Contract Source Code:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
pragma solidity ^0.8.0;
/**
* @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
* instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
* be specified by overriding the virtual {_implementation} function.
*
* Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
* different contract through the {_delegate} function.
*
* The success and return data of the delegated call will be returned back to the caller of the proxy.
*/
abstract contract Proxy {
/**
* @dev Delegates the current call to `implementation`.
*
* This function does not return to its internal call site, it will return directly to the external caller.
*/
function _delegate(address implementation) internal virtual {
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 This is a virtual function that should be overridden so it returns the address to which the fallback function
* and {_fallback} should delegate.
*/
function _implementation() internal view virtual returns (address);
/**
* @dev Delegates the current call to the address returned by `_implementation()`.
*
* This function does not return to its internal call site, it will return directly to the external caller.
*/
function _fallback() internal virtual {
_beforeFallback();
_delegate(_implementation());
}
/**
* @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
* function in the contract matches the call data.
*/
fallback() external payable virtual {
_fallback();
}
/**
* @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
* is empty.
*/
receive() external payable virtual {
_fallback();
}
/**
* @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
* call, or as part of the Solidity `fallback` or `receive` functions.
*
* If overridden should call `super._beforeFallback()`.
*/
function _beforeFallback() internal virtual {}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/proxy/Proxy.sol";
contract OrionProxy is Proxy
{
/**
* @dev Emitted when the implementation is upgraded.
* @param implementation Address of the new implementation.
*/
event Upgraded(address indexed implementation);
/**
* @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);
constructor()
{
assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1));
_setAdmin(msg.sender);
}
/**
* @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
{
require(msg.sender == _admin(),"Need only owner access");
_setImplementation(newImplementation);
}
/**
* @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
{
require(msg.sender == _admin(),"Need only owner access");
require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
_setAdmin(newAdmin);
}
//ERC1967
/**
* @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 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
/**
* @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 address.
*/
function _implementation() internal view virtual override returns (address impl) {
bytes32 slot = IMPLEMENTATION_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
impl := sload(slot)
}
}
/**
* @return adm The admin slot.
*/
function _admin() internal view returns (address adm) {
bytes32 slot = ADMIN_SLOT;
assembly {
adm := sload(slot)
}
}
/**
* @dev Stores a new address in the EIP1967 implementation slot.
*/
function _setImplementation(address newImplementation) private {
emit Upgraded(newImplementation);
bytes32 slot = IMPLEMENTATION_SLOT;
// solhint-disable-next-line no-inline-assembly
assembly {
sstore(slot, newImplementation)
}
}
/**
* @dev Sets the address of the proxy admin.
* @param newAdmin Address of the new proxy admin.
*/
function _setAdmin(address newAdmin) internal {
emit AdminChanged(_admin(), newAdmin);
bytes32 slot = ADMIN_SLOT;
assembly {
sstore(slot, newAdmin)
}
}
function implementation() external view returns (address)
{
return _implementation();
}
function admin() external view returns (address)
{
return _admin();
}
}