core/vm: set basefee to 0 internally on eth_call (#28470)

* core/vm: set basefee to 0 internally on eth_call

* core: nicer 0-basefee, make it work for blob fees too

* internal/ethapi: make tests a bit more complex

* core: fix blob fee checker

* core: make code a bit more readable

* core: fix some test error strings

* core/vm: Get rid of weird comment

* core: dict wrong typo

Author: karalabe

core/evm.go

@@ -77,11 +77,15 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 
 // NewEVMTxContext creates a new transaction context for a single transaction.
 func NewEVMTxContext(msg *Message) vm.TxContext {
-	return vm.TxContext{
+	ctx := vm.TxContext{
 		Origin:     msg.From,
 		GasPrice:   new(big.Int).Set(msg.GasPrice),
 		BlobHashes: msg.BlobHashes,
 	}
+	if msg.BlobGasFeeCap != nil {
+		ctx.BlobFeeCap = new(big.Int).Set(msg.BlobGasFeeCap)
+	}
+	return ctx
 }
 
 // GetHashFn returns a GetHashFunc which retrieves header hashes by number

core/state_processor_test.go

@@ -95,14 +95,15 @@ func TestStateProcessorErrors(t *testing.T) {
 		}), signer, key1)
 		return tx
 	}
-	var mkBlobTx = func(nonce uint64, to common.Address, gasLimit uint64, gasTipCap, gasFeeCap *big.Int, hashes []common.Hash) *types.Transaction {
+	var mkBlobTx = func(nonce uint64, to common.Address, gasLimit uint64, gasTipCap, gasFeeCap, blobGasFeeCap *big.Int, hashes []common.Hash) *types.Transaction {
 		tx, err := types.SignTx(types.NewTx(&types.BlobTx{
 			Nonce:      nonce,
 			GasTipCap:  uint256.MustFromBig(gasTipCap),
 			GasFeeCap:  uint256.MustFromBig(gasFeeCap),
 			Gas:        gasLimit,
 			To:         to,
 			BlobHashes: hashes,
+			BlobFeeCap: uint256.MustFromBig(blobGasFeeCap),
 			Value:      new(uint256.Int),
 		}), signer, key1)
 		if err != nil {
@@ -196,7 +197,7 @@ func TestStateProcessorErrors(t *testing.T) {
 				txs: []*types.Transaction{
 					mkDynamicTx(0, common.Address{}, params.TxGas, big.NewInt(0), big.NewInt(0)),
 				},
-				want: "could not apply tx 0 [0xc4ab868fef0c82ae0387b742aee87907f2d0fc528fc6ea0a021459fb0fc4a4a8]: max fee per gas less than block base fee: address 0x71562b71999873DB5b286dF957af199Ec94617F7, maxFeePerGas: 0 baseFee: 875000000",
+				want: "could not apply tx 0 [0xc4ab868fef0c82ae0387b742aee87907f2d0fc528fc6ea0a021459fb0fc4a4a8]: max fee per gas less than block base fee: address 0x71562b71999873DB5b286dF957af199Ec94617F7, maxFeePerGas: 0, baseFee: 875000000",
 			},
 			{ // ErrTipVeryHigh
 				txs: []*types.Transaction{
@@ -247,9 +248,9 @@ func TestStateProcessorErrors(t *testing.T) {
 			},
 			{ // ErrBlobFeeCapTooLow
 				txs: []*types.Transaction{
-					mkBlobTx(0, common.Address{}, params.TxGas, big.NewInt(1), big.NewInt(1), []common.Hash{(common.Hash{1})}),
+					mkBlobTx(0, common.Address{}, params.TxGas, big.NewInt(1), big.NewInt(1), big.NewInt(0), []common.Hash{(common.Hash{1})}),
 				},
-				want: "could not apply tx 0 [0x6c11015985ce82db691d7b2d017acda296db88b811c3c60dc71449c76256c716]: max fee per gas less than block base fee: address 0x71562b71999873DB5b286dF957af199Ec94617F7, maxFeePerGas: 1 baseFee: 875000000",
+				want: "could not apply tx 0 [0x6c11015985ce82db691d7b2d017acda296db88b811c3c60dc71449c76256c716]: max fee per gas less than block base fee: address 0x71562b71999873DB5b286dF957af199Ec94617F7, maxFeePerGas: 1, baseFee: 875000000",
 			},
 		} {
 			block := GenerateBadBlock(gspec.ToBlock(), beacon.New(ethash.NewFaker()), tt.txs, gspec.Config)

