Contract Source Code:
//SPDX-License-Identifier: MIT
pragma solidity ^0.8.15;
pragma abicoder v2;
// import "@openzeppelin/[email protected]/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "@openzeppelin/contracts/utils/Strings.sol";
import "@uniswap/v3-periphery/contracts/interfaces/ISwapRouter.sol";
import "@uniswap/v3-periphery/contracts/libraries/TransferHelper.sol";
import "@uniswap/v3-periphery/contracts/interfaces/IPeripheryPayments.sol";
import "@opengsn/contracts/src/BaseRelayRecipient.sol";
interface IWETH9 {
function withdraw(uint256 wad) external;
}
contract SwapC is BaseRelayRecipient, Ownable {
using Strings for uint256;
using ECDSA for bytes32;
address public signer;
address public paymaster;
mapping(address => uint256) walletToAmountWithdrawn;
string public override versionRecipient = "2.2.5";
ISwapRouter public immutable swapRouter = ISwapRouter(0xE592427A0AEce92De3Edee1F18E0157C05861564);
// mainnet
address public constant USDC = 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;
address public constant WETH9 = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
address public constant FORWARDER = 0xAa3E82b4c4093b4bA13Cb5714382C99ADBf750cA;
// goerli
// address public constant USDC = 0xD87Ba7A50B2E7E660f678A895E4B72E7CB4CCd9C;
// address public constant WETH9 = 0xB4FBF271143F4FBf7B91A5ded31805e42b2208d6;
// address public constant FORWARDER = 0x7A95fA73250dc53556d264522150A940d4C50238;
// rinkeby
// address public constant USDC = 0xeb8f08a975Ab53E34D8a0330E0D34de942C95926;
// address public constant WETH9 = 0xc778417E063141139Fce010982780140Aa0cD5Ab;
// address public constant FORWARDER = 0x83A54884bE4657706785D7309cf46B58FE5f6e8a;
uint24 public poolFee = 3000;
uint256 public paymasterFee = 33000;
constructor(address _signer, address _paymaster) {
signer = _signer;
paymaster = _paymaster;
_setTrustedForwarder(FORWARDER);
IERC20(USDC).approve(address(swapRouter), 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
}
function updateSigner(address _signer) external onlyOwner {
signer = _signer;
}
function updatePaymaster(address _paymaster) external onlyOwner {
paymaster = _paymaster;
}
function updateForwarder(address _forwarder) external onlyOwner {
_setTrustedForwarder(_forwarder);
}
function updatePoolFee(uint24 _poolFee) external onlyOwner {
poolFee = _poolFee;
}
function updatePaymasterFee(uint256 _paymasterFee) external onlyOwner {
paymasterFee = _paymasterFee;
}
function collectEth(uint256 totalAmountUSDC, bytes calldata signature) public {
address sender = _msgSender();
require(totalAmountUSDC > walletToAmountWithdrawn[sender], "Already collected");
string memory message = string(abi.encodePacked("swapc|", Strings.toHexString(uint256(uint160(sender)), 20), "|", totalAmountUSDC.toString()));
bytes32 hashedMessage = keccak256(abi.encodePacked(message));
address recoveredAddress = keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hashedMessage)).recover(signature);
require(recoveredAddress == signer, "Unauthorized signature");
uint256 usdcToConvert = totalAmountUSDC - walletToAmountWithdrawn[sender];
walletToAmountWithdrawn[sender] = totalAmountUSDC;
uint256 ethAmount = swapToEth(usdcToConvert);
uint256 ethForPaymaster = ethAmount * paymasterFee / 100000;
(bool ret, ) = paymaster.call{value: ethForPaymaster}("");
require(ret);
payable(sender).transfer(ethAmount - ethForPaymaster);
}
function swapToEth(
uint256 amountIn
) internal returns (uint256 amountOut) {
ISwapRouter.ExactInputSingleParams memory params = ISwapRouter.ExactInputSingleParams({
tokenIn: USDC,
tokenOut: WETH9,
fee: poolFee,
recipient: address(this),
deadline: block.timestamp,
amountIn: amountIn,
amountOutMinimum: 0,
sqrtPriceLimitX96: 0
});
amountOut = swapRouter.exactInputSingle(params);
IWETH9(WETH9).withdraw(amountOut);
}
/**
* @dev Accept direct ether transfers
*/
receive() external payable {}
function _msgData() internal override (Context, BaseRelayRecipient) virtual view returns (bytes calldata ret) {
return BaseRelayRecipient._msgData();
}
function _msgSender() internal override (Context, BaseRelayRecipient) virtual view returns (address ret) {
return BaseRelayRecipient._msgSender();
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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 anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing 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);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/cryptography/ECDSA.sol)
pragma solidity ^0.8.0;
import "../Strings.sol";
/**
* @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
*
* These functions can be used to verify that a message was signed by the holder
* of the private keys of a given address.
