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// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.7.0 <0.9.0;
import "../common/Enum.sol";
import "../common/SelfAuthorized.sol";
import "./Executor.sol";
/// @title Module Manager - A contract that manages modules that can execute transactions via this contract
/// @author Stefan George - <stefan@gnosis.pm>
/// @author Richard Meissner - <richard@gnosis.pm>
contract ModuleManager is SelfAuthorized, Executor {
event EnabledModule(address module);
event DisabledModule(address module);
event ExecutionFromModuleSuccess(address indexed module);
event ExecutionFromModuleFailure(address indexed module);
address internal constant SENTINEL_MODULES = address(0x1);
mapping(address => address) internal modules;
function setupModules(address to, bytes memory data) internal {
require(modules[SENTINEL_MODULES] == address(0), "GS100");
modules[SENTINEL_MODULES] = SENTINEL_MODULES;
if (to != address(0))
// Setup has to complete successfully or transaction fails.
require(execute(to, 0, data, Enum.Operation.DelegateCall, gasleft()), "GS000");
}
/// @dev Allows to add a module to the whitelist.
/// This can only be done via a Safe transaction.
/// @notice Enables the module `module` for the Safe.
/// @param module Module to be whitelisted.
function enableModule(address module) public authorized {
// Module address cannot be null or sentinel.
require(module != address(0) && module != SENTINEL_MODULES, "GS101");
// Module cannot be added twice.
require(modules[module] == address(0), "GS102");
modules[module] = modules[SENTINEL_MODULES];
modules[SENTINEL_MODULES] = module;
emit EnabledModule(module);
}
/// @dev Allows to remove a module from the whitelist.
/// This can only be done via a Safe transaction.
/// @notice Disables the module `module` for the Safe.
/// @param prevModule Module that pointed to the module to be removed in the linked list
/// @param module Module to be removed.
function disableModule(address prevModule, address module) public authorized {
// Validate module address and check that it corresponds to module index.
require(module != address(0) && module != SENTINEL_MODULES, "GS101");
require(modules[prevModule] == module, "GS103");
modules[prevModule] = modules[module];
modules[module] = address(0);
emit DisabledModule(module);
}
/// @dev Allows a Module to execute a Safe transaction without any further confirmations.
/// @param to Destination address of module transaction.
/// @param value Ether value of module transaction.
/// @param data Data payload of module transaction.
/// @param operation Operation type of module transaction.
function execTransactionFromModule(
address to,
uint256 value,
bytes memory data,
Enum.Operation operation
) public virtual returns (bool success) {
// Only whitelisted modules are allowed.
require(msg.sender != SENTINEL_MODULES && modules[msg.sender] != address(0), "GS104");
// Execute transaction without further confirmations.
success = execute(to, value, data, operation, gasleft());
if (success) emit ExecutionFromModuleSuccess(msg.sender);
else emit ExecutionFromModuleFailure(msg.sender);
}
/// @dev Allows a Module to execute a Safe transaction without any further confirmations and return data
/// @param to Destination address of module transaction.
/// @param value Ether value of module transaction.
/// @param data Data payload of module transaction.
/// @param operation Operation type of module transaction.
function execTransactionFromModuleReturnData(
address to,
uint256 value,
bytes memory data,
Enum.Operation operation
) public returns (bool success, bytes memory returnData) {
success = execTransactionFromModule(to, value, data, operation);
// solhint-disable-next-line no-inline-assembly
assembly {
// Load free memory location
let ptr := mload(0x40)
// We allocate memory for the return data by setting the free memory location to
// current free memory location + data size + 32 bytes for data size value
mstore(0x40, add(ptr, add(returndatasize(), 0x20)))
// Store the size
mstore(ptr, returndatasize())
// Store the data
returndatacopy(add(ptr, 0x20), 0, returndatasize())
// Point the return data to the correct memory location
returnData := ptr
}
}
/// @dev Returns if an module is enabled
/// @return True if the module is enabled
function isModuleEnabled(address module) public view returns (bool) {
return SENTINEL_MODULES != module && modules[module] != address(0);
}
/// @dev Returns array of modules.
/// @param start Start of the page.
/// @param pageSize Maximum number of modules that should be returned.
/// @return array Array of modules.
/// @return next Start of the next page.
function getModulesPaginated(address start, uint256 pageSize) external view returns (address[] memory array, address next) {
// Init array with max page size
array = new address[](pageSize);
// Populate return array
uint256 moduleCount = 0;
address currentModule = modules[start];
while (currentModule != address(0x0) && currentModule != SENTINEL_MODULES && moduleCount < pageSize) {
array[moduleCount] = currentModule;
currentModule = modules[currentModule];
moduleCount++;
}
next = currentModule;
// Set correct size of returned array
// solhint-disable-next-line no-inline-assembly
assembly {
mstore(array, moduleCount)
}
}
}