laconicd/x/evm/keeper/state_transition.go
Loredana Cirstea 77d9e29923
fix: GasMeter reset in AnteHandler EthGasConsumeDecorator (#964)
* Fix GasMeter reset in AnteHandler - EthGasConsumeDecorator

Conforming to the spec:
e7066c4271/docs/basics/gas-fees.md
> Set newCtx.GasMeter to 0, with a limit of GasWanted.
> This step is extremely important, as it not only makes sure the transaction cannot consume infinite gas,
> but also that ctx.GasMeter is reset in-between each DeliverTx
> (ctx is set to newCtx after anteHandler is run, and the anteHandler is run each time DeliverTx is called).

* Compute gasWanted in ante handler based on msg gas

* Tests - check gas meter limit after EthGasConsumeDecorator ante handler runs

* Update CHANGELOG.md

* EthGasConsumeDecorator ante handler resets the gas meter only for CheckTx

* Reset the gas meter in Keeper.EthereumTx to an infinite gas meter

* Fix TestOutOfGasWhenDeployContract error check

* Move gas meter reset to the innermost EthAnteHandle

* add NewInfiniteGasMeterWithLimit for setting the user provided gas limit

Fixes block's consumed gas calculation in the block creation phase.

* Fix lint

* Fix lint

Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com>
2022-03-06 15:09:28 +01:00

