laconicd/app/ante/eth.go
Federico Kunze bb91d8d93d
ante, evm: fix panic when checking BlockGasMeter (#120)
* ante, evm: fix panic when checking BlockGasMeter

* update block gas limit function
2021-06-14 10:24:08 -04:00

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package ante
import (
"math/big"
sdk "github.com/cosmos/cosmos-sdk/types"
sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
authante "github.com/cosmos/cosmos-sdk/x/auth/ante"
ethermint "github.com/cosmos/ethermint/types"
evmtypes "github.com/cosmos/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/params"
)
// EVMKeeper defines the expected keeper interface used on the Eth AnteHandler
type EVMKeeper interface {
vm.StateDB
ChainID() *big.Int
GetParams(ctx sdk.Context) evmtypes.Params
GetChainConfig(ctx sdk.Context) (evmtypes.ChainConfig, bool)
WithContext(ctx sdk.Context)
ResetRefundTransient(ctx sdk.Context)
NewEVM(msg core.Message, config *params.ChainConfig) *vm.EVM
}
// EthSigVerificationDecorator validates an ethereum signatures
type EthSigVerificationDecorator struct {
evmKeeper EVMKeeper
}
// NewEthSigVerificationDecorator creates a new EthSigVerificationDecorator
func NewEthSigVerificationDecorator(ek EVMKeeper) EthSigVerificationDecorator {
return EthSigVerificationDecorator{
evmKeeper: ek,
}
}
// AnteHandle validates checks that the registered chain id is the same as the one on the message, and
// that the signer address matches the one defined on the message.
func (esvd EthSigVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
// no need to verify signatures on recheck tx
if ctx.IsReCheckTx() {
return next(ctx, tx, simulate)
}
if len(tx.GetMsgs()) != 1 {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrInvalidRequest, "only 1 ethereum msg supported per tx, got %d", len(tx.GetMsgs()))
}
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
infCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
chainID := esvd.evmKeeper.ChainID()
config, found := esvd.evmKeeper.GetChainConfig(infCtx)
if !found {
return ctx, evmtypes.ErrChainConfigNotFound
}
ethCfg := config.EthereumConfig(chainID)
blockNum := big.NewInt(ctx.BlockHeight())
signer := ethtypes.MakeSigner(ethCfg, blockNum)
msg := tx.GetMsgs()[0]
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{})
}
sender, err := signer.Sender(msgEthTx.AsTransaction())
if err != nil {
return ctx, sdkerrors.Wrap(sdkerrors.ErrorInvalidSigner, err.Error())
}
// set up the sender to the transaction field if not already
msgEthTx.From = sender.Hex()
return next(ctx, msgEthTx, simulate)
}
// EthAccountVerificationDecorator validates an account balance checks
type EthAccountVerificationDecorator struct {
ak AccountKeeper
bankKeeper BankKeeper
evmKeeper EVMKeeper
}
// NewEthAccountVerificationDecorator creates a new EthAccountVerificationDecorator
func NewEthAccountVerificationDecorator(ak AccountKeeper, bankKeeper BankKeeper, ek EVMKeeper) EthAccountVerificationDecorator {
return EthAccountVerificationDecorator{
ak: ak,
bankKeeper: bankKeeper,
evmKeeper: ek,
}
}
// AnteHandle validates checks that the sender balance is greater than the total transaction cost.
// The account will be set to store if it doesn't exis, i.e cannot be found on store.