*/
library ECDSA {
enum RecoverError {
NoError,
InvalidSignature,
InvalidSignatureLength,
InvalidSignatureS,
InvalidSignatureV
}
function _throwError(RecoverError error) private pure {
if (error == RecoverError.NoError) {
return; // no error: do nothing
} else if (error == RecoverError.InvalidSignature) {
revert("ECDSA: invalid signature");
} else if (error == RecoverError.InvalidSignatureLength) {
revert("ECDSA: invalid signature length");
} else if (error == RecoverError.InvalidSignatureS) {
revert("ECDSA: invalid signature 's' value");
} else if (error == RecoverError.InvalidSignatureV) {
revert("ECDSA: invalid signature 'v' value");
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature` or error string. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*
* Documentation for signature generation:
* - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
* - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
*
* _Available since v4.3._
*/
function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
// Check the signature length
// - case 65: r,s,v signature (standard)
// - case 64: r,vs signature (cf https://eips.ethereum.org/EIPS/eip-2098) _Available since v4.1._
if (signature.length == 65) {
bytes32 r;
bytes32 s;
uint8 v;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
/// @solidity memory-safe-assembly
assembly {
r := mload(add(signature, 0x20))
s := mload(add(signature, 0x40))
v := byte(0, mload(add(signature, 0x60)))
}
return tryRecover(hash, v, r, s);
} else if (signature.length == 64) {
bytes32 r;
bytes32 vs;
// ecrecover takes the signature parameters, and the only way to get them
// currently is to use assembly.
/// @solidity memory-safe-assembly
assembly {
r := mload(add(signature, 0x20))
vs := mload(add(signature, 0x40))
}
return tryRecover(hash, r, vs);
} else {
return (address(0), RecoverError.InvalidSignatureLength);
}
}
/**
* @dev Returns the address that signed a hashed message (`hash`) with
* `signature`. This address can then be used for verification purposes.
*
* The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
* this function rejects them by requiring the `s` value to be in the lower
* half order, and the `v` value to be either 27 or 28.
*
* IMPORTANT: `hash` _must_ be the result of a hash operation for the
* verification to be secure: it is possible to craft signatures that
* recover to arbitrary addresses for non-hashed data. A safe way to ensure
* this is by receiving a hash of the original message (which may otherwise
* be too long), and then calling {toEthSignedMessageHash} on it.
*/
function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, signature);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
*
* See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address, RecoverError) {
bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
uint8 v = uint8((uint256(vs) >> 255) + 27);
return tryRecover(hash, v, r, s);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
*
* _Available since v4.2._
*/
function recover(
bytes32 hash,
bytes32 r,
bytes32 vs
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, r, vs);
_throwError(error);
return recovered;
}
/**
* @dev Overload of {ECDSA-tryRecover} that receives the `v`,
* `r` and `s` signature fields separately.
*
* _Available since v4.3._
*/
function tryRecover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address, RecoverError) {
// EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
// unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
// the valid range for s in (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): v ∈ {27, 28}. Most
// signatures from current libraries generate a unique signature with an s-value in the lower half order.
//
// If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
// with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
// vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
// these malleable signatures as well.
if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
return (address(0), RecoverError.InvalidSignatureS);
}
if (v != 27 && v != 28) {
return (address(0), RecoverError.InvalidSignatureV);
}
// If the signature is valid (and not malleable), return the signer address
address signer = ecrecover(hash, v, r, s);
if (signer == address(0)) {
return (address(0), RecoverError.InvalidSignature);
}
return (signer, RecoverError.NoError);
}
/**
* @dev Overload of {ECDSA-recover} that receives the `v`,
* `r` and `s` signature fields separately.
*/
function recover(
bytes32 hash,
uint8 v,
bytes32 r,
bytes32 s
) internal pure returns (address) {
(address recovered, RecoverError error) = tryRecover(hash, v, r, s);
_throwError(error);
return recovered;
}
/**
* @dev Returns an Ethereum Signed Message, created from a `hash`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
// 32 is the length in bytes of hash,
// enforced by the type signature above
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n32", hash));
}
/**
* @dev Returns an Ethereum Signed Message, created from `s`. This
* produces hash corresponding to the one signed with the
* https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
* JSON-RPC method as part of EIP-191.
*
* See {recover}.
*/
function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(s.length), s));
}
/**
* @dev Returns an Ethereum Signed Typed Data, created from a
* `domainSeparator` and a `structHash`. This produces hash corresponding
* to the one signed with the
* https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
* JSON-RPC method as part of EIP-712.
*
* See {recover}.
