feat(exo-gateway): add oracleInfo

ExocoreNetwork/exocore#159 adds a new `oracleInfo` parameter to the
`IAssets.sol` precompile when registering tokens. This PR follows that
change.

Previously, multiple tokens could be registered with a single call to
ExocoreGateway. However, that resulted in too many variables (and too
much gas) for Solidity to handle within a single function. To that end,
and keeping in mind that addition of new tokens isn't likely to be a
frequent occurrence, the function's capabilities have been tempered to
support only a single token within the transaction.

As a side effect, this fixes ExocoreNetwork#80

script/3_Setup.s.sol

@@ -1,9 +1,11 @@
 pragma solidity ^0.8.19;
 
-import "../src/interfaces/IClientChainGateway.sol";
+import {GatewayStorage} from "../src/storage/GatewayStorage.sol";
 
+import "../src/interfaces/IClientChainGateway.sol";
 import "../src/interfaces/IExocoreGateway.sol";
 import "../src/interfaces/IVault.sol";
+
 import {NonShortCircuitEndpointV2Mock} from "../test/mocks/NonShortCircuitEndpointV2Mock.sol";
 
 import {BaseScript} from "./BaseScript.sol";
@@ -86,41 +88,53 @@ contract SetupScript is BaseScript {
         exocoreGateway.registerOrUpdateClientChain(
             clientChainId, address(clientGateway).toBytes32(), 20, "ClientChain", "EVM compatible network", "secp256k1"
         );
-        vm.stopBroadcast();
 
         // 3. adding tokens to the whtielist of both Exocore and client chain gateway to enable restaking
 
         // first we read decimals from client chain ERC20 token contract to prepare for token data
-        vm.selectFork(clientChain);
         bytes32[] memory whitelistTokensBytes32 = new bytes32[](2);
         uint8[] memory decimals = new uint8[](2);
         uint256[] memory tvlLimits = new uint256[](2);
         string[] memory names = new string[](2);
-        string[] memory metaData = new string[](2);
+        string[] memory metaDatas = new string[](2);
+        string[] memory oracleInfos = new string[](2);
 
         // this stands for LST restaking for restakeToken
         whitelistTokensBytes32[0] = bytes32(bytes20(address(restakeToken)));
         decimals[0] = restakeToken.decimals();
         tvlLimits[0] = 1e10 ether;
         names[0] = "RestakeToken";
-        metaData[0] = "ERC20 LST token";
+        metaDatas[0] = "ERC20 LST token";
+        oracleInfos[0] = "{'a': 'b'}";
 
         // this stands for Native Restaking for ETH
         whitelistTokensBytes32[1] = bytes32(bytes20(VIRTUAL_STAKED_ETH_ADDRESS));
         decimals[1] = 18;
         tvlLimits[1] = 1e8 ether;
         names[1] = "StakedETH";
-        metaData[1] = "natively staked ETH on Ethereum";
-        vm.stopBroadcast();
+        metaDatas[1] = "natively staked ETH on Ethereum";
+        oracleInfos[1] = "{'b': 'a'}";
 
         // second add whitelist tokens and their meta data on Exocore side to enable LST Restaking and Native Restaking,
         // and this would also add token addresses to client chain gateway's whitelist
-        vm.selectFork(exocore);
-        uint256 messageLength = TOKEN_ADDRESS_BYTES_LENGTH * whitelistTokensBytes32.length + 2;
-        uint256 nativeFee = exocoreGateway.quote(clientChainId, new bytes(messageLength));
-        exocoreGateway.addOrUpdateWhitelistTokens{value: nativeFee}(
-            clientChainId, whitelistTokensBytes32, decimals, tvlLimits, names, metaData
-        );
+        uint256 nativeFee;
+        for (uint256 i = 0; i < whitelistTokensBytes32.length; i++) {
+            nativeFee = exocoreGateway.quote(
+                clientChainId,
+                abi.encodePacked(
+                    GatewayStorage.Action.REQUEST_ADD_WHITELIST_TOKEN, abi.encodePacked(whitelistTokensBytes32[i])
+                )
+            );
+            exocoreGateway.addOrUpdateWhitelistToken{value: nativeFee}(
+                clientChainId,
+                whitelistTokensBytes32[i],
+                decimals[i],
+                tvlLimits[i],
+                names[i],
+                metaDatas[i],
+                oracleInfos[i]
+            );
+        }
         vm.stopBroadcast();
     }
 

src/core/Bootstrap.sol

@@ -195,10 +195,10 @@ contract Bootstrap is
             whitelistTokens.push(token);
             isWhitelistedToken[token] = true;
 
