laconicd/app/ante/eth.go

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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"
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"github.com/palantir/stacktrace"
ethermint "github.com/tharsis/ethermint/types"
evmtypes "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/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
WithContext(ctx sdk.Context)
ResetRefundTransient(ctx sdk.Context)
GetCoinbaseAddress() (common.Address, error)
NewEVM(msg core.Message, config *params.ChainConfig, params evmtypes.Params, coinbase common.Address) *vm.EVM
GetCodeHash(addr common.Address) common.Hash
}
// EthSigVerificationDecorator validates an ethereum signatures
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type EthSigVerificationDecorator struct {
evmKeeper EVMKeeper
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}
// 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.
// It's not skipped for RecheckTx, because it set `From` address which is critical from other ante handler to work.
// Failure in RecheckTx will prevent tx to be included into block, especially when CheckTx succeed, in which case user
// won't see the error message.
func (esvd EthSigVerificationDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
if tx == nil || len(tx.GetMsgs()) != 1 {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "only 1 ethereum msg supported per tx"),
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"",
)
}
chainID := esvd.evmKeeper.ChainID()
params := esvd.evmKeeper.GetParams(ctx)
ethCfg := params.ChainConfig.EthereumConfig(chainID)
blockNum := big.NewInt(ctx.BlockHeight())
signer := ethtypes.MakeSigner(ethCfg, blockNum)
msg := tx.GetMsgs()[0]
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{}),
"failed to cast transaction",
)
}
sender, err := signer.Sender(msgEthTx.AsTransaction())
if err != nil {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrap(sdkerrors.ErrorInvalidSigner, err.Error()),
"couldn't retrieve sender address ('%s') from the ethereum transaction",
msgEthTx.From,
)
}
// set up the sender to the transaction field if not already
msgEthTx.From = sender.Hex()
return next(ctx, msgEthTx, simulate)
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}
// EthAccountVerificationDecorator validates an account balance checks
type EthAccountVerificationDecorator struct {
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ak AccountKeeper
bankKeeper BankKeeper
evmKeeper EVMKeeper
}
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// NewEthAccountVerificationDecorator creates a new EthAccountVerificationDecorator
func NewEthAccountVerificationDecorator(ak AccountKeeper, bankKeeper BankKeeper, ek EVMKeeper) EthAccountVerificationDecorator {
return EthAccountVerificationDecorator{
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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
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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)
}
avd.evmKeeper.WithContext(ctx)
evmDenom := avd.evmKeeper.GetParams(ctx).EvmDenom
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for i, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{}),
"failed to cast transaction %d", i,
)
}
txData, err := evmtypes.UnpackTxData(msgEthTx.Data)
if err != nil {
return ctx, stacktrace.Propagate(err, "failed to unpack tx data any for tx %d", i)
}
// sender address should be in the tx cache from the previous AnteHandle call
from := msgEthTx.GetFrom()
if from.Empty() {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrInvalidAddress, "from address cannot be empty"),
"sender address should have been in the tx field from the previous AnteHandle call",
)
}
// check whether the sender address is EOA
fromAddr := common.BytesToAddress(from)
codeHash := avd.evmKeeper.GetCodeHash(fromAddr)
if codeHash != common.BytesToHash(evmtypes.EmptyCodeHash) {
return ctx, stacktrace.Propagate(sdkerrors.Wrapf(sdkerrors.ErrInvalidType,
"the sender is not EOA: address <%v>, codeHash <%s>", fromAddr, codeHash), "")
}
acc := avd.ak.GetAccount(ctx, from)
if acc == nil {
acc = avd.ak.NewAccountWithAddress(ctx, from)
avd.ak.SetAccount(ctx, acc)
}
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// validate sender has enough funds to pay for tx cost
balance := avd.bankKeeper.GetBalance(ctx, from, evmDenom)
cost := txData.Cost()
if balance.Amount.BigInt().Cmp(cost) < 0 {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(
sdkerrors.ErrInsufficientFunds,
"sender balance < tx cost (%s < %s%s)", balance, txData.Cost(), evmDenom,
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),
"sender should have had enough funds to pay for tx cost = fee + amount (%s = %s + %s)", cost, txData.Fee(), txData.GetValue(),
)
}
}
// recover the original gas meter
avd.evmKeeper.WithContext(ctx)
return next(ctx, tx, simulate)
}
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// EthNonceVerificationDecorator checks that the account nonce from the transaction matches
// the sender account sequence.
