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Diffstat (limited to 'core/vm/evm.go')
-rw-r--r-- | core/vm/evm.go | 557 |
1 files changed, 557 insertions, 0 deletions
diff --git a/core/vm/evm.go b/core/vm/evm.go new file mode 100644 index 0000000..ff3587c --- /dev/null +++ b/core/vm/evm.go @@ -0,0 +1,557 @@ +// Copyright 2014 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum 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 go-ethereum 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 go-ethereum library. If not, see <http://www.gnu.org/licenses/>. + +package vm + +import ( + "fmt" + "math/big" + "sync/atomic" + "time" + + "github.com/ava-labs/coreth/params" + "github.com/ava-labs/go-ethereum/common" + "github.com/ava-labs/go-ethereum/crypto" +) + +// emptyCodeHash is used by create to ensure deployment is disallowed to already +// deployed contract addresses (relevant after the account abstraction). +var emptyCodeHash = crypto.Keccak256Hash(nil) + +type ( + // CanTransferFunc is the signature of a transfer guard function + CanTransferFunc func(StateDB, common.Address, *big.Int) bool + CanTransferMCFunc func(StateDB, common.Address, common.Address, *common.Hash, *big.Int) int + // TransferFunc is the signature of a transfer function + TransferFunc func(StateDB, common.Address, common.Address, *big.Int) + TransferMCFunc func(StateDB, common.Address, common.Address, *common.Hash, *big.Int) + // GetHashFunc returns the n'th block hash in the blockchain + // and is used by the BLOCKHASH EVM op code. + GetHashFunc func(uint64) common.Hash +) + +// run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter. +func run(evm *EVM, contract *Contract, input []byte, readOnly bool) ([]byte, error) { + if contract.CodeAddr != nil { + precompiles := PrecompiledContractsHomestead + if evm.chainRules.IsByzantium { + precompiles = PrecompiledContractsByzantium + } + if evm.chainRules.IsIstanbul { + precompiles = PrecompiledContractsIstanbul + } + if p := precompiles[*contract.CodeAddr]; p != nil { + return RunPrecompiledContract(p, input, contract) + } + } + for _, interpreter := range evm.interpreters { + if interpreter.CanRun(contract.Code) { + if evm.interpreter != interpreter { + // Ensure that the interpreter pointer is set back + // to its current value upon return. + defer func(i Interpreter) { + evm.interpreter = i + }(evm.interpreter) + evm.interpreter = interpreter + } + return interpreter.Run(contract, input, readOnly) + } + } + return nil, ErrNoCompatibleInterpreter +} + +// Context provides the EVM with auxiliary information. Once provided +// it shouldn't be modified. +type Context struct { + // CanTransfer returns whether the account contains + // sufficient ether to transfer the value + CanTransfer CanTransferFunc + CanTransferMC CanTransferMCFunc + // Transfer transfers ether from one account to the other + Transfer TransferFunc + TransferMultiCoin TransferMCFunc + // GetHash returns the hash corresponding to n + GetHash GetHashFunc + + // Message information + Origin common.Address // Provides information for ORIGIN + GasPrice *big.Int // Provides information for GASPRICE + + // Block information + Coinbase common.Address // Provides information for COINBASE + GasLimit uint64 // Provides information for GASLIMIT + BlockNumber *big.Int // Provides information for NUMBER + Time *big.Int // Provides information for TIME + Difficulty *big.Int // Provides information for DIFFICULTY +} + +// EVM is the Ethereum Virtual Machine base object and provides +// the necessary tools to run a contract on the given state with +// the provided context. It should be noted that any error +// generated through any of the calls should be considered a +// revert-state-and-consume-all-gas operation, no checks on +// specific errors should ever be performed. The interpreter makes +// sure that any errors generated are to be considered faulty code. +// +// The EVM should never be reused and is not thread safe. +type EVM struct { + // Context provides auxiliary blockchain related information + Context + // StateDB gives access to the underlying state + StateDB StateDB + // Depth is the current call stack + depth int + + // chainConfig