-            // deploy the corresponding vault if not deployed before
-            if (address(tokenToVault[token]) == address(0)) {
-                _deployVault(token);
-            }
+            // tokens cannot be removed from the whitelist. hence, if the token is not in the
+            // whitelist, it means that it is missing a vault. we do not need to check for a
+            // pre-existing vault.
+            _deployVault(token);
 
             emit WhitelistTokenAdded(token);
         }

src/core/ClientChainGateway.sol

@@ -69,8 +69,8 @@ contract ClientChainGateway is
             revert Errors.ZeroAddress();
         }
 
-        _whiteListFunctionSelectors[Action.REQUEST_ADD_WHITELIST_TOKENS] =
-            this.afterReceiveAddWhitelistTokensRequest.selector;
+        _whiteListFunctionSelectors[Action.REQUEST_ADD_WHITELIST_TOKEN] =
+            this.afterReceiveAddWhitelistTokenRequest.selector;
 
         bootstrapped = true;
 

src/core/ClientGatewayLzReceiver.sol

@@ -290,40 +290,34 @@ abstract contract ClientGatewayLzReceiver is PausableUpgradeable, OAppReceiverUp
         }
     }
 
-    /// @notice Called after an add-whitelist-tokens response is received.
+    /// @notice Called after an add-whitelist-token response is received.
     /// @param requestPayload The request payload.
     // Though `_deployVault` would make external call to newly created `Vault` contract and initialize it,
     // `Vault` contract belongs to Exocore and we could make sure its implementation does not have dangerous behavior
     // like reentrancy.
     // slither-disable-next-line reentrancy-no-eth
-    function afterReceiveAddWhitelistTokensRequest(bytes calldata requestPayload)
+    function afterReceiveAddWhitelistTokenRequest(bytes calldata requestPayload)
         public
         onlyCalledFromThis
         whenNotPaused
     {
-        uint8 count = uint8(requestPayload[0]);
-        uint256 expectedLength = count * TOKEN_ADDRESS_BYTES_LENGTH + 1;
-        if (requestPayload.length != expectedLength) {
-            revert InvalidAddWhitelistTokensRequest(expectedLength, requestPayload.length);
+        address token = address(bytes20(abi.decode(requestPayload, (bytes32))));
+        if (token == address(0)) {
+            revert Errors.ZeroAddress();
         }
-
-        for (uint256 i = 0; i < count; ++i) {
-            uint256 start = i * TOKEN_ADDRESS_BYTES_LENGTH + 1;
-            uint256 end = start + TOKEN_ADDRESS_BYTES_LENGTH;
-            address token = address(bytes20(requestPayload[start:end]));
-
-            if (!isWhitelistedToken[token]) {
-                isWhitelistedToken[token] = true;
-                whitelistTokens.push(token);
-
-                // deploy the corresponding vault if not deployed before
-                if (token != VIRTUAL_STAKED_ETH_ADDRESS && address(tokenToVault[token]) == address(0)) {
-                    _deployVault(token);
-                }
-
-                emit WhitelistTokenAdded(token);
-            }
+        if (isWhitelistedToken[token]) {
+            // grave error, should never happen
+            revert Errors.ClientChainGatewayAlreadyWhitelisted(token);
+        }
+        isWhitelistedToken[token] = true;
+        whitelistTokens.push(token);
+        // deploy the corresponding vault if not deployed before
+        if (token != VIRTUAL_STAKED_ETH_ADDRESS) {
+            // since it is no longer possible to remove a token from the whitelist, the check for existing vault
+            // is not necessary.
+            _deployVault(token);
         }
+        emit WhitelistTokenAdded(token);
     }
 
