feat: min gas prices config (#3340)

The minimum gas price configuration is a mechanism to prevent spam and
ensure that only transactions with sufficient fees are processed. It
achieves this by setting a minimum cost per unit of gas that a
transaction must meet to be included in the mempool.

The following condition is checked by the validator: the gas and fees
provided by the user must meet this condition before the transaction can
be included in the mempool and subsequently processed by the VM.
 
Gas Fee  => Gas Wanted x Min Gas Prices 

A node operator can set the min gas prices as following

`gnoland config set application.min_gas_prices "1000ugnot/1gas"
`

Co-authored-by: Nathan Toups <[email protected]>

gno.land/cmd/gnoland/start.go

@@ -26,6 +26,7 @@ import (
 	"github.com/gnolang/gno/tm2/pkg/crypto"
 	"github.com/gnolang/gno/tm2/pkg/events"
 	osm "github.com/gnolang/gno/tm2/pkg/os"
+
 	"github.com/gnolang/gno/tm2/pkg/std"
 	"github.com/gnolang/gno/tm2/pkg/telemetry"
 	"go.uber.org/zap"
@@ -234,9 +235,10 @@ func execStart(ctx context.Context, c *startCfg, io commands.IO) error {
 
 	// Create a top-level shared event switch
 	evsw := events.NewEventSwitch()
+	minGasPrices := cfg.Application.MinGasPrices
 
 	// Create application and node
-	cfg.LocalApp, err = gnoland.NewApp(nodeDir, c.skipFailingGenesisTxs, evsw, logger)
+	cfg.LocalApp, err = gnoland.NewApp(nodeDir, c.skipFailingGenesisTxs, evsw, logger, minGasPrices)
 	if err != nil {
 		return fmt.Errorf("unable to create the Gnoland app, %w", err)
 	}

gno.land/pkg/gnoland/app.go

@@ -39,6 +39,7 @@ type AppOptions struct {
 	EventSwitch       events.EventSwitch // required
 	VMOutput          io.Writer          // optional
 	InitChainerConfig                    // options related to InitChainer
+	MinGasPrices      string             // optional
 }
 
 // TestAppOptions provides a "ready" default [AppOptions] for use with
@@ -79,9 +80,13 @@ func NewAppWithOptions(cfg *AppOptions) (abci.Application, error) {
 	mainKey := store.NewStoreKey("main")
 	baseKey := store.NewStoreKey("base")
 
+	//  set sdk app options
+	var appOpts []func(*sdk.BaseApp)
+	if cfg.MinGasPrices != "" {
+		appOpts = append(appOpts, sdk.SetMinGasPrices(cfg.MinGasPrices))
+	}
 	// Create BaseApp.
-	// TODO: Add a consensus based min gas prices for the node, by default it does not check
-	baseApp := sdk.NewBaseApp("gnoland", cfg.Logger, cfg.DB, baseKey, mainKey)
+	baseApp := sdk.NewBaseApp("gnoland", cfg.Logger, cfg.DB, baseKey, mainKey, appOpts...)
 	baseApp.SetAppVersion("dev")
 
 	// Set mounts for BaseApp's MultiStore.
@@ -181,6 +186,7 @@ func NewApp(
 	skipFailingGenesisTxs bool,
 	evsw events.EventSwitch,
 	logger *slog.Logger,
+	minGasPrices string,
 ) (abci.Application, error) {
 	var err error
 
@@ -191,6 +197,7 @@ func NewApp(
 			GenesisTxResultHandler: PanicOnFailingTxResultHandler,
 			StdlibDir:              filepath.Join(gnoenv.RootDir(), "gnovm", "stdlibs"),
 		},
+		MinGasPrices: minGasPrices,
 	}
 	if skipFailingGenesisTxs {
 		cfg.GenesisTxResultHandler = NoopGenesisTxResultHandler

gno.land/pkg/gnoland/app_test.go

@@ -134,7 +134,7 @@ func TestNewApp(t *testing.T) {
 	// NewApp should have good defaults and manage to run InitChain.
 	td := t.TempDir()
 
-	app, err := NewApp(td, true, events.NewEventSwitch(), log.NewNoopLogger())
+	app, err := NewApp(td, true, events.NewEventSwitch(), log.NewNoopLogger(), "")
 	require.NoError(t, err, "NewApp should be successful")
 
 	resp := app.InitChain(abci.RequestInitChain{

tm2/pkg/bft/config/config.go

@@ -18,6 +18,7 @@ import (
 	"github.com/gnolang/gno/tm2/pkg/errors"
 	osm "github.com/gnolang/gno/tm2/pkg/os"
 	p2p "github.com/gnolang/gno/tm2/pkg/p2p/config"
+	sdk "github.com/gnolang/gno/tm2/pkg/sdk/config"
 	telemetry "github.com/gnolang/gno/tm2/pkg/telemetry/config"
 )
 
@@ -55,6 +56,7 @@ type Config struct {
 	Consensus    *cns.ConsensusConfig `json:"consensus" toml:"consensus" comment:"##### consensus configuration options #####"`
 	TxEventStore *eventstore.Config   `json:"tx_event_store" toml:"tx_event_store" comment:"##### event store #####"`
 	Telemetry    *telemetry.Config    `json:"telemetry" toml:"telemetry" comment:"##### node telemetry #####"`
+	Application  *sdk.AppConfig       `json:"application" toml:"application" comment:"##### app settings #####"`
 }
 