*/
function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
return keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _HEX_SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
pragma abicoder v2;
import '@uniswap/v3-core/contracts/interfaces/callback/IUniswapV3SwapCallback.sol';
/// @title Router token swapping functionality
/// @notice Functions for swapping tokens via Uniswap V3
interface ISwapRouter is IUniswapV3SwapCallback {
struct ExactInputSingleParams {
address tokenIn;
address tokenOut;
uint24 fee;
address recipient;
uint256 deadline;
uint256 amountIn;
uint256 amountOutMinimum;
uint160 sqrtPriceLimitX96;
}
/// @notice Swaps `amountIn` of one token for as much as possible of another token
/// @param params The parameters necessary for the swap, encoded as `ExactInputSingleParams` in calldata
/// @return amountOut The amount of the received token
function exactInputSingle(ExactInputSingleParams calldata params) external payable returns (uint256 amountOut);
struct ExactInputParams {
bytes path;
address recipient;
uint256 deadline;
uint256 amountIn;
uint256 amountOutMinimum;
}
/// @notice Swaps `amountIn` of one token for as much as possible of another along the specified path
/// @param params The parameters necessary for the multi-hop swap, encoded as `ExactInputParams` in calldata
/// @return amountOut The amount of the received token
function exactInput(ExactInputParams calldata params) external payable returns (uint256 amountOut);
struct ExactOutputSingleParams {
address tokenIn;
address tokenOut;
uint24 fee;
address recipient;
uint256 deadline;
uint256 amountOut;
uint256 amountInMaximum;
uint160 sqrtPriceLimitX96;
}
/// @notice Swaps as little as possible of one token for `amountOut` of another token
/// @param params The parameters necessary for the swap, encoded as `ExactOutputSingleParams` in calldata
/// @return amountIn The amount of the input token
function exactOutputSingle(ExactOutputSingleParams calldata params) external payable returns (uint256 amountIn);
struct ExactOutputParams {
bytes path;
address recipient;
uint256 deadline;
uint256 amountOut;
uint256 amountInMaximum;
}
/// @notice Swaps as little as possible of one token for `amountOut` of another along the specified path (reversed)
/// @param params The parameters necessary for the multi-hop swap, encoded as `ExactOutputParams` in calldata
/// @return amountIn The amount of the input token
function exactOutput(ExactOutputParams calldata params) external payable returns (uint256 amountIn);
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.6.0;
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
library TransferHelper {
/// @notice Transfers tokens from the targeted address to the given destination
/// @notice Errors with 'STF' if transfer fails
/// @param token The contract address of the token to be transferred
/// @param from The originating address from which the tokens will be transferred
/// @param to The destination address of the transfer
/// @param value The amount to be transferred
function safeTransferFrom(
address token,
address from,
address to,
uint256 value
) internal {
(bool success, bytes memory data) =
token.call(abi.encodeWithSelector(IERC20.transferFrom.selector, from, to, value));
require(success && (data.length == 0 || abi.decode(data, (bool))), 'STF');
}
/// @notice Transfers tokens from msg.sender to a recipient
/// @dev Errors with ST if transfer fails
/// @param token The contract address of the token which will be transferred
/// @param to The recipient of the transfer
/// @param value The value of the transfer
function safeTransfer(
address token,
address to,
uint256 value
) internal {
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.transfer.selector, to, value));
require(success && (data.length == 0 || abi.decode(data, (bool))), 'ST');
}
/// @notice Approves the stipulated contract to spend the given allowance in the given token
/// @dev Errors with 'SA' if transfer fails
/// @param token The contract address of the token to be approved
/// @param to The target of the approval
/// @param value The amount of the given token the target will be allowed to spend
function safeApprove(
address token,
address to,
uint256 value
) internal {
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(IERC20.approve.selector, to, value));
require(success && (data.length == 0 || abi.decode(data, (bool))), 'SA');
}
/// @notice Transfers ETH to the recipient address
/// @dev Fails with `STE`
/// @param to The destination of the transfer
/// @param value The value to be transferred
function safeTransferETH(address to, uint256 value) internal {
(bool success, ) = to.call{value: value}(new bytes(0));
require(success, 'STE');
}
}
// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity >=0.7.5;
/// @title Periphery Payments
/// @notice Functions to ease deposits and withdrawals of ETH
interface IPeripheryPayments {
/// @notice Unwraps the contract's WETH9 balance and sends it to recipient as ETH.
/// @dev The amountMinimum parameter prevents malicious contracts from stealing WETH9 from users.