contains information about the current chain + chainConfig *params.ChainConfig + // chain rules contains the chain rules for the current epoch + chainRules params.Rules + // virtual machine configuration options used to initialise the + // evm. + vmConfig Config + // global (to this context) ethereum virtual machine + // used throughout the execution of the tx. + interpreters []Interpreter + interpreter Interpreter + // abort is used to abort the EVM calling operations + // NOTE: must be set atomically + abort int32 + // callGasTemp holds the gas available for the current call. This is needed because the + // available gas is calculated in gasCall* according to the 63/64 rule and later + // applied in opCall*. + callGasTemp uint64 +} + +// NewEVM returns a new EVM. The returned EVM is not thread safe and should +// only ever be used *once*. +func NewEVM(ctx Context, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *EVM { + evm := &EVM{ + Context: ctx, + StateDB: statedb, + vmConfig: vmConfig, + chainConfig: chainConfig, + chainRules: chainConfig.Rules(ctx.BlockNumber), + interpreters: make([]Interpreter, 0, 1), + } + + if chainConfig.IsEWASM(ctx.BlockNumber) { + // to be implemented by EVM-C and Wagon PRs. + // if vmConfig.EWASMInterpreter != "" { + // extIntOpts := strings.Split(vmConfig.EWASMInterpreter, ":") + // path := extIntOpts[0] + // options := []string{} + // if len(extIntOpts) > 1 { + // options = extIntOpts[1..] + // } + // evm.interpreters = append(evm.interpreters, NewEVMVCInterpreter(evm, vmConfig, options)) + // } else { + // evm.interpreters = append(evm.interpreters, NewEWASMInterpreter(evm, vmConfig)) + // } + panic("No supported ewasm interpreter yet.") + } + + // vmConfig.EVMInterpreter will be used by EVM-C, it won't be checked here + // as we always want to have the built-in EVM as the failover option. + evm.interpreters = append(evm.interpreters, NewEVMInterpreter(evm, vmConfig)) + evm.interpreter = evm.interpreters[0] + + return evm +} + +// Cancel cancels any running EVM operation. This may be called concurrently and +// it's safe to be called multiple times. +func (evm *EVM) Cancel() { + atomic.StoreInt32(&evm.abort, 1) +} + +// Cancelled returns true if Cancel has been called +func (evm *EVM) Cancelled() bool { + return atomic.LoadInt32(&evm.abort) == 1 +} + +// Interpreter returns the current interpreter +func (evm *EVM) Interpreter() Interpreter { + return evm.interpreter +} + +// Call executes the contract associated with the addr with the given input as +// parameters. It also handles any necessary value transfer required and takes +// the necessary steps to create accounts and reverses the state in case of an +// execution error or failed value transfer. +func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) { + if evm.vmConfig.NoRecursion && evm.depth > 0 { + return nil, gas, nil + } + + // Fail if we're trying to execute above the call depth limit + if evm.depth > int(params.CallCreateDepth) { + return nil, gas, ErrDepth + } + // Fail if we're trying to transfer more than the available balance + if !evm.Context.CanTransfer(evm.StateDB, caller.Address(), value) { + return nil, gas, ErrInsufficientBalance + } + + var ( + to = AccountRef(addr) + snapshot = evm.StateDB.Snapshot() + ) + if !evm.StateDB.Exist(addr) { + precompiles := PrecompiledContractsHomestead + if evm.chainRules.IsByzantium { + precompiles = PrecompiledContractsByzantium + } + if evm.chainRules.IsIstanbul { + precompiles = PrecompiledContractsIstanbul + } + if precompiles[addr] == nil && evm.chainRules.IsEIP158 && value.Sign() == 0 { + // Calling a non existing account, don't do anything, but ping the tracer + if evm.vmConfig.Debug && evm.depth == 0 { + evm.vmConfig.Tracer.CaptureStart(caller.Address(), addr, false, input, gas, value) + evm.vmConfig.Tracer.CaptureEnd(ret, 0, 0, nil) + } + return nil, gas, nil + } + evm.StateDB.CreateAccount(addr) + } + evm.Transfer(evm.StateDB, caller.Address(), to.Address(), value) + // Initialise a new contract and set the code that is to be used by the EVM. + // The contract is a scoped environment for this execution context only. + contract := NewContract(caller, to, value, gas) + contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) + + // Even if the account has no code, we need to continue because it might be a precompile + start := time.Now() + + // Capture the tracer start/end events in debug mode + if evm.vmConfig.Debug && evm.depth == 0 { + evm.vmConfig.Tracer.CaptureStart(caller.Address(), addr, false, input, gas, value) + + defer func() { // Lazy evaluation of the parameters + evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err) + }() + } + ret, err = run(evm, contract, input, false) + + // When an error was returned by the EVM or when setting the creation code + // above we revert to the snapshot and consume any gas remaining. Additionally + // when we're in homestead this also counts for code storage gas errors. + if err != nil { + evm.StateDB.RevertToSnapshot(snapshot) + if err != errExecutionReverted { + contract.UseGas(contract.Gas) + } + } + return ret, contract.Gas, err +} + +// This allows the user transfer balance of a specified coinId in addition to a normal Call(). +func (evm *EVM) CallExpert(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int, coinID *common.Hash, value2 *big.Int) (ret []byte, leftOverGas uint64, err error) { + fmt.Println("CallExpert") + if evm.vmConfig.NoRecursion && evm.depth > 0 { + return nil, gas, nil + } + + // Fail if we're trying to execute above the call depth limit + if evm.depth > int(params.CallCreateDepth) { + return nil, gas, ErrDepth + } + // Fail if we're trying to transfer more than the available balance + if !evm.Context.CanTransfer(evm.StateDB, caller.Address(), value) { + return nil, gas, ErrInsufficientBalance + } + + var to = AccountRef(addr) + mcerr := evm.Context.CanTransferMC(evm.StateDB, caller.Address(), to.Address(), coinID, value2) + if mcerr == 1 { + return nil, gas, ErrInsufficientBalance + } else if mcerr != 0 { + return nil, gas, ErrIncompatibleAccount + } + + var snapshot = evm.StateDB.Snapshot() + + if !evm.StateDB.Exist(addr) { + precompiles := PrecompiledContractsHomestead + if evm.chainRules.IsByzantium { + precompiles = PrecompiledContractsByzantium + } + if evm.chainRules.IsIstanbul { + precompiles = PrecompiledContractsIstanbul + } + if precompiles[addr] == nil && evm.chainRules.IsEIP158 && value.Sign() == 0 { + // Calling a non existing account, don't do anything, but ping the tracer + if evm.vmConfig.Debug && evm.depth == 0 { + evm.vmConfig.Tracer.CaptureStart(caller.Address(), addr, false, input, gas, value) + evm.vmConfig.Tracer.CaptureEnd(ret, 0, 0, nil) + } + return nil, gas, nil + } + evm.StateDB.CreateAccount(addr) + } + evm.Transfer(evm.StateDB, caller.Address(), to.Address(), value) + evm.TransferMultiCoin(evm.StateDB, caller.Address(), to.Address(), coinID, value2) + // Initialise a new contract and set the code that is to be used by the EVM. + // The contract is a scoped environment for this execution context only. + contract := NewContract(caller, to, value, gas) + contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) + + // Even if the account has no code, we need to continue because it might be a precompile + start := time.Now() + + // Capture the tracer start/end events in debug mode + if evm.vmConfig.Debug && evm.depth == 0 { + evm.vmConfig.Tracer.CaptureStart(caller.Address(), addr, false, input, gas, value) + + defer func() { // Lazy evaluation of the parameters + evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err) + }() + } + ret, err = run(evm, contract, input, false) + + // When an error was returned by the EVM or when setting the creation code + // above we revert to the snapshot and consume any gas remaining. Additionally + // when we're in homestead this also counts for code storage gas errors. + if err != nil { + evm.StateDB.RevertToSnapshot(snapshot) + if err != errExecutionReverted { + contract.UseGas(contract.Gas) + } + } + return ret, contract.Gas, err +} + +// CallCode executes the contract associated with the addr with the given input +// as parameters. It also handles any necessary value transfer required and takes +// the necessary steps to create accounts and reverses the state in case of an +// execution error or failed value transfer. +// +// CallCode differs