draft: ban-deposits-interop first RFC draft

op-node/rollup/derive/attributes.go

@@ -121,9 +121,19 @@ func (ba *FetchingAttributesBuilder) PreparePayloadAttributes(ctx context.Contex
 		return nil, NewCriticalError(fmt.Errorf("failed to create l1InfoTx: %w", err))
 	}
 
-	txs := make([]hexutil.Bytes, 0, 1+len(depositTxs)+len(upgradeTxs))
+	var postDeposits []hexutil.Bytes
+	if ba.rollupCfg.IsInterop(nextL2Time) {
+		depositsCompleteTx, err := DepositsCompleteBytes(seqNumber, l1Info)
+		if err != nil {
+			return nil, NewCriticalError(fmt.Errorf("failed to create depositsCompleteTx: %w", err))
+		}
+		postDeposits = append(postDeposits, depositsCompleteTx)
+	}
+
+	txs := make([]hexutil.Bytes, 0, 1+len(depositTxs)+len(postDeposits)+len(upgradeTxs))
 	txs = append(txs, l1InfoTx)
 	txs = append(txs, depositTxs...)
+	txs = append(txs, postDeposits...)
 	txs = append(txs, upgradeTxs...)
 
 	var withdrawals *types.Withdrawals

op-node/rollup/derive/l1_block_info.go

@@ -20,14 +20,19 @@ import (
 const (
 	L1InfoFuncBedrockSignature = "setL1BlockValues(uint64,uint64,uint256,bytes32,uint64,bytes32,uint256,uint256)"
 	L1InfoFuncEcotoneSignature = "setL1BlockValuesEcotone()"
+	L1InfoFuncIsthmusSignature = "setL2BlockValuesIsthmus()"
+	DepositsCompleteSignature  = "depositsComplete()"
 	L1InfoArguments            = 8
 	L1InfoBedrockLen           = 4 + 32*L1InfoArguments
 	L1InfoEcotoneLen           = 4 + 32*5 // after Ecotone upgrade, args are packed into 5 32-byte slots
+	DepositsCompleteLen        = 4        // only the selector
 )
 
 var (
 	L1InfoFuncBedrockBytes4 = crypto.Keccak256([]byte(L1InfoFuncBedrockSignature))[:4]
 	L1InfoFuncEcotoneBytes4 = crypto.Keccak256([]byte(L1InfoFuncEcotoneSignature))[:4]
+	L1InfoFuncIsthmusBytes4 = crypto.Keccak256([]byte(L1InfoFuncIsthmusSignature))[:4]
+	DepositsCompleteBytes4  = crypto.Keccak256([]byte(DepositsCompleteSignature))[:4]
 	L1InfoDepositerAddress  = common.HexToAddress("0xdeaddeaddeaddeaddeaddeaddeaddeaddead0001")
 	L1BlockAddress          = predeploys.L1BlockAddr
 	ErrInvalidFormat        = errors.New("invalid ecotone l1 block info format")
@@ -144,7 +149,7 @@ func (info *L1BlockInfo) unmarshalBinaryBedrock(data []byte) error {
 	return nil
 }
 
-// Ecotone Binary Format
+// Isthmus & Ecotone Binary Format
 // +---------+--------------------------+
 // | Bytes   | Field                    |
 // +---------+--------------------------+
@@ -160,10 +165,32 @@ func (info *L1BlockInfo) unmarshalBinaryBedrock(data []byte) error {
 // | 32      | BatcherHash              |
 // +---------+--------------------------+
 