/// @param amountMinimum The minimum amount of WETH9 to unwrap
/// @param recipient The address receiving ETH
function unwrapWETH9(uint256 amountMinimum, address recipient) external payable;
/// @notice Refunds any ETH balance held by this contract to the `msg.sender`
/// @dev Useful for bundling with mint or increase liquidity that uses ether, or exact output swaps
/// that use ether for the input amount
function refundETH() external payable;
/// @notice Transfers the full amount of a token held by this contract to recipient
/// @dev The amountMinimum parameter prevents malicious contracts from stealing the token from users
/// @param token The contract address of the token which will be transferred to `recipient`
/// @param amountMinimum The minimum amount of token required for a transfer
/// @param recipient The destination address of the token
function sweepToken(
address token,
uint256 amountMinimum,
address recipient
) external payable;
}
// SPDX-License-Identifier: MIT
// solhint-disable no-inline-assembly
pragma solidity >=0.6.9;
import "./interfaces/IRelayRecipient.sol";
/**
* A base contract to be inherited by any contract that want to receive relayed transactions
* A subclass must use "_msgSender()" instead of "msg.sender"
*/
abstract contract BaseRelayRecipient is IRelayRecipient {
/*
* Forwarder singleton we accept calls from
*/
address private _trustedForwarder;
function trustedForwarder() public virtual view returns (address){
return _trustedForwarder;
}
function _setTrustedForwarder(address _forwarder) internal {
_trustedForwarder = _forwarder;
}
function isTrustedForwarder(address forwarder) public virtual override view returns(bool) {
return forwarder == _trustedForwarder;
}
/**
* return the sender of this call.
* if the call came through our trusted forwarder, return the original sender.
* otherwise, return `msg.sender`.
* should be used in the contract anywhere instead of msg.sender
*/
function _msgSender() internal override virtual view returns (address ret) {
if (msg.data.length >= 20 && isTrustedForwarder(msg.sender)) {
// At this point we know that the sender is a trusted forwarder,
// so we trust that the last bytes of msg.data are the verified sender address.
// extract sender address from the end of msg.data
assembly {
ret := shr(96,calldataload(sub(calldatasize(),20)))
}
} else {
ret = msg.sender;
}
}
/**
* return the msg.data of this call.
* if the call came through our trusted forwarder, then the real sender was appended as the last 20 bytes
* of the msg.data - so this method will strip those 20 bytes off.
* otherwise (if the call was made directly and not through the forwarder), return `msg.data`
* should be used in the contract instead of msg.data, where this difference matters.
*/
function _msgData() internal override virtual view returns (bytes calldata ret) {
if (msg.data.length >= 20 && isTrustedForwarder(msg.sender)) {
return msg.data[0:msg.data.length-20];
} else {
return msg.data;
}
}
}
// 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: GPL-2.0-or-later
pragma solidity >=0.5.0;
/// @title Callback for IUniswapV3PoolActions#swap
/// @notice Any contract that calls IUniswapV3PoolActions#swap must implement this interface
interface IUniswapV3SwapCallback {
/// @notice Called to `msg.sender` after executing a swap via IUniswapV3Pool#swap.
/// @dev In the implementation you must pay the pool tokens owed for the swap.
/// The caller of this method must be checked to be a UniswapV3Pool deployed by the canonical UniswapV3Factory.
/// amount0Delta and amount1Delta can both be 0 if no tokens were swapped.
/// @param amount0Delta The amount of token0 that was sent (negative) or must be received (positive) by the pool by
/// the end of the swap. If positive, the callback must send that amount of token0 to the pool.
/// @param amount1Delta The amount of token1 that was sent (negative) or must be received (positive) by the pool by
/// the end of the swap. If positive, the callback must send that amount of token1 to the pool.
/// @param data Any data passed through by the caller via the IUniswapV3PoolActions#swap call
function uniswapV3SwapCallback(
int256 amount0Delta,
int256 amount1Delta,
bytes calldata data
) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (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
pragma solidity >=0.6.0;
/**
* a contract must implement this interface in order to support relayed transaction.
* It is better to inherit the BaseRelayRecipient as its implementation.
*/
abstract contract IRelayRecipient {
/**
* return if the forwarder is trusted to forward relayed transactions to us.
* the forwarder is required to verify the sender's signature, and verify
* the call is not a replay.
*/
function isTrustedForwarder(address forwarder) public virtual view returns(bool);
/**
* return the sender of this call.
* if the call came through our trusted forwarder, then the real sender is appended as the last 20 bytes
* of the msg.data.
* otherwise, return `msg.sender`
* should be used in the contract anywhere instead of msg.sender
*/
function _msgSender() internal virtual view returns (address);
/**
* return the msg.data of this call.
* if the call came through our trusted forwarder, then the real sender was appended as the last 20 bytes
* of the msg.data - so this method will strip those 20 bytes off.
* otherwise (if the call was made directly and not through the forwarder), return `msg.data`
* should be used in the contract instead of msg.data, where this difference matters.
*/
function _msgData() internal virtual view returns (bytes calldata);
function versionRecipient() external virtual view returns (string memory);
}