Sleep 2 seconds and try again", "error", err)
time.Sleep(2 * time.Second)
}
}
if err != nil {
log.Error("Expect witness root not in stateDB", "err", err)
return coreTypes.VerifyRetryLater
}
d.insertMu.Lock()
defer d.insertMu.Unlock()
if block.Position.Height != 0 {
chainLastHeight, empty := d.blockchain.GetChainLastConfirmedHeight(block.Position.ChainID)
if empty {
var exist bool
chainLastHeight, exist = d.chainHeight[block.Position.ChainID]
if !exist {
log.Error("Something wrong")
return coreTypes.VerifyInvalidBlock
}
}
// check if chain block height is sequential
if chainLastHeight != block.Position.Height-1 {
log.Error("Check confirmed block height fail", "chain", block.Position.ChainID, "height", block.Position.Height-1)
return coreTypes.VerifyRetryLater
}
}
// set state to the pending height
var latestState *state.StateDB
if d.lastPendingHeight == 0 {
latestState, err = d.blockchain.State()
if err != nil {
log.Error("Get current state", "error", err)
return coreTypes.VerifyInvalidBlock
}
} else {
latestState, err = d.blockchain.StateAt(d.blockchain.GetPendingBlockByHeight(d.lastPendingHeight).Root())
if err != nil {
log.Error("Get pending state", "error", err)
return coreTypes.VerifyInvalidBlock
}
}
var transactions types.Transactions
err = rlp.Decode(bytes.NewReader(block.Payload), &transactions)
if err != nil {
log.Error("Payload rlp decode", "error", err)
return coreTypes.VerifyInvalidBlock
}
// check if nonce is sequential and return first nonce of every address
addresses, err := d.validateNonce(transactions)
if err != nil {
log.Error("Get address nonce", "error", err)
return coreTypes.VerifyInvalidBlock
}
// check all address nonce
chainID := big.NewInt(int64(block.Position.ChainID))
chainNums := new(big.Int).SetUint64(uint64(d.gov.GetNumChains(block.Position.Round)))
for address, firstNonce := range addresses {
if !d.checkChain(address, chainNums, chainID) {
log.Error("check chain fail", "address", address)
return coreTypes.VerifyInvalidBlock
}
var expectNonce uint64
// get last nonce from confirmed blocks
lastConfirmedNonce, empty, err := d.blockchain.GetLastNonceFromConfirmedBlocks(block.Position.ChainID, address)
if err != nil {
log.Error("Get last nonce from confirmed blocks", "error", err)
return coreTypes.VerifyInvalidBlock
} else if empty {
// get expect nonce from latest state when confirmed block is empty
expectNonce = latestState.GetNonce(address)
} else {
expectNonce = lastConfirmedNonce + 1
}
if expectNonce != firstNonce {
log.Error("Nonce check error", "expect", expectNonce, "firstNonce", firstNonce)
return coreTypes.VerifyInvalidBlock
}
}
// get balance from state
addressesBalance := map[common.Address]*big.Int{}
for address := range addresses {
addressesBalance[address] = latestState.GetBalance(address)
}
// replay confirmed block tx to correct balance
confirmedBlocks := d.blockchain.GetConfirmedBlocksByChainID(block.Position.ChainID)
for _, block := range confirmedBlocks {
var txs types.Transactions
err := rlp.Decode(bytes.NewReader(block.Payload), &txs)
if err != nil {
log.Error("Decode confirmed block", "error", err)
return coreTypes.VerifyInvalidBlock
}
for _, tx := range txs {
msg, err := tx.AsMessage(types.MakeSigner(d.blockchain.Config(), new(big.Int)))
if err != nil {
log.Error("Tx to message", "error", err)
return coreTypes.VerifyInvalidBlock
}
balance, exist := addressesBalance[msg.From()]
if exist {
maxGasUsed := new(big.Int).Mul(new(big.Int).SetUint64(msg.Gas()), msg.GasPrice())
balance = new(big.Int).Sub(balance, maxGasUsed)
balance = new(big.Int).Sub(balance, msg.Value())
if balance.Cmp(big.NewInt(0)) <= 0 {
log.Error("Replay confirmed tx fail", "reason", "not enough balance")
return coreTypes.VerifyInvalidBlock