// This AnteHandler decorator will fail if:
// - any of the msgs is not a MsgEthereumTx
// - from address is empty
// - account balance is lower than the transaction cost
func (avd EthAccountVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
if !ctx.IsCheckTx() {
return next(ctx, tx, simulate)
}
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
infCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
evmDenom := avd.evmKeeper.GetParams(infCtx).EvmDenom
for _, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{})
}
// sender address should be in the tx cache from the previous AnteHandle call
from := msgEthTx.GetFrom()
if from.Empty() {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrInvalidAddress, "from address cannot be empty")
}
acc := avd.ak.GetAccount(infCtx, from)
if acc == nil {
acc = avd.ak.NewAccountWithAddress(infCtx, from)
avd.ak.SetAccount(infCtx, acc)
}
// validate sender has enough funds to pay for gas cost
balance := avd.bankKeeper.GetBalance(infCtx, from, evmDenom)
if balance.Amount.BigInt().Cmp(msgEthTx.Cost()) < 0 {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrInsufficientFunds,
"sender balance < tx gas cost (%s < %s%s)", balance.String(), msgEthTx.Cost().String(), evmDenom,
)
}
}
return next(ctx, tx, simulate)
}
// EthNonceVerificationDecorator checks that the account nonce from the transaction matches
// the sender account sequence.
type EthNonceVerificationDecorator struct {
ak AccountKeeper
}
// NewEthNonceVerificationDecorator creates a new EthNonceVerificationDecorator
func NewEthNonceVerificationDecorator(ak AccountKeeper) EthNonceVerificationDecorator {
return EthNonceVerificationDecorator{
ak: ak,
}
}
// AnteHandle validates that the transaction nonces are valid and equivalent to the sender accounts
// current nonce.
func (nvd EthNonceVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
// no need to check the nonce on ReCheckTx
if ctx.IsReCheckTx() {
return next(ctx, tx, simulate)
}
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
infCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
for _, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{})
}
// sender address should be in the tx cache from the previous AnteHandle call
seq, err := nvd.ak.GetSequence(infCtx, msgEthTx.GetFrom())
if err != nil {
return ctx, err
}
// if multiple transactions are submitted in succession with increasing nonces,
// all will be rejected except the first, since the first needs to be included in a block
// before the sequence increments
if msgEthTx.Data.Nonce != seq {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrInvalidSequence,
"invalid nonce; got %d, expected %d", msgEthTx.Data.Nonce, seq,
)
}
}
return next(ctx, tx, simulate)
}
// EthGasConsumeDecorator validates enough intrinsic gas for the transaction and
// gas consumption.
type EthGasConsumeDecorator struct {
ak AccountKeeper
bankKeeper BankKeeper
evmKeeper EVMKeeper
}
// NewEthGasConsumeDecorator creates a new EthGasConsumeDecorator
func NewEthGasConsumeDecorator(ak AccountKeeper, bankKeeper BankKeeper, ek EVMKeeper) EthGasConsumeDecorator {
return EthGasConsumeDecorator{
ak: ak,
bankKeeper: bankKeeper,
evmKeeper: ek,
}
}
// AnteHandle validates that the Ethereum tx message has enough to cover intrinsic gas
// (during CheckTx only) and that the sender has enough balance to pay for the gas cost.
//
// Intrinsic gas for a transaction is the amount of gas that the transaction uses before the
// transaction is executed. The gas is a constant value plus any cost inccured by additional bytes
// of data supplied with the transaction.
