Contract Name:
ElsProxyBasedOFT
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../../registry/RegistryClient.sol";
import "../ethlasApp/IEthlasFees.sol";
import "../token/oft/OFTCore.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
/**
* @dev Based on LayerZero OmnichainFungibleToken
*
* Use this contract only on the BASE CHAIN. It locks tokens on source,
* on outgoing send(), and unlocks tokens when receiving from other chains.
*
*/
contract ElsProxyBasedOFT is OFTCore, RegistryClient {
using SafeERC20 for IERC20;
IERC20 public immutable token;
address public ethlasWallet;
string public ethlasFeesId;
constructor(
address _regAddr,
address _ethlasWallet,
string memory _ethlasFeesId,
address _lzEndpoint,
address _proxyToken
) OFTCore(_lzEndpoint) {
setAddr(_regAddr);
ethlasWallet = _ethlasWallet;
ethlasFeesId = _ethlasFeesId;
token = IERC20(_proxyToken);
}
function circulatingSupply()
public
view
virtual
override
returns (uint256)
{
unchecked {
return token.totalSupply() - token.balanceOf(address(this));
}
}
function _debitFrom(
address _from,
uint16,
bytes memory,
uint256 _amount
) internal virtual override {
require(_from == _msgSender(), "Owner is not send caller");
token.safeTransferFrom(_from, address(this), _amount);
}
function _creditTo(
uint16,
address _toAddress,
uint256 _amount
) internal virtual override {
token.safeTransfer(_toAddress, _amount);
}
function sendFrom(
address _from,
uint16 _dstChainId,
bytes memory _toAddress,
uint256 _amount,
address payable _refundAddress,
address _zroPaymentAddress,
bytes memory _adapterParams
) public payable virtual override {
require(_refundAddress == ethlasWallet, "refund must be ethlas wallet");
(uint256 nativeFee, ) = estimateSendFee(
_dstChainId,
_toAddress,
_amount,
false,
_adapterParams
);
address eFeesAddr = lookupContractAddr(ethlasFeesId);
require(eFeesAddr != address(0), "fees address not found");
IEthlasFees eFees = IEthlasFees(eFeesAddr);
uint256 ethlasFee = eFees.getFee(_dstChainId, _amount, nativeFee);
uint256 pSlip = eFees.percentSlip();
require(msg.value >= nativeFee, "Insufficient fee amount sent");
uint256 eFeeShare = msg.value - nativeFee;
if (eFeeShare < ethlasFee) {
uint256 percentUnder = 100 - (100 * eFeeShare) / ethlasFee;
require(percentUnder <= pSlip, "insufficlient ethlas fee amount");
}
super.sendFrom(
_from,
_dstChainId,
_toAddress,
_amount,
_refundAddress,
_zroPaymentAddress,
_adapterParams
);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/access/Ownable.sol";
interface IRegistry {
function getAddr(string memory id) external view returns (address);
function updateAddr(string memory id, address addr) external;
}
/**
* @dev used to look up other Ethlas contract addresses by name from Ethlas contract registry
*/
contract RegistryClient is Ownable {
address public registryAddr;
function setAddr(address addr) internal {
registryAddr = addr;
}
function updateAddr(address addr) external onlyOwner {
registryAddr = addr;
}
function lookupContractAddr(string memory contractName) internal view returns (address) {
require(registryAddr != address(0), "registry address not initialized");
IRegistry reg = IRegistry(registryAddr);
return reg.getAddr(contractName);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "../../lzApp/NonblockingLzApp.sol";
import "./IOFTCore.sol";
import "@openzeppelin/contracts/utils/introspection/ERC165.sol";
abstract contract OFTCore is NonblockingLzApp, ERC165, IOFTCore {
constructor(address _lzEndpoint) NonblockingLzApp(_lzEndpoint) {}
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return interfaceId == type(IOFTCore).interfaceId || super.supportsInterface(interfaceId);
}
function estimateSendFee(uint16 _dstChainId, bytes memory _toAddress, uint _amount, bool _useZro, bytes memory _adapterParams) public view virtual override returns (uint nativeFee, uint zroFee) {
// mock the payload for send()
bytes memory payload = abi.encode(_toAddress, _amount);
return lzEndpoint.estimateFees(_dstChainId, address(this), payload, _useZro, _adapterParams);
}
function sendFrom(address _from, uint16 _dstChainId, bytes memory _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) public payable virtual override {
_send(_from, _dstChainId, _toAddress, _amount, _refundAddress, _zroPaymentAddress, _adapterParams);
}
function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
// decode and load the toAddress
(bytes memory toAddressBytes, uint amount) = abi.decode(_payload, (bytes, uint));
address toAddress;
assembly {
toAddress := mload(add(toAddressBytes, 20))
}
_creditTo(_srcChainId, toAddress, amount);
emit ReceiveFromChain(_srcChainId, _srcAddress, toAddress, amount, _nonce);
