10a57fc3d4
This commit is a preparation for the upcoming metropolis hardfork. It prepares the state, core and vm packages such that integration with metropolis becomes less of a hassle. * Difficulty calculation requires header instead of individual parameters * statedb.StartRecord renamed to statedb.Prepare and added Finalise method required by metropolis, which removes unwanted accounts from the state (i.e. selfdestruct) * State keeps record of destructed objects (in addition to dirty objects) * core/vm pre-compiles may now return errors * core/vm pre-compiles gas check now take the full byte slice as argument instead of just the size * core/vm now keeps several hard-fork instruction tables instead of a single instruction table and removes the need for hard-fork checks in the instructions * core/vm contains a empty restruction function which is added in preparation of metropolis write-only mode operations * Adds the bn256 curve * Adds and sets the metropolis chain config block parameters (2^64-1)
315 lines
12 KiB
Go
315 lines
12 KiB
Go
// Copyright 2014 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package vm
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import (
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"math/big"
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"sync/atomic"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/crypto"
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"github.com/ethereum/go-ethereum/params"
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)
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type (
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CanTransferFunc func(StateDB, common.Address, *big.Int) bool
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TransferFunc func(StateDB, common.Address, common.Address, *big.Int)
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// GetHashFunc returns the nth block hash in the blockchain
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// and is used by the BLOCKHASH EVM op code.
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GetHashFunc func(uint64) common.Hash
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)
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// run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter.
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func run(evm *EVM, snapshot int, contract *Contract, input []byte) ([]byte, error) {
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if contract.CodeAddr != nil {
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precompiledContracts := PrecompiledContracts
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if p := precompiledContracts[*contract.CodeAddr]; p != nil {
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return RunPrecompiledContract(p, input, contract)
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}
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}
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return evm.interpreter.Run(snapshot, contract, input)
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}
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// Context provides the EVM with auxiliary information. Once provided
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// it shouldn't be modified.
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type Context struct {
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// CanTransfer returns whether the account contains
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// sufficient ether to transfer the value
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CanTransfer CanTransferFunc
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// Transfer transfers ether from one account to the other
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Transfer TransferFunc
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// GetHash returns the hash corresponding to n
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GetHash GetHashFunc
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// Message information
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Origin common.Address // Provides information for ORIGIN
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GasPrice *big.Int // Provides information for GASPRICE
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// Block information
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Coinbase common.Address // Provides information for COINBASE
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GasLimit *big.Int // Provides information for GASLIMIT
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BlockNumber *big.Int // Provides information for NUMBER
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Time *big.Int // Provides information for TIME
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Difficulty *big.Int // Provides information for DIFFICULTY
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}
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// EVM is the Ethereum Virtual Machine base object and provides
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// the necessary tools to run a contract on the given state with
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// the provided context. It should be noted that any error
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// generated through any of the calls should be considered a
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// revert-state-and-consume-all-gas operation, no checks on
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// specific errors should ever be performed. The interpreter makes
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// sure that any errors generated are to be considered faulty code.
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//
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// The EVM should never be reused and is not thread safe.
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type EVM struct {
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// Context provides auxiliary blockchain related information
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Context
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// StateDB gives access to the underlying state
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StateDB StateDB
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// Depth is the current call stack
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depth int
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// chainConfig contains information about the current chain
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chainConfig *params.ChainConfig
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// chain rules contains the chain rules for the current epoch
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chainRules params.Rules
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// virtual machine configuration options used to initialise the
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// evm.
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vmConfig Config
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// global (to this context) ethereum virtual machine
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// used throughout the execution of the tx.
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interpreter *Interpreter
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// abort is used to abort the EVM calling operations
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// NOTE: must be set atomically
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abort int32
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}
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// NewEVM retutrns a new EVM evmironment. The returned EVM is not thread safe
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// and should only ever be used *once*.
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func NewEVM(ctx Context, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *EVM {
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evm := &EVM{
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Context: ctx,
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StateDB: statedb,
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vmConfig: vmConfig,
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chainConfig: chainConfig,
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chainRules: chainConfig.Rules(ctx.BlockNumber),
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}
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evm.interpreter = NewInterpreter(evm, vmConfig)
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return evm
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}
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// Cancel cancels any running EVM operation. This may be called concurrently and
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// it's safe to be called multiple times.
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func (evm *EVM) Cancel() {
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atomic.StoreInt32(&evm.abort, 1)
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}
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// Call executes the contract associated with the addr with the given input as parameters. It also handles any
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// necessary value transfer required and takes the necessary steps to create accounts and reverses the state in
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// case of an execution error or failed value transfer.
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func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
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if evm.vmConfig.NoRecursion && evm.depth > 0 {
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return nil, gas, nil
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}
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// Depth check execution. Fail if we're trying to execute above the
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// limit.
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if evm.depth > int(params.CallCreateDepth) {
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return nil, gas, ErrDepth
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}
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if !evm.Context.CanTransfer(evm.StateDB, caller.Address(), value) {
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return nil, gas, ErrInsufficientBalance
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}
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var (
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to = AccountRef(addr)
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snapshot = evm.StateDB.Snapshot()
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)
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if !evm.StateDB.Exist(addr) {
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if PrecompiledContracts[addr] == nil && evm.ChainConfig().IsEIP158(evm.BlockNumber) && value.Sign() == 0 {
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return nil, gas, nil
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}
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evm.StateDB.CreateAccount(addr)
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}
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evm.Transfer(evm.StateDB, caller.Address(), to.Address(), value)
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// initialise a new contract and set the code that is to be used by the
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// E The contract is a scoped evmironment for this execution context
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// only.