from Call in the sense that it executes the given address' +// code with the caller as context. +func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) { + if evm.vmConfig.NoRecursion && evm.depth > 0 { + return nil, gas, nil + } + + // Fail if we're trying to execute above the call depth limit + if evm.depth > int(params.CallCreateDepth) { + return nil, gas, ErrDepth + } + // Fail if we're trying to transfer more than the available balance + if !evm.CanTransfer(evm.StateDB, caller.Address(), value) { + return nil, gas, ErrInsufficientBalance + } + + var ( + snapshot = evm.StateDB.Snapshot() + to = AccountRef(caller.Address()) + ) + // Initialise a new contract and set the code that is to be used by the EVM. + // The contract is a scoped environment for this execution context only. + contract := NewContract(caller, to, value, gas) + contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) + + ret, err = run(evm, contract, input, false) + if err != nil { + evm.StateDB.RevertToSnapshot(snapshot) + if err != errExecutionReverted { + contract.UseGas(contract.Gas) + } + } + return ret, contract.Gas, err +} + +// DelegateCall executes the contract associated with the addr with the given input +// as parameters. It reverses the state in case of an execution error. +// +// DelegateCall differs from CallCode in the sense that it executes the given address' +// code with the caller as context and the caller is set to the caller of the caller. +func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) { + if evm.vmConfig.NoRecursion && evm.depth > 0 { + return nil, gas, nil + } + // Fail if we're trying to execute above the call depth limit + if evm.depth > int(params.CallCreateDepth) { + return nil, gas, ErrDepth + } + + var ( + snapshot = evm.StateDB.Snapshot() + to = AccountRef(caller.Address()) + ) + + // Initialise a new contract and make initialise the delegate values + contract := NewContract(caller, to, nil, gas).AsDelegate() + contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) + + ret, err = run(evm, contract, input, false) + if err != nil { + evm.StateDB.RevertToSnapshot(snapshot) + if err != errExecutionReverted { + contract.UseGas(contract.Gas) + } + } + return ret, contract.Gas, err +} + +// StaticCall executes the contract associated with the addr with the given input +// as parameters while disallowing any modifications to the state during the call. +// Opcodes that attempt to perform such modifications will result in exceptions +// instead of performing the modifications. +func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) { + if evm.vmConfig.NoRecursion && evm.depth > 0 { + return nil, gas, nil + } + // Fail if we're trying to execute above the call depth limit + if evm.depth > int(params.CallCreateDepth) { + return nil, gas, ErrDepth + } + + var ( + to = AccountRef(addr) + snapshot = evm.StateDB.Snapshot() + ) + // Initialise a new contract and set the code that is to be used by the EVM. + // The contract is a scoped environment for this execution context only. + contract := NewContract(caller, to, new(big.Int), gas) + contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr)) + + // We do an AddBalance of zero here, just in order to trigger a touch. + // This doesn't matter on Mainnet, where all empties are gone at the time of Byzantium, + // but is the correct thing to do and matters on other networks, in tests, and potential + // future scenarios + evm.StateDB.AddBalance(addr, bigZero) + + // When an error was returned by the EVM or when setting the creation code + // above we revert to the snapshot and consume any gas remaining. Additionally + // when we're in Homestead this also counts for code storage gas errors. + ret, err = run(evm, contract, input, true) + if err != nil { + evm.StateDB.RevertToSnapshot(snapshot) + if err != errExecutionReverted { + contract.UseGas(contract.Gas) + } + } + return ret, contract.Gas, err +} + +type codeAndHash struct { + code []byte + hash common.Hash +} + +func (c *codeAndHash) Hash() common.Hash { + if c.hash == (common.Hash{}) { + c.hash = crypto.Keccak256Hash(c.code) + } + return c.hash +} + +// create creates a new contract using code as deployment