}
function _send(address _from, uint16 _dstChainId, bytes memory _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) internal virtual {
_debitFrom(_from, _dstChainId, _toAddress, _amount);
bytes memory payload = abi.encode(_toAddress, _amount);
_lzSend(_dstChainId, payload, _refundAddress, _zroPaymentAddress, _adapterParams);
uint64 nonce = lzEndpoint.getOutboundNonce(_dstChainId, address(this));
emit SendToChain(_from, _dstChainId, _toAddress, _amount, nonce);
}
function _debitFrom(address _from, uint16 _dstChainId, bytes memory _toAddress, uint _amount) internal virtual;
function _creditTo(uint16 _srcChainId, address _toAddress, uint _amount) internal virtual;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
/**
* @dev Interface of the IOFT core standard
*/
interface IOFTCore is IERC165 {
/**
* @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
* _dstChainId - L0 defined chain id to send tokens too
* _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
* _amount - amount of the tokens to transfer
* _useZro - indicates to use zro to pay L0 fees
* _adapterParam - flexible bytes array to indicate messaging adapter services in L0
*/
function estimateSendFee(uint16 _dstChainId, bytes calldata _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
/**
* @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
* `_from` the owner of token
* `_dstChainId` the destination chain identifier
* `_toAddress` can be any size depending on the `dstChainId`.
* `_amount` the quantity of tokens in wei
* `_refundAddress` the address LayerZero refunds if too much message fee is sent
* `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
* `_adapterParams` is a flexible bytes array to indicate messaging adapter services
*/
function sendFrom(address _from, uint16 _dstChainId, bytes calldata _toAddress, uint _amount, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
/**
* @dev returns the circulating amount of tokens on current chain
*/
function circulatingSupply() external view returns (uint);
/**
* @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
* `_nonce` is the outbound nonce
*/
event SendToChain(address indexed _sender, uint16 indexed _dstChainId, bytes indexed _toAddress, uint _amount, uint64 _nonce);
/**
* @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
* `_nonce` is the inbound nonce.
*/
event ReceiveFromChain(uint16 indexed _srcChainId, bytes indexed _srcAddress, address indexed _toAddress, uint _amount, uint64 _nonce);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./LzApp.sol";
/*
* the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
* this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
* NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
*/
abstract contract NonblockingLzApp is LzApp {
constructor(address _endpoint) LzApp(_endpoint) {}
mapping(uint16 => mapping(bytes => mapping(uint64 => bytes32))) public failedMessages;
event MessageFailed(uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes _payload);
// overriding the virtual function in LzReceiver
function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual override {
// try-catch all errors/exceptions
try this.nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload) {
// do nothing
} catch {
// error / exception
failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload);
}
}
function nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) public virtual {
// only internal transaction
require(_msgSender() == address(this), "NonblockingLzApp: caller must be LzApp");
_nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
}
//@notice override this function
function _nonblockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;
function retryMessage(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) public payable virtual {
// assert there is message to retry
bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
require(payloadHash != bytes32(0), "NonblockingLzApp: no stored message");
require(keccak256(_payload) == payloadHash, "NonblockingLzApp: invalid payload");
// clear the stored message
failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
// execute the message. revert if it fails again
_nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/access/Ownable.sol";
import "../interfaces/ILayerZeroReceiver.sol";
import "../interfaces/ILayerZeroUserApplicationConfig.sol";
import "../interfaces/ILayerZeroEndpoint.sol";
/*
* a generic LzReceiver implementation
*/
abstract contract LzApp is Ownable, ILayerZeroReceiver, ILayerZeroUserApplicationConfig {
ILayerZeroEndpoint public immutable lzEndpoint;
mapping(uint16 => bytes) public trustedRemoteLookup;