core/state_transition.go

@@ -287,11 +287,11 @@ func (st *StateTransition) preCheck() error {
 				msg.From.Hex(), codeHash)
 		}
 	}
-
 	// Make sure that transaction gasFeeCap is greater than the baseFee (post london)
 	if st.evm.ChainConfig().IsLondon(st.evm.Context.BlockNumber) {
 		// Skip the checks if gas fields are zero and baseFee was explicitly disabled (eth_call)
-		if !st.evm.Config.NoBaseFee || msg.GasFeeCap.BitLen() > 0 || msg.GasTipCap.BitLen() > 0 {
+		skipCheck := st.evm.Config.NoBaseFee && msg.GasFeeCap.BitLen() == 0 && msg.GasTipCap.BitLen() == 0
+		if !skipCheck {
 			if l := msg.GasFeeCap.BitLen(); l > 256 {
 				return fmt.Errorf("%w: address %v, maxFeePerGas bit length: %d", ErrFeeCapVeryHigh,
 					msg.From.Hex(), l)
@@ -307,7 +307,7 @@ func (st *StateTransition) preCheck() error {
 			// This will panic if baseFee is nil, but basefee presence is verified
 			// as part of header validation.
 			if msg.GasFeeCap.Cmp(st.evm.Context.BaseFee) < 0 {
-				return fmt.Errorf("%w: address %v, maxFeePerGas: %s baseFee: %s", ErrFeeCapTooLow,
+				return fmt.Errorf("%w: address %v, maxFeePerGas: %s, baseFee: %s", ErrFeeCapTooLow,
 					msg.From.Hex(), msg.GasFeeCap, st.evm.Context.BaseFee)
 			}
 		}
@@ -324,17 +324,21 @@ func (st *StateTransition) preCheck() error {
 			}
 		}
 	}
-
+	// Check that the user is paying at least the current blob fee
 	if st.evm.ChainConfig().IsCancun(st.evm.Context.BlockNumber, st.evm.Context.Time) {
 		if st.blobGasUsed() > 0 {
-			// Check that the user is paying at least the current blob fee
-			blobFee := st.evm.Context.BlobBaseFee
-			if st.msg.BlobGasFeeCap.Cmp(blobFee) < 0 {
-				return fmt.Errorf("%w: address %v have %v want %v", ErrBlobFeeCapTooLow, st.msg.From.Hex(), st.msg.BlobGasFeeCap, blobFee)
+			// Skip the checks if gas fields are zero and blobBaseFee was explicitly disabled (eth_call)
+			skipCheck := st.evm.Config.NoBaseFee && msg.BlobGasFeeCap.BitLen() == 0
+			if !skipCheck {
+				// This will panic if blobBaseFee is nil, but blobBaseFee presence
+				// is verified as part of header validation.
+				if msg.BlobGasFeeCap.Cmp(st.evm.Context.BlobBaseFee) < 0 {
+					return fmt.Errorf("%w: address %v blobGasFeeCap: %v, blobBaseFee: %v", ErrBlobFeeCapTooLow,
+						msg.From.Hex(), msg.BlobGasFeeCap, st.evm.Context.BlobBaseFee)
+				}
 			}
 		}
 	}
-
 	return st.buyGas()
 }
 

core/vm/evm.go

@@ -72,8 +72,8 @@ type BlockContext struct {
 	BlockNumber *big.Int       // Provides information for NUMBER
 	Time        uint64         // Provides information for TIME
 	Difficulty  *big.Int       // Provides information for DIFFICULTY
-	BaseFee     *big.Int       // Provides information for BASEFEE
-	BlobBaseFee *big.Int       // Provides information for BLOBBASEFEE
+	BaseFee     *big.Int       // Provides information for BASEFEE (0 if vm runs with NoBaseFee flag and 0 gas price)
+	BlobBaseFee *big.Int       // Provides information for BLOBBASEFEE (0 if vm runs with NoBaseFee flag and 0 blob gas price)
 	Random      *common.Hash   // Provides information for PREVRANDAO
 }
 
@@ -82,8 +82,9 @@ type BlockContext struct {
 type TxContext struct {
 	// Message information
 	Origin     common.Address // Provides information for ORIGIN
-	GasPrice   *big.Int       // Provides information for GASPRICE
+	GasPrice   *big.Int       // Provides information for GASPRICE (and is used to zero the basefee if NoBaseFee is set)
 	BlobHashes []common.Hash  // Provides information for BLOBHASH
+	BlobFeeCap *big.Int       // Is used to zero the blobbasefee if NoBaseFee is set
 }
 
 // EVM is the Ethereum Virtual Machine base object and provides
@@ -125,6 +126,17 @@ type EVM struct {
 // NewEVM returns a new EVM. The returned EVM is not thread safe and should
 // only ever be used *once*.
 func NewEVM(blockCtx BlockContext, txCtx TxContext, statedb StateDB, chainConfig *params.ChainConfig, config Config) *EVM {
+	// If basefee tracking is disabled (eth_call, eth_estimateGas, etc), and no
+	// gas prices were specified, lower the basefee to 0 to avoid breaking EVM
+	// invariants (basefee < feecap)
+	if config.NoBaseFee {
+		if txCtx.GasPrice.BitLen() == 0 {
+			blockCtx.BaseFee = new(big.Int)
+		}
+		if txCtx.BlobFeeCap != nil && txCtx.BlobFeeCap.BitLen() == 0 {
+			blockCtx.BlobBaseFee = new(big.Int)
+		}
+	}
 	evm := &EVM{
 		Context:     blockCtx,
 		TxContext:   txCtx,
@@ -160,14 +172,6 @@ func (evm *EVM) Interpreter() *EVMInterpreter {
 	return evm.interpreter
 }
 