+func (info *L1BlockInfo) marshalBinaryIsthmus() ([]byte, error) {
+	out, err := marshalBinaryEcotoneOrIsthmus(info, true)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal Isthmus l1 block info: %w", err)
+	}
+	return out, nil
+}
+
 func (info *L1BlockInfo) marshalBinaryEcotone() ([]byte, error) {
-	w := bytes.NewBuffer(make([]byte, 0, L1InfoEcotoneLen))
-	if err := solabi.WriteSignature(w, L1InfoFuncEcotoneBytes4); err != nil {
-		return nil, err
+	out, err := marshalBinaryEcotoneOrIsthmus(info, true)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal Ecotone l1 block info: %w", err)
+	}
+	return out, nil
+}
+
+func marshalBinaryEcotoneOrIsthmus(info *L1BlockInfo, isIsthmus ...bool) ([]byte, error) {
+	w := bytes.NewBuffer(make([]byte, 0, L1InfoEcotoneLen)) // Ecotone and Isthmus have the same length
+	if isIsthmus != nil && isIsthmus[0] {
+		if err := solabi.WriteSignature(w, L1InfoFuncIsthmusBytes4); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := solabi.WriteSignature(w, L1InfoFuncEcotoneBytes4); err != nil {
+			return nil, err
+		}
 	}
 	if err := binary.Write(w, binary.BigEndian, info.BaseFeeScalar); err != nil {
 		return nil, err
@@ -200,14 +227,21 @@ func (info *L1BlockInfo) marshalBinaryEcotone() ([]byte, error) {
 	return w.Bytes(), nil
 }
 
+func (info *L1BlockInfo) unmarshalBinaryIsthmus(data []byte) error {
+	return unmarshalBinaryWithSignatureAndData(info, L1InfoFuncIsthmusBytes4, data)
+}
 func (info *L1BlockInfo) unmarshalBinaryEcotone(data []byte) error {
+	return unmarshalBinaryWithSignatureAndData(info, L1InfoFuncEcotoneBytes4, data)
+}
+
+func unmarshalBinaryWithSignatureAndData(info *L1BlockInfo, signature []byte, data []byte) error {
 	if len(data) != L1InfoEcotoneLen {
 		return fmt.Errorf("data is unexpected length: %d", len(data))
 	}
 	r := bytes.NewReader(data)
 
 	var err error
-	if _, err := solabi.ReadAndValidateSignature(r, L1InfoFuncEcotoneBytes4); err != nil {
+	if _, err := solabi.ReadAndValidateSignature(r, signature); err != nil {
 		return err
 	}
 	if err := binary.Read(r, binary.BigEndian, &info.BaseFeeScalar); err != nil {
@@ -250,9 +284,19 @@ func isEcotoneButNotFirstBlock(rollupCfg *rollup.Config, l2BlockTime uint64) boo
 	return rollupCfg.IsEcotone(l2BlockTime) && !rollupCfg.IsEcotoneActivationBlock(l2BlockTime)
 }
 