event SetTrustedRemote(uint16 _srcChainId, bytes _srcAddress);
constructor(address _endpoint) {
lzEndpoint = ILayerZeroEndpoint(_endpoint);
}
function lzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) public virtual override {
// lzReceive must be called by the endpoint for security
require(_msgSender() == address(lzEndpoint), "LzApp: invalid endpoint caller");
bytes memory trustedRemote = trustedRemoteLookup[_srcChainId];
// if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
require(_srcAddress.length == trustedRemote.length && keccak256(_srcAddress) == keccak256(trustedRemote), "LzApp: invalid source sending contract");
_blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
}
// abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
function _blockingLzReceive(uint16 _srcChainId, bytes memory _srcAddress, uint64 _nonce, bytes memory _payload) internal virtual;
function _lzSend(uint16 _dstChainId, bytes memory _payload, address payable _refundAddress, address _zroPaymentAddress, bytes memory _adapterParams) internal virtual {
bytes memory trustedRemote = trustedRemoteLookup[_dstChainId];
require(trustedRemote.length != 0, "LzApp: destination chain is not a trusted source");
lzEndpoint.send{value: msg.value}(_dstChainId, trustedRemote, _payload, _refundAddress, _zroPaymentAddress, _adapterParams);
}
//---------------------------UserApplication config----------------------------------------
function getConfig(uint16 _version, uint16 _chainId, address, uint _configType) external view returns (bytes memory) {
return lzEndpoint.getConfig(_version, _chainId, address(this), _configType);
}
// generic config for LayerZero user Application
function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external override onlyOwner {
lzEndpoint.setConfig(_version, _chainId, _configType, _config);
}
function setSendVersion(uint16 _version) external override onlyOwner {
lzEndpoint.setSendVersion(_version);
}
function setReceiveVersion(uint16 _version) external override onlyOwner {
lzEndpoint.setReceiveVersion(_version);
}
function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external override onlyOwner {
lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
}
// allow owner to set it multiple times.
function setTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress) external onlyOwner {
trustedRemoteLookup[_srcChainId] = _srcAddress;
emit SetTrustedRemote(_srcChainId, _srcAddress);
}
//--------------------------- VIEW FUNCTION ----------------------------------------
function isTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool) {
bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
return keccak256(trustedSource) == keccak256(_srcAddress);
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
interface ILayerZeroUserApplicationConfig {
// @notice set the configuration of the LayerZero messaging library of the specified version
// @param _version - messaging library version
// @param _chainId - the chainId for the pending config change
// @param _configType - type of configuration. every messaging library has its own convention.
// @param _config - configuration in the bytes. can encode arbitrary content.
function setConfig(uint16 _version, uint16 _chainId, uint _configType, bytes calldata _config) external;
// @notice set the send() LayerZero messaging library version to _version
// @param _version - new messaging library version
function setSendVersion(uint16 _version) external;
// @notice set the lzReceive() LayerZero messaging library version to _version
// @param _version - new messaging library version
function setReceiveVersion(uint16 _version) external;
// @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
// @param _srcChainId - the chainId of the source chain
// @param _srcAddress - the contract address of the source contract at the source chain
function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
interface ILayerZeroReceiver {
// @notice LayerZero endpoint will invoke this function to deliver the message on the destination
// @param _srcChainId - the source endpoint identifier
// @param _srcAddress - the source sending contract address from the source chain
// @param _nonce - the ordered message nonce
// @param _payload - the signed payload is the UA bytes has encoded to be sent
function lzReceive(uint16 _srcChainId, bytes calldata _srcAddress, uint64 _nonce, bytes calldata _payload) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
import "./ILayerZeroUserApplicationConfig.sol";
interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
// @notice send a LayerZero message to the specified address at a LayerZero endpoint.