501 lines
19 KiB
Go

package keeper
import (
"math"
"math/big"
tmtypes "github.com/tendermint/tendermint/types"
sdk "github.com/cosmos/cosmos-sdk/types"
sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
ethermint "github.com/tharsis/ethermint/types"
"github.com/tharsis/ethermint/x/evm/statedb"
"github.com/tharsis/ethermint/x/evm/types"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
ethtypes "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/params"
)
// GasToRefund calculates the amount of gas the state machine should refund to the sender. It is
// capped by the refund quotient value.
// Note: do not pass 0 to refundQuotient
func GasToRefund(availableRefund, gasConsumed, refundQuotient uint64) uint64 {
// Apply refund counter
refund := gasConsumed / refundQuotient
if refund > availableRefund {
return availableRefund
}
return refund
}
// EVMConfig creates the EVMConfig based on current state
func (k *Keeper) EVMConfig(ctx sdk.Context) (*types.EVMConfig, error) {
params := k.GetParams(ctx)
ethCfg := params.ChainConfig.EthereumConfig(k.eip155ChainID)
// get the coinbase address from the block proposer
coinbase, err := k.GetCoinbaseAddress(ctx)
if err != nil {
return nil, sdkerrors.Wrap(err, "failed to obtain coinbase address")
}
baseFee := k.BaseFee(ctx, ethCfg)
return &types.EVMConfig{
Params: params,
ChainConfig: ethCfg,
CoinBase: coinbase,
BaseFee: baseFee,
}, nil
}
// TxConfig load `TxConfig` from current transient storage
func (k *Keeper) TxConfig(ctx sdk.Context, txHash common.Hash) statedb.TxConfig {
return statedb.NewTxConfig(
common.BytesToHash(ctx.HeaderHash()), // BlockHash
txHash, // TxHash
uint(k.GetTxIndexTransient(ctx)), // TxIndex
uint(k.GetLogSizeTransient(ctx)), // LogIndex
)
}
// NewEVM generates a go-ethereum VM from the provided Message fields and the chain parameters
// (ChainConfig and module Params). It additionally sets the validator operator address as the
// coinbase address to make it available for the COINBASE opcode, even though there is no
// beneficiary of the coinbase transaction (since we're not mining).
func (k *Keeper) NewEVM(
ctx sdk.Context,
msg core.Message,
cfg *types.EVMConfig,
tracer vm.EVMLogger,
stateDB vm.StateDB,
) *vm.EVM {
blockCtx := vm.BlockContext{
CanTransfer: core.CanTransfer,
Transfer: core.Transfer,
GetHash: k.GetHashFn(ctx),
Coinbase: cfg.CoinBase,
GasLimit: ethermint.BlockGasLimit(ctx),
BlockNumber: big.NewInt(ctx.BlockHeight()),
Time: big.NewInt(ctx.BlockHeader().Time.Unix()),
Difficulty: big.NewInt(0), // unused. Only required in PoW context
BaseFee: cfg.BaseFee,
}
txCtx := core.NewEVMTxContext(msg)
if tracer == nil {
tracer = k.Tracer(ctx, msg, cfg.ChainConfig)
}
vmConfig := k.VMConfig(ctx, msg, cfg, tracer)
return vm.NewEVM(blockCtx, txCtx, stateDB, cfg.ChainConfig, vmConfig)
}
// VMConfig creates an EVM configuration from the debug setting and the extra EIPs enabled on the
// module parameters. The config generated uses the default JumpTable from the EVM.
func (k Keeper) VMConfig(ctx sdk.Context, msg core.Message, cfg *types.EVMConfig, tracer vm.EVMLogger) vm.Config {
noBaseFee := true
if types.IsLondon(cfg.ChainConfig, ctx.BlockHeight()) {
noBaseFee = k.feeMarketKeeper.GetParams(ctx).NoBaseFee
}
var debug bool
if _, ok := tracer.(types.NoOpTracer); !ok {
debug = true
}
return vm.Config{
Debug: debug,
Tracer: tracer,
NoBaseFee: noBaseFee,
ExtraEips: cfg.Params.EIPs(),
}
}
// GetHashFn implements vm.GetHashFunc for Ethermint. It handles 3 cases:
// 1. The requested height matches the current height from context (and thus same epoch number)
// 2. The requested height is from an previous height from the same chain epoch
// 3. The requested height is from a height greater than the latest one
func (k Keeper) GetHashFn(ctx sdk.Context) vm.GetHashFunc {
return func(height uint64) common.Hash {
h, err := ethermint.SafeInt64(height)
if err != nil {
k.Logger(ctx).Error("failed to cast height to int64", "error", err)
return common.Hash{}
}
switch {
case ctx.BlockHeight() == h:
// Case 1: The requested height matches the one from the context so we can retrieve the header
// hash directly from the context.
// Note: The headerHash is only set at begin block, it will be nil in case of a query context
headerHash := ctx.HeaderHash()
if len(headerHash) != 0 {
return common.BytesToHash(headerHash)
}
// only recompute the hash if not set (eg: checkTxState)
contextBlockHeader := ctx.BlockHeader()
header, err := tmtypes.HeaderFromProto(&contextBlockHeader)
if err != nil {