+// isInteropButNotFirstBlock returns whether the specified block is subject to the Isthmus upgrade,
+// but is not the actiation block itself.
+func isInteropButNotFirstBlock(rollupCfg *rollup.Config, l2BlockTime uint64) bool {
+	return rollupCfg.IsInterop(l2BlockTime) && !rollupCfg.IsInteropActivationBlock(l2BlockTime)
+}
+
 // L1BlockInfoFromBytes is the inverse of L1InfoDeposit, to see where the L2 chain is derived from
 func L1BlockInfoFromBytes(rollupCfg *rollup.Config, l2BlockTime uint64, data []byte) (*L1BlockInfo, error) {
 	var info L1BlockInfo
+	// Important, this should be ordered from most recent to oldest
+	if isInteropButNotFirstBlock(rollupCfg, l2BlockTime) {
+		return &info, info.unmarshalBinaryIsthmus(data)
+	}
 	if isEcotoneButNotFirstBlock(rollupCfg, l2BlockTime) {
 		return &info, info.unmarshalBinaryEcotone(data)
 	}
@@ -271,7 +315,8 @@ func L1InfoDeposit(rollupCfg *rollup.Config, sysCfg eth.SystemConfig, seqNumber
 		BatcherAddr:    sysCfg.BatcherAddr,
 	}
 	var data []byte
-	if isEcotoneButNotFirstBlock(rollupCfg, l2BlockTime) {
+
+	if isInteropButNotFirstBlock(rollupCfg, l2BlockTime) {
 		l1BlockInfo.BlobBaseFee = block.BlobBaseFee()
 		if l1BlockInfo.BlobBaseFee == nil {
 			// The L2 spec states to use the MIN_BLOB_GASPRICE from EIP-4844 if not yet active on L1.
@@ -283,11 +328,19 @@ func L1InfoDeposit(rollupCfg *rollup.Config, sysCfg eth.SystemConfig, seqNumber
 		}
 		l1BlockInfo.BlobBaseFeeScalar = scalars.BlobBaseFeeScalar
 		l1BlockInfo.BaseFeeScalar = scalars.BaseFeeScalar
-		out, err := l1BlockInfo.marshalBinaryEcotone()
-		if err != nil {
-			return nil, fmt.Errorf("failed to marshal Ecotone l1 block info: %w", err)
+		if isEcotoneButNotFirstBlock(rollupCfg, l2BlockTime) {
+			out, err := l1BlockInfo.marshalBinaryEcotone()
+			if err != nil {
+				return nil, fmt.Errorf("failed to marshal Ecotone l1 block info: %w", err)
+			}
+			data = out
+		} else {
+			out, err := l1BlockInfo.marshalBinaryIsthmus()
+			if err != nil {
+				return nil, fmt.Errorf("failed to marshal Isthmus l1 block info: %w", err)
+			}
+			data = out
 		}
-		data = out
 	} else {
 		l1BlockInfo.L1FeeOverhead = sysCfg.Overhead
 		l1BlockInfo.L1FeeScalar = sysCfg.Scalar
@@ -335,3 +388,34 @@ func L1InfoDepositBytes(rollupCfg *rollup.Config, sysCfg eth.SystemConfig, seqNu
 	}
 	return opaqueL1Tx, nil
 }
+
+func DepositsCompleteDeposit(seqNumber uint64, block eth.BlockInfo) (*types.DepositTx, error) {
+	source := L1InfoDepositSource{
+		L1BlockHash: block.Hash(),
+		SeqNumber:   seqNumber,
+	}
+	out := &types.DepositTx{
+		SourceHash:          source.SourceHash(),
+		From:                L1InfoDepositerAddress,
+		To:                  &L1BlockAddress,
+		Mint:                nil,
+		Value:               big.NewInt(0),
+		Gas:                 50_000,
+		IsSystemTransaction: false,
+		Data:                DepositsCompleteBytes4,
+	}
+	return out, nil
+}
+
+func DepositsCompleteBytes(seqNumber uint64, l1Info eth.BlockInfo) ([]byte, error) {
+	dep, err := DepositsCompleteDeposit(seqNumber, l1Info)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create DepositsComplete tx: %w", err)
+	}
+	depositsCompleteTx := types.NewTx(dep)
+	opaqueDepositsCompleteTx, err := depositsCompleteTx.MarshalBinary()
+	if err != nil {
+		return nil, fmt.Errorf("failed to encode DepositsComplete tx: %w", err)
+	}
+	return opaqueDepositsCompleteTx, nil
+}

op-node/rollup/types.go

@@ -499,6 +499,7 @@ func (c *Config) IsHoloceneActivationBlock(l2BlockTime uint64) bool {
 		!c.IsHolocene(l2BlockTime-c.BlockTime)
 }
 
+// TODO rename to IsIsthmusActivationBlock (this will require quite a bit of renaming)
 func (c *Config) IsInteropActivationBlock(l2BlockTime uint64) bool {
 	return c.IsInterop(l2BlockTime) &&
 		l2BlockTime >= c.BlockTime &&

packages/contracts-bedrock/src/L2/CrossL2Inbox.sol

@@ -17,6 +17,14 @@ interface IDependencySet {
     function isInDependencySet(uint256 _chainId) external view returns (bool);
 }
 