 }

src/core/ExocoreGateway.sol

@@ -177,51 +177,52 @@ contract ExocoreGateway is
     /// @notice If we want to activate client chain's native restaking, we should add the corresponding virtual
     /// token address to the whitelist, bytes32(bytes20(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)) for Ethereum
     /// native restaking for example.
-    function addOrUpdateWhitelistTokens(
+    function addOrUpdateWhitelistToken(
         uint32 clientChainId,
-        bytes32[] calldata tokens,
-        uint8[] calldata decimals,
-        uint256[] calldata tvlLimits,
-        string[] calldata names,
-        string[] calldata metaData
+        bytes32 token,
+        uint8 decimals,
+        uint256 tvlLimit,
+        string calldata name,
+        string calldata metaData,
+        string calldata oracleInfo
     ) external payable onlyOwner whenNotPaused nonReentrant {
-        // The registration of the client chain is left for the precompile to validate.
-        _validateWhitelistTokensInput(tokens, decimals, tvlLimits, names, metaData);
-
-        bool success;
-        bool updated;
-        for (uint256 i = 0; i < tokens.length; ++i) {
-            require(tokens[i] != bytes32(0), "ExocoreGateway: token cannot be zero address");
-            require(tvlLimits[i] > 0, "ExocoreGateway: tvl limit should not be zero");
-            require(bytes(names[i]).length != 0, "ExocoreGateway: name cannot be empty");
-            require(bytes(metaData[i]).length != 0, "ExocoreGateway: meta data cannot be empty");
-
-            (success, updated) = ASSETS_CONTRACT.registerOrUpdateTokens(
-                clientChainId, abi.encodePacked(tokens[i]), decimals[i], tvlLimits[i], names[i], metaData[i]
-            );
+        require(token != bytes32(0), "ExocoreGateway: token cannot be zero address");
+        require(tvlLimit > 0, "ExocoreGateway: tvl limit should not be zero");
+        require(bytes(name).length != 0, "ExocoreGateway: name cannot be empty");
+        require(bytes(metaData).length != 0, "ExocoreGateway: meta data cannot be empty");
+        require(bytes(oracleInfo).length != 0, "ExocoreGateway: oracleInfo cannot be empty");
+
+        (bool success, bool updated) = ASSETS_CONTRACT.registerOrUpdateTokens(
+            clientChainId,
+            abi.encodePacked(token), // convert to bytes from bytes32
+            decimals,
+            tvlLimit,
+            name,
+            metaData,
+            oracleInfo
+        );
 
-            if (success) {
-                if (!updated) {
-                    emit WhitelistTokenAdded(clientChainId, tokens[i]);
-                } else {
-                    emit WhitelistTokenUpdated(clientChainId, tokens[i]);
+        if (success) {
+            if (!updated) {
+                if (msg.value == 0) {
+                    revert Errors.ZeroValue();
                 }
+                emit WhitelistTokenAdded(clientChainId, token);
+                _sendInterchainMsg(
+                    clientChainId,
+                    Action.REQUEST_ADD_WHITELIST_TOKEN,
+                    abi.encodePacked(token), // convert for decoding it on the receiving end
+                    false
+                );
             } else {
-                if (!updated) {
-                    revert AddWhitelistTokenFailed(tokens[i]);
-                } else {
-                    revert UpdateWhitelistTokenFailed(tokens[i]);
+                if (msg.value != 0) {
+                    revert Errors.NonZeroValue();
                 }
+                emit WhitelistTokenUpdated(clientChainId, token);
             }
-        }
-
-        if (!updated) {
-            _sendInterchainMsg(
-                clientChainId,
-                Action.REQUEST_ADD_WHITELIST_TOKENS,
-                abi.encodePacked(uint8(tokens.length), tokens),
-                false
-            );
+        } else {
+            // if the precompile call didn't succeed, we don't know if it is an update.
+            revert AddOrUpdateWhitelistTokenFailed(token);
         }
     }
 
@@ -258,32 +259,6 @@ contract ExocoreGateway is
         }
     }
 
-    /// @dev Validates the input for whitelist tokens.
-    /// @param tokens The list of token addresses, length must be <= 255.
-    /// @param decimals The list of token decimals, length must be equal to that of @param tokens.
-    /// @param tvlLimits The list of token TVL limits, length must be equal to that of @param tokens.
-    /// @param names The list of token names, length must be equal to that of @param tokens.
-    /// @param metaData The list of token meta data, length must be equal to that of @param tokens.
-    function _validateWhitelistTokensInput(
-        bytes32[] calldata tokens,
-        uint8[] calldata decimals,
-        uint256[] calldata tvlLimits,
-        string[] calldata names,
-        string[] calldata metaData
-    ) internal pure {
-        uint256 expectedLength = tokens.length;
-        if (expectedLength > type(uint8).max) {
-            revert WhitelistTokensListTooLong();
-        }
-
-        if (
-            decimals.length != expectedLength || tvlLimits.length != expectedLength || names.length != expectedLength
-                || metaData.length != expectedLength
-        ) {
-            revert InvalidWhitelistTokensInput();
-        }
-    }
-
     /// @dev Validates that the client chain id is registered.
     /// @dev This is designed to be called only in the cases wherein the precompile isn't used.
     /// @dev In all other situations, it is the responsibility of the precompile to perform such

src/interfaces/IExocoreGateway.sol

@@ -41,21 +41,27 @@ interface IExocoreGateway is IOAppReceiver, IOAppCore {
         string calldata signatureType
     ) external;
 