k.Logger(ctx).Error("failed to cast tendermint header from proto", "error", err)
return common.Hash{}
}
headerHash = header.Hash()
return common.BytesToHash(headerHash)
case ctx.BlockHeight() > h:
// Case 2: if the chain is not the current height we need to retrieve the hash from the store for the
// current chain epoch. This only applies if the current height is greater than the requested height.
histInfo, found := k.stakingKeeper.GetHistoricalInfo(ctx, h)
if !found {
k.Logger(ctx).Debug("historical info not found", "height", h)
return common.Hash{}
}
header, err := tmtypes.HeaderFromProto(&histInfo.Header)
if err != nil {
k.Logger(ctx).Error("failed to cast tendermint header from proto", "error", err)
return common.Hash{}
}
return common.BytesToHash(header.Hash())
default:
// Case 3: heights greater than the current one returns an empty hash.
return common.Hash{}
}
}
}
// ApplyTransaction runs and attempts to perform a state transition with the given transaction (i.e Message), that will
// only be persisted (committed) to the underlying KVStore if the transaction does not fail.
//
// Gas tracking
//
// Ethereum consumes gas according to the EVM opcodes instead of general reads and writes to store. Because of this, the
// state transition needs to ignore the SDK gas consumption mechanism defined by the GasKVStore and instead consume the
// amount of gas used by the VM execution. The amount of gas used is tracked by the EVM and returned in the execution
// result.
//
// Prior to the execution, the starting tx gas meter is saved and replaced with an infinite gas meter in a new context
// in order to ignore the SDK gas consumption config values (read, write, has, delete).
// After the execution, the gas used from the message execution will be added to the starting gas consumed, taking into
// consideration the amount of gas returned. Finally, the context is updated with the EVM gas consumed value prior to
// returning.
//
// For relevant discussion see: https://github.com/cosmos/cosmos-sdk/discussions/9072
func (k *Keeper) ApplyTransaction(ctx sdk.Context, tx *ethtypes.Transaction) (*types.MsgEthereumTxResponse, error) {
var (
bloom *big.Int
bloomReceipt ethtypes.Bloom
)
cfg, err := k.EVMConfig(ctx)
if err != nil {
return nil, sdkerrors.Wrap(err, "failed to load evm config")
}
txConfig := k.TxConfig(ctx, tx.Hash())
// get the signer according to the chain rules from the config and block height
signer := ethtypes.MakeSigner(cfg.ChainConfig, big.NewInt(ctx.BlockHeight()))
msg, err := tx.AsMessage(signer, cfg.BaseFee)
if err != nil {
return nil, sdkerrors.Wrap(err, "failed to return ethereum transaction as core message")
}
// snapshot to contain the tx processing and post processing in same scope
var commit func()
tmpCtx := ctx
if k.hooks != nil {
// Create a cache context to revert state when tx hooks fails,
// the cache context is only committed when both tx and hooks executed successfully.
// Didn't use `Snapshot` because the context stack has exponential complexity on certain operations,
// thus restricted to be used only inside `ApplyMessage`.
tmpCtx, commit = ctx.CacheContext()
}
// pass true to commit the StateDB
res, err := k.ApplyMessageWithConfig(tmpCtx, msg, nil, true, cfg, txConfig)
if err != nil {
return nil, sdkerrors.Wrap(err, "failed to apply ethereum core message")
}
logs := types.LogsToEthereum(res.Logs)
// Compute block bloom filter
if len(logs) > 0 {
bloom = k.GetBlockBloomTransient(ctx)
bloom.Or(bloom, big.NewInt(0).SetBytes(ethtypes.LogsBloom(logs)))
bloomReceipt = ethtypes.BytesToBloom(bloom.Bytes())
}
if !res.Failed() {
cumulativeGasUsed := res.GasUsed
if ctx.BlockGasMeter() != nil {
limit := ctx.BlockGasMeter().Limit()
consumed := ctx.BlockGasMeter().GasConsumed()
cumulativeGasUsed = uint64(math.Min(float64(cumulativeGasUsed+consumed), float64(limit)))
}
var contractAddr common.Address
if msg.To() == nil {
contractAddr = crypto.CreateAddress(msg.From(), msg.Nonce())
}
receipt := &ethtypes.Receipt{
Type: tx.Type(),
PostState: nil, // TODO: intermediate state root
Status: ethtypes.ReceiptStatusSuccessful,
CumulativeGasUsed: cumulativeGasUsed,
Bloom: bloomReceipt,
Logs: logs,
TxHash: txConfig.TxHash,
ContractAddress: contractAddr,
GasUsed: res.GasUsed,
BlockHash: txConfig.BlockHash,
BlockNumber: big.NewInt(ctx.BlockHeight()),
TransactionIndex: txConfig.TxIndex,
}
// Only call hooks if tx executed successfully.
if err = k.PostTxProcessing(tmpCtx, msg.From(), tx.To(), receipt); err != nil {
// If hooks return error, revert the whole tx.
res.VmError = types.ErrPostTxProcessing.Error()