+/// @title IL1Block
+/// @notice Interface for L1Block with only `isDeposit()` method.
+interface IL1Block {
+    /// @notice Returns whether the call was triggered from a a deposit or not.
+    /// @return True if the current call was triggered by a deposit transaction, and false otherwise.
+    function isDeposit() external view returns (bool);
+}
+
 /// @notice Thrown when a non-written transient storage slot is attempted to be read from.
 error NotEntered();
 
@@ -29,6 +37,9 @@ error InvalidChainId();
 /// @notice Thrown when trying to execute a cross chain message and the target call fails.
 error TargetCallFailed();
 
+/// @notice Thrown when trying to execute a cross chain message on a deposit transaction.
+error NoExecutingDeposits();
+
 /// @custom:proxied
 /// @custom:predeploy 0x4200000000000000000000000000000000000022
 /// @title CrossL2Inbox
@@ -56,8 +67,8 @@ contract CrossL2Inbox is ICrossL2Inbox, ISemver, TransientReentrancyAware {
     bytes32 internal constant CHAINID_SLOT = 0x6e0446e8b5098b8c8193f964f1b567ec3a2bdaeba33d36acb85c1f1d3f92d313;
 
     /// @notice Semantic version.
-    /// @custom:semver 1.0.0-beta.4
-    string public constant version = "1.0.0-beta.4";
+    /// @custom:semver 1.1.0-beta.4
+    string public constant version = "1.1.0-beta.4";
 
     /// @notice Emitted when a cross chain message is being executed.
     /// @param msgHash Hash of message payload being executed.
@@ -107,6 +118,9 @@ contract CrossL2Inbox is ICrossL2Inbox, ISemver, TransientReentrancyAware {
         payable
         reentrantAware
     {
+        // We need to know if this is being called on a depositTx
+        if (IL1Block(Predeploys.L1_BLOCK_ATTRIBUTES).isDeposit()) revert NoExecutingDeposits();
+
         // Check the Identifier.
         _checkIdentifier(_id);
 

packages/contracts-bedrock/src/L2/L1Block.sol

@@ -4,6 +4,7 @@ pragma solidity 0.8.15;
 import { ISemver } from "src/universal/ISemver.sol";
 import { Constants } from "src/libraries/Constants.sol";
 import { GasPayingToken, IGasToken } from "src/libraries/GasPayingToken.sol";
+import { Predeploys } from "src/libraries/Predeploys.sol";
 import "src/libraries/L1BlockErrors.sol";
 
 /// @custom:proxied
@@ -57,9 +58,14 @@ contract L1Block is ISemver, IGasToken {
     /// @notice The latest L1 blob base fee.
     uint256 public blobBaseFee;
 
-    /// @custom:semver 1.4.1-beta.1
+    /// @notice Storage slot that the isDeposit is stored at.
+    ///         This is a custom slot that is not part of the standard storage layout.
+    /// keccak256(abi.encode(uint256(keccak256("l1Block.identifier.isDeposit")) - 1)) & ~bytes32(uint256(0xff))
+    uint256 internal constant IS_DEPOSIT_SLOT = 0x921bd3a089295c6e5540e8fba8195448d253efd6f2e3e495b499b627dc36a300;
+
+    /// @custom:semver 1.5.1-beta.1
     function version() public pure virtual returns (string memory) {
-        return "1.4.1-beta.1";
+        return "1.5.1-beta.1";
     }
 
     /// @notice Returns the gas paying token, its decimals, name and symbol.
@@ -87,6 +93,15 @@ contract L1Block is ISemver, IGasToken {
         return token != Constants.ETHER;
     }
 
