Contract Source Code:
// SPDX-License-Identifier: GPL-3.0-only
// Copyright 2020 Compound Labs, Inc.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holder nor the names of its
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
pragma solidity ^0.7.5;
import "../libraries/SafeMath.sol";
contract Timelock {
using SafeMath for uint256;
event NewAdmin(address indexed newAdmin);
event NewPendingAdmin(address indexed newPendingAdmin);
event NewDelay(uint256 indexed newDelay);
event CancelTransaction(
bytes32 indexed txHash,
address indexed target,
uint256 value,
string signature,
bytes data,
uint256 eta
);
event ExecuteTransaction(
bytes32 indexed txHash,
address indexed target,
uint256 value,
string signature,
bytes data,
uint256 eta
);
event QueueTransaction(
bytes32 indexed txHash,
address indexed target,
uint256 value,
string signature,
bytes data,
uint256 eta
);
uint256 public constant GRACE_PERIOD = 14 days;
uint256 public constant MINIMUM_DELAY = 2 days;
uint256 public constant MAXIMUM_DELAY = 30 days;
address public admin;
address public pendingAdmin;
uint256 public delay;
mapping(bytes32 => bool) public queuedTransactions;
constructor(address admin_, uint256 delay_) {
require(delay_ >= MINIMUM_DELAY, "Timelock::constructor: Delay must exceed minimum delay.");
require(
delay_ <= MAXIMUM_DELAY,
"Timelock::setDelay: Delay must not exceed maximum delay."
);
admin = admin_;
delay = delay_;
}
// solhint-disable no-empty-blocks
receive() external payable {}
function gracePeriod() public pure returns (uint256) {
return GRACE_PERIOD;
}
function setDelay(uint256 delay_) public {
require(msg.sender == address(this), "Timelock::setDelay: Call must come from Timelock.");
require(delay_ >= MINIMUM_DELAY, "Timelock::setDelay: Delay must exceed minimum delay.");
require(
delay_ <= MAXIMUM_DELAY,
"Timelock::setDelay: Delay must not exceed maximum delay."
);
delay = delay_;
emit NewDelay(delay);
}
function acceptAdmin() public {
require(
msg.sender == pendingAdmin,
"Timelock::acceptAdmin: Call must come from pendingAdmin."
);
admin = msg.sender;
pendingAdmin = address(0);
emit NewAdmin(admin);
}
function setPendingAdmin(address pendingAdmin_) public {
require(
msg.sender == address(this),
"Timelock::setPendingAdmin: Call must come from Timelock."
);
pendingAdmin = pendingAdmin_;
emit NewPendingAdmin(pendingAdmin);
}
function queueTransaction(
address target,
uint256 value,
string calldata signature,
bytes calldata data,
uint256 eta
) public returns (bytes32) {
require(msg.sender == admin, "Timelock::queueTransaction: Call must come from admin.");
require(
eta >= getBlockTimestamp().add(delay),
"Timelock::queueTransaction: Estimated execution block must satisfy delay."
);
bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));
queuedTransactions[txHash] = true;
emit QueueTransaction(txHash, target, value, signature, data, eta);
return txHash;
}
function cancelTransaction(
address target,
uint256 value,
string calldata signature,
bytes calldata data,
uint256 eta
) public {
require(msg.sender == admin, "Timelock::cancelTransaction: Call must come from admin.");
bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));
queuedTransactions[txHash] = false;
emit CancelTransaction(txHash, target, value, signature, data, eta);
}
function executeTransaction(
address target,
uint256 value,
string calldata signature,
bytes calldata data,
uint256 eta
) public payable returns (bytes memory) {
require(msg.sender == admin, "Timelock::executeTransaction: Call must come from admin.");
bytes32 txHash = keccak256(abi.encode(target, value, signature, data, eta));
require(
queuedTransactions[txHash],
"Timelock::executeTransaction: Transaction hasn't been queued."
);
require(
getBlockTimestamp() >= eta,
"Timelock::executeTransaction: Transaction hasn't surpassed time lock."
);
require(
getBlockTimestamp() <= eta.add(GRACE_PERIOD),
"Timelock::executeTransaction: Transaction is stale."
);
queuedTransactions[txHash] = false;
bytes memory callData;
if (bytes(signature).length == 0) {
callData = data;
} else {
callData = abi.encodePacked(bytes4(keccak256(bytes(signature))), data);
}
// solhint-disable avoid-low-level-calls
(bool success, bytes memory returnData) = target.call{value: value}(callData);
require(success, "Timelock::executeTransaction: Transaction execution reverted.");
emit ExecuteTransaction(txHash, target, value, signature, data, eta);
return returnData;
}
function getBlockTimestamp() internal view returns (uint256) {
// solium-disable-next-line security/no-block-members
return block.timestamp;
}
}
// SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.7.5;
// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)
library SafeMath {
function add(uint256 x, uint256 y) internal pure returns (uint256 z) {
require((z = x + y) >= x, "ds-math-add-overflow");
}
function sub(uint256 x, uint256 y) internal pure returns (uint256 z) {
require((z = x - y) <= x, "ds-math-sub-underflow");
}
function mul(uint256 x, uint256 y) internal pure returns (uint256 z) {
require(y == 0 || (z = x * y) / y == x, "ds-math-mul-overflow");
}
}