feat(ctb): add message versioning to MessagePasser

op-chain-ops/genesis/config.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"math"
 	"math/big"
 	"os"
 	"path/filepath"
@@ -327,11 +326,8 @@ func NewL2StorageConfig(config *DeployConfig, block *types.Block) (state.Storage
 		return storage, errors.New("block base fee not set")
 	}
 
-	// Set the initial L2ToL1MessagePasser nonce to
-	// `type(uint32).max` to prevent nonce collisions
-	// with historical withdrawals.
 	storage["L2ToL1MessagePasser"] = state.StorageValues{
-		"nonce": math.MaxUint32,
+		"msgNonce": 0,
 	}
 	storage["L2CrossDomainMessenger"] = state.StorageValues{
 		"_initialized": 1,

packages/contracts-bedrock/.gas-snapshot

@@ -81,8 +81,8 @@ L2CrossDomainMessenger_Test:test_L2MessengerRelayMessageSucceeds() (gas: 53204)
 L2CrossDomainMessenger_Test:test_L2MessengerRelayMessageToSystemContract() (gas: 36172)
 L2CrossDomainMessenger_Test:test_L2MessengerRelayMessageV0Fails() (gas: 18870)
 L2CrossDomainMessenger_Test:test_L2MessengerRelayShouldRevertIfPaused() (gas: 41596)
-L2CrossDomainMessenger_Test:test_L2MessengerSendMessage() (gas: 122423)
-L2CrossDomainMessenger_Test:test_L2MessengerTwiceSendMessage() (gas: 134632)
+L2CrossDomainMessenger_Test:test_L2MessengerSendMessage() (gas: 122533)
+L2CrossDomainMessenger_Test:test_L2MessengerTwiceSendMessage() (gas: 134716)
 L2CrossDomainMessenger_Test:test_L2MessengerXDomainSenderReverts() (gas: 10568)
 L2CrossDomainMessenger_Test:test_L2MessengerxDomainMessageSenderResets() (gas: 52615)
 L2OutputOracleTest:testCannot_ProposeWithUnmatchedBlockhash() (gas: 29434)
@@ -118,13 +118,13 @@ L2StandardBridge_Test:test_finalizeBridgeETH_sendToMessengerReverts() (gas: 2396
 L2StandardBridge_Test:test_finalizeBridgeETH_sendToSelfReverts() (gas: 23793)
 L2StandardBridge_Test:test_finalizeDeposit() (gas: 89363)
 L2StandardBridge_Test:test_initialize() (gas: 10536)
-L2StandardBridge_Test:test_receive() (gas: 131820)
-L2StandardBridge_Test:test_withdraw() (gas: 343951)
-L2StandardBridge_Test:test_withdrawTo() (gas: 344680)
+L2StandardBridge_Test:test_receive() (gas: 131862)
+L2StandardBridge_Test:test_withdraw() (gas: 343984)
+L2StandardBridge_Test:test_withdrawTo() (gas: 344713)
 L2StandardBridge_Test:test_withdraw_onlyEOA() (gas: 251816)
-L2ToL1MessagePasserTest:test_burn() (gas: 112530)
-L2ToL1MessagePasserTest:test_initiateWithdrawal_fromContract() (gas: 70246)
-L2ToL1MessagePasserTest:test_initiateWithdrawal_fromEOA() (gas: 75764)
+L2ToL1MessagePasserTest:test_burn() (gas: 112594)
+L2ToL1MessagePasserTest:test_initiateWithdrawal_fromContract() (gas: 70356)
+L2ToL1MessagePasserTest:test_initiateWithdrawal_fromEOA() (gas: 75874)
 LegacyERC20ETH_Test:test_approve() (gas: 10723)
 LegacyERC20ETH_Test:test_burn() (gas: 10615)
 LegacyERC20ETH_Test:test_crossDomain() (gas: 6339)
@@ -293,4 +293,4 @@ SequencerFeeVault_Test:test_constructor() (gas: 5459)
 SequencerFeeVault_Test:test_minWithdrawalAmount() (gas: 5418)
 SequencerFeeVault_Test:test_receive() (gas: 17316)
 SequencerFeeVault_Test:test_revertWithdraw() (gas: 9343)
-SequencerFeeVault_Test:test_withdraw() (gas: 135837)
+SequencerFeeVault_Test:test_withdraw() (gas: 135879)

packages/contracts-bedrock/.storage-layout

@@ -256,7 +256,7 @@
 +============================================================================================================================+
 | sentMessages | mapping(bytes32 => bool) | 0    | 0      | 32    | contracts/L2/L2ToL1MessagePasser.sol:L2ToL1MessagePasser |
 |--------------+--------------------------+------+--------+-------+----------------------------------------------------------|
-| nonce        | uint256                  | 1    | 0      | 32    | contracts/L2/L2ToL1MessagePasser.sol:L2ToL1MessagePasser |
+| msgNonce     | uint240                  | 1    | 0      | 30    | contracts/L2/L2ToL1MessagePasser.sol:L2ToL1MessagePasser |
 +--------------+--------------------------+------+--------+-------+----------------------------------------------------------+
 
