evm: Per chain transceivers

Author: bruce-riley

evm/script/helpers/DeployWormholeNttBase.sol

@@ -100,7 +100,8 @@ contract DeployWormholeNttBase is ParseNttConfig {
         }
 
         // Hardcoded to one since these scripts handle Wormhole-only deployments.
-        INttManager(nttManager).setThreshold(1);
+        // TODO: We need the sourceChainId to set the threshold. Also need to enable sending and receiving.
+        // INttManager(nttManager).setThreshold(1);
         console2.log("Threshold set on NttManager: %d", uint256(1));
     }
 

evm/src/NttManager/ManagerBase.sol

@@ -52,7 +52,6 @@ abstract contract ManagerBase is
     }
 
     function _migrate() internal virtual override {
-        _checkThresholdInvariants();
         _checkTransceiversInvariants();
     }
 
@@ -68,13 +67,6 @@ abstract contract ManagerBase is
 
     // =============== Storage Getters/Setters ==============================================
 
-    function _getThresholdStorage() private pure returns (_Threshold storage $) {
-        uint256 slot = uint256(THRESHOLD_SLOT);
-        assembly ("memory-safe") {
-            $.slot := slot
-        }
-    }
-
     function _getMessageAttestationsStorage()
         internal
         pure
@@ -139,15 +131,19 @@ abstract contract ManagerBase is
         bytes32 nttManagerMessageHash =
             TransceiverStructs.nttManagerMessageDigest(sourceChainId, payload);
 
+        // The `msg.sender` is the transceiver. Get the index for it.
+        uint8 index = _getTransceiverInfosStorage()[msg.sender].index;
+
+        // TODO: Is there a race condition with disabling a transceiver while a tx is outstanding?
+        if (!_isRecvTransceiverEnabledForChain(sourceChainId, index)) {
+            revert CallerNotTransceiver(msg.sender);
+        }
+
         // set the attested flag for this transceiver.
         // NOTE: Attestation is idempotent (bitwise or 1), but we revert
         // anyway to ensure that the client does not continue to initiate calls
         // to receive the same message through the same transceiver.
-        if (
-            transceiverAttestedToMessage(
-                nttManagerMessageHash, _getTransceiverInfosStorage()[msg.sender].index
-            )
-        ) {
+        if (transceiverAttestedToMessage(nttManagerMessageHash, index)) {
             revert TransceiverAlreadyAttestedToMessage(nttManagerMessageHash);
         }
         _setTransceiverAttestedToMessage(nttManagerMessageHash, msg.sender);
@@ -162,7 +158,7 @@ abstract contract ManagerBase is
     ) internal returns (bytes32, bool) {
         bytes32 digest = TransceiverStructs.nttManagerMessageDigest(sourceChainId, message);
 
-        if (!isMessageApproved(digest)) {
+        if (!isMessageApproved(sourceChainId, digest)) {
             revert MessageNotApproved(digest);
         }
 
@@ -225,7 +221,7 @@ abstract contract ManagerBase is
         )
     {
         // cache enabled transceivers to avoid multiple storage reads
-        address[] memory enabledTransceivers = _getEnabledTransceiversStorage();
+        address[] memory enabledTransceivers = getEnabledSendTransceiversForChain(recipientChain);
 
         TransceiverStructs.TransceiverInstruction[] memory instructions;
 
@@ -280,15 +276,16 @@ abstract contract ManagerBase is
     }
 
     /// @inheritdoc IManagerBase
-    function getThreshold() public view returns (uint8) {
-        return _getThresholdStorage().num;
+    /// @dev This is here because it is defined in IManagerBase.
+    function getThreshold(
+        uint16 sourceChainId
+    ) public view returns (uint8) {
+        return _getPerChainRecvTransceiverDataStorage()[sourceChainId].threshold;
     }
 
     /// @inheritdoc IManagerBase
-    function isMessageApproved(
-        bytes32 digest
-    ) public view returns (bool) {
-        uint8 threshold = getThreshold();
+    function isMessageApproved(uint16 sourceChainId, bytes32 digest) public view returns (bool) {
+        uint8 threshold = getThreshold(sourceChainId);
         return messageAttestations(digest) >= threshold && threshold > 0;
     }
 
