Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
import "../libraries/math/SafeMath.sol";
import "../libraries/token/IERC20.sol";
import "../libraries/token/SafeERC20.sol";
import "../libraries/utils/Address.sol";
import "../tokens/interfaces/IWETH.sol";
import "./interfaces/IVault.sol";
import "./interfaces/IRouter.sol";
contract Router is IRouter {
using SafeMath for uint256;
using SafeERC20 for IERC20;
using Address for address payable;
address public gov;
// wrapped BNB / ETH
address public weth;
address public usdn;
address public vault;
mapping (address => bool) public plugins;
mapping (address => mapping (address => bool)) public approvedPlugins;
event Swap(address account, address tokenIn, address tokenOut, uint256 amountIn, uint256 amountOut);
modifier onlyGov() {
require(msg.sender == gov, "Router: forbidden");
_;
}
constructor(address _vault, address _usdn, address _weth) public {
vault = _vault;
usdn = _usdn;
weth = _weth;
gov = msg.sender;
}
receive() external payable {
require(msg.sender == weth, "Router: invalid sender");
}
function setGov(address _gov) external onlyGov {
gov = _gov;
}
function addPlugin(address _plugin) external override onlyGov {
plugins[_plugin] = true;
}
function removePlugin(address _plugin) external onlyGov {
plugins[_plugin] = false;
}
function approvePlugin(address _plugin) external {
approvedPlugins[msg.sender][_plugin] = true;
}
function denyPlugin(address _plugin) external {
approvedPlugins[msg.sender][_plugin] = false;
}
function pluginTransfer(address _token, address _account, address _receiver, uint256 _amount) external override {
_validatePlugin(_account);
IERC20(_token).safeTransferFrom(_account, _receiver, _amount);
}
function pluginIncreasePosition(address _account, address _collateralToken, address _indexToken, uint256 _sizeDelta, bool _isLong) external override {
_validatePlugin(_account);
IVault(vault).increasePosition(_account, _collateralToken, _indexToken, _sizeDelta, _isLong);
}
function pluginDecreasePosition(address _account, address _collateralToken, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address _receiver) external override returns (uint256) {
_validatePlugin(_account);
return IVault(vault).decreasePosition(_account, _collateralToken, _indexToken, _collateralDelta, _sizeDelta, _isLong, _receiver);
}
function directPoolDeposit(address _token, uint256 _amount) external {
IERC20(_token).safeTransferFrom(_sender(), vault, _amount);
IVault(vault).directPoolDeposit(_token);
}
function swap(address[] memory _path, uint256 _amountIn, uint256 _minOut, address _receiver) public override {
IERC20(_path[0]).safeTransferFrom(_sender(), vault, _amountIn);
uint256 amountOut = _swap(_path, _minOut, _receiver);
emit Swap(msg.sender, _path[0], _path[_path.length - 1], _amountIn, amountOut);
}
function swapETHToTokens(address[] memory _path, uint256 _minOut, address _receiver) external payable {
require(_path[0] == weth, "Router: invalid _path");
_transferETHToVault();
uint256 amountOut = _swap(_path, _minOut, _receiver);
emit Swap(msg.sender, _path[0], _path[_path.length - 1], msg.value, amountOut);
}
function swapTokensToETH(address[] memory _path, uint256 _amountIn, uint256 _minOut, address payable _receiver) external {
require(_path[_path.length - 1] == weth, "Router: invalid _path");
IERC20(_path[0]).safeTransferFrom(_sender(), vault, _amountIn);
uint256 amountOut = _swap(_path, _minOut, address(this));
_transferOutETH(amountOut, _receiver);
emit Swap(msg.sender, _path[0], _path[_path.length - 1], _amountIn, amountOut);
}
function increasePosition(address[] memory _path, address _indexToken, uint256 _amountIn, uint256 _minOut, uint256 _sizeDelta, bool _isLong, uint256 _price) external {
if (_amountIn > 0) {
IERC20(_path[0]).safeTransferFrom(_sender(), vault, _amountIn);
}
if (_path.length > 1 && _amountIn > 0) {
uint256 amountOut = _swap(_path, _minOut, address(this));
IERC20(_path[_path.length - 1]).safeTransfer(vault, amountOut);
}
_increasePosition(_path[_path.length - 1], _indexToken, _sizeDelta, _isLong, _price);
}
function increasePositionETH(address[] memory _path, address _indexToken, uint256 _minOut, uint256 _sizeDelta, bool _isLong, uint256 _price) external payable {
require(_path[0] == weth, "Router: invalid _path");
if (msg.value > 0) {
_transferETHToVault();
}
if (_path.length > 1 && msg.value > 0) {
uint256 amountOut = _swap(_path, _minOut, address(this));
IERC20(_path[_path.length - 1]).safeTransfer(vault, amountOut);
}
_increasePosition(_path[_path.length - 1], _indexToken, _sizeDelta, _isLong, _price);
}
function decreasePosition(address _collateralToken, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address _receiver, uint256 _price) external {
_decreasePosition(_collateralToken, _indexToken, _collateralDelta, _sizeDelta, _isLong, _receiver, _price);
}
function decreasePositionETH(address _collateralToken, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address payable _receiver, uint256 _price) external {