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type EthNonceVerificationDecorator struct {
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ak AccountKeeper
}
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// 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.
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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)
}
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for i, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{}),
"failed to cast transaction %d", i,
)
}
// sender address should be in the tx cache from the previous AnteHandle call
seq, err := nvd.ak.GetSequence(ctx, msgEthTx.GetFrom())
if err != nil {
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return ctx, stacktrace.Propagate(err, "sequence not found for address %s", msgEthTx.From)
}
txData, err := evmtypes.UnpackTxData(msgEthTx.Data)
if err != nil {
return ctx, stacktrace.Propagate(err, "failed to unpack tx data")
}
// 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 txData.GetNonce() != seq {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(
sdkerrors.ErrInvalidSequence,
"invalid nonce; got %d, expected %d", txData.GetNonce(), seq,
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),
"",
)
}
}
return next(ctx, tx, simulate)
}
// EthGasConsumeDecorator validates enough intrinsic gas for the transaction and
// gas consumption.
type EthGasConsumeDecorator struct {
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ak AccountKeeper
bankKeeper BankKeeper
evmKeeper EVMKeeper
}
// NewEthGasConsumeDecorator creates a new EthGasConsumeDecorator
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func NewEthGasConsumeDecorator(ak AccountKeeper, bankKeeper BankKeeper, ek EVMKeeper) EthGasConsumeDecorator {
return EthGasConsumeDecorator{
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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) {
// reset the refund gas value in the keeper for the current transaction
egcd.evmKeeper.ResetRefundTransient(ctx)
params := egcd.evmKeeper.GetParams(ctx)
ethCfg := params.ChainConfig.EthereumConfig(egcd.evmKeeper.ChainID())
blockHeight := big.NewInt(ctx.BlockHeight())
homestead := ethCfg.IsHomestead(blockHeight)
istanbul := ethCfg.IsIstanbul(blockHeight)
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for i, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{}),
"failed to cast transaction %d", i,
)
}
txData, err := evmtypes.UnpackTxData(msgEthTx.Data)
if err != nil {
return ctx, stacktrace.Propagate(err, "failed to unpack tx data")
}
isContractCreation := txData.GetTo() == nil
// fetch sender account from signature
signerAcc, err := authante.GetSignerAcc(ctx, egcd.ak, msgEthTx.GetFrom())
if err != nil {
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return ctx, stacktrace.Propagate(err, "account not found for sender %s", msgEthTx.From)
}
gasLimit := txData.GetGas()
var accessList ethtypes.AccessList
if txData.GetAccessList() != nil {
accessList = txData.GetAccessList()
}
intrinsicGas, err := core.IntrinsicGas(txData.GetData(), accessList, isContractCreation, homestead, istanbul)
if err != nil {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrap(err, "failed to compute intrinsic gas cost"),
"failed to retrieve intrinsic gas, contract creation = %t; homestead = %t, istanbul = %t", isContractCreation, homestead, istanbul)
}
// 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 := txData.Fee() // fee = gas limit * gas price
evmDenom := egcd.evmKeeper.GetParams(ctx).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, ctx, signerAcc, fees); err != nil {
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return ctx, stacktrace.Propagate(
err,
"failed to deduct full gas cost %s from the user %s balance", fees, msgEthTx.From,
)
}
}
// 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) {
ctd.evmKeeper.WithContext(ctx)
params := ctd.evmKeeper.GetParams(ctx)
ethCfg := params.ChainConfig.EthereumConfig(ctd.evmKeeper.ChainID())
signer := ethtypes.MakeSigner(ethCfg, big.NewInt(ctx.BlockHeight()))
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for i, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{}),
"failed to cast transaction %d", i,
)
}
coreMsg, err := msgEthTx.AsMessage(signer)
if err != nil {
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return ctx, stacktrace.Propagate(
err,
"failed to create an ethereum core.Message from signer %T", signer,
)
}
// NOTE: pass in an empty coinbase address as we don't need it for the check below
evm := ctd.evmKeeper.NewEVM(coreMsg, ethCfg, params, common.Address{})
// 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()) {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrInsufficientFunds, "address %s", coreMsg.From()),
"failed to transfer %s using the EVM block context transfer function", coreMsg.Value(),
)
}
}
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) {
params := ald.evmKeeper.GetParams(ctx)
ethCfg := params.ChainConfig.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(ctx)
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for i, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{}),
"failed to cast transaction %d", i,
)
}
sender := common.BytesToAddress(msgEthTx.GetFrom())
txData, err := evmtypes.UnpackTxData(msgEthTx.Data)
if err != nil {
return ctx, stacktrace.Propagate(err, "failed to unpack tx data")
}
ald.evmKeeper.PrepareAccessList(sender, txData.GetTo(), vm.ActivePrecompiles(rules), txData.GetAccessList())
}
// set the original gas meter
ald.evmKeeper.WithContext(ctx)
return next(ctx, tx, simulate)
}
// EthIncrementSenderSequenceDecorator increments the sequence of the signers.
