Reject proposal if max block gas is exceeded (#674)

* Reject proposal if max block gas is exceeded

* fix test

* fix test

app/app.go

@@ -943,6 +943,13 @@ func (app *App) ClearOptimisticProcessingInfo() {
 }
 
 func (app *App) ProcessProposalHandler(ctx sdk.Context, req *abci.RequestProcessProposal) (*abci.ResponseProcessProposal, error) {
+	// TODO: this check decodes transactions which is redone in subsequent processing. We might be able to optimize performance
+	// by recording the decoding results and avoid decoding again later on.
+	if !app.checkTotalBlockGasWanted(ctx, req.Txs) {
+		return &abci.ResponseProcessProposal{
+			Status: abci.ResponseProcessProposal_REJECT,
+		}, nil
+	}
 	if app.optimisticProcessingInfo == nil {
 		completionSignal := make(chan struct{}, 1)
 		optimisticProcessingInfo := &OptimisticProcessingInfo{
@@ -1468,6 +1475,28 @@ func (app *App) RegisterTendermintService(clientCtx client.Context) {
 	tmservice.RegisterTendermintService(app.BaseApp.GRPCQueryRouter(), clientCtx, app.interfaceRegistry)
 }
 
+func (app *App) checkTotalBlockGasWanted(ctx sdk.Context, txs [][]byte) bool {
+	totalGasWanted := uint64(0)
+	for _, tx := range txs {
+		decoded, err := app.txDecoder(tx)
+		if err != nil {
+			// such tx will not be processed and thus won't consume gas. Skipping
+			continue
+		}
+		feeTx, ok := decoded.(sdk.FeeTx)
+		if !ok {
+			// such tx will not be processed and thus won't consume gas. Skipping
+			continue
+		}
+		totalGasWanted += feeTx.GetGas()
+		if totalGasWanted > uint64(ctx.ConsensusParams().Block.MaxGas) {
+			// early return
+			return false
+		}
+	}
+	return true
+}
+
 // GetMaccPerms returns a copy of the module account permissions
 func GetMaccPerms() map[string][]string {
 	dupMaccPerms := make(map[string][]string)

app/app_test.go

@@ -15,6 +15,7 @@ import (
 	oracletypes "github.com/sei-protocol/sei-chain/x/oracle/types"
 	"github.com/stretchr/testify/require"
 	abci "github.com/tendermint/tendermint/abci/types"
+	"github.com/tendermint/tendermint/proto/tendermint/types"
 )
 
 func TestEmptyBlockIdempotency(t *testing.T) {
@@ -267,3 +268,26 @@ func TestProcessOracleAndOtherTxsSuccess(t *testing.T) {
 
 	require.Equal(t, 2, len(txResults))
 }
+
+func TestInvalidProposalWithExcessiveGasWanted(t *testing.T) {
+	tm := time.Now().UTC()
+	valPub := secp256k1.GenPrivKey().PubKey()
+
+	testWrapper := app.NewTestWrapper(t, tm, valPub)
+	ap := testWrapper.App
+	ctx := testWrapper.Ctx.WithConsensusParams(&types.ConsensusParams{
+		Block: &types.BlockParams{MaxGas: 10},
+	})
+	emptyTxBuilder := app.MakeEncodingConfig().TxConfig.NewTxBuilder()
+	txEncoder := app.MakeEncodingConfig().TxConfig.TxEncoder()
+	emptyTxBuilder.SetGasLimit(10)
+	emptyTx, _ := txEncoder(emptyTxBuilder.GetTx())
+
+	badProposal := abci.RequestProcessProposal{
+		Txs:    [][]byte{emptyTx, emptyTx},
+		Height: 1,
+	}
+	res, err := ap.ProcessProposalHandler(ctx, &badProposal)
+	require.Nil(t, err)
+	require.Equal(t, abci.ResponseProcessProposal_REJECT, res.Status)
+}