}
addressesBalance[msg.From()] = balance
}
}
}
// validate tx to check available balance
blockGasLimit := new(big.Int).SetUint64(core.CalcGasLimit(d.blockchain.CurrentBlock(), d.config.GasFloor, d.config.GasCeil))
blockGasUsed := new(big.Int)
for _, tx := range transactions {
msg, err := tx.AsMessage(types.MakeSigner(d.blockchain.Config(), new(big.Int)))
if err != nil {
log.Error("Tx to message", "error", err)
return coreTypes.VerifyInvalidBlock
}
balance, _ := addressesBalance[msg.From()]
maxGasUsed := new(big.Int).Mul(new(big.Int).SetUint64(msg.Gas()), msg.GasPrice())
intrinsicGas, err := core.IntrinsicGas(msg.Data(), msg.To() == nil, true)
if err != nil {
log.Error("Calculate intrinsic gas fail", "err", err)
return coreTypes.VerifyInvalidBlock
}
if big.NewInt(int64(intrinsicGas)).Cmp(maxGasUsed) > 0 {
log.Error("Intrinsic gas is larger than (gas limit * gas price)", "intrinsic", intrinsicGas, "maxGasUsed", maxGasUsed)
return coreTypes.VerifyInvalidBlock
}
balance = new(big.Int).Sub(balance, maxGasUsed)
balance = new(big.Int).Sub(balance, msg.Value())
if balance.Cmp(big.NewInt(0)) < 0 {
log.Error("Tx fail", "reason", "not enough balance")
return coreTypes.VerifyInvalidBlock
}
blockGasUsed = new(big.Int).Add(blockGasUsed, new(big.Int).SetUint64(tx.Gas()))
if blockGasLimit.Cmp(blockGasUsed) < 0 {
log.Error("Reach block gas limit", "limit", blockGasLimit)
return coreTypes.VerifyInvalidBlock
}
addressesBalance[msg.From()] = balance
}
return coreTypes.VerifyOK
}
// BlockDelivered is called when a block is add to the compaction chain.
func (d *DexconApp) BlockDelivered(blockHash coreCommon.Hash, result coreTypes.FinalizationResult) {
d.insertMu.Lock()
defer d.insertMu.Unlock()
block := d.blockchain.GetConfirmedBlockByHash(blockHash)
if block == nil {
panic("Can not get confirmed block")
}
var transactions types.Transactions
err := rlp.Decode(bytes.NewReader(block.Payload), &transactions)
if err != nil {
log.Error("Payload rlp decode failed", "error", err)
panic(err)
}
block.Payload = nil
dexconMeta, err := rlp.EncodeToBytes(block)
if err != nil {
panic(err)
}
newBlock := types.NewBlock(&types.Header{
Number: new(big.Int).SetUint64(result.Height),
Time: big.NewInt(result.Timestamp.Unix()),
Coinbase: common.BytesToAddress(block.ProposerID.Bytes()),
// TODO(bojie): fix it
GasLimit: 8000000,
Difficulty: big.NewInt(1),
Round: block.Position.Round,
DexconMeta: dexconMeta,
Randomness: result.Randomness,
}, transactions, nil, nil)
_, err = d.blockchain.ProcessPendingBlock(newBlock, &block.Witness)
if err != nil {
log.Error("Insert chain", "error", err)
panic(err)
}
log.Info("Insert pending block success", "height", result.Height)
d.chainHeight[block.Position.ChainID] = block.Position.Height
d.blockchain.RemoveConfirmedBlock(blockHash)
d.notify(result.Height)
}
// BlockConfirmed is called when a block is confirmed and added to lattice.
func (d *DexconApp) BlockConfirmed(block coreTypes.Block) {
d.blockchain.AddConfirmedBlock(&block)
}
func (d *DexconApp) validateNonce(txs types.Transactions) (map[common.Address]uint64, error) {
addressFirstNonce := map[common.Address]uint64{}
addressNonce := map[common.Address]uint64{}
for _, tx := range txs {
msg, err := tx.AsMessage(types.MakeSigner(d.blockchain.Config(), new(big.Int)))
if err != nil {
return nil, err
}
if _, exist := addressFirstNonce[msg.From()]; exist {
if addressNonce[msg.From()]+1 != msg.Nonce() {
return nil, fmt.Errorf("address nonce check error: expect %v actual %v", addressNonce[msg.From()]+1, msg.Nonce())
}
addressNonce[msg.From()] = msg.Nonce()
continue
} else {
addressNonce[msg.From()] = msg.Nonce()
addressFirstNonce[msg.From()] = msg.Nonce()
}
}
return addressFirstNonce, nil
}
