Auto-swap non-osmo tx fees to osmo (#1145)

Co-authored-by: Matt, Park <[email protected]>
Co-authored-by: Aleksandr Bezobchuk <[email protected]>
Co-authored-by: Aleksandr Bezobchuk <[email protected]>
Co-authored-by: Matt, Park <[email protected]>
Co-authored-by: Dev Ojha <[email protected]>
Co-authored-by: Dev Ojha <[email protected]>

app/ante.go

@@ -3,14 +3,13 @@ package app
 import (
 	wasm "github.com/CosmWasm/wasmd/x/wasm"
 	wasmkeeper "github.com/CosmWasm/wasmd/x/wasm/keeper"
-	channelkeeper "github.com/cosmos/ibc-go/v2/modules/core/04-channel/keeper"
-	ibcante "github.com/cosmos/ibc-go/v2/modules/core/ante"
 
 	servertypes "github.com/cosmos/cosmos-sdk/server/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	ante "github.com/cosmos/cosmos-sdk/x/auth/ante"
 	"github.com/cosmos/cosmos-sdk/x/auth/signing"
-	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+	channelkeeper "github.com/cosmos/ibc-go/v2/modules/core/04-channel/keeper"
+	ibcante "github.com/cosmos/ibc-go/v2/modules/core/ante"
 
 	txfeeskeeper "github.com/osmosis-labs/osmosis/v7/x/txfees/keeper"
 	txfeestypes "github.com/osmosis-labs/osmosis/v7/x/txfees/types"
@@ -23,7 +22,7 @@ func NewAnteHandler(
 	wasmConfig wasm.Config,
 	txCounterStoreKey sdk.StoreKey,
 	ak ante.AccountKeeper,
-	bankKeeper authtypes.BankKeeper,
+	bankKeeper txfeestypes.BankKeeper,
 	txFeesKeeper *txfeeskeeper.Keeper,
 	spotPriceCalculator txfeestypes.SpotPriceCalculator,
 	sigGasConsumer ante.SignatureVerificationGasConsumer,
@@ -32,7 +31,7 @@ func NewAnteHandler(
 ) sdk.AnteHandler {
 	mempoolFeeOptions := txfeestypes.NewMempoolFeeOptions(appOpts)
 	mempoolFeeDecorator := txfeeskeeper.NewMempoolFeeDecorator(*txFeesKeeper, mempoolFeeOptions)
-
+	deductFeeDecorator := txfeeskeeper.NewDeductFeeDecorator(*txFeesKeeper, ak, bankKeeper, nil)
 	return sdk.ChainAnteDecorators(
 		ante.NewSetUpContextDecorator(), // outermost AnteDecorator. SetUpContext must be called first
 		wasmkeeper.NewLimitSimulationGasDecorator(wasmConfig.SimulationGasLimit),
@@ -45,7 +44,7 @@ func NewAnteHandler(
 		ante.TxTimeoutHeightDecorator{},
 		ante.NewValidateMemoDecorator(ak),
 		ante.NewConsumeGasForTxSizeDecorator(ak),
-		ante.NewDeductFeeDecorator(ak, bankKeeper, nil),
+		deductFeeDecorator,
 		ante.NewSetPubKeyDecorator(ak), // SetPubKeyDecorator must be called before all signature verification decorators
 		ante.NewValidateSigCountDecorator(ak),
 		ante.NewSigGasConsumeDecorator(ak, sigGasConsumer),

app/apptesting/test_suite.go

@@ -22,6 +22,10 @@ import (
 	gammtypes "github.com/osmosis-labs/osmosis/v7/x/gamm/types"
 	lockupkeeper "github.com/osmosis-labs/osmosis/v7/x/lockup/keeper"
 	lockuptypes "github.com/osmosis-labs/osmosis/v7/x/lockup/types"
+
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/cosmos/cosmos-sdk/types/tx/signing"
+	authsigning "github.com/cosmos/cosmos-sdk/x/auth/signing"
 )
 
 type KeeperTestHelper struct {
@@ -228,6 +232,26 @@ func (keeperTestHelper *KeeperTestHelper) LockTokens(addr sdk.AccAddress, coins
 	return msgResponse.ID
 }
 