-    /// @notice Adds a list of whitelisted tokens to the client chain.
+    /// @notice Add a single whitelisted token to the client chain.
     /// @param clientChainId The LayerZero chain id of the client chain.
-    /// @param tokens The list of token addresses to be whitelisted.
-    /// @param decimals The list of token decimals, in the same order as the tokens list.
-    /// @param tvlLimits The list of token TVL limits (typically max supply),in the same order as the tokens list.
-    /// @param names The names of the tokens, in the same order as the tokens list.
-    /// @param metaData The meta information of the tokens, in the same order as the tokens list.
+    /// @param token The token address to be whitelisted.
+    /// @param decimals The decimals of the token.
+    /// @param tvlLimit The TVL limit of the token.
+    /// @param name The name of the token.
+    /// @param metaData The meta information of the token.
+    /// @param oracleInfo The oracle information of the token.
     /// @dev The chain must be registered before adding tokens.
-    function addOrUpdateWhitelistTokens(
+    /// @dev This function is payable because it sends a message to the client chain if
+    ///      the token is not already registered.
+    /// @dev Previously, we tried to use this function for multiple tokens, but that
+    ///      results in too many local variables (stack too deep).
+    function addOrUpdateWhitelistToken(
         uint32 clientChainId,
-        bytes32[] calldata tokens,
-        uint8[] calldata decimals,
-        uint256[] calldata tvlLimits,
-        string[] calldata names,
-        string[] calldata metaData
+        bytes32 token,
+        uint8 decimals,
+        uint256 tvlLimit,
+        string calldata name,
+        string calldata metaData,
+        string calldata oracleInfo
     ) external payable;
 
 }

src/interfaces/precompiles/IAssets.sol

@@ -65,6 +65,7 @@ interface IAssets {
     /// maxSupply if there is no limit
     /// @param name is the name of the token
     /// @param metaData is the arbitrary metadata of the token
+    /// @param oracleInfo is the oracle information of the token
     /// @return success if the token registration is successful
     /// @return updated whether the token was added or updated
     function registerOrUpdateTokens(
@@ -73,7 +74,8 @@ interface IAssets {
         uint8 decimals,
         uint256 tvlLimit,
         string calldata name,
-        string calldata metaData
+        string calldata metaData,
+        string calldata oracleInfo
     ) external returns (bool success, bool updated);
 
     /// QUERIES

src/libraries/Errors.sol

@@ -23,11 +23,10 @@ library Errors {
     /// @dev Thrown when passed-in amount is zero
     error ZeroAmount();
 
-    /// @dev Thrown when the passed-in value is not zero
+    /// @dev Thrown when the passed-in msg.value is not zero but should be
     error NonZeroValue();
 
-    /// @dev Thrown wehn the passed-in value is zero
-    /// @dev This is used when the value in question is not an amount
+    /// @dev Thrown when the passed-in msg.value is zero but should not be
     error ZeroValue();
 
     /// @dev Index out of array bounds
@@ -124,7 +123,7 @@ library Errors {
     error ClientChainGatewayAddWhitelistTooManyTokens();
 
     /// @dev ClientChainGateway: token should not be whitelisted before
-    error ClientChainGatewayAlreadyWhitelisted();
+    error ClientChainGatewayAlreadyWhitelisted(address token);
 
     //////////////////////////////////////
     //  ClientGatewayLzReceiver Errors  //

src/storage/ExocoreGatewayStorage.sol

@@ -156,13 +156,9 @@ contract ExocoreGatewayStorage is GatewayStorage {
     /// @param clientChainId The LayerZero chain ID of the client chain.
     error RegisterClientChainToExocoreFailed(uint32 clientChainId);
 
-    /// @notice Thrown when a whitelist token addition fails
+    /// @notice Thrown when a whitelist token addition or update fails
     /// @param token The address of the token.
-    error AddWhitelistTokenFailed(bytes32 token);
-
-    /// @notice Thrown when a whitelist token update fails
-    /// @param token The address of the token.
-    error UpdateWhitelistTokenFailed(bytes32 token);
+    error AddOrUpdateWhitelistTokenFailed(bytes32 token);
 
     /// @notice Thrown when the whitelist tokens input is invalid.
     error InvalidWhitelistTokensInput();

src/storage/GatewayStorage.sol

@@ -15,7 +15,7 @@ contract GatewayStorage {
         REQUEST_UNDELEGATE_FROM,
         REQUEST_DEPOSIT_THEN_DELEGATE_TO,
         REQUEST_MARK_BOOTSTRAP,
-        REQUEST_ADD_WHITELIST_TOKENS,
+        REQUEST_ADD_WHITELIST_TOKEN,
         REQUEST_ASSOCIATE_OPERATOR,
         REQUEST_DISSOCIATE_OPERATOR,
         RESPOND