uint256 amountOut = _decreasePosition(_collateralToken, _indexToken, _collateralDelta, _sizeDelta, _isLong, address(this), _price);
_transferOutETH(amountOut, _receiver);
}
function decreasePositionAndSwap(address[] memory _path, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address _receiver, uint256 _price, uint256 _minOut) external {
uint256 amount = _decreasePosition(_path[0], _indexToken, _collateralDelta, _sizeDelta, _isLong, address(this), _price);
IERC20(_path[0]).safeTransfer(vault, amount);
_swap(_path, _minOut, _receiver);
}
function decreasePositionAndSwapETH(address[] memory _path, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address payable _receiver, uint256 _price, uint256 _minOut) external {
require(_path[_path.length - 1] == weth, "Router: invalid _path");
uint256 amount = _decreasePosition(_path[0], _indexToken, _collateralDelta, _sizeDelta, _isLong, address(this), _price);
IERC20(_path[0]).safeTransfer(vault, amount);
uint256 amountOut = _swap(_path, _minOut, address(this));
_transferOutETH(amountOut, _receiver);
}
function _increasePosition(address _collateralToken, address _indexToken, uint256 _sizeDelta, bool _isLong, uint256 _price) private {
if (_isLong) {
require(IVault(vault).getMaxPrice(_indexToken) <= _price, "Router: mark price higher than limit");
} else {
require(IVault(vault).getMinPrice(_indexToken) >= _price, "Router: mark price lower than limit");
}
IVault(vault).increasePosition(_sender(), _collateralToken, _indexToken, _sizeDelta, _isLong);
}
function _decreasePosition(address _collateralToken, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address _receiver, uint256 _price) private returns (uint256) {
if (_isLong) {
require(IVault(vault).getMinPrice(_indexToken) >= _price, "Router: mark price lower than limit");
} else {
require(IVault(vault).getMaxPrice(_indexToken) <= _price, "Router: mark price higher than limit");
}
return IVault(vault).decreasePosition(_sender(), _collateralToken, _indexToken, _collateralDelta, _sizeDelta, _isLong, _receiver);
}
function _transferETHToVault() private {
IWETH(weth).deposit{value: msg.value}();
IERC20(weth).safeTransfer(vault, msg.value);
}
function _transferOutETH(uint256 _amountOut, address payable _receiver) private {
IWETH(weth).withdraw(_amountOut);
_receiver.sendValue(_amountOut);
}
function _swap(address[] memory _path, uint256 _minOut, address _receiver) private returns (uint256) {
if (_path.length == 2) {
return _vaultSwap(_path[0], _path[1], _minOut, _receiver);
}
if (_path.length == 3) {
uint256 midOut = _vaultSwap(_path[0], _path[1], 0, address(this));
IERC20(_path[1]).safeTransfer(vault, midOut);
return _vaultSwap(_path[1], _path[2], _minOut, _receiver);
}
revert("Router: invalid _path.length");
}
function _vaultSwap(address _tokenIn, address _tokenOut, uint256 _minOut, address _receiver) private returns (uint256) {
uint256 amountOut;
if (_tokenOut == usdn) { // buyUSDN
amountOut = IVault(vault).buyUSDN(_tokenIn, _receiver);
} else if (_tokenIn == usdn) { // sellUSDN
amountOut = IVault(vault).sellUSDN(_tokenOut, _receiver);
} else { // swap
amountOut = IVault(vault).swap(_tokenIn, _tokenOut, _receiver);
}
require(amountOut >= _minOut, "Router: insufficient amountOut");
return amountOut;
}
function _sender() private view returns (address) {
return msg.sender;
}
function _validatePlugin(address _account) private view {
require(plugins[msg.sender], "Router: invalid plugin");
require(approvedPlugins[_account][msg.sender], "Router: plugin not approved");
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
interface IRouter {
function addPlugin(address _plugin) external;
function pluginTransfer(address _token, address _account, address _receiver, uint256 _amount) external;
function pluginIncreasePosition(address _account, address _collateralToken, address _indexToken, uint256 _sizeDelta, bool _isLong) external;
function pluginDecreasePosition(address _account, address _collateralToken, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address _receiver) external returns (uint256);
function swap(address[] memory _path, uint256 _amountIn, uint256 _minOut, address _receiver) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
import "./IVaultUtils.sol";
interface IVault {
function isInitialized() external view returns (bool);
function isSwapEnabled() external view returns (bool);
function isLeverageEnabled() external view returns (bool);
function setVaultUtils(IVaultUtils _vaultUtils) external;
function setError(uint256 _errorCode, string calldata _error) external;
function router() external view returns (address);
function usdn() external view returns (address);
function gov() external view returns (address);
function whitelistedTokenCount() external view returns (uint256);
function maxLeverage() external view returns (uint256);
function minProfitTime() external view returns (uint256);
function hasDynamicFees() external view returns (bool);
function fundingInterval() external view returns (uint256);
function totalTokenWeights() external view returns (uint256);