//
// This AnteHandler decorator will fail if:
// - the transaction contains more than one message
// - the message is not a MsgEthereumTx
// - sender account cannot be found
// - transaction's gas limit is lower than the intrinsic gas
// - user doesn't have enough balance to deduct the transaction fees (gas_limit * gas_price)
// - transaction or block gas meter runs out of gas
func (egcd EthGasConsumeDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
infCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
// reset the refund gas value in the keeper for the current transaction
egcd.evmKeeper.ResetRefundTransient(infCtx)
config, found := egcd.evmKeeper.GetChainConfig(infCtx)
if !found {
return ctx, evmtypes.ErrChainConfigNotFound
}
ethCfg := config.EthereumConfig(egcd.evmKeeper.ChainID())
blockHeight := big.NewInt(ctx.BlockHeight())
homestead := ethCfg.IsHomestead(blockHeight)
istanbul := ethCfg.IsIstanbul(blockHeight)
for _, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{})
}
isContractCreation := msgEthTx.To() == nil
// fetch sender account from signature
signerAcc, err := authante.GetSignerAcc(infCtx, egcd.ak, msgEthTx.GetFrom())
if err != nil {
return ctx, err
}
gasLimit := msgEthTx.GetGas()
var accessList ethtypes.AccessList
if msgEthTx.Data.Accesses != nil {
accessList = *msgEthTx.Data.Accesses.ToEthAccessList()
}
intrinsicGas, err := core.IntrinsicGas(msgEthTx.Data.Input, accessList, isContractCreation, homestead, istanbul)
if err != nil {
return ctx, sdkerrors.Wrap(err, "failed to compute intrinsic gas cost")
}
// intrinsic gas verification during CheckTx
if ctx.IsCheckTx() && gasLimit < intrinsicGas {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrOutOfGas, "gas limit too low: %d (gas limit) < %d (intrinsic gas)", gasLimit, intrinsicGas)
}
// calculate the fees paid to validators based on gas limit and price
feeAmt := msgEthTx.Fee() // fee = gas limit * gas price
evmDenom := egcd.evmKeeper.GetParams(infCtx).EvmDenom
fees := sdk.Coins{sdk.NewCoin(evmDenom, sdk.NewIntFromBigInt(feeAmt))}
// deduct the full gas cost from the user balance
if err := authante.DeductFees(egcd.bankKeeper, infCtx, signerAcc, fees); err != nil {
return ctx, err
}
// consume intrinsic gas for the current transaction. After runTx is executed on Baseapp, the
// application will consume gas from the block gas pool.
ctx.GasMeter().ConsumeGas(intrinsicGas, "intrinsic gas")
}
// TODO: deprecate after https://github.com/cosmos/cosmos-sdk/issues/9514 is fixed on SDK
blockGasLimit := ethermint.BlockGasLimit(ctx)
// NOTE: safety check
if blockGasLimit > 0 {
// generate a copy of the gas pool (i.e block gas meter) to see if we've run out of gas for this block
// if current gas consumed is greater than the limit, this funcion panics and the error is recovered on the Baseapp
gasPool := sdk.NewGasMeter(blockGasLimit)
gasPool.ConsumeGas(ctx.GasMeter().GasConsumedToLimit(), "gas pool check")
}
// we know that we have enough gas on the pool to cover the intrinsic gas
// set up the updated context to the evm Keeper
egcd.evmKeeper.WithContext(ctx)
return next(ctx, tx, simulate)
}
// CanTransferDecorator checks if the sender is allowed to transfer funds according to the EVM block
// context rules.
type CanTransferDecorator struct {
evmKeeper EVMKeeper
}
// NewCanTransferDecorator creates a new CanTransferDecorator instance.
func NewCanTransferDecorator(evmKeeper EVMKeeper) CanTransferDecorator {
return CanTransferDecorator{
evmKeeper: evmKeeper,
}
}
// AnteHandle creates an EVM from the message and calls the BlockContext CanTransfer function to
// see if the address can execute the transaction.
func (ctd CanTransferDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
infCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
ctd.evmKeeper.WithContext(infCtx)
config, found := ctd.evmKeeper.GetChainConfig(infCtx)
if !found {
return ctx, evmtypes.ErrChainConfigNotFound
}
ethCfg := config.EthereumConfig(ctd.evmKeeper.ChainID())
signer := ethtypes.MakeSigner(ethCfg, big.NewInt(ctx.BlockHeight()))
for _, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", msg)
}
coreMsg, err := msgEthTx.AsMessage(signer)
if err != nil {
return ctx, err
}
evm := ctd.evmKeeper.NewEVM(coreMsg, ethCfg)
// check that caller has enough balance to cover asset transfer for **topmost** call
// NOTE: here the gas consumed is from the context with the infinite gas meter
if coreMsg.Value().Sign() > 0 && !evm.Context.CanTransfer(ctd.evmKeeper, coreMsg.From(), coreMsg.Value()) {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrInsufficientFunds, "address %s", coreMsg.From().Hex())
}
}
ctd.evmKeeper.WithContext(ctx)
// set the original gas meter
return next(ctx, tx, simulate)
}
// AccessListDecorator prepare an access list for the sender if Yolov3/Berlin/EIPs 2929 and 2930 are
// applicable at the current block number.