k.Logger(ctx).Error("tx post processing failed", "error", err)
} else if commit != nil {
// PostTxProcessing is successful, commit the tmpCtx
commit()
ctx.EventManager().EmitEvents(tmpCtx.EventManager().Events())
}
}
// refund gas in order to match the Ethereum gas consumption instead of the default SDK one.
if err = k.RefundGas(ctx, msg, msg.Gas()-res.GasUsed, cfg.Params.EvmDenom); err != nil {
return nil, sdkerrors.Wrapf(err, "failed to refund gas leftover gas to sender %s", msg.From())
}
if len(logs) > 0 {
// Update transient block bloom filter
k.SetBlockBloomTransient(ctx, bloom)
k.SetLogSizeTransient(ctx, uint64(txConfig.LogIndex)+uint64(len(logs)))
}
k.SetTxIndexTransient(ctx, uint64(txConfig.TxIndex)+1)
totalGasUsed, err := k.AddTransientGasUsed(ctx, res.GasUsed)
if err != nil {
return nil, sdkerrors.Wrap(err, "failed to add transient gas used")
}
// reset the gas meter for current cosmos transaction
k.ResetGasMeterAndConsumeGas(ctx, totalGasUsed)
return res, nil
}
// ApplyMessageWithConfig computes the new state by applying the given message against the existing state.
// If the message fails, the VM execution error with the reason will be returned to the client
// and the transaction won't be committed to the store.
//
// Reverted state
//
// The snapshot and rollback are supported by the `statedb.StateDB`.
//
// Different Callers
//
// It's called in three scenarios:
// 1. `ApplyTransaction`, in the transaction processing flow.
// 2. `EthCall/EthEstimateGas` grpc query handler.
// 3. Called by other native modules directly.
//
// Prechecks and Preprocessing
//
// All relevant state transition prechecks for the MsgEthereumTx are performed on the AnteHandler,
// prior to running the transaction against the state. The prechecks run are the following:
//
// 1. the nonce of the message caller is correct
// 2. caller has enough balance to cover transaction fee(gaslimit * gasprice)
// 3. the amount of gas required is available in the block
// 4. the purchased gas is enough to cover intrinsic usage
// 5. there is no overflow when calculating intrinsic gas
// 6. caller has enough balance to cover asset transfer for **topmost** call
//
// The preprocessing steps performed by the AnteHandler are:
//
// 1. set up the initial access list (iff fork > Berlin)
//
// Tracer parameter
//
// It should be a `vm.Tracer` object or nil, if pass `nil`, it'll create a default one based on keeper options.
//
// Commit parameter
//
// If commit is true, the `StateDB` will be committed, otherwise discarded.
func (k *Keeper) ApplyMessageWithConfig(ctx sdk.Context, msg core.Message, tracer vm.EVMLogger, commit bool, cfg *types.EVMConfig, txConfig statedb.TxConfig) (*types.MsgEthereumTxResponse, error) {
var (
ret []byte // return bytes from evm execution
vmErr error // vm errors do not effect consensus and are therefore not assigned to err
)
// return error if contract creation or call are disabled through governance
if !cfg.Params.EnableCreate && msg.To() == nil {
return nil, sdkerrors.Wrap(types.ErrCreateDisabled, "failed to create new contract")
} else if !cfg.Params.EnableCall && msg.To() != nil {
return nil, sdkerrors.Wrap(types.ErrCallDisabled, "failed to call contract")
}
stateDB := statedb.New(ctx, k, txConfig)
evm := k.NewEVM(ctx, msg, cfg, tracer, stateDB)
sender := vm.AccountRef(msg.From())
contractCreation := msg.To() == nil
isLondon := cfg.ChainConfig.IsLondon(evm.Context.BlockNumber)
intrinsicGas, err := k.GetEthIntrinsicGas(ctx, msg, cfg.ChainConfig, contractCreation)
if err != nil {
// should have already been checked on Ante Handler
return nil, sdkerrors.Wrap(err, "intrinsic gas failed")
}
// Should check again even if it is checked on Ante Handler, because eth_call don't go through Ante Handler.
if msg.Gas() < intrinsicGas {
// eth_estimateGas will check for this exact error
return nil, sdkerrors.Wrap(core.ErrIntrinsicGas, "apply message")
}
leftoverGas := msg.Gas() - intrinsicGas
// access list preparation is moved from ante handler to here, because it's needed when `ApplyMessage` is called
// under contexts where ante handlers are not run, for example `eth_call` and `eth_estimateGas`.
if rules := cfg.ChainConfig.Rules(big.NewInt(ctx.BlockHeight()), cfg.ChainConfig.MergeForkBlock != nil); rules.IsBerlin {
stateDB.PrepareAccessList(msg.From(), msg.To(), vm.ActivePrecompiles(rules), msg.AccessList())
}
if contractCreation {
// take over the nonce management from evm:
// - reset sender's nonce to msg.Nonce() before calling evm.
