Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity 0.8.3;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
import "./interfaces/IDiamondLoupe.sol";
import "./interfaces/IDiamondCut.sol";
import "./interfaces/IERC173.sol";
import "./libraries/LibDiamond.sol";
contract Router {
struct DiamondArgs {
address owner;
}
constructor(
IDiamondCut.FacetCut[] memory _diamondCut,
DiamondArgs memory _args
) {
LibDiamond.diamondCut(_diamondCut, address(0), new bytes(0));
LibDiamond.setContractOwner(_args.owner);
LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
// adding ERC165 data
ds.supportedInterfaces[type(IERC165).interfaceId] = true;
ds.supportedInterfaces[type(IDiamondCut).interfaceId] = true;
ds.supportedInterfaces[type(IDiamondLoupe).interfaceId] = true;
ds.supportedInterfaces[type(IERC173).interfaceId] = true;
}
// Find facet for function that is called and execute the
// function if a facet is found and return any value.
fallback() external payable {
LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
address facet = ds.selectorToFacetAndPosition[msg.sig].facetAddress;
require(facet != address(0), "Diamond: Function does not exist");
assembly {
calldatacopy(0, 0, calldatasize())
let result := delegatecall(gas(), facet, 0, calldatasize(), 0, 0)
returndatacopy(0, 0, returndatasize())
switch result
case 0 {
revert(0, returndatasize())
}
default {
return(0, returndatasize())
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.3;
// A loupe is a small magnifying glass used to look at diamonds.
// These functions look at diamonds
interface IDiamondLoupe {
/// These functions are expected to be called frequently
/// by tools.
struct Facet {
address facetAddress;
bytes4[] functionSelectors;
}
/// @notice Gets all facet addresses and their four byte function selectors.
/// @return facets_ Facet
function facets() external view returns (Facet[] memory facets_);
/// @notice Gets all the function selectors supported by a specific facet.
/// @param _facet The facet address.
/// @return facetFunctionSelectors_
function facetFunctionSelectors(address _facet)
external
view
returns (bytes4[] memory facetFunctionSelectors_);
/// @notice Get all the facet addresses used by a diamond.
/// @return facetAddresses_
function facetAddresses()
external
view
returns (address[] memory facetAddresses_);
/// @notice Gets the facet that supports the given selector.
/// @dev If facet is not found return address(0).
/// @param _functionSelector The function selector.
/// @return facetAddress_ The facet address.
function facetAddress(bytes4 _functionSelector)
external
view
returns (address facetAddress_);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.3;
interface IDiamondCut {
enum FacetCutAction {
Add,
Replace,
Remove
}
// Add=0, Replace=1, Remove=2
struct FacetCut {
address facetAddress;
FacetCutAction action;
bytes4[] functionSelectors;
}
/// @notice Add/replace/remove any number of functions and optionally execute
/// a function with delegatecall
/// @param _diamondCut Contains the facet addresses and function selectors
/// @param _init The address of the contract or facet to execute _calldata
/// @param _calldata A function call, including function selector and arguments
/// _calldata is executed with delegatecall on _init
function diamondCut(
FacetCut[] calldata _diamondCut,
address _init,
bytes calldata _calldata
) external;
event DiamondCut(FacetCut[] _diamondCut, address _init, bytes _calldata);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.3;
/// @title ERC-173 Contract Ownership Standard
/// Note: the ERC-165 identifier for this interface is 0x7f5828d0
/* is ERC165 */
interface IERC173 {
/// @dev This emits when ownership of a contract changes.
event OwnershipTransferred(
address indexed previousOwner,
address indexed newOwner
);
/// @notice Get the address of the owner
/// @return owner_ The address of the owner.
function owner() external view returns (address owner_);
/// @notice Set the address of the new owner of the contract
/// @dev Set _newOwner to address(0) to renounce any ownership.
/// @param _newOwner The address of the new owner of the contract
function transferOwnership(address _newOwner) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.3;
import "../interfaces/IDiamondCut.sol";
library LibDiamond {
bytes32 constant DIAMOND_STORAGE_POSITION =
keccak256("diamond.standard.diamond.storage");
struct FacetAddressAndPosition {
address facetAddress;
uint16 functionSelectorPosition; // position in facetFunctionSelectors.functionSelectors array
}
struct FacetFunctionSelectors {
bytes4[] functionSelectors;
uint16 facetAddressPosition; // position of facetAddress in facetAddresses array
}
struct DiamondStorage {
// maps function selector to the facet address and
// the position of the selector in the facetFunctionSelectors.selectors array
mapping(bytes4 => FacetAddressAndPosition) selectorToFacetAndPosition;
// maps facet addresses to function selectors
mapping(address => FacetFunctionSelectors) facetFunctionSelectors;
// facet addresses
address[] facetAddresses;
// Used to query if a contract implements an interface.