// @param _dstChainId - the destination chain identifier
// @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
// @param _payload - a custom bytes payload to send to the destination contract
// @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
// @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
// @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
function send(uint16 _dstChainId, bytes calldata _destination, bytes calldata _payload, address payable _refundAddress, address _zroPaymentAddress, bytes calldata _adapterParams) external payable;
// @notice used by the messaging library to publish verified payload
// @param _srcChainId - the source chain identifier
// @param _srcAddress - the source contract (as bytes) at the source chain
// @param _dstAddress - the address on destination chain
// @param _nonce - the unbound message ordering nonce
// @param _gasLimit - the gas limit for external contract execution
// @param _payload - verified payload to send to the destination contract
function receivePayload(uint16 _srcChainId, bytes calldata _srcAddress, address _dstAddress, uint64 _nonce, uint _gasLimit, bytes calldata _payload) external;
// @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
// @param _srcChainId - the source chain identifier
// @param _srcAddress - the source chain contract address
function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (uint64);
// @notice get the outboundNonce from this source chain which, consequently, is always an EVM
// @param _srcAddress - the source chain contract address
function getOutboundNonce(uint16 _dstChainId, address _srcAddress) external view returns (uint64);
// @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
// @param _dstChainId - the destination chain identifier
// @param _userApplication - the user app address on this EVM chain
// @param _payload - the custom message to send over LayerZero
// @param _payInZRO - if false, user app pays the protocol fee in native token
// @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
function estimateFees(uint16 _dstChainId, address _userApplication, bytes calldata _payload, bool _payInZRO, bytes calldata _adapterParam) external view returns (uint nativeFee, uint zroFee);
// @notice get this Endpoint's immutable source identifier
function getChainId() external view returns (uint16);
// @notice the interface to retry failed message on this Endpoint destination
// @param _srcChainId - the source chain identifier
// @param _srcAddress - the source chain contract address
// @param _payload - the payload to be retried
function retryPayload(uint16 _srcChainId, bytes calldata _srcAddress, bytes calldata _payload) external;
// @notice query if any STORED payload (message blocking) at the endpoint.
// @param _srcChainId - the source chain identifier
// @param _srcAddress - the source chain contract address
function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress) external view returns (bool);
// @notice query if the _libraryAddress is valid for sending msgs.
// @param _userApplication - the user app address on this EVM chain
function getSendLibraryAddress(address _userApplication) external view returns (address);
// @notice query if the _libraryAddress is valid for receiving msgs.
// @param _userApplication - the user app address on this EVM chain
function getReceiveLibraryAddress(address _userApplication) external view returns (address);
// @notice query if the non-reentrancy guard for send() is on
// @return true if the guard is on. false otherwise
function isSendingPayload() external view returns (bool);
// @notice query if the non-reentrancy guard for receive() is on
// @return true if the guard is on. false otherwise
function isReceivingPayload() external view returns (bool);
// @notice get the configuration of the LayerZero messaging library of the specified version
// @param _version - messaging library version
// @param _chainId - the chainId for the pending config change
// @param _userApplication - the contract address of the user application
// @param _configType - type of configuration. every messaging library has its own convention.
function getConfig(uint16 _version, uint16 _chainId, address _userApplication, uint _configType) external view returns (bytes memory);
// @notice get the send() LayerZero messaging library version
// @param _userApplication - the contract address of the user application
function getSendVersion(address _userApplication) external view returns (uint16);
// @notice get the lzReceive() LayerZero messaging library version
// @param _userApplication - the contract address of the user application
function getReceiveVersion(address _userApplication) external view returns (uint16);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
interface IEthlasFees {
function getFee(
uint16 _dstChainId,
uint256 _amount,
uint256 _estimatedFee
) external view returns (uint256);
function percentSlip() external returns (uint256);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
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
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://consensys.net/diligence/blog/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.8.0/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
/**
* @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
/**
* @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
* calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
*/
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 oldAllowance = token.allowance(address(this), spender);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
* to be set to zero before setting it to a non-zero value, such as USDT.
*/
function forceApprove(IERC20 token, address spender, uint256 value) internal {
bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
* Revert on invalid signature.
*/
function safePermit(
IERC20Permit token,
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) internal {
uint256 nonceBefore = token.nonces(owner);
token.permit(owner, spender, value, deadline, v, r, s);
uint256 nonceAfter = token.nonces(owner);
require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*
* This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
*/
function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
// and not revert is the subcall reverts.
(bool success, bytes memory returndata) = address(token).call(data);
return
success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*/
interface IERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
* given ``owner``'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
/**
* @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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);
/**
* @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 `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, 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 `from` to `to` 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 from, address to, uint256 amount) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
_transferOwnership(address(0));
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}