Add Proxies from OpenZeppelin SDK (#2335)

This commit is contained in:
Francisco Giordano
2020-08-27 21:02:42 -03:00
committed by GitHub
parent 0b489f4d79
commit cb791a1b21
17 changed files with 1618 additions and 0 deletions

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// SPDX-License-Identifier: MIT
pragma solidity >=0.4.24 <0.7.0;
/**
* @title Initializable
*
* @dev Helper contract to support initializer functions. To use it, replace
* the constructor with a function that has the `initializer` modifier.
* WARNING: Unlike constructors, initializer functions must be manually
* invoked. This applies both to deploying an Initializable contract, as well
* as extending an Initializable contract via inheritance.
* WARNING: When used with inheritance, manual care must be taken to not invoke
* a parent initializer twice, or ensure that all initializers are idempotent,
* because this is not dealt with automatically as with constructors.
*/
contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
*/
bool private _initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private _initializing;
/**
* @dev Modifier to use in the initializer function of a contract.
*/
modifier initializer() {
require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");
bool isTopLevelCall = !_initializing;
if (isTopLevelCall) {
_initializing = true;
_initialized = true;
}
_;
if (isTopLevelCall) {
_initializing = false;
}
}
/// @dev Returns true if and only if the function is running in the constructor
function _isConstructor() private view returns (bool) {
// extcodesize checks the size of the code stored in an address, and
// address returns the current address. Since the code is still not
// deployed when running a constructor, any checks on its code size will
// yield zero, making it an effective way to detect if a contract is
// under construction or not.
address self = address(this);
uint256 cs;
// solhint-disable-next-line no-inline-assembly
assembly { cs := extcodesize(self) }
return cs == 0;
}
}

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contracts/proxy/Proxy.sol Normal file
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// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/**
* @title Proxy
* @dev Implements delegation of calls to other contracts, with proper
* forwarding of return values and bubbling of failures.
* It defines a fallback function that delegates all calls to the address
* returned by the abstract _implementation() internal function.
*/
abstract contract Proxy {
/**
* @dev Fallback function.
* Implemented entirely in `_fallback`.
*/
fallback () payable external {
_fallback();
}
/**
* @dev Receive function.
* Implemented entirely in `_fallback`.
*/
receive () payable external {
_fallback();
}
/**
* @return The Address of the implementation.
*/
function _implementation() internal virtual view returns (address);
/**
* @dev Delegates execution to an implementation contract.
* This is a low level function that doesn't return to its internal call site.
* It will return to the external caller whatever the implementation returns.
* @param implementation Address to delegate.
*/
function _delegate(address implementation) internal {
// solhint-disable-next-line no-inline-assembly
assembly {
// Copy msg.data. We take full control of memory in this inline assembly
// block because it will not return to Solidity code. We overwrite the
// Solidity scratch pad at memory position 0.
calldatacopy(0, 0, calldatasize())
// Call the implementation.
// out and outsize are 0 because we don't know the size yet.
let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
// Copy the returned data.
returndatacopy(0, 0, returndatasize())
switch result
// delegatecall returns 0 on error.
case 0 { revert(0, returndatasize()) }
default { return(0, returndatasize()) }
}
}
/**
* @dev Function that is run as the first thing in the fallback function.
* Can be redefined in derived contracts to add functionality.
* Redefinitions must call super._willFallback().
*/
function _willFallback() internal virtual {
}
/**
* @dev fallback implementation.
* Extracted to enable manual triggering.
*/
function _fallback() internal {
_willFallback();
_delegate(_implementation());
}
}

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// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "../access/Ownable.sol";
import "./TransparentUpgradeableProxy.sol";
/**
* @title ProxyAdmin
* @dev This contract is the admin of a proxy, and is in charge
* of upgrading it as well as transferring it to another admin.
*/
contract ProxyAdmin is Ownable {
/**
* @dev Returns the current implementation of a proxy.
* This is needed because only the proxy admin can query it.
* @return The address of the current implementation of the proxy.
*/
function getProxyImplementation(TransparentUpgradeableProxy proxy) public view returns (address) {
// We need to manually run the static call since the getter cannot be flagged as view
// bytes4(keccak256("implementation()")) == 0x5c60da1b
(bool success, bytes memory returndata) = address(proxy).staticcall(hex"5c60da1b");
require(success);
return abi.decode(returndata, (address));
}
/**
* @dev Returns the admin of a proxy. Only the admin can query it.
* @return The address of the current admin of the proxy.
*/
function getProxyAdmin(TransparentUpgradeableProxy proxy) public view returns (address) {
// We need to manually run the static call since the getter cannot be flagged as view
// bytes4(keccak256("admin()")) == 0xf851a440
(bool success, bytes memory returndata) = address(proxy).staticcall(hex"f851a440");
require(success);
return abi.decode(returndata, (address));
}
/**
* @dev Changes the admin of a proxy.
* @param proxy Proxy to change admin.
* @param newAdmin Address to transfer proxy administration to.
*/
function changeProxyAdmin(TransparentUpgradeableProxy proxy, address newAdmin) public onlyOwner {
proxy.changeAdmin(newAdmin);
}
/**
* @dev Upgrades a proxy to the newest implementation of a contract.
* @param proxy Proxy to be upgraded.
* @param implementation the address of the Implementation.
*/
function upgrade(TransparentUpgradeableProxy proxy, address implementation) public onlyOwner {
proxy.upgradeTo(implementation);
}
/**
* @dev Upgrades a proxy to the newest implementation of a contract and forwards a function call to it.
* This is useful to initialize the proxied contract.
* @param proxy Proxy to be upgraded.
* @param implementation Address of the Implementation.
* @param data Data to send as msg.data in the low level call.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
*/
function upgradeAndCall(TransparentUpgradeableProxy proxy, address implementation, bytes memory data) public payable onlyOwner {
proxy.upgradeToAndCall{value: msg.value}(implementation, data);
}
}