+func (keeperTestHelper *KeeperTestHelper) BuildTx(
+	txBuilder client.TxBuilder,
+	msgs []sdk.Msg,
+	sigV2 signing.SignatureV2,
+	memo string, txFee sdk.Coins,
+	gasLimit uint64,
+) authsigning.Tx {
+	err := txBuilder.SetMsgs(msgs[0])
+	keeperTestHelper.Require().NoError(err)
+
+	err = txBuilder.SetSignatures(sigV2)
+	keeperTestHelper.Require().NoError(err)
+
+	txBuilder.SetMemo(memo)
+	txBuilder.SetFeeAmount(txFee)
+	txBuilder.SetGasLimit(gasLimit)
+
+	return txBuilder.GetTx()
+}
+
 // CreateRandomAccounts is a function return a list of randomly generated AccAddresses
 func CreateRandomAccounts(numAccts int) []sdk.AccAddress {
 	testAddrs := make([]sdk.AccAddress, numAccts)

app/keepers.go

@@ -329,10 +329,17 @@ func (app *OsmosisApp) InitNormalKeepers(
 	)
 	app.PoolIncentivesKeeper = &poolIncentivesKeeper
 
+	// Note: gammKeeper is expected to satisfy the SpotPriceCalculator interface parameter
 	txFeesKeeper := txfeeskeeper.NewKeeper(
 		appCodec,
+		app.AccountKeeper,
+		app.BankKeeper,
+		app.EpochsKeeper,
 		keys[txfeestypes.StoreKey],
 		app.GAMMKeeper,
+		app.GAMMKeeper,
+		txfeestypes.FeeCollectorName,
+		txfeestypes.NonNativeFeeCollectorName,
 	)
 	app.TxFeesKeeper = &txFeesKeeper
 
@@ -437,6 +444,7 @@ func (app *OsmosisApp) SetupHooks() {
 	app.EpochsKeeper.SetHooks(
 		epochstypes.NewMultiEpochHooks(
 			// insert epoch hooks receivers here
+			app.TxFeesKeeper.Hooks(),
 			app.SuperfluidKeeper.Hooks(),
 			app.IncentivesKeeper.Hooks(),
 			app.MintKeeper.Hooks(),

app/modules.go

@@ -127,6 +127,7 @@ var moduleAccountPermissions = map[string][]string{
 	poolincentivestypes.ModuleName:           nil,
 	superfluidtypes.ModuleName:               {authtypes.Minter, authtypes.Burner},
 	txfeestypes.ModuleName:                   nil,
+	txfeestypes.NonNativeFeeCollectorName:    nil,
 	wasm.ModuleName:                          {authtypes.Burner},
 }
 

x/txfees/keeper/feedecorator.go

@@ -1,11 +1,15 @@
 package keeper
 
 import (
+	"fmt"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 
 	"github.com/osmosis-labs/osmosis/v7/x/txfees/keeper/txfee_filters"
 	"github.com/osmosis-labs/osmosis/v7/x/txfees/types"
+
+	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
 )
 
