package core import ( "fmt" "math/big" "sync" "time" "github.com/ethereum/go-ethereum/common" "github.com/ethereum/go-ethereum/core/state" "github.com/ethereum/go-ethereum/core/types" "github.com/ethereum/go-ethereum/core/vm" "github.com/ethereum/go-ethereum/crypto" "github.com/ethereum/go-ethereum/event" "github.com/ethereum/go-ethereum/logger" "github.com/ethereum/go-ethereum/logger/glog" "github.com/ethereum/go-ethereum/params" "github.com/ethereum/go-ethereum/pow" "gopkg.in/fatih/set.v0" ) const ( // must be bumped when consensus algorithm is changed, this forces the upgradedb // command to be run (forces the blocks to be imported again using the new algorithm) BlockChainVersion = 3 ) type BlockProcessor struct { db common.Database extraDb common.Database // Mutex for locking the block processor. Blocks can only be handled one at a time mutex sync.Mutex // Canonical block chain bc *ChainManager // non-persistent key/value memory storage mem map[string]*big.Int // Proof of work used for validating Pow pow.PoW events event.Subscription eventMux *event.TypeMux } func NewBlockProcessor(db, extra common.Database, pow pow.PoW, chainManager *ChainManager, eventMux *event.TypeMux) *BlockProcessor { sm := &BlockProcessor{ db: db, extraDb: extra, mem: make(map[string]*big.Int), Pow: pow, bc: chainManager, eventMux: eventMux, } return sm } func (sm *BlockProcessor) TransitionState(statedb *state.StateDB, parent, block *types.Block, transientProcess bool) (receipts types.Receipts, err error) { coinbase := statedb.GetOrNewStateObject(block.Coinbase()) coinbase.SetGasLimit(block.GasLimit()) // Process the transactions on to parent state receipts, err = sm.ApplyTransactions(coinbase, statedb, block, block.Transactions(), transientProcess) if err != nil { return nil, err } return receipts, nil } func (self *BlockProcessor) ApplyTransaction(coinbase *state.StateObject, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *big.Int, transientProcess bool) (*types.Receipt, *big.Int, error) { // If we are mining this block and validating we want to set the logs back to 0 cb := statedb.GetStateObject(coinbase.Address()) _, gas, err := ApplyMessage(NewEnv(statedb, self.bc, tx, header), tx, cb) if err != nil && err != vm.OutOfGasError { return nil, nil, err } // Update the state with pending changes statedb.SyncIntermediate() usedGas.Add(usedGas, gas) receipt := types.NewReceipt(statedb.Root().Bytes(), usedGas) receipt.TxHash = tx.Hash() if MessageCreatesContract(tx) { from, _ := tx.From() receipt.ContractAddress = crypto.CreateAddress(from, tx.Nonce()) } logs := statedb.GetLogs(tx.Hash()) receipt.SetLogs(logs) receipt.Bloom = types.CreateBloom(types.Receipts{receipt}) glog.V(logger.Debug).Infoln(receipt) // Notify all subscribers if !transientProcess { go self.eventMux.Post(TxPostEvent{tx}) go self.eventMux.Post(logs) } return receipt, gas, err } func (self *BlockProcessor) ChainManager() *ChainManager { return self.bc } func (self *BlockProcessor) ApplyTransactions(coinbase *state.StateObject, statedb *state.StateDB, block *types.Block, txs types.Transactions, transientProcess bool) (types.Receipts, error) { var ( receipts types.Receipts totalUsedGas = big.NewInt(0) err error cumulativeSum = new(big.Int) header = block.Header() ) for i, tx := range txs { statedb.StartRecord(tx.Hash(), block.Hash(), i) receipt, txGas, err := self.ApplyTransaction(coinbase, statedb, header, tx, totalUsedGas, transientProcess) if err != nil && err != vm.OutOfGasError { return nil, err } if err != nil { glog.V(logger.Core).Infoln("TX err:", err) } receipts = append(receipts, receipt) cumulativeSum.Add(cumulativeSum, new(big.Int).Mul(txGas, tx.GasPrice())) } if block.GasUsed().Cmp(totalUsedGas) != 0 { return nil, ValidationError(fmt.Sprintf("gas used error (%v / %v)", block.GasUsed(), totalUsedGas)) } if transientProcess { go self.eventMux.Post(PendingBlockEvent{block, statedb.Logs()}) } return receipts, err } func (sm *BlockProcessor) RetryProcess(block *types.Block) (logs state.Logs, err error) { // Processing a blocks may never happen simultaneously sm.mutex.Lock() defer sm.mutex.Unlock() if !sm.bc.HasBlock(block.ParentHash()) { return nil, ParentError(block.ParentHash()) } parent := sm.bc.GetBlock(block.ParentHash()) // FIXME Change to full header validation. See #1225 errch := make(chan bool) go func() { errch <- sm.Pow.Verify(block) }() logs, _, err = sm.processWithParent(block, parent) if !