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// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "./UpgradeableProxy.sol";
/**
* @title TransparentUpgradeableProxy
* @dev This contract combines an upgradeability proxy with an authorization
* mechanism for administrative tasks.
* All external functions in this contract must be guarded by the
* `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
* feature proposal that would enable this to be done automatically.
*/
contract TransparentUpgradeableProxy is UpgradeableProxy {
/**
* Contract constructor.
* @param _logic address of the initial implementation.
* @param _admin Address of the proxy administrator.
* @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
* This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
*/
constructor(address _logic, address _admin, bytes memory _data) public payable UpgradeableProxy(_logic, _data) {
assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
_setAdmin(_admin);
}
/**
* @dev Emitted when the administration has been transferred.
* @param previousAdmin Address of the previous admin.
* @param newAdmin Address of the new admin.
*/
event AdminChanged(address previousAdmin, address newAdmin);
/**
* @dev Storage slot with the admin of the contract.
* This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
* validated in the constructor.
*/
bytes32 private constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
/**
* @dev Modifier to check whether the `msg.sender` is the admin.
* If it is, it will run the function. Otherwise, it will delegate the call
* to the implementation.
*/
modifier ifAdmin() {
if (msg.sender == _admin()) {
_;
} else {
_fallback();
}
}
/**
* @return The address of the proxy admin.
*/
function admin() external ifAdmin returns (address) {
return _admin();
}
/**
* @return The address of the implementation.
*/
function implementation() external ifAdmin returns (address) {
return _implementation();
}
/**
* @dev Changes the admin of the proxy.
* Only the current admin can call this function.
* @param newAdmin Address to transfer proxy administration to.
*/
function changeAdmin(address newAdmin) external ifAdmin {
require(newAdmin != address(0), "TransparentUpgradeableProxy: new admin is the zero address");
emit AdminChanged(_admin(), newAdmin);
_setAdmin(newAdmin);
}
/**
* @dev Upgrade the backing implementation of the proxy.
* Only the admin can call this function.
* @param newImplementation Address of the new implementation.
*/
function upgradeTo(address newImplementation) external ifAdmin {
_upgradeTo(newImplementation);
}
/**
* @dev Upgrade the backing implementation of the proxy and call a function
* on the new implementation.
* This is useful to initialize the proxied contract.
* @param newImplementation Address of the new implementation.
* @param data Data to send as msg.data in the low level call.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
*/
function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
_upgradeTo(newImplementation);
// solhint-disable-next-line avoid-low-level-calls
(bool success,) = newImplementation.delegatecall(data);
require(success);
}
/**
* @return adm The admin slot.
*/
function _admin() internal view returns (address adm) {
bytes32 slot = _ADMIN_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
adm := sload(slot)
}
}
/**
* @dev Sets the address of the proxy admin.
* @param newAdmin Address of the new proxy admin.
*/
function _setAdmin(address newAdmin) internal {
bytes32 slot = _ADMIN_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
sstore(slot, newAdmin)
}
}
/**
* @dev Only fallback when the sender is not the admin.
*/
function _willFallback() internal override virtual {
require(msg.sender != _admin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
super._willFallback();
}
}

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// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
import "./Proxy.sol";
import "../utils/Address.sol";
/**
* @title UpgradeableProxy
* @dev This contract implements a proxy that allows to change the
* implementation address to which it will delegate.
* Such a change is called an implementation upgrade.
*/
contract UpgradeableProxy is Proxy {
/**
* @dev Contract constructor.
* @param _logic Address of the initial implementation.
* @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
* It should include the signature and the parameters of the function to be called, as described in
* https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
* This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
*/
constructor(address _logic, bytes memory _data) public payable {
assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
_setImplementation(_logic);
if(_data.length > 0) {
// solhint-disable-next-line avoid-low-level-calls
(bool success,) = _logic.delegatecall(_data);
require(success);
}
}
/**
* @dev Emitted when the implementation is upgraded.
* @param implementation Address of the new implementation.
*/
event Upgraded(address indexed implementation);
/**
* @dev Storage slot with the address of the current implementation.
* This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
* validated in the constructor.
*/
bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
/**
* @dev Returns the current implementation.
* @return impl Address of the current implementation
*/
function _implementation() internal override view returns (address impl) {
bytes32 slot = _IMPLEMENTATION_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
impl := sload(slot)
}
}
/**
* @dev Upgrades the proxy to a new implementation.
* @param newImplementation Address of the new implementation.
*/
function _upgradeTo(address newImplementation) internal {
_setImplementation(newImplementation);
emit Upgraded(newImplementation);
}
/**
* @dev Sets the implementation address of the proxy.
* @param newImplementation Address of the new implementation.
*/
function _setImplementation(address newImplementation) internal {
require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");
bytes32 slot = _IMPLEMENTATION_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
sstore(slot, newImplementation)
}
}
}