cmd, eth, internal, les: add gasprice cap

cmd/geth/main.go

@@ -186,6 +186,7 @@ var (
 		utils.IPCPathFlag,
 		utils.InsecureUnlockAllowedFlag,
 		utils.RPCGlobalGasCap,
+		utils.RPCGlobalGasPriceCap,
 	}
 
 	whisperFlags = []cli.Flag{

cmd/geth/usage.go

@@ -176,6 +176,7 @@ var AppHelpFlagGroups = []flagGroup{
 			utils.GraphQLCORSDomainFlag,
 			utils.GraphQLVirtualHostsFlag,
 			utils.RPCGlobalGasCap,
+			utils.RPCGlobalGasPriceCap,
 			utils.JSpathFlag,
 			utils.ExecFlag,
 			utils.PreloadJSFlag,

cmd/utils/flags.go

@@ -478,6 +478,10 @@ var (
 		Name:  "rpc.gascap",
 		Usage: "Sets a cap on gas that can be used in eth_call/estimateGas",
 	}
+	RPCGlobalGasPriceCap = cli.Uint64Flag{
+		Name:  "rpc.gaspricecap",
+		Usage: "Sets a cap on gasprice that can be used in sendTransaction/sendRawTransaction",
+	}
 	// Logging and debug settings
 	EthStatsURLFlag = cli.StringFlag{
 		Name:  "ethstats",
@@ -1560,6 +1564,9 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 	if ctx.GlobalIsSet(RPCGlobalGasCap.Name) {
 		cfg.RPCGasCap = new(big.Int).SetUint64(ctx.GlobalUint64(RPCGlobalGasCap.Name))
 	}
+	if ctx.GlobalIsSet(RPCGlobalGasPriceCap.Name) {
+		cfg.RPCGasPriceCap = new(big.Int).SetUint64(ctx.GlobalUint64(RPCGlobalGasPriceCap.Name))
+	}
 	if ctx.GlobalIsSet(DNSDiscoveryFlag.Name) {
 		urls := ctx.GlobalString(DNSDiscoveryFlag.Name)
 		if urls == "" {

eth/api_backend.go

@@ -293,6 +293,10 @@ func (b *EthAPIBackend) RPCGasCap() *big.Int {
 	return b.eth.config.RPCGasCap
 }
 
+func (b *EthAPIBackend) RPCGasPriceCap() *big.Int {
+	return b.eth.config.RPCGasPriceCap
+}
+
 func (b *EthAPIBackend) BloomStatus() (uint64, uint64) {
 	sections, _, _ := b.eth.bloomIndexer.Sections()
 	return params.BloomBitsBlocks, sections

eth/config.go

@@ -159,6 +159,9 @@ type Config struct {
 	// RPCGasCap is the global gas cap for eth-call variants.
 	RPCGasCap *big.Int `toml:",omitempty"`
 
+	// RPCGasPriceCap is the global gasprice cap for send-transction variants.
+	RPCGasPriceCap *big.Int `toml:",omitempty"`
+
 	// Checkpoint is a hardcoded checkpoint which can be nil.
 	Checkpoint *params.TrustedCheckpoint `toml:",omitempty"`
 

internal/ethapi/api.go

@@ -1520,6 +1520,11 @@ func (args *SendTxArgs) toTransaction() *types.Transaction {
 
 // SubmitTransaction is a helper function that submits tx to txPool and logs a message.
 func SubmitTransaction(ctx context.Context, b Backend, tx *types.Transaction) (common.Hash, error) {
+	// If the gasprice cap is already specified, ensure the
+	// gasprice of given transaction is _reasonable_.
+	if b.RPCGasPriceCap() != nil && tx.GasPrice().Cmp(b.RPCGasPriceCap()) > 0 {
+		return common.Hash{}, fmt.Errorf("gasprice(%s) exceeds the maximum setting(%s)", hexutil.EncodeBig(tx.GasPrice()), hexutil.EncodeBig(b.RPCGasPriceCap()))
+	}
 	if err := b.SendTx(ctx, tx); err != nil {
 		return common.Hash{}, err
 	}

internal/ethapi/backend.go

@@ -45,7 +45,8 @@ type Backend interface {
 	ChainDb() ethdb.Database
 	AccountManager() *accounts.Manager
 	ExtRPCEnabled() bool
-	RPCGasCap() *big.Int // global gas cap for eth_call over rpc: DoS protection
+	RPCGasCap() *big.Int      // global gas cap for eth_call over rpc: DoS protection
+	RPCGasPriceCap() *big.Int // global gas price cap for all transaction related APIs
 
 	// Blockchain API
 	SetHead(number uint64)

les/api_backend.go

@@ -262,6 +262,10 @@ func (b *LesApiBackend) RPCGasCap() *big.Int {
 	return b.eth.config.RPCGasCap
 }
 
+func (b *LesApiBackend) RPCGasPriceCap() *big.Int {
+	return b.eth.config.RPCGasPriceCap
+}
+
 func (b *LesApiBackend) BloomStatus() (uint64, uint64) {
 	if b.eth.bloomIndexer == nil {
 		return 0, 0