// Used to implement ERC-165.
mapping(bytes4 => bool) supportedInterfaces;
// owner of the contract
address contractOwner;
}
function diamondStorage()
internal
pure
returns (DiamondStorage storage ds)
{
bytes32 position = DIAMOND_STORAGE_POSITION;
assembly {
ds.slot := position
}
}
event OwnershipTransferred(
address indexed previousOwner,
address indexed newOwner
);
function setContractOwner(address _newOwner) internal {
DiamondStorage storage ds = diamondStorage();
address previousOwner = ds.contractOwner;
ds.contractOwner = _newOwner;
emit OwnershipTransferred(previousOwner, _newOwner);
}
function contractOwner() internal view returns (address contractOwner_) {
contractOwner_ = diamondStorage().contractOwner;
}
function enforceIsContractOwner() internal view {
require(
msg.sender == diamondStorage().contractOwner,
"LibDiamond: Must be contract owner"
);
}
event DiamondCut(
IDiamondCut.FacetCut[] _diamondCut,
address _init,
bytes _calldata
);
// Internal function version of diamondCut
function diamondCut(
IDiamondCut.FacetCut[] memory _diamondCut,
address _init,
bytes memory _calldata
) internal {
for (
uint256 facetIndex;
facetIndex < _diamondCut.length;
facetIndex++
) {
IDiamondCut.FacetCutAction action = _diamondCut[facetIndex].action;
if (action == IDiamondCut.FacetCutAction.Add) {
addFunctions(
_diamondCut[facetIndex].facetAddress,
_diamondCut[facetIndex].functionSelectors
);
} else if (action == IDiamondCut.FacetCutAction.Replace) {
replaceFunctions(
_diamondCut[facetIndex].facetAddress,
_diamondCut[facetIndex].functionSelectors
);
} else if (action == IDiamondCut.FacetCutAction.Remove) {
removeFunctions(
_diamondCut[facetIndex].facetAddress,
_diamondCut[facetIndex].functionSelectors
);
} else {
revert("LibDiamondCut: Incorrect FacetCutAction");
}
}
emit DiamondCut(_diamondCut, _init, _calldata);
initializeDiamondCut(_init, _calldata);
}
function addFunctions(
address _facetAddress,
bytes4[] memory _functionSelectors
) internal {
require(
_functionSelectors.length > 0,
"LibDiamondCut: No selectors in facet to cut"
);
DiamondStorage storage ds = diamondStorage();
// uint16 selectorCount = uint16(diamondStorage().selectors.length);
require(
_facetAddress != address(0),
"LibDiamondCut: Add facet can't be address(0)"
);
uint16 selectorPosition = uint16(
ds.facetFunctionSelectors[_facetAddress].functionSelectors.length
);
// add new facet address if it does not exist
if (selectorPosition == 0) {
enforceHasContractCode(
_facetAddress,
"LibDiamondCut: New facet has no code"
);
ds
.facetFunctionSelectors[_facetAddress]
.facetAddressPosition = uint16(ds.facetAddresses.length);
ds.facetAddresses.push(_facetAddress);
}
for (
uint256 selectorIndex;
selectorIndex < _functionSelectors.length;
selectorIndex++
) {
bytes4 selector = _functionSelectors[selectorIndex];
address oldFacetAddress = ds
.selectorToFacetAndPosition[selector]
.facetAddress;
require(
oldFacetAddress == address(0),
"LibDiamondCut: Can't add function that already exists"
);
addFunction(ds, selector, selectorPosition, _facetAddress);
selectorPosition++;
}
}
function replaceFunctions(
address _facetAddress,
bytes4[] memory _functionSelectors
) internal {
require(
_functionSelectors.length > 0,
"LibDiamondCut: No selectors in facet to cut"
);
DiamondStorage storage ds = diamondStorage();
require(
_facetAddress != address(0),
"LibDiamondCut: Add facet can't be address(0)"
);
uint16 selectorPosition = uint16(
ds.facetFunctionSelectors[_facetAddress].functionSelectors.length
);
// add new facet address if it does not exist
if (selectorPosition == 0) {
enforceHasContractCode(
_facetAddress,
"LibDiamondCut: New facet has no code"
);
ds
.facetFunctionSelectors[_facetAddress]
.facetAddressPosition = uint16(ds.facetAddresses.length);
ds.facetAddresses.push(_facetAddress);
}
for (
uint256 selectorIndex;
selectorIndex < _functionSelectors.length;
selectorIndex++
) {
bytes4 selector = _functionSelectors[selectorIndex];
address oldFacetAddress = ds
.selectorToFacetAndPosition[selector]
.facetAddress;
require(