-// SetBlockContext updates the block context of the EVM.
-func (evm *EVM) SetBlockContext(blockCtx BlockContext) {
-	evm.Context = blockCtx
-	num := blockCtx.BlockNumber
-	timestamp := blockCtx.Time
-	evm.chainRules = evm.chainConfig.Rules(num, blockCtx.Random != nil, timestamp)
-}
-
 // Call executes the contract associated with the addr with the given input as
 // parameters. It also handles any necessary value transfer required and takes
 // the necessary steps to create accounts and reverses the state in case of an

core/vm/runtime/env.go

@@ -26,6 +26,7 @@ func NewEnv(cfg *Config) *vm.EVM {
 		Origin:     cfg.Origin,
 		GasPrice:   cfg.GasPrice,
 		BlobHashes: cfg.BlobHashes,
+		BlobFeeCap: cfg.BlobFeeCap,
 	}
 	blockContext := vm.BlockContext{
 		CanTransfer: core.CanTransfer,

core/vm/runtime/runtime.go

@@ -46,6 +46,7 @@ type Config struct {
 	BaseFee     *big.Int
 	BlobBaseFee *big.Int
 	BlobHashes  []common.Hash
+	BlobFeeCap  *big.Int
 	Random      *common.Hash
 
 	State     *state.StateDB
@@ -97,7 +98,7 @@ func setDefaults(cfg *Config) {
 		cfg.BaseFee = big.NewInt(params.InitialBaseFee)
 	}
 	if cfg.BlobBaseFee == nil {
-		cfg.BlobBaseFee = new(big.Int)
+		cfg.BlobBaseFee = big.NewInt(params.BlobTxMinBlobGasprice)
 	}
 }
 

internal/ethapi/api_test.go

@@ -678,6 +678,47 @@ func TestEstimateGas(t *testing.T) {
 			},
 			expectErr: core.ErrInsufficientFunds,
 		},
+		// Test for a bug where the gas price was set to zero but the basefee non-zero
+		//
+		// contract BasefeeChecker {
+		//    constructor() {
+		//        require(tx.gasprice >= block.basefee);
+		//        if (tx.gasprice > 0) {
+		//            require(block.basefee > 0);
+		//        }
+		//    }
+		//}
+		{
+			blockNumber: rpc.LatestBlockNumber,
+			call: TransactionArgs{
+				From:     &accounts[0].addr,
+				Input:    hex2Bytes("6080604052348015600f57600080fd5b50483a1015601c57600080fd5b60003a111560315760004811603057600080fd5b5b603f80603e6000396000f3fe6080604052600080fdfea264697066735822122060729c2cee02b10748fae5200f1c9da4661963354973d9154c13a8e9ce9dee1564736f6c63430008130033"),
+				GasPrice: (*hexutil.Big)(big.NewInt(1_000_000_000)), // Legacy as pricing
+			},
+			expectErr: nil,
+			want:      67617,
+		},
+		{
+			blockNumber: rpc.LatestBlockNumber,
+			call: TransactionArgs{
+				From:         &accounts[0].addr,
+				Input:        hex2Bytes("6080604052348015600f57600080fd5b50483a1015601c57600080fd5b60003a111560315760004811603057600080fd5b5b603f80603e6000396000f3fe6080604052600080fdfea264697066735822122060729c2cee02b10748fae5200f1c9da4661963354973d9154c13a8e9ce9dee1564736f6c63430008130033"),
+				MaxFeePerGas: (*hexutil.Big)(big.NewInt(1_000_000_000)), // 1559 gas pricing
+			},
+			expectErr: nil,
+			want:      67617,
+		},
+		{
+			blockNumber: rpc.LatestBlockNumber,
+			call: TransactionArgs{
+				From:         &accounts[0].addr,
+				Input:        hex2Bytes("6080604052348015600f57600080fd5b50483a1015601c57600080fd5b60003a111560315760004811603057600080fd5b5b603f80603e6000396000f3fe6080604052600080fdfea264697066735822122060729c2cee02b10748fae5200f1c9da4661963354973d9154c13a8e9ce9dee1564736f6c63430008130033"),
+				GasPrice:     nil, // No legacy gas pricing
+				MaxFeePerGas: nil, // No 1559 gas pricing
+			},
+			expectErr: nil,
+			want:      67595,
+		},
 	}
 	for i, tc := range testSuite {
 		result, err := api.EstimateGas(context.Background(), tc.call, &rpc.BlockNumberOrHash{BlockNumber: &tc.blockNumber}, &tc.overrides)