SymmioPartyB

The SymmioPartyB contract acts as a management contract for solvers or "Party B" . This contract allows for controlled interaction with the Symmio platform and external addresses for managing roles and permissions.

Key Changes in 0.8.4:

• Reentrancy Protection: The _executeCall method now uses a custom nonReentrant modifier to prevent reentrancy attacks without altering the storage layout.

• Access Control & Multicast Whitelisting: The contract restricts calls based on roles (e.g., MANAGER_ROLE, TRUSTED_ROLE) and maintains a whitelist for destinations allowed in multicast operations

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Initialization

The SymmioPartyB contract uses upgradeable libraries for pausing and access control. During initialization, it sets the admin roles and the address of the Symmio contract.

initialize()

Function Signature:

function initialize(address admin, address symmioAddress_) public initializer;

Parameters:

• admin: The address to receive the DEFAULT_ADMIN_ROLE, TRUSTED_ROLE, and MANAGER_ROLE.

• symmioAddress_: The address of the Symmio contract with which this contract will interact.

Example:

symmioPartyB.initialize(adminAddress, symmioAddress);

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Configuration

setSymmioAddress()

Description: Updates the address of the Symmio contract. Only callable by users with the DEFAULT_ADMIN_ROLE.

Function Signature:

function setSymmioAddress(address addr) external onlyRole(DEFAULT_ADMIN_ROLE);

Parameters:

• addr: The new Symmio contract address.

Example:

symmioPartyB.setSymmioAddress(newSymmioAddress);

Events Emitted:

• SetSymmioAddress(address oldSymmioAddress, address newSymmioAddress)

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setRestrictedSelector()

Description: Restricts or lifts restrictions on specific function selectors. If a selector is restricted, only callers with the MANAGER_ROLE may invoke the function on the Symmio contract.

Function Signature:

function setRestrictedSelector(bytes4 selector, bool state) external onlyRole(DEFAULT_ADMIN_ROLE);

Parameters:

• selector: The function selector to restrict/unrestrict.

• state: true to restrict, false to unrestrict.

Example:

bytes4 selector = bytes4(keccak256("someFunction()"));
symmioPartyB.setRestrictedSelector(selector, true);

Events Emitted:

• SetRestrictedSelector(bytes4 selector, bool state)

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setMulticastWhitelist()

Description: Allows a manager to add or remove an address from the multicast whitelist. Only addresses on the whitelist can be called via the multicasting functionality.

Function Signature:

function setMulticastWhitelist(address addr, bool state) external onlyRole(MANAGER_ROLE);

Parameters:

• addr: The address to update.

• state: true to whitelist, false to remove.

Example:

symmioPartyB.setMulticastWhitelist(targetAddress, true);

Events Emitted:

• SetMulticastWhitelist(address addr, bool state)

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Token Approvals

_approve()

Description: Approves a specified ERC20 token amount for spending by the Symmio contract. Only callable by users with the TRUSTED_ROLE and when the contract is not paused.

Function Signature:

function _approve(address token, uint256 amount) external onlyRole(TRUSTED_ROLE) whenNotPaused;

Parameters:

• token: The ERC20 token address.

• amount: The amount to approve.

Example:

symmioPartyB._approve(tokenAddress, 1000);

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Execution Functions

_executeCall()

Description: Executes a low-level call to a destination address using the provided call data. This function now includes a custom nonReentrant modifier to prevent reentrancy attacks. It enforces role-based access control depending on the destination and function selector.

Function Signature:

function _executeCall(address destAddress, bytes memory callData) internal nonReentrant;

Parameters:

• destAddress: The destination address for the call.

• callData: The call data (must be at least 4 bytes).

Key Logic:

• Validates that destAddress is not zero.

• Checks the length of callData.

• If calling the Symmio contract (destAddress == symmioAddress), extracts the function selector and enforces:

  • If restricted, the caller must have MANAGER_ROLE.

  • Otherwise, the caller must have either MANAGER_ROLE or TRUSTED_ROLE.

• If calling another contract, verifies that the destination is whitelisted.

• Executes the call and reverts if it fails.

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_call()

Executes multiple calls to the Symmio contract by iterating over an array of call data, using _executeCall for each entry.

Function Signature:

function _call(bytes[] calldata _callDatas) external whenNotPaused;

Parameters:

• _callDatas: An array of call data bytes.

Example Usage:

bytes[] memory calls = new bytes[](2);
// Populate calls with call data...
symmioPartyB._call(calls);

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_multicastCall()

Description: Allows the caller to execute multiple calls to various destination addresses in a single transaction. Each destination address must correspond to a call data element, and reentrancy protection is enforced on each call.

Function Signature:

function _multicastCall(address[] calldata destAddresses, bytes[] calldata _callDatas) external whenNotPaused;

Parameters:

• destAddresses: An array of destination addresses.

• _callDatas: An array of call data bytes.

Example Usage:

address[] memory targets = new address[](2);
targets[0] = targetAddress1;
targets[1] = targetAddress2;
bytes[] memory callsData = new bytes[](2);
// Populate callsData...
symmioPartyB._multicastCall(targets, callsData);

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Token Withdrawal

withdrawERC20()

Allows an authorized manager to withdraw ERC20 tokens from the contract to the caller's address.

Function Signature:

function withdrawERC20(address token, uint256 amount) external onlyRole(MANAGER_ROLE);

Parameters:

• token: The ERC20 token address.

• amount: The amount to withdraw.

Example Usage:

symmioPartyB.withdrawERC20(tokenAddress, 100);

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Pausable Functions

pause() / unpause()

Description: Allows users with the PAUSER_ROLE to pause the contract and users with the UNPAUSER_ROLE to unpause it, thereby controlling the execution of functions.

Function Signatures:

function pause() external onlyRole(PAUSER_ROLE);
function unpause() external onlyRole(UNPAUSER_ROLE);

Example Usage:

symmioPartyB.pause();
symmioPartyB.unpause();