+    /// @notice Returns whether the call was triggered from a a deposit or not.
+    /// @notice This function is only callable by the CrossL2Inbox contract.
+    function isDeposit() external view returns (bool isDeposit_) {
+        if (msg.sender != Predeploys.CROSS_L2_INBOX) revert NotCrossL2Inbox();
+        assembly {
+            isDeposit_ := sload(IS_DEPOSIT_SLOT)
+        }
+    }
+
     /// @custom:legacy
     /// @notice Updates the L1 block values.
     /// @param _number         L1 blocknumber.
@@ -97,6 +112,7 @@ contract L1Block is ISemver, IGasToken {
     /// @param _batcherHash    Versioned hash to authenticate batcher by.
     /// @param _l1FeeOverhead  L1 fee overhead.
     /// @param _l1FeeScalar    L1 fee scalar.
+    /// @param _isDeposit      isDeposit flag
     function setL1BlockValues(
         uint64 _number,
         uint64 _timestamp,
@@ -105,7 +121,8 @@ contract L1Block is ISemver, IGasToken {
         uint64 _sequenceNumber,
         bytes32 _batcherHash,
         uint256 _l1FeeOverhead,
-        uint256 _l1FeeScalar
+        uint256 _l1FeeScalar,
+        bool _isDeposit
     )
         external
     {
@@ -119,6 +136,19 @@ contract L1Block is ISemver, IGasToken {
         batcherHash = _batcherHash;
         l1FeeOverhead = _l1FeeOverhead;
         l1FeeScalar = _l1FeeScalar;
+        isDeposit = _isDeposit;
+    }
+
+    /// @notice Updates the `isDeposit` flag and sets the L1 block values for an Isthmus upgraded chain.
+    ///         It updates the L1 block values through the `setL1BlockValuesEcotone` function.
+    ///         It forwards the calldata to the internally-used `setL1BlockValuesEcotone` function.
+    function setL1BlockValuesIsthmus() external {
+        // Set the isDeposit flag to true.
+        assembly {
+            sstore(IS_DEPOSIT_SLOT, 1)
+        }
+
+        setL1BlockValuesEcotone();
     }
 
     /// @notice Updates the L1 block values for an Ecotone upgraded chain.
@@ -133,7 +163,7 @@ contract L1Block is ISemver, IGasToken {
     ///   7. _blobBaseFee        L1 blob base fee.
     ///   8. _hash               L1 blockhash.
     ///   9. _batcherHash        Versioned hash to authenticate batcher by.
-    function setL1BlockValuesEcotone() external {
+    function setL1BlockValuesEcotone() public {
         address depositor = DEPOSITOR_ACCOUNT();
         assembly {
             // Revert if the caller is not the depositor account.
@@ -152,6 +182,17 @@ contract L1Block is ISemver, IGasToken {
         }
     }
 
+    /// @notice Resets the isDeposit flag.
+    ///         Should only be called by the depositor account after the deposits are complete.
+    function depositsComplete() external {
+        if (msg.sender != DEPOSITOR_ACCOUNT()) revert NotDepositor();
+
+        // Set the isDeposit flag to false.
+        assembly {
+            sstore(IS_DEPOSIT_SLOT, 0)
+        }
+    }
+
     /// @notice Sets the gas paying token for the L2 system. Can only be called by the special
     ///         depositor account. This function is not called on every L2 block but instead
     ///         only called by specially crafted L1 deposit transactions.
@@ -162,4 +203,10 @@ contract L1Block is ISemver, IGasToken {
 
         emit GasPayingTokenSet({ token: _token, decimals: _decimals, name: _name, symbol: _symbol });
     }
+
+    /// @notice Resets the isDeposit flag.
+    function depositsComplete() external {
+        if (msg.sender != DEPOSITOR_ACCOUNT()) revert NotDepositor();
+        isDeposit = false;
+    }
 }

packages/contracts-bedrock/src/libraries/L1BlockErrors.sol

@@ -4,6 +4,9 @@ pragma solidity ^0.8.0;
 /// @notice Error returns when a non-depositor account tries to set L1 block values.
 error NotDepositor();
 
+/// @notice Error when a non-cross L2 Inbox sender tries to call the `isDeposit()` method.
+error NotCrossL2Inbox();
+
 /// @notice Error when a chain ID is not in the interop dependency set.
 error NotDependency();