code. +func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64, value *big.Int, address common.Address) ([]byte, common.Address, uint64, error) { + // Depth check execution. Fail if we're trying to execute above the + // limit. + if evm.depth > int(params.CallCreateDepth) { + return nil, common.Address{}, gas, ErrDepth + } + if !evm.CanTransfer(evm.StateDB, caller.Address(), value) { + return nil, common.Address{}, gas, ErrInsufficientBalance + } + nonce := evm.StateDB.GetNonce(caller.Address()) + evm.StateDB.SetNonce(caller.Address(), nonce+1) + + // Ensure there's no existing contract already at the designated address + contractHash := evm.StateDB.GetCodeHash(address) + if evm.StateDB.GetNonce(address) != 0 || (contractHash != (common.Hash{}) && contractHash != emptyCodeHash) { + return nil, common.Address{}, 0, ErrContractAddressCollision + } + // Create a new account on the state + snapshot := evm.StateDB.Snapshot() + evm.StateDB.CreateAccount(address) + if evm.chainRules.IsEIP158 { + evm.StateDB.SetNonce(address, 1) + } + evm.Transfer(evm.StateDB, caller.Address(), address, value) + + // Initialise a new contract and set the code that is to be used by the EVM. + // The contract is a scoped environment for this execution context only. + contract := NewContract(caller, AccountRef(address), value, gas) + contract.SetCodeOptionalHash(&address, codeAndHash) + + if evm.vmConfig.NoRecursion && evm.depth > 0 { + return nil, address, gas, nil + } + + if evm.vmConfig.Debug && evm.depth == 0 { + evm.vmConfig.Tracer.CaptureStart(caller.Address(), address, true, codeAndHash.code, gas, value) + } + start := time.Now() + + ret, err := run(evm, contract, nil, false) + + // check whether the max code size has been exceeded + maxCodeSizeExceeded := evm.chainRules.IsEIP158 && len(ret) > params.MaxCodeSize + // if the contract creation ran successfully and no errors were returned + // calculate the gas required to store the code. If the code could not + // be stored due to not enough gas set an error and let it be handled + // by the error checking condition below. + if err == nil && !maxCodeSizeExceeded { + createDataGas := uint64(len(ret)) * params.CreateDataGas + if contract.UseGas(createDataGas) { + evm.StateDB.SetCode(address, ret) + } else { + err = ErrCodeStoreOutOfGas + } + } + + // When an error was returned by the EVM or when setting the creation code + // above we revert to the snapshot and consume any gas remaining. Additionally + // when we're in homestead this also counts for code storage gas errors. + if maxCodeSizeExceeded || (err != nil && (evm.chainRules.IsHomestead || err != ErrCodeStoreOutOfGas)) { + evm.StateDB.RevertToSnapshot(snapshot) + if err != errExecutionReverted { + contract.UseGas(contract.Gas) + } + } + // Assign err if contract code size exceeds the max while the err is still empty. + if maxCodeSizeExceeded && err == nil { + err = errMaxCodeSizeExceeded + } + if evm.vmConfig.Debug && evm.depth == 0 { + evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err) + } + return ret, address, contract.Gas, err + +} + +// Create creates a new contract using code as deployment code. +func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) { + contractAddr = crypto.CreateAddress(caller.Address(), evm.StateDB.GetNonce(caller.Address())) + return evm.create(caller, &codeAndHash{code: code}, gas, value, contractAddr) +} + +// Create2 creates a new contract using code as deployment code. +// +// The different between Create2 with Create is Create2 uses sha3(0xff ++ msg.sender ++ salt ++ sha3(init_code))[12:] +// instead of the usual sender-and-nonce-hash as the address where the contract is initialized at. +func (evm *EVM) Create2(caller ContractRef, code []byte, gas uint64, endowment *big.Int, salt *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) { + codeAndHash := &codeAndHash{code: code} + contractAddr = crypto.CreateAddress2(caller.Address(), common.BigToHash(salt), codeAndHash.Hash().Bytes()) + return evm.create(caller, codeAndHash, gas, endowment, contractAddr) +} + +// ChainConfig returns the environment's chain configuration +func (evm *EVM) ChainConfig() *params.ChainConfig { return evm.chainConfig } |