<-errch { return nil, ValidationError("Block's nonce is invalid (= %x)", block.Nonce) } return logs, err } // Process block will attempt to process the given block's transactions and applies them // on top of the block's parent state (given it exists) and will return wether it was // successful or not. func (sm *BlockProcessor) Process(block *types.Block) (logs state.Logs, receipts types.Receipts, err error) { // Processing a blocks may never happen simultaneously sm.mutex.Lock() defer sm.mutex.Unlock() if sm.bc.HasBlock(block.Hash()) { return nil, nil, &KnownBlockError{block.Number(), block.Hash()} } if !sm.bc.HasBlock(block.ParentHash()) { return nil, nil, ParentError(block.ParentHash()) } parent := sm.bc.GetBlock(block.ParentHash()) return sm.processWithParent(block, parent) } func (sm *BlockProcessor) processWithParent(block, parent *types.Block) (logs state.Logs, receipts types.Receipts, err error) { // Create a new state based on the parent's root (e.g., create copy) state := state.New(parent.Root(), sm.db) header := block.Header() uncles := block.Uncles() txs := block.Transactions() // Block validation if err = ValidateHeader(sm.Pow, header, parent, false); err != nil { return } // There can be at most two uncles if len(uncles) > 2 { return nil, nil, ValidationError("Block can only contain maximum 2 uncles (contained %v)", len(uncles)) } receipts, err = sm.TransitionState(state, parent, block, false) if err != nil { return } // Validate the received block's bloom with the one derived from the generated receipts. // For valid blocks this should always validate to true. rbloom := types.CreateBloom(receipts) if rbloom != header.Bloom { err = fmt.Errorf("unable to replicate block's bloom=%x", rbloom) return } // The transactions Trie's root (R = (Tr [[i, RLP(T1)], [i, RLP(T2)], ... [n, RLP(Tn)]])) // can be used by light clients to make sure they've received the correct Txs txSha := types.DeriveSha(txs) if txSha != header.TxHash { err = fmt.Errorf("invalid transaction root hash. received=%x calculated=%x", header.TxHash, txSha) return } // Tre receipt Trie's root (R = (Tr [[H1, R1], ... [Hn, R1]])) receiptSha := types.DeriveSha(receipts) if receiptSha != header.ReceiptHash { err = fmt.Errorf("invalid receipt root hash. received=%x calculated=%x", header.ReceiptHash, receiptSha) return } // Verify UncleHash before running other uncle validations unclesSha := types.CalcUncleHash(uncles) if unclesSha != header.UncleHash { err = fmt.Errorf("invalid uncles root hash. received=%x calculated=%x", header.UncleHash, unclesSha) return } // Verify uncles if err = sm.VerifyUncles(state, block, parent); err != nil { return } // Accumulate static rewards; block reward, uncle's and uncle inclusion. AccumulateRewards(state, header, uncles) // Commit state objects/accounts to a temporary trie (does not save) // used to calculate the state root. state.SyncObjects() if header.Root != state.Root() { err = fmt.Errorf("invalid merkle root. received=%x got=%x", header.Root, state.Root()) return } // Sync the current block's state to the database state.Sync() return state.Logs(), receipts, nil } var ( big8 = big.NewInt(8) big32 = big.NewInt(32) ) // AccumulateRewards credits the coinbase of the given block with the // mining reward. The total reward consists of the static block reward // and rewards for included uncles. The coinbase of each uncle block is // also rewarded. func AccumulateRewards(statedb *state.StateDB, header *types.Header, uncles []*types.Header) { reward := new(big.Int).Set(BlockReward) r := new(big.Int) for _, uncle := range uncles { r.Add(uncle.Number, big8) r.Sub(r, header.Number) r.Mul(r, BlockReward) r.Div(r, big8) statedb.AddBalance(uncle.Coinbase, r) r.Div(BlockReward, big32) reward.Add(reward, r) } statedb.AddBalance(header.Coinbase, reward) } func (sm *BlockProcessor) VerifyUncles(statedb *state.StateDB, block, parent *types.Block) error { uncles := set.New() ancestors := make(map[common.Hash]*types.Block) for _, ancestor := range sm.bc.GetBlocksFromHash(block.ParentHash(), 7) { ancestors[ancestor.Hash()] = ancestor // Include ancestors uncles in the uncle set. Uncles must be unique. for _, uncle := range ancestor.Uncles() { uncles.Add(uncle.Hash()) } } ancestors[block.Hash()] = block uncles.Add(block.Hash()) for i, uncle := range block.Uncles() { hash := uncle.Hash() if uncles.Has(hash) { // Error not unique return UncleError("uncle[%d](%x) not unique", i, hash[:4]) } uncles.Add(hash) if ancestors[hash] != nil { branch := fmt.Sprintf(" O - %x\n |\n", block.Hash()) for h := range ancestors { branch += fmt.Sprintf(" O - %x\n |\n", h) } glog.Infoln(branch) return UncleError("uncle[%d](%x) is ancestor", i, hash[:4]) } if ancestors[uncle.ParentHash] == nil || uncle.ParentHash == parent.Hash() { return UncleError("uncle[%d](%x)'s parent is not ancestor (%x)", i, hash[:4], uncle.ParentHash[0:4]) } if err := ValidateHeader(sm.Pow, uncle, ancestors[uncle.ParentHash], true); err != nil { return ValidationError(fmt.Sprintf("uncle[%d](%x) header invalid: %v", i, hash[:4], err)) } } return nil } // GetBlockReceipts returns the receipts beloniging to the block hash func (sm *BlockProcessor) GetBlockReceipts(bhash common.Hash) types.Receipts { if block := sm.ChainManager().GetBlock(bhash); block != nil { return GetReceiptsFromBlock(sm.extraDb, block) } return nil } // GetLogs returns the logs of the given block. This method is using a two step approach // where it tries to get it from the (updated) method which gets them from the receipts or // the depricated way by re-processing the block. func (sm *BlockProcessor) GetLogs(block *types.Block) (logs state.Logs, err error) { receipts := GetReceiptsFromBlock(sm.extraDb, block) if len(receipts) > 0 { // coalesce logs for _, receipt := range receipts { logs = append(logs, receipt.Logs()...) } return } // TODO: remove backward compatibility var ( parent = sm.bc.GetBlock(block.ParentHash()) state = state.New(parent.Root(), sm.db) ) sm.TransitionState(state, parent, block, true) return state.Logs(), nil } // See YP section 4.3.4. "Block Header Validity" // Validates a block. Returns an error if the block is invalid. func ValidateHeader(pow pow.PoW, block *types.Header, parent *types.Block, checkPow bool) error { if big.NewInt(int64(len(block.Extra))).Cmp(params.MaximumExtraDataSize) == 1 { return fmt.Errorf("Block extra data too long (%d)", len(block.Extra)) } if block.Time > uint64(time.Now().Unix()) { return BlockFutureErr } if block.Time <= parent.Time() { return BlockEqualTSErr } expd := CalcDifficulty(int64(block.Time), int64(parent.Time()), parent.Difficulty()) if expd.Cmp(block.Difficulty) != 0 { return fmt.Errorf("Difficulty check failed for block %v, %v", block.Difficulty, expd) } var a, b *big.Int a = parent.GasLimit() a = a.Sub(a, block.GasLimit) a.Abs(a) b = parent.GasLimit() b = b.Div(b, params.GasLimitBoundDivisor) if !(a.Cmp(b) < 0) || (block.GasLimit.Cmp(params.MinGasLimit) == -1) { return fmt.Errorf("GasLimit check failed for block %v (%v > %v)", block.GasLimit, a, b) } num := parent.Number() num.Sub(block.Number, num) if num.Cmp(big.NewInt(1)) != 0 { return BlockNumberErr } if checkPow { // Verify the nonce of the block. Return an error if it's not valid if !pow.Verify(types.NewBlockWithHeader(block)) { return ValidationError("Block's nonce is invalid (= %x)", block.Nonce) } } return nil }