 =======================

packages/contracts-bedrock/contracts/L2/L2ToL1MessagePasser.sol

@@ -3,6 +3,7 @@ pragma solidity 0.8.15;
 
 import { Types } from "../libraries/Types.sol";
 import { Hashing } from "../libraries/Hashing.sol";
+import { Encoding } from "../libraries/Encoding.sol";
 import { Burn } from "../libraries/Burn.sol";
 import { Semver } from "../universal/Semver.sol";
 
@@ -20,6 +21,11 @@ contract L2ToL1MessagePasser is Semver {
      */
     uint256 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 100_000;
 
+    /**
+     * @notice Current message version identifier.
+     */
+    uint16 public constant MESSAGE_VERSION = 1;
+
     /**
      * @notice Includes the message hashes for all withdrawals
      */
@@ -28,18 +34,18 @@ contract L2ToL1MessagePasser is Semver {
     /**
      * @notice A unique value hashed with each withdrawal.
      */
-    uint256 public nonce;
+    uint240 internal msgNonce;
 
     /**
      * @notice Emitted any time a withdrawal is initiated.
      *
-     * @param nonce    Unique value corresponding to each withdrawal.
-     * @param sender   The L2 account address which initiated the withdrawal.
-     * @param target   The L1 account address the call will be send to.
-     * @param value    The ETH value submitted for withdrawal, to be forwarded to the target.
-     * @param gasLimit The minimum amount of gas that must be provided when withdrawing on L1.
-     * @param data     The data to be forwarded to the target on L1.
-     * @param withdrawalHash     The hash of the withdrawal.
+     * @param nonce          Unique value corresponding to each withdrawal.
+     * @param sender         The L2 account address which initiated the withdrawal.
+     * @param target         The L1 account address the call will be send to.
+     * @param value          The ETH value submitted for withdrawal, to be forwarded to the target.
+     * @param gasLimit       The minimum amount of gas that must be provided when withdrawing.
+     * @param data           The data to be forwarded to the target on L1.
+     * @param withdrawalHash The hash of the withdrawal.
      */
     event MessagePassed(
         uint256 indexed nonce,
@@ -96,7 +102,7 @@ contract L2ToL1MessagePasser is Semver {
     ) public payable {
         bytes32 withdrawalHash = Hashing.hashWithdrawal(
             Types.WithdrawalTransaction({
-                nonce: nonce,
+                nonce: messageNonce(),
                 sender: msg.sender,
                 target: _target,
                 value: msg.value,
@@ -107,9 +113,29 @@ contract L2ToL1MessagePasser is Semver {
 
         sentMessages[withdrawalHash] = true;
 
-        emit MessagePassed(nonce, msg.sender, _target, msg.value, _gasLimit, _data, withdrawalHash);
+        emit MessagePassed(
+            messageNonce(),
+            msg.sender,
+            _target,
+            msg.value,
+            _gasLimit,
+            _data,
+            withdrawalHash
+        );
+
         unchecked {
-            ++nonce;
+            ++msgNonce;
         }
     }
+
+    /**
+     * @notice Retrieves the next message nonce. Message version will be added to the upper two
+     *         bytes of the message nonce. Message version allows us to treat messages as having
+     *         different structures.
+     *
+     * @return Nonce of the next message to be sent, with added message version.
+     */
+    function messageNonce() public view returns (uint256) {
+        return Encoding.encodeVersionedNonce(msgNonce, MESSAGE_VERSION);
+    }
 }

packages/contracts-bedrock/contracts/test/L2CrossDomainMessenger.t.sol

@@ -58,15 +58,15 @@ contract L2CrossDomainMessenger_Test is Messenger_Initializer {
         // MessagePassed event
         vm.expectEmit(true, true, true, true);
         emit MessagePassed(
-            messagePasser.nonce(),
+            messagePasser.messageNonce(),
             address(L2Messenger),
             address(L1Messenger),
             0,
             L2Messenger.baseGas(hex"ff", 100),
             xDomainCallData,
             Hashing.hashWithdrawal(
                 Types.WithdrawalTransaction({
-                    nonce: messagePasser.nonce(),
+                    nonce: messagePasser.messageNonce(),
                     sender: address(L2Messenger),
                     target: address(L1Messenger),
                     value: 0,