imp(fees): only allow user to pass in aevmos native token as transaction fees

CHANGELOG.md

@@ -77,6 +77,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 - (werc20) [#1990](https://github.com/evmos/evmos/pull/1990) Add WERC-20 Precompile events.
 - (distribution) [#1992](https://github.com/evmos/evmos/pull/1992) Remove outdated check utility for distribution approval.
 - (erc20) [#1994](https://github.com/evmos/evmos/pull/1994) Add tests for ERC20 precompile type utilities.
+- (fees) [#1998](https://github.com/evmos/evmos/pull/1998) Only allow user to pass in aevmos native token as transaction fees.
 - (erc20) [#2005](https://github.com/evmos/evmos/pull/2005) Add tests for ERC20 precompile approvals.
 - (bin) [#2007](https://github.com/evmos/evmos/pull/2007) Add commands in Makefile for building binary with rocksDB and pebbleDB
 - (erc20) [#2009](https://github.com/evmos/evmos/pull/2009) Add ERC20 precompile transaction unit tests.

app/ante/cosmos/min_price.go

@@ -3,12 +3,14 @@
 package cosmos
 
 import (
+	"fmt"
 	"math/big"
 
 	errorsmod "cosmossdk.io/errors"
+	evmante "github.com/evmos/evmos/v15/app/ante/evm"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	errortypes "github.com/cosmos/cosmos-sdk/types/errors"
-	evmante "github.com/evmos/evmos/v15/app/ante/evm"
 )
 
 // MinGasPriceDecorator will check if the transaction's fee is at least as large
@@ -35,20 +37,28 @@ func (mpd MinGasPriceDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate
 
 	minGasPrice := mpd.feesKeeper.GetParams(ctx).MinGasPrice
 
+	feeCoins := feeTx.GetFee()
+	evmParams := mpd.evmKeeper.GetParams(ctx)
+	evmDenom := evmParams.GetEvmDenom()
+
+	// only allow user to pass in aevmos native token as transaction fees
+	validFees := len(feeCoins) == 0 || (len(feeCoins) == 1 && feeCoins.GetDenomByIndex(0) == evmDenom)
+	if !validFees && !simulate {
+		return ctx, fmt.Errorf("expected only use native token %s for fee, but got %s", evmDenom, feeCoins.String())
+	}
+
 	// Short-circuit if min gas price is 0 or if simulating
 	if minGasPrice.IsZero() || simulate {
 		return next(ctx, tx, simulate)
 	}
-	evmParams := mpd.evmKeeper.GetParams(ctx)
-	evmDenom := evmParams.GetEvmDenom()
+
 	minGasPrices := sdk.DecCoins{
 		{
 			Denom:  evmDenom,
 			Amount: minGasPrice,
 		},
 	}
 
-	feeCoins := feeTx.GetFee()
 	gas := feeTx.GetGas()
 
 	requiredFees := make(sdk.Coins, 0)

app/ante/cosmos/min_price_test.go

@@ -1,7 +1,10 @@
 package cosmos_test
 
 import (
+	"fmt"
+
 	sdkmath "cosmossdk.io/math"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	cosmosante "github.com/evmos/evmos/v15/app/ante/cosmos"
@@ -115,7 +118,68 @@ func (suite *AnteTestSuite) TestMinGasPriceDecorator() {
 				return txBuilder.GetTx()
 			},
 			false,
-			"provided fee < minimum global fee",
+			fmt.Sprintf("expected only use native token %s for fee", denom),
+			true,
+		},
+		{
+			"valid cosmos tx with MinGasPrices = 0, gasPrice = 0, valid fee",
+			func() sdk.Tx {
+				params := suite.app.FeeMarketKeeper.GetParams(suite.ctx)
+				params.MinGasPrice = sdk.ZeroDec()
+				err := suite.app.FeeMarketKeeper.SetParams(suite.ctx, params)
+				suite.Require().NoError(err)
+
+				txBuilder := suite.CreateTestCosmosTxBuilderWithFees(sdk.Coins{sdk.Coin{Amount: sdkmath.NewInt(0), Denom: denom}}, &testMsg)
+				return txBuilder.GetTx()
+			},
+			true,
+			"",
+			true,
+		},
+		{
+			"valid cosmos tx with MinGasPrices = 0, gasPrice = 0, nil fees, means len(fees) == 0",
+			func() sdk.Tx {
+				params := suite.app.FeeMarketKeeper.GetParams(suite.ctx)
+				params.MinGasPrice = sdk.ZeroDec()
+				err := suite.app.FeeMarketKeeper.SetParams(suite.ctx, params)
+				suite.Require().NoError(err)
+
+				txBuilder := suite.CreateTestCosmosTxBuilderWithFees(nil, &testMsg)
+				return txBuilder.GetTx()
+			},
+			true,
+			"",
+			true,
+		},
+		{
+			"valid cosmos tx with MinGasPrices = 0, gasPrice = 0, empty fees, means len(fees) == 0",
+			func() sdk.Tx {
+				params := suite.app.FeeMarketKeeper.GetParams(suite.ctx)
+				params.MinGasPrice = sdk.ZeroDec()
+				err := suite.app.FeeMarketKeeper.SetParams(suite.ctx, params)
+				suite.Require().NoError(err)
+
+				txBuilder := suite.CreateTestCosmosTxBuilderWithFees(sdk.Coins{}, &testMsg)
+				return txBuilder.GetTx()
+			},
+			true,
+			"",
+			true,
+		},
+		{
+			"valid cosmos tx with MinGasPrices = 0, gasPrice = 0, invalid fees",
+			func() sdk.Tx {
+				params := suite.app.FeeMarketKeeper.GetParams(suite.ctx)
+				params.MinGasPrice = sdk.ZeroDec()
+				err := suite.app.FeeMarketKeeper.SetParams(suite.ctx, params)
+				suite.Require().NoError(err)
+
+				fees := sdk.Coins{sdk.Coin{Amount: sdkmath.NewInt(0), Denom: denom}, sdk.Coin{Amount: sdkmath.NewInt(10), Denom: "stake"}}
+				txBuilder := suite.CreateTestCosmosTxBuilderWithFees(fees, &testMsg)
+				return txBuilder.GetTx()
+			},
+			false,
+			fmt.Sprintf("expected only use native token %s for fee", denom),
 			true,
 		},
 	}

app/ante/cosmos/utils_test.go

@@ -32,6 +32,15 @@ func (suite *AnteTestSuite) CreateTestCosmosTxBuilder(gasPrice sdkmath.Int, deno
 	return txBuilder
 }
 
+func (suite *AnteTestSuite) CreateTestCosmosTxBuilderWithFees(fees sdk.Coins, msgs ...sdk.Msg) client.TxBuilder {
+	txBuilder := suite.clientCtx.TxConfig.NewTxBuilder()
+	txBuilder.SetGasLimit(TestGasLimit)
+	txBuilder.SetFeeAmount(fees)
+	err := txBuilder.SetMsgs(msgs...)
+	suite.Require().NoError(err)
+	return txBuilder
+}
+
 func newMsgExec(grantee sdk.AccAddress, msgs []sdk.Msg) *authz.MsgExec {
 	msg := authz.NewMsgExec(grantee, msgs)
 	return &msg