// - increase sender's nonce by one no matter the result.
stateDB.SetNonce(sender.Address(), msg.Nonce())
ret, _, leftoverGas, vmErr = evm.Create(sender, msg.Data(), leftoverGas, msg.Value())
stateDB.SetNonce(sender.Address(), msg.Nonce()+1)
} else {
ret, leftoverGas, vmErr = evm.Call(sender, *msg.To(), msg.Data(), leftoverGas, msg.Value())
}
refundQuotient := params.RefundQuotient
// After EIP-3529: refunds are capped to gasUsed / 5
if isLondon {
refundQuotient = params.RefundQuotientEIP3529
}
// calculate gas refund
if msg.Gas() < leftoverGas {
return nil, sdkerrors.Wrap(types.ErrGasOverflow, "apply message")
}
gasUsed := msg.Gas() - leftoverGas
refund := GasToRefund(stateDB.GetRefund(), gasUsed, refundQuotient)
if refund > gasUsed {
return nil, sdkerrors.Wrap(types.ErrGasOverflow, "apply message")
}
gasUsed -= refund
// EVM execution error needs to be available for the JSON-RPC client
var vmError string
if vmErr != nil {
vmError = vmErr.Error()
}
// The dirty states in `StateDB` is either committed or discarded after return
if commit {
if err := stateDB.Commit(); err != nil {
return nil, sdkerrors.Wrap(err, "failed to commit stateDB")
}
}
return &types.MsgEthereumTxResponse{
GasUsed: gasUsed,
VmError: vmError,
Ret: ret,
Logs: types.NewLogsFromEth(stateDB.Logs()),
Hash: txConfig.TxHash.Hex(),
}, nil
}
// ApplyMessage calls ApplyMessageWithConfig with default EVMConfig
func (k *Keeper) ApplyMessage(ctx sdk.Context, msg core.Message, tracer vm.EVMLogger, commit bool) (*types.MsgEthereumTxResponse, error) {
cfg, err := k.EVMConfig(ctx)
if err != nil {
return nil, sdkerrors.Wrap(err, "failed to load evm config")
}
txConfig := statedb.NewEmptyTxConfig(common.BytesToHash(ctx.HeaderHash()))
return k.ApplyMessageWithConfig(ctx, msg, tracer, commit, cfg, txConfig)
}
// GetEthIntrinsicGas returns the intrinsic gas cost for the transaction
func (k *Keeper) GetEthIntrinsicGas(ctx sdk.Context, msg core.Message, cfg *params.ChainConfig, isContractCreation bool) (uint64, error) {
height := big.NewInt(ctx.BlockHeight())
homestead := cfg.IsHomestead(height)
istanbul := cfg.IsIstanbul(height)
return core.IntrinsicGas(msg.Data(), msg.AccessList(), isContractCreation, homestead, istanbul)
}
// RefundGas transfers the leftover gas to the sender of the message, caped to half of the total gas
// consumed in the transaction. Additionally, the function sets the total gas consumed to the value
// returned by the EVM execution, thus ignoring the previous intrinsic gas consumed during in the
// AnteHandler.
func (k *Keeper) RefundGas(ctx sdk.Context, msg core.Message, leftoverGas uint64, denom string) error {
// Return EVM tokens for remaining gas, exchanged at the original rate.
remaining := new(big.Int).Mul(new(big.Int).SetUint64(leftoverGas), msg.GasPrice())
switch remaining.Sign() {
case -1:
// negative refund errors
return sdkerrors.Wrapf(types.ErrInvalidRefund, "refunded amount value cannot be negative %d", remaining.Int64())
case 1:
// positive amount refund
refundedCoins := sdk.Coins{sdk.NewCoin(denom, sdk.NewIntFromBigInt(remaining))}
// refund to sender from the fee collector module account, which is the escrow account in charge of collecting tx fees
err := k.bankKeeper.SendCoinsFromModuleToAccount(ctx, authtypes.FeeCollectorName, msg.From().Bytes(), refundedCoins)
if err != nil {
err = sdkerrors.Wrapf(sdkerrors.ErrInsufficientFunds, "fee collector account failed to refund fees: %s", err.Error())
return sdkerrors.Wrapf(err, "failed to refund %d leftover gas (%s)", leftoverGas, refundedCoins.String())
}
default:
// no refund, consume gas and update the tx gas meter
}
return nil
}
// ResetGasMeterAndConsumeGas reset first the gas meter consumed value to zero and set it back to the new value
// 'gasUsed'
func (k *Keeper) ResetGasMeterAndConsumeGas(ctx sdk.Context, gasUsed uint64) {
// reset the gas count
ctx.GasMeter().RefundGas(ctx.GasMeter().GasConsumed(), "reset the gas count")
ctx.GasMeter().ConsumeGas(gasUsed, "apply evm transaction")
}
// GetCoinbaseAddress returns the block proposer's validator operator address.
func (k Keeper) GetCoinbaseAddress(ctx sdk.Context) (common.Address, error) {
consAddr := sdk.ConsAddress(ctx.BlockHeader().ProposerAddress)
validator, found := k.stakingKeeper.GetValidatorByConsAddr(ctx, consAddr)
if !found {
return common.Address{}, sdkerrors.Wrapf(
stakingtypes.ErrNoValidatorFound,
"failed to retrieve validator from block proposer address %s",
consAddr.String(),
)
}
coinbase := common.BytesToAddress(validator.GetOperator())
return coinbase, nil
}