bug: use custom ante handler to reject redundant transactions in sima…

…pp (#884)

* add custom ante handler

* add godoc and changelog entry

Co-authored-by: Carlos Rodriguez <crodveg@gmail.com>

CHANGELOG.md

@@ -78,6 +78,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
+* (testing) [\#884](https://github.com/cosmos/ibc-go/pull/884) Add and use in simapp a custom ante handler that rejects redundant transactions
+
 ## [v2.0.2](https://github.com/cosmos/ibc-go/releases/tag/v2.0.2) - 2021-12-15
 
 ### Dependencies

testing/simapp/ante_handler.go

@@ -0,0 +1,56 @@
+package simapp
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	"github.com/cosmos/cosmos-sdk/x/auth/ante"
+
+	channelkeeper "github.com/cosmos/ibc-go/v3/modules/core/04-channel/keeper"
+	ibcante "github.com/cosmos/ibc-go/v3/modules/core/ante"
+)
+
+// HandlerOptions extend the SDK's AnteHandler options by requiring the IBC
+// channel keeper.
+type HandlerOptions struct {
+	ante.HandlerOptions
+
+	IBCChannelkeeper channelkeeper.Keeper
+}
+
+// NewAnteHandler creates a new ante handler
+func NewAnteHandler(options HandlerOptions) (sdk.AnteHandler, error) {
+	if options.AccountKeeper == nil {
+		return nil, sdkerrors.Wrap(sdkerrors.ErrLogic, "account keeper is required for AnteHandler")
+	}
+	if options.BankKeeper == nil {
+		return nil, sdkerrors.Wrap(sdkerrors.ErrLogic, "bank keeper is required for AnteHandler")
+	}
+	if options.SignModeHandler == nil {
+		return nil, sdkerrors.Wrap(sdkerrors.ErrLogic, "sign mode handler is required for ante builder")
+	}
+
+	var sigGasConsumer = options.SigGasConsumer
+	if sigGasConsumer == nil {
+		sigGasConsumer = ante.DefaultSigVerificationGasConsumer
+	}
+
+	anteDecorators := []sdk.AnteDecorator{
+		ante.NewSetUpContextDecorator(),
+		ante.NewRejectExtensionOptionsDecorator(),
+		ante.NewMempoolFeeDecorator(),
+		ante.NewValidateBasicDecorator(),
+		ante.NewTxTimeoutHeightDecorator(),
+		ante.NewValidateMemoDecorator(options.AccountKeeper),
+		ante.NewConsumeGasForTxSizeDecorator(options.AccountKeeper),
+		ante.NewDeductFeeDecorator(options.AccountKeeper, options.BankKeeper, options.FeegrantKeeper),
+		// SetPubKeyDecorator must be called before all signature verification decorators
+		ante.NewSetPubKeyDecorator(options.AccountKeeper),
+		ante.NewValidateSigCountDecorator(options.AccountKeeper),
+		ante.NewSigGasConsumeDecorator(options.AccountKeeper, sigGasConsumer),
+		ante.NewSigVerificationDecorator(options.AccountKeeper, options.SignModeHandler),
+		ante.NewIncrementSequenceDecorator(options.AccountKeeper),
+		ibcante.NewAnteDecorator(options.IBCChannelkeeper),
+	}
+
+	return sdk.ChainAnteDecorators(anteDecorators...), nil
+}

testing/simapp/app.go

@@ -494,13 +494,16 @@ func NewSimApp(
 	// initialize BaseApp
 	app.SetInitChainer(app.InitChainer)
 	app.SetBeginBlocker(app.BeginBlocker)
-	anteHandler, err := ante.NewAnteHandler(
-		ante.HandlerOptions{
-			AccountKeeper:   app.AccountKeeper,
-			BankKeeper:      app.BankKeeper,
-			SignModeHandler: encodingConfig.TxConfig.SignModeHandler(),
-			FeegrantKeeper:  app.FeeGrantKeeper,
-			SigGasConsumer:  ante.DefaultSigVerificationGasConsumer,
+	anteHandler, err := NewAnteHandler(
+		HandlerOptions{
+			HandlerOptions: ante.HandlerOptions{
+				AccountKeeper:   app.AccountKeeper,
+				BankKeeper:      app.BankKeeper,
+				SignModeHandler: encodingConfig.TxConfig.SignModeHandler(),
+				FeegrantKeeper:  app.FeeGrantKeeper,
+				SigGasConsumer:  ante.DefaultSigVerificationGasConsumer,
+			},
+			IBCChannelkeeper: app.IBCKeeper.ChannelKeeper,
 		},
 	)
 	if err != nil {