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contract := NewContract(caller, to, value, gas)
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contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
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ret, err = run(evm, snapshot, contract, input)
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// When an error was returned by the EVM or when setting the creation code
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// above we revert to the snapshot and consume any gas remaining. Additionally
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// when we're in homestead this also counts for code storage gas errors.
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if err != nil {
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contract.UseGas(contract.Gas)
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evm.StateDB.RevertToSnapshot(snapshot)
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}
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return ret, contract.Gas, err
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}
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// CallCode executes the contract associated with the addr with the given input as parameters. It also handles any
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// necessary value transfer required and takes the necessary steps to create accounts and reverses the state in
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// case of an execution error or failed value transfer.
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//
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// CallCode differs from Call in the sense that it executes the given address' code with the caller as context.
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func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
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if evm.vmConfig.NoRecursion && evm.depth > 0 {
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return nil, gas, nil
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}
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// Depth check execution. Fail if we're trying to execute above the
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// limit.
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if evm.depth > int(params.CallCreateDepth) {
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return nil, gas, ErrDepth
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}
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if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
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return nil, gas, ErrInsufficientBalance
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}
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var (
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snapshot = evm.StateDB.Snapshot()
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to = AccountRef(caller.Address())
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)
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// initialise a new contract and set the code that is to be used by the
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// E The contract is a scoped evmironment for this execution context
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// only.
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contract := NewContract(caller, to, value, gas)
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contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
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ret, err = run(evm, snapshot, contract, input)
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if err != nil {
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contract.UseGas(contract.Gas)
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evm.StateDB.RevertToSnapshot(snapshot)
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}
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return ret, contract.Gas, err
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}
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// DelegateCall executes the contract associated with the addr with the given input as parameters.
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// It reverses the state in case of an execution error.
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//
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// DelegateCall differs from CallCode in the sense that it executes the given address' code with the caller as context
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// and the caller is set to the caller of the caller.
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func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
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if evm.vmConfig.NoRecursion && evm.depth > 0 {
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return nil, gas, nil
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}
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// Depth check execution. Fail if we're trying to execute above the
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// limit.
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if evm.depth > int(params.CallCreateDepth) {
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return nil, gas, ErrDepth
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}
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var (
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snapshot = evm.StateDB.Snapshot()
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to = AccountRef(caller.Address())
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)
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// Iinitialise a new contract and make initialise the delegate values
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contract := NewContract(caller, to, nil, gas).AsDelegate()
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contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
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ret, err = run(evm, snapshot, contract, input)
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if err != nil {
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contract.UseGas(contract.Gas)
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evm.StateDB.RevertToSnapshot(snapshot)
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}
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return ret, contract.Gas, err
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}
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// Create creates a new contract using code as deployment code.
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func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
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if evm.vmConfig.NoRecursion && evm.depth > 0 {
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return nil, common.Address{}, gas, nil
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}
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// Depth check execution. Fail if we're trying to execute above the
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// limit.
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if evm.depth > int(params.CallCreateDepth) {
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return nil, common.Address{}, gas, ErrDepth
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}
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if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
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return nil, common.Address{}, gas, ErrInsufficientBalance
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}
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// Create a new account on the state
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nonce := evm.StateDB.GetNonce(caller.Address())
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evm.StateDB.SetNonce(caller.Address(), nonce+1)
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snapshot := evm.StateDB.Snapshot()
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contractAddr = crypto.CreateAddress(caller.Address(), nonce)
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evm.StateDB.CreateAccount(contractAddr)
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if evm.ChainConfig().IsEIP158(evm.BlockNumber) {
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evm.StateDB.SetNonce(contractAddr, 1)
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}
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evm.Transfer(evm.StateDB, caller.Address(), contractAddr, value)
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// initialise a new contract and set the code that is to be used by the
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// E The contract is a scoped evmironment for this execution context
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// only.
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contract := NewContract(caller, AccountRef(contractAddr), value, gas)
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contract.SetCallCode(&contractAddr, crypto.Keccak256Hash(code), code)
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ret, err = run(evm, snapshot, contract, nil)
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// check whether the max code size has been exceeded
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maxCodeSizeExceeded := len(ret) > params.MaxCodeSize
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// if the contract creation ran successfully and no errors were returned
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// calculate the gas required to store the code. If the code could not
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// be stored due to not enough gas set an error and let it be handled
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// by the error checking condition below.
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if err == nil && !maxCodeSizeExceeded {
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createDataGas := uint64(len(ret)) * params.CreateDataGas
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if contract.UseGas(createDataGas) {
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evm.StateDB.SetCode(contractAddr, ret)
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} else {
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err = ErrCodeStoreOutOfGas
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}
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}
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// When an error was returned by the EVM or when setting the creation code
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// above we revert to the snapshot and consume any gas remaining. Additionally
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// when we're in homestead this also counts for code storage gas errors.
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if maxCodeSizeExceeded ||
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(err != nil && (evm.ChainConfig().IsHomestead(evm.BlockNumber) || err != ErrCodeStoreOutOfGas)) {
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contract.UseGas(contract.Gas)
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evm.StateDB.RevertToSnapshot(snapshot)
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}
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// If the vm returned with an error the return value should be set to nil.
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// This isn't consensus critical but merely to for behaviour reasons such as
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// tests, RPC calls, etc.
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if err != nil {
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ret = nil
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}
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return ret, contractAddr, contract.Gas, err
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}
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// ChainConfig returns the evmironment's chain configuration
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func (evm *EVM) ChainConfig() *params.ChainConfig { return evm.chainConfig }
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// Interpreter returns the EVM interpreter
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func (evm *EVM) Interpreter() *Interpreter { return evm.interpreter }
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