oldFacetAddress != _facetAddress,
"LibDiamondCut: Can't replace function with same function"
);
removeFunction(ds, oldFacetAddress, selector);
// add function
addFunction(ds, selector, selectorPosition, _facetAddress);
selectorPosition++;
}
}
function removeFunctions(
address _facetAddress,
bytes4[] memory _functionSelectors
) internal {
require(
_functionSelectors.length > 0,
"LibDiamondCut: No selectors in facet to cut"
);
DiamondStorage storage ds = diamondStorage();
// if function does not exist then do nothing and return
require(
_facetAddress == address(0),
"LibDiamondCut: Remove facet address must be address(0)"
);
for (
uint256 selectorIndex;
selectorIndex < _functionSelectors.length;
selectorIndex++
) {
bytes4 selector = _functionSelectors[selectorIndex];
address oldFacetAddress = ds
.selectorToFacetAndPosition[selector]
.facetAddress;
removeFunction(ds, oldFacetAddress, selector);
}
}
function addFunction(
DiamondStorage storage ds,
bytes4 _selector,
uint16 _selectorPosition,
address _facetAddress
) internal {
ds
.selectorToFacetAndPosition[_selector]
.functionSelectorPosition = _selectorPosition;
ds.facetFunctionSelectors[_facetAddress].functionSelectors.push(
_selector
);
ds.selectorToFacetAndPosition[_selector].facetAddress = _facetAddress;
}
function removeFunction(
DiamondStorage storage ds,
address _facetAddress,
bytes4 _selector
) internal {
require(
_facetAddress != address(0),
"LibDiamondCut: Can't remove function that doesn't exist"
);
// an immutable function is a function defined directly in a diamond
require(
_facetAddress != address(this),
"LibDiamondCut: Can't remove immutable function"
);
// replace selector with last selector, then delete last selector
uint256 selectorPosition = ds
.selectorToFacetAndPosition[_selector]
.functionSelectorPosition;
uint256 lastSelectorPosition = ds
.facetFunctionSelectors[_facetAddress]
.functionSelectors
.length - 1;
// if not the same then replace _selector with lastSelector
if (selectorPosition != lastSelectorPosition) {
bytes4 lastSelector = ds
.facetFunctionSelectors[_facetAddress]
.functionSelectors[lastSelectorPosition];
ds.facetFunctionSelectors[_facetAddress].functionSelectors[
selectorPosition
] = lastSelector;
ds
.selectorToFacetAndPosition[lastSelector]
.functionSelectorPosition = uint16(selectorPosition);
}
// delete the last selector
ds.facetFunctionSelectors[_facetAddress].functionSelectors.pop();
delete ds.selectorToFacetAndPosition[_selector];
// if no more selectors for facet address then delete the facet address
if (lastSelectorPosition == 0) {
// replace facet address with last facet address and delete last facet address
uint256 lastFacetAddressPosition = ds.facetAddresses.length - 1;
uint256 facetAddressPosition = ds
.facetFunctionSelectors[_facetAddress]
.facetAddressPosition;
if (facetAddressPosition != lastFacetAddressPosition) {
address lastFacetAddress = ds.facetAddresses[
lastFacetAddressPosition
];
ds.facetAddresses[facetAddressPosition] = lastFacetAddress;
ds
.facetFunctionSelectors[lastFacetAddress]
.facetAddressPosition = uint16(facetAddressPosition);
}
ds.facetAddresses.pop();
delete ds
.facetFunctionSelectors[_facetAddress]
.facetAddressPosition;
}
}
function initializeDiamondCut(address _init, bytes memory _calldata)
internal
{
if (_init == address(0)) {
require(
_calldata.length == 0,
"LibDiamondCut: _init is address(0) but_calldata is not empty"
);
} else {
require(
_calldata.length > 0,
"LibDiamondCut: _calldata is empty but _init is not address(0)"
);
if (_init != address(this)) {
enforceHasContractCode(
_init,
"LibDiamondCut: _init address has no code"
);
}
(bool success, bytes memory error) = _init.delegatecall(_calldata);
if (!success) {
if (error.length > 0) {
// bubble up the error
revert(string(error));
} else {
revert("LibDiamondCut: _init function reverted");
}
}
}
}
function enforceHasContractCode(
address _contract,
string memory _errorMessage
) internal view {
uint256 contractSize;
assembly {
contractSize := extcodesize(_contract)
}
require(contractSize > 0, _errorMessage);
}
}