 // DefaultConfig returns a default configuration for a Tendermint node
@@ -67,6 +69,7 @@ func DefaultConfig() *Config {
 		Consensus:    cns.DefaultConsensusConfig(),
 		TxEventStore: eventstore.DefaultEventStoreConfig(),
 		Telemetry:    telemetry.DefaultTelemetryConfig(),
+		Application:  sdk.DefaultAppConfig(),
 	}
 }
 
@@ -183,6 +186,7 @@ func TestConfig() *Config {
 		Consensus:    cns.TestConsensusConfig(),
 		TxEventStore: eventstore.DefaultEventStoreConfig(),
 		Telemetry:    telemetry.DefaultTelemetryConfig(),
+		Application:  sdk.DefaultAppConfig(),
 	}
 }
 
@@ -238,6 +242,9 @@ func (cfg *Config) ValidateBasic() error {
 	if err := cfg.Consensus.ValidateBasic(); err != nil {
 		return errors.Wrap(err, "Error in [consensus] section")
 	}
+	if err := cfg.Application.ValidateBasic(); err != nil {
+		return errors.Wrap(err, "Error in [application] section")
+	}
 	return nil
 }
 

tm2/pkg/sdk/auth/ante.go

@@ -387,9 +387,10 @@ func EnsureSufficientMempoolFees(ctx sdk.Context, fee std.Fee) sdk.Result {
 				if prod1.Cmp(prod2) >= 0 {
 					return sdk.Result{}
 				} else {
+					fee := new(big.Int).Quo(prod2, gpg)
 					return abciResult(std.ErrInsufficientFee(
 						fmt.Sprintf(
-							"insufficient fees; got: {Gas-Wanted: %d, Gas-Fee %s}, fee required: %+v as minimum gas price set by the node", feeGasPrice.Gas, feeGasPrice.Price, gp,
+							"insufficient fees; got: {Gas-Wanted: %d, Gas-Fee %s}, fee required: %d with %+v as minimum gas price set by the node", feeGasPrice.Gas, feeGasPrice.Price, fee, gp,
 						),
 					))
 				}

tm2/pkg/sdk/config/config.go

@@ -0,0 +1,35 @@
+package config
+
+import (
+	"github.com/gnolang/gno/tm2/pkg/errors"
+	"github.com/gnolang/gno/tm2/pkg/std"
+)
+
+// -----------------------------------------------------------------------------
+// Application Config
+
+// AppConfig defines the configuration options for the Application
+type AppConfig struct {
+	// Lowest gas prices accepted by a validator in the form of "100tokenA/3gas;10tokenB/5gas" separated by semicolons
+	MinGasPrices string `json:"min_gas_prices" toml:"min_gas_prices" comment:"Lowest gas prices accepted by a validator"`
+}
+
+// DefaultAppConfig returns a default configuration for the application
+func DefaultAppConfig() *AppConfig {
+	return &AppConfig{
+		MinGasPrices: "",
+	}
+}
+
+// ValidateBasic performs basic validation, checking format and param bounds, etc., and
+// returns an error if any check fails.
+func (cfg *AppConfig) ValidateBasic() error {
+	if cfg.MinGasPrices == "" {
+		return nil
+	}
+	if _, err := std.ParseGasPrices(cfg.MinGasPrices); err != nil {
+		return errors.Wrap(err, "invalid min gas prices")
+	}
+
+	return nil
+}

tm2/pkg/sdk/config/config_test.go

@@ -0,0 +1,36 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateAppConfig(t *testing.T) {
+	c := DefaultAppConfig()
+	c.MinGasPrices = "" // empty
+
+	testCases := []struct {
+		testName     string
+		minGasPrices string
+		expectErr    bool
+	}{
+		{"invalid min gas prices invalid gas", "10token/1", true},
+		{"invalid min gas prices invalid gas denom", "9token/0gs", true},
+		{"invalid min gas prices zero gas", "10token/0gas", true},
+		{"invalid min gas prices no gas", "10token/gas", true},
+		{"invalid min gas prices negtive gas", "10token/-1gas", true},
+		{"invalid min gas prices invalid denom", "10$token/2gas", true},
+		{"invalid min gas prices invalid second denom", "10token/2gas;10/3gas", true},
+		{"valid min gas prices", "10foo/3gas;5bar/3gas", false},
+	}
+
+	cfg := DefaultAppConfig()
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.testName, func(t *testing.T) {
+			cfg.MinGasPrices = tc.minGasPrices
+			assert.Equal(t, tc.expectErr, cfg.ValidateBasic() != nil)
+		})
+	}
+}

tm2/pkg/std/gasprice.go

@@ -29,9 +29,11 @@ func ParseGasPrice(gasprice string) (GasPrice, error) {
 	if gas.Denom != "gas" {
 		return GasPrice{}, errors.New("invalid gas price: %s (invalid gas denom)", gasprice)
 	}
-	if gas.Amount == 0 {
-		return GasPrice{}, errors.New("invalid gas price: %s (gas can not be zero)", gasprice)
+
+	if gas.Amount <= 0 {
+		return GasPrice{}, errors.New("invalid gas price: %s (invalid gas amount)", gasprice)
 	}
+
 	return GasPrice{
 		Gas:   gas.Amount,
 		Price: price,