eth_estimateGas: default feeCap to base fee (#10495)

After [EIP-1559](https://eips.ethereum.org/EIPS/eip-1559) gas fee must
be greater or equal to block's base fee – otherwise `eth_estimateGas`
might fail with the fee defaulting to 0 (see
#10373 (comment)).

Also, this PR removes the `blockNrOrHash` argument from
`eth_estimateGas`. geth doesn't have it. Moreover, it was effectively
ignored by the previous code anyway with the exception of determining
gas limit.

Author: yperbasis

turbo/jsonrpc/eth_api.go

@@ -90,7 +90,7 @@ type EthAPI interface {
 
 	// Sending related (see ./eth_call.go)
 	Call(ctx context.Context, args ethapi2.CallArgs, blockNrOrHash rpc.BlockNumberOrHash, overrides *ethapi2.StateOverrides) (hexutility.Bytes, error)
-	EstimateGas(ctx context.Context, argsOrNil *ethapi2.CallArgs, blockNrOrHash *rpc.BlockNumberOrHash) (hexutil.Uint64, error)
+	EstimateGas(ctx context.Context, argsOrNil *ethapi2.CallArgs) (hexutil.Uint64, error)
 	SendRawTransaction(ctx context.Context, encodedTx hexutility.Bytes) (common.Hash, error)
 	SendTransaction(_ context.Context, txObject interface{}) (common.Hash, error)
 	Sign(ctx context.Context, _ common.Address, _ hexutility.Bytes) (hexutility.Bytes, error)

turbo/jsonrpc/eth_call.go

@@ -111,7 +111,7 @@ func headerByNumberOrHash(ctx context.Context, tx kv.Tx, blockNrOrHash rpc.Block
 }
 
 // EstimateGas implements eth_estimateGas. Returns an estimate of how much gas is necessary to allow the transaction to complete. The transaction will not be added to the blockchain.
-func (api *APIImpl) EstimateGas(ctx context.Context, argsOrNil *ethapi2.CallArgs, blockNrOrHash *rpc.BlockNumberOrHash) (hexutil.Uint64, error) {
+func (api *APIImpl) EstimateGas(ctx context.Context, argsOrNil *ethapi2.CallArgs) (hexutil.Uint64, error) {
 	var args ethapi2.CallArgs
 	// if we actually get CallArgs here, we use them
 	if argsOrNil != nil {
@@ -135,36 +135,39 @@ func (api *APIImpl) EstimateGas(ctx context.Context, argsOrNil *ethapi2.CallArgs
 		args.From = new(libcommon.Address)
 	}
 
-	bNrOrHash := rpc.BlockNumberOrHashWithNumber(rpc.PendingBlockNumber)
-	if blockNrOrHash != nil {
-		bNrOrHash = *blockNrOrHash
+	chainConfig, err := api.chainConfig(ctx, dbtx)
+	if err != nil {
+		return 0, err
 	}
 
-	// Determine the highest gas limit can be used during the estimation.
-	if args.Gas != nil && uint64(*args.Gas) >= params.TxGas {
-		hi = uint64(*args.Gas)
-	} else {
-		// Retrieve the block to act as the gas ceiling
-		h, err := headerByNumberOrHash(ctx, dbtx, bNrOrHash, api)
+	latestCanBlockNumber, latestCanHash, isLatest, err := rpchelper.GetCanonicalBlockNumber(latestNumOrHash, dbtx, api.filters) // DoCall cannot be executed on non-canonical blocks
+	if err != nil {
+		return 0, err
+	}
+
+	// try and get the block from the lru cache first then try DB before failing
+	block := api.tryBlockFromLru(latestCanHash)
+	if block == nil {
+		block, err = api.blockWithSenders(ctx, dbtx, latestCanHash, latestCanBlockNumber)
 		if err != nil {
 			return 0, err
 		}
-		if h == nil {
-			// if a block number was supplied and there is no header return 0
-			if blockNrOrHash != nil {
-				return 0, nil
-			}
+	}
+	if block == nil {
+		return 0, fmt.Errorf("could not find latest block in cache or db")
+	}
 
-			// block number not supplied, so we haven't found a pending block, read the latest block instead
-			h, err = headerByNumberOrHash(ctx, dbtx, latestNumOrHash, api)
-			if err != nil {
-				return 0, err
-			}
-			if h == nil {
-				return 0, nil
-			}
-		}
-		hi = h.GasLimit
+	stateReader, err := rpchelper.CreateStateReaderFromBlockNumber(ctx, dbtx, latestCanBlockNumber, isLatest, 0, api.stateCache, chainConfig.ChainName)
+	if err != nil {
+		return 0, err
+	}
+	header := block.HeaderNoCopy()
+
+	// Determine the highest gas limit can be used during the estimation.
+	if args.Gas != nil && uint64(*args.Gas) >= params.TxGas {
+		hi = uint64(*args.Gas)
+	} else {
+		hi = header.GasLimit
 	}
 
 	var feeCap *big.Int
@@ -174,6 +177,8 @@ func (api *APIImpl) EstimateGas(ctx context.Context, argsOrNil *ethapi2.CallArgs
 		feeCap = args.GasPrice.ToInt()
 	} else if args.MaxFeePerGas != nil {
 		feeCap = args.MaxFeePerGas.ToInt()
+	} else if header.BaseFee != nil {
+		feeCap = new(big.Int).Set(header.BaseFee)
 	} else {
 		feeCap = libcommon.Big0
 	}
@@ -218,35 +223,8 @@ func (api *APIImpl) EstimateGas(ctx context.Context, argsOrNil *ethapi2.CallArgs
 	}
 	gasCap = hi
 
-	chainConfig, err := api.chainConfig(ctx, dbtx)
-	if err != nil {
-		return 0, err
-	}
 	engine := api.engine()
 
-	latestCanBlockNumber, latestCanHash, isLatest, err := rpchelper.GetCanonicalBlockNumber(latestNumOrHash, dbtx, api.filters) // DoCall cannot be executed on non-canonical blocks
-	if err != nil {
-		return 0, err
-	}
-
-	// try and get the block from the lru cache first then try DB before failing
-	block := api.tryBlockFromLru(latestCanHash)
-	if block == nil {
-		block, err = api.blockWithSenders(ctx, dbtx, latestCanHash, latestCanBlockNumber)
-		if err != nil {
-			return 0, err
-		}
-	}
-	if block == nil {
-		return 0, fmt.Errorf("could not find latest block in cache or db")
-	}
-
-	stateReader, err := rpchelper.CreateStateReaderFromBlockNumber(ctx, dbtx, latestCanBlockNumber, isLatest, 0, api.stateCache, chainConfig.ChainName)
-	if err != nil {
-		return 0, err
-	}
-	header := block.HeaderNoCopy()
-
 	caller, err := transactions.NewReusableCaller(engine, stateReader, nil, header, args, api.GasCap, latestNumOrHash, dbtx, api._blockReader, chainConfig, api.evmCallTimeout)
 	if err != nil {
 		return 0, err

turbo/jsonrpc/eth_call_test.go

@@ -49,7 +49,7 @@ func TestEstimateGas(t *testing.T) {
 	if _, err := api.EstimateGas(context.Background(), &ethapi.CallArgs{
 		From: &from,
 		To:   &to,
-	}, nil); err != nil {
+	}); err != nil {
 		t.Errorf("calling EstimateGas: %v", err)
 	}
 }