rpc, internal/ethapi: default rpc gascap at 25M + better error message (ethereum#21229)

* rpc, internal/ethapi: default rpc gascap at 50M + better error message

* eth,internal: make globalgascap uint64

* core/tests: fix compilation failure

* eth/config: gascap at 25M + minor review concerns

Author: holiman

cmd/utils/flags.go

@@ -476,7 +476,8 @@ var (
 	}
 	RPCGlobalGasCap = cli.Uint64Flag{
 		Name:  "rpc.gascap",
-		Usage: "Sets a cap on gas that can be used in eth_call/estimateGas",
+		Usage: "Sets a cap on gas that can be used in eth_call/estimateGas (0=infinite)",
+		Value: eth.DefaultConfig.RPCGasCap,
 	}
 	RPCGlobalTxFeeCap = cli.Float64Flag{
 		Name:  "rpc.txfeecap",
@@ -1563,7 +1564,12 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 		cfg.EVMInterpreter = ctx.GlobalString(EVMInterpreterFlag.Name)
 	}
 	if ctx.GlobalIsSet(RPCGlobalGasCap.Name) {
-		cfg.RPCGasCap = new(big.Int).SetUint64(ctx.GlobalUint64(RPCGlobalGasCap.Name))
+		cfg.RPCGasCap = ctx.GlobalUint64(RPCGlobalGasCap.Name)
+	}
+	if cfg.RPCGasCap != 0 {
+		log.Info("Set global gas cap", "cap", cfg.RPCGasCap)
+	} else {
+		log.Info("Global gas cap disabled")
 	}
 	if ctx.GlobalIsSet(RPCGlobalTxFeeCap.Name) {
 		cfg.RPCTxFeeCap = ctx.GlobalFloat64(RPCGlobalTxFeeCap.Name)

core/tx_pool_test.go

@@ -18,6 +18,7 @@ package core
 
 import (
 	"crypto/ecdsa"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"math/big"
@@ -245,7 +246,7 @@ func TestInvalidTransactions(t *testing.T) {
 
 	balance := new(big.Int).Add(tx.Value(), new(big.Int).Mul(new(big.Int).SetUint64(tx.Gas()), tx.GasPrice()))
 	pool.currentState.AddBalance(from, balance)
-	if err := pool.AddRemote(tx); err != ErrIntrinsicGas {
+	if err := pool.AddRemote(tx); !errors.Is(err, ErrIntrinsicGas) {
 		t.Error("expected", ErrIntrinsicGas, "got", err)
 	}
 

eth/api_backend.go

@@ -289,7 +289,7 @@ func (b *EthAPIBackend) ExtRPCEnabled() bool {
 	return b.extRPCEnabled
 }
 
-func (b *EthAPIBackend) RPCGasCap() *big.Int {
+func (b *EthAPIBackend) RPCGasCap() uint64 {
 	return b.eth.config.RPCGasCap
 }
 

eth/config.go

@@ -59,7 +59,8 @@ var DefaultConfig = Config{
 		GasPrice: big.NewInt(params.GWei),
 		Recommit: 3 * time.Second,
 	},
-	TxPool: core.DefaultTxPoolConfig,
+	TxPool:    core.DefaultTxPoolConfig,
+	RPCGasCap: 25000000,
 	GPO: gasprice.Config{
 		Blocks:     20,
 		Percentile: 60,
@@ -158,7 +159,7 @@ type Config struct {
 	EVMInterpreter string
 
 	// RPCGasCap is the global gas cap for eth-call variants.
-	RPCGasCap *big.Int `toml:",omitempty"`
+	RPCGasCap uint64 `toml:",omitempty"`
 
 	// RPCTxFeeCap is the global transaction fee(price * gaslimit) cap for
 	// send-transction variants. The unit is ether.