@@ -354,63 +351,21 @@ abstract contract ManagerBase is
         address transceiver
     ) external onlyOwner {
         _setTransceiver(transceiver);
-
-        _Threshold storage _threshold = _getThresholdStorage();
-        // We do not automatically increase the threshold here.
-        // Automatically increasing the threshold can result in a scenario
-        // where in-flight messages can't be redeemed.
-        // For example: Assume there is 1 Transceiver and the threshold is 1.
-        // If we were to add a new Transceiver, the threshold would increase to 2.
-        // However, all messages that are either in-flight or that are sent on
-        // a source chain that does not yet have 2 Transceivers will only have been
-        // sent from a single transceiver, so they would never be able to get
-        // redeemed.
-        // Instead, we leave it up to the owner to manually update the threshold
-        // after some period of time, ideally once all chains have the new Transceiver
-        // and transfers that were sent via the old configuration are all complete.
-        // However if the threshold is 0 (the initial case) we do increment to 1.
-        if (_threshold.num == 0) {
-            _threshold.num = 1;
-        }
-
-        emit TransceiverAdded(transceiver, _getNumTransceiversStorage().enabled, _threshold.num);
-
-        _checkThresholdInvariants();
+        emit TransceiverAdded(transceiver, _getNumTransceiversStorage().enabled);
     }
 
     /// @inheritdoc IManagerBase
     function removeTransceiver(
         address transceiver
     ) external onlyOwner {
         _removeTransceiver(transceiver);
-
-        _Threshold storage _threshold = _getThresholdStorage();
-        uint8 numEnabledTransceivers = _getNumTransceiversStorage().enabled;
-
-        if (numEnabledTransceivers < _threshold.num) {
-            _threshold.num = numEnabledTransceivers;
-        }
-
-        emit TransceiverRemoved(transceiver, _threshold.num);
-
-        _checkThresholdInvariants();
+        emit TransceiverRemoved(transceiver);
     }
 
     /// @inheritdoc IManagerBase
-    function setThreshold(
-        uint8 threshold
-    ) external onlyOwner {
-        if (threshold == 0) {
-            revert ZeroThreshold();
-        }
-
-        _Threshold storage _threshold = _getThresholdStorage();
-        uint8 oldThreshold = _threshold.num;
-
-        _threshold.num = threshold;
-        _checkThresholdInvariants();
-
-        emit ThresholdChanged(oldThreshold, threshold);
+    /// @dev This is here because it is defined in IManagerBase.
+    function setThreshold(uint16 sourceChainId, uint8 threshold) external onlyOwner {
+        _setThreshold(sourceChainId, threshold);
     }
 
     // =============== Internal ==============================================================
@@ -480,20 +435,4 @@ abstract contract ManagerBase is
             );
         }
     }
-
-    function _checkThresholdInvariants() internal view {
-        uint8 threshold = _getThresholdStorage().num;
-        _NumTransceivers memory numTransceivers = _getNumTransceiversStorage();
-
-        // invariant: threshold <= enabledTransceivers.length
-        if (threshold > numTransceivers.enabled) {
-            revert ThresholdTooHigh(threshold, numTransceivers.enabled);
-        }
-
-        if (numTransceivers.registered > 0) {
-            if (threshold == 0) {
-                revert ZeroThreshold();
-            }
-        }
-    }
 }

evm/src/NttManager/NttManager.sol

@@ -68,7 +68,6 @@ contract NttManager is INttManager, RateLimiter, ManagerBase {
 
     function _initialize() internal virtual override {
         __NttManager_init();
-        _checkThresholdInvariants();
         _checkTransceiversInvariants();
     }
 
@@ -192,7 +191,7 @@ contract NttManager is INttManager, RateLimiter, ManagerBase {
         // Compute manager message digest and record transceiver attestation.
         bytes32 nttManagerMessageHash = _recordTransceiverAttestation(sourceChainId, payload);
 
-        if (isMessageApproved(nttManagerMessageHash)) {
+        if (isMessageApproved(sourceChainId, nttManagerMessageHash)) {
             executeMsg(sourceChainId, sourceNttManagerAddress, payload);
         }
     }