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type EthIncrementSenderSequenceDecorator struct {
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ak AccountKeeper
}
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// 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.
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func (issd EthIncrementSenderSequenceDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
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for i, msg := range tx.GetMsgs() {
msgEthTx, ok := msg.(*evmtypes.MsgEthereumTx)
if !ok {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(sdkerrors.ErrUnknownRequest, "invalid transaction type %T, expected %T", tx, &evmtypes.MsgEthereumTx{}),
"failed to cast transaction %d", i,
)
}
txData, err := evmtypes.UnpackTxData(msgEthTx.Data)
if err != nil {
return ctx, stacktrace.Propagate(err, "failed to unpack tx data")
}
// 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 txData.GetTo() == 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(ctx, addr)
if acc == nil {
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return ctx, stacktrace.Propagate(
sdkerrors.Wrapf(
sdkerrors.ErrUnknownAddress,
"account %s (%s) is nil", common.BytesToAddress(addr.Bytes()), addr,
),
"signer account not found",
)
}
if err := acc.SetSequence(acc.GetSequence() + 1); err != nil {
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return ctx, stacktrace.Propagate(err, "failed to set sequence to %d", acc.GetSequence()+1)
}
issd.ak.SetAccount(ctx, acc)
}
}
// set the original gas meter
return next(ctx, tx, simulate)
}
// EthValidateBasicDecorator is adapted from ValidateBasicDecorator from cosmos-sdk, it ignores ErrNoSignatures
type EthValidateBasicDecorator struct{}
// NewEthValidateBasicDecorator creates a new EthValidateBasicDecorator
func NewEthValidateBasicDecorator() EthValidateBasicDecorator {
return EthValidateBasicDecorator{}
}
// AnteHandle handles basic validation of tx
func (vbd EthValidateBasicDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (sdk.Context, error) {
// no need to validate basic on recheck tx, call next antehandler
if ctx.IsReCheckTx() {
return next(ctx, tx, simulate)
}
err := tx.ValidateBasic()
// ErrNoSignatures is fine with eth tx
if err != nil && err != sdkerrors.ErrNoSignatures {
return ctx, stacktrace.Propagate(err, "tx basic validation failed")
}
return next(ctx, tx, simulate)
}
// EthSetupContextDecorator is adapted from SetUpContextDecorator from cosmos-sdk, it ignores gas consumption
// by setting the gas meter to infinite
type EthSetupContextDecorator struct{}
func NewEthSetUpContextDecorator() EthSetupContextDecorator {
return EthSetupContextDecorator{}
}
func (esc EthSetupContextDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
// all transactions must implement GasTx
_, ok := tx.(authante.GasTx)
if !ok {
return newCtx, sdkerrors.Wrap(sdkerrors.ErrTxDecode, "Tx must be GasTx")
}
newCtx = ctx.WithGasMeter(sdk.NewInfiniteGasMeter())
return next(newCtx, tx, simulate)
}