type AccessListDecorator struct {
evmKeeper EVMKeeper
}
// NewAccessListDecorator creates a new AccessListDecorator.
func NewAccessListDecorator(evmKeeper EVMKeeper) AccessListDecorator {
return AccessListDecorator{
evmKeeper: evmKeeper,
}
}
// AnteHandle handles the preparatory steps for executing an EVM state transition with
// regards to both EIP-2929 and EIP-2930:
//
// - Add sender to access list (2929)
// - Add destination to access list (2929)
// - Add precompiles to access list (2929)
// - Add the contents of the optional tx access list (2930)
//
// The AnteHandler will only prepare the access list if Yolov3/Berlin/EIPs 2929 and 2930 are applicable at the current number.
func (ald AccessListDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
infCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
config, found := ald.evmKeeper.GetChainConfig(infCtx)
if !found {
return ctx, evmtypes.ErrChainConfigNotFound
}
ethCfg := config.EthereumConfig(ald.evmKeeper.ChainID())
rules := ethCfg.Rules(big.NewInt(ctx.BlockHeight()))
// we don't need to prepare the access list if the chain is not currently on the Berlin upgrade
if !rules.IsBerlin {
return next(ctx, tx, simulate)
}
// setup the keeper context before setting the access list
ald.evmKeeper.WithContext(infCtx)
for _, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", msg)
}
sender := common.BytesToAddress(msgEthTx.GetFrom())
ald.evmKeeper.PrepareAccessList(sender, msgEthTx.To(), vm.ActivePrecompiles(rules), *msgEthTx.Data.Accesses.ToEthAccessList())
}
// set the original gas meter
ald.evmKeeper.WithContext(ctx)
return next(ctx, tx, simulate)
}
// EthIncrementSenderSequenceDecorator increments the sequence of the signers.
type EthIncrementSenderSequenceDecorator struct {
ak AccountKeeper
}
// NewEthIncrementSenderSequenceDecorator creates a new EthIncrementSenderSequenceDecorator.
func NewEthIncrementSenderSequenceDecorator(ak AccountKeeper) EthIncrementSenderSequenceDecorator {
return EthIncrementSenderSequenceDecorator{
ak: ak,
}
}
// AnteHandle handles incrementing the sequence of the signer (i.e sender). If the transaction is a
// contract creation, the nonce will be incremented during the transaction execution and not within
// this AnteHandler decorator.
func (issd EthIncrementSenderSequenceDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
// get and set account must be called with an infinite gas meter in order to prevent
// additional gas from being deducted.
infCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
for _, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type: %T", msg)
}
// NOTE: on contract creation, the nonce is incremented within the EVM Create function during tx execution
// and not previous to the state transition ¯\_(ツ)_/¯
if msgEthTx.To() == nil {
// contract creation, don't increment sequence on AnteHandler but on tx execution
// continue to the next item
continue
}
// increment sequence of all signers
for _, addr := range msg.GetSigners() {
acc := issd.ak.GetAccount(infCtx, addr)
if acc == nil {
return ctx, sdkerrors.Wrapf(
sdkerrors.ErrUnknownAddress,
"account %s (%s) is nil", common.BytesToAddress(addr.Bytes()), addr,
)
}
if err := acc.SetSequence(acc.GetSequence() + 1); err != nil {
return ctx, err
}
issd.ak.SetAccount(infCtx, acc)
}
}
// set the original gas meter
return next(ctx, tx, simulate)
}