eth/gen_config.go

@@ -741,7 +741,7 @@ type CallArgs struct {
 }
 
 // ToMessage converts CallArgs to the Message type used by the core evm
-func (args *CallArgs) ToMessage(globalGasCap *big.Int) types.Message {
+func (args *CallArgs) ToMessage(globalGasCap uint64) types.Message {
 	// Set sender address or use zero address if none specified.
 	var addr common.Address
 	if args.From != nil {
@@ -753,9 +753,9 @@ func (args *CallArgs) ToMessage(globalGasCap *big.Int) types.Message {
 	if args.Gas != nil {
 		gas = uint64(*args.Gas)
 	}
-	if globalGasCap != nil && globalGasCap.Uint64() < gas {
+	if globalGasCap != 0 && globalGasCap < gas {
 		log.Warn("Caller gas above allowance, capping", "requested", gas, "cap", globalGasCap)
-		gas = globalGasCap.Uint64()
+		gas = globalGasCap
 	}
 	gasPrice := new(big.Int)
 	if args.GasPrice != nil {
@@ -790,7 +790,7 @@ type account struct {
 	StateDiff *map[common.Hash]common.Hash `json:"stateDiff"`
 }
 
-func DoCall(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides map[common.Address]account, vmCfg vm.Config, timeout time.Duration, globalGasCap *big.Int) (*core.ExecutionResult, error) {
+func DoCall(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides map[common.Address]account, vmCfg vm.Config, timeout time.Duration, globalGasCap uint64) (*core.ExecutionResult, error) {
 	defer func(start time.Time) { log.Debug("Executing EVM call finished", "runtime", time.Since(start)) }(time.Now())
 
 	state, header, err := b.StateAndHeaderByNumberOrHash(ctx, blockNrOrHash)
@@ -861,7 +861,10 @@ func DoCall(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.Blo
 	if evm.Cancelled() {
 		return nil, fmt.Errorf("execution aborted (timeout = %v)", timeout)
 	}
-	return result, err
+	if err != nil {
+		return result, fmt.Errorf("err: %w (supplied gas %d)", err, msg.Gas())
+	}
+	return result, nil
 }
 
 func newRevertError(result *core.ExecutionResult) *revertError {
@@ -916,7 +919,7 @@ func (s *PublicBlockChainAPI) Call(ctx context.Context, args CallArgs, blockNrOr
 	return result.Return(), result.Err
 }
 
-func DoEstimateGas(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, gasCap *big.Int) (hexutil.Uint64, error) {
+func DoEstimateGas(ctx context.Context, b Backend, args CallArgs, blockNrOrHash rpc.BlockNumberOrHash, gasCap uint64) (hexutil.Uint64, error) {
 	// Binary search the gas requirement, as it may be higher than the amount used
 	var (
 		lo  uint64 = params.TxGas - 1
@@ -964,9 +967,9 @@ func DoEstimateGas(ctx context.Context, b Backend, args CallArgs, blockNrOrHash
 		}
 	}
 	// Recap the highest gas allowance with specified gascap.
-	if gasCap != nil && hi > gasCap.Uint64() {
+	if gasCap != 0 && hi > gasCap {
 		log.Warn("Caller gas above allowance, capping", "requested", hi, "cap", gasCap)
-		hi = gasCap.Uint64()
+		hi = gasCap
 	}
 	cap = hi
 
@@ -976,7 +979,7 @@ func DoEstimateGas(ctx context.Context, b Backend, args CallArgs, blockNrOrHash
 
 		result, err := DoCall(ctx, b, args, blockNrOrHash, nil, vm.Config{}, 0, gasCap)
 		if err != nil {
-			if err == core.ErrIntrinsicGas {
+			if errors.Is(err, core.ErrIntrinsicGas) {
 				return true, nil, nil // Special case, raise gas limit
 			}
 			return true, nil, err // Bail out

internal/ethapi/api.go

@@ -45,8 +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
 	RPCTxFeeCap() float64 // global tx fee cap for all transaction related APIs
+	RPCGasCap() uint64    // global gas cap for eth_call over rpc: DoS protection
 
 	// Blockchain API
 	SetHead(number uint64)

internal/ethapi/backend.go

@@ -258,7 +258,7 @@ func (b *LesApiBackend) ExtRPCEnabled() bool {
 	return b.extRPCEnabled
 }
 
-func (b *LesApiBackend) RPCGasCap() *big.Int {
+func (b *LesApiBackend) RPCGasCap() uint64 {
 	return b.eth.config.RPCGasCap
 }