 // MempoolFeeDecorator will check if the transaction's fee is at least as large
@@ -121,3 +125,114 @@ func (mfd MempoolFeeDecorator) GetMinBaseGasPriceForTx(ctx sdk.Context, baseDeno
 	}
 	return cfgMinGasPrice
 }
+
+// DeductFeeDecorator deducts fees from the first signer of the tx.
+// If the first signer does not have the funds to pay for the fees, we return an InsufficientFunds error.
+// We call next AnteHandler if fees successfully deducted.
+//
+// CONTRACT: Tx must implement FeeTx interface to use DeductFeeDecorator
+type DeductFeeDecorator struct {
+	ak             types.AccountKeeper
+	bankKeeper     types.BankKeeper
+	feegrantKeeper types.FeegrantKeeper
+	txFeesKeeper   Keeper
+}
+
+func NewDeductFeeDecorator(tk Keeper, ak types.AccountKeeper, bk types.BankKeeper, fk types.FeegrantKeeper) DeductFeeDecorator {
+	return DeductFeeDecorator{
+		ak:             ak,
+		bankKeeper:     bk,
+		feegrantKeeper: fk,
+		txFeesKeeper:   tk,
+	}
+}
+
+func (dfd DeductFeeDecorator) AnteHandle(ctx sdk.Context, tx sdk.Tx, simulate bool, next sdk.AnteHandler) (newCtx sdk.Context, err error) {
+	feeTx, ok := tx.(sdk.FeeTx)
+	if !ok {
+		return ctx, sdkerrors.Wrap(sdkerrors.ErrTxDecode, "Tx must be a FeeTx")
+	}
+
+	// checks to make sure the module account has been set to collect fees in base token
+	if addr := dfd.ak.GetModuleAddress(types.FeeCollectorName); addr == nil {
+		return ctx, fmt.Errorf("Fee collector module account (%s) has not been set", types.FeeCollectorName)
+	}
+
+	// checks to make sure a separate module account has been set to collect fees not in base token
+	if addrNonNativeFee := dfd.ak.GetModuleAddress(types.NonNativeFeeCollectorName); addrNonNativeFee == nil {
+		return ctx, fmt.Errorf("non native fee collector module account (%s) has not been set", types.NonNativeFeeCollectorName)
+	}
+
+	// fee can be in any denom (checked for validity later)
+	fee := feeTx.GetFee()
+	feePayer := feeTx.FeePayer()
+	feeGranter := feeTx.FeeGranter()
+
+	// set the fee payer as the default address to deduct fees from
+	deductFeesFrom := feePayer
+
+	// If a fee granter was set, deduct fee from the fee granter's account.
+	if feeGranter != nil {
+		if dfd.feegrantKeeper == nil {
+			return ctx, sdkerrors.Wrap(sdkerrors.ErrInvalidRequest, "fee grants is not enabled")
+		} else if !feeGranter.Equals(feePayer) {
+			err := dfd.feegrantKeeper.UseGrantedFees(ctx, feeGranter, feePayer, fee, tx.GetMsgs())
+			if err != nil {
+				return ctx, sdkerrors.Wrapf(err, "%s not allowed to pay fees from %s", feeGranter, feePayer)
+			}
+		}
+
+		// if no errors, change the account that is charged for fees to the fee granter
+		deductFeesFrom = feeGranter
+	}
+
+	deductFeesFromAcc := dfd.ak.GetAccount(ctx, deductFeesFrom)
+	if deductFeesFromAcc == nil {
+		return ctx, sdkerrors.Wrapf(sdkerrors.ErrUnknownAddress, "fee payer address: %s does not exist", deductFeesFrom)
+	}
+
+	// deducts the fees and transfer them to the module account
+	if !feeTx.GetFee().IsZero() {
+		err = DeductFees(dfd.txFeesKeeper, dfd.bankKeeper, ctx, deductFeesFromAcc, feeTx.GetFee())
+		if err != nil {
+			return ctx, err
+		}
+	}
+
+	ctx.EventManager().EmitEvents(sdk.Events{sdk.NewEvent(sdk.EventTypeTx,
+		sdk.NewAttribute(sdk.AttributeKeyFee, feeTx.GetFee().String()),
+	)})
+
+	return next(ctx, tx, simulate)
+}
+
+// DeductFees deducts fees from the given account and transfers them to the set module account.
+func DeductFees(txFeesKeeper types.TxFeesKeeper, bankKeeper types.BankKeeper, ctx sdk.Context, acc authtypes.AccountI, fees sdk.Coins) error {
+	// Checks the validity of the fee tokens (sorted, have positive amount, valid and unique denomination)
+	if !fees.IsValid() {
+		return sdkerrors.Wrapf(sdkerrors.ErrInsufficientFee, "invalid fee amount: %s", fees)
+	}
+
+	// pulls base denom from TxFeesKeeper (should be uOSMO)
+	baseDenom, err := txFeesKeeper.GetBaseDenom(ctx)
+	if err != nil {
+		return err
+	}
+
+	// checks if input fee is uOSMO (assumes only one fee token exists in the fees array (as per the check in mempoolFeeDecorator))
+	if fees[0].Denom == baseDenom {
+		// sends to FeeCollectorName module account
+		err := bankKeeper.SendCoinsFromAccountToModule(ctx, acc.GetAddress(), types.FeeCollectorName, fees)
+		if err != nil {
+			return sdkerrors.Wrapf(sdkerrors.ErrInsufficientFunds, err.Error())
+		}
+	} else {
+		// sends to NonNativeFeeCollectorName module account
+		err := bankKeeper.SendCoinsFromAccountToModule(ctx, acc.GetAddress(), types.NonNativeFeeCollectorName, fees)
+		if err != nil {
+			return sdkerrors.Wrapf(sdkerrors.ErrInsufficientFunds, err.Error())
+		}
+	}
+
+	return nil
+}