function getTargetUsdnAmount(address _token) external view returns (uint256);
function inManagerMode() external view returns (bool);
function inPrivateLiquidationMode() external view returns (bool);
function maxGasPrice() external view returns (uint256);
function approvedRouters(address _account, address _router) external view returns (bool);
function isLiquidator(address _account) external view returns (bool);
function isManager(address _account) external view returns (bool);
function minProfitBasisPoints(address _token) external view returns (uint256);
function tokenBalances(address _token) external view returns (uint256);
function lastFundingTimes(address _token) external view returns (uint256);
function setMaxLeverage(uint256 _maxLeverage) external;
function setInManagerMode(bool _inManagerMode) external;
function setManager(address _manager, bool _isManager) external;
function setIsSwapEnabled(bool _isSwapEnabled) external;
function setIsLeverageEnabled(bool _isLeverageEnabled) external;
function setMaxGasPrice(uint256 _maxGasPrice) external;
function setUsdnAmount(address _token, uint256 _amount) external;
function setBufferAmount(address _token, uint256 _amount) external;
function setMaxGlobalShortSize(address _token, uint256 _amount) external;
function setInPrivateLiquidationMode(bool _inPrivateLiquidationMode) external;
function setLiquidator(address _liquidator, bool _isActive) external;
function setFundingRate(uint256 _fundingInterval, uint256 _fundingRateFactor, uint256 _stableFundingRateFactor) external;
function setFees(
uint256 _taxBasisPoints,
uint256 _stableTaxBasisPoints,
uint256 _mintBurnFeeBasisPoints,
uint256 _swapFeeBasisPoints,
uint256 _stableSwapFeeBasisPoints,
uint256 _marginFeeBasisPoints,
uint256 _liquidationFeeUsd,
uint256 _minProfitTime,
bool _hasDynamicFees
) external;
function setTokenConfig(
address _token,
uint256 _tokenDecimals,
uint256 _redemptionBps,
uint256 _minProfitBps,
uint256 _maxUsdnAmount,
bool _isStable,
bool _isShortable
) external;
function setPriceFeed(address _priceFeed) external;
function withdrawFees(address _token, address _receiver) external returns (uint256);
function directPoolDeposit(address _token) external;
function buyUSDN(address _token, address _receiver) external returns (uint256);
function sellUSDN(address _token, address _receiver) external returns (uint256);
function swap(address _tokenIn, address _tokenOut, address _receiver) external returns (uint256);
function increasePosition(address _account, address _collateralToken, address _indexToken, uint256 _sizeDelta, bool _isLong) external;
function decreasePosition(address _account, address _collateralToken, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address _receiver) external returns (uint256);
function validateLiquidation(address _account, address _collateralToken, address _indexToken, bool _isLong, bool _raise) external view returns (uint256, uint256);
function liquidatePosition(address _account, address _collateralToken, address _indexToken, bool _isLong, address _feeReceiver) external;
function tokenToUsdMin(address _token, uint256 _tokenAmount) external view returns (uint256);
function priceFeed() external view returns (address);
function fundingRateFactor() external view returns (uint256);
function stableFundingRateFactor() external view returns (uint256);
function cumulativeFundingRates(address _token) external view returns (uint256);
function getNextFundingRate(address _token) external view returns (uint256);
function getFeeBasisPoints(address _token, uint256 _usdnDelta, uint256 _feeBasisPoints, uint256 _taxBasisPoints, bool _increment) external view returns (uint256);
function liquidationFeeUsd() external view returns (uint256);
function taxBasisPoints() external view returns (uint256);
function stableTaxBasisPoints() external view returns (uint256);
function mintBurnFeeBasisPoints() external view returns (uint256);
function swapFeeBasisPoints() external view returns (uint256);
function stableSwapFeeBasisPoints() external view returns (uint256);
function marginFeeBasisPoints() external view returns (uint256);
function allWhitelistedTokensLength() external view returns (uint256);
function allWhitelistedTokens(uint256) external view returns (address);
function whitelistedTokens(address _token) external view returns (bool);
function stableTokens(address _token) external view returns (bool);
function shortableTokens(address _token) external view returns (bool);
function feeReserves(address _token) external view returns (uint256);
function globalShortSizes(address _token) external view returns (uint256);
function globalShortAveragePrices(address _token) external view returns (uint256);
function maxGlobalShortSizes(address _token) external view returns (uint256);
function tokenDecimals(address _token) external view returns (uint256);
function tokenWeights(address _token) external view returns (uint256);
function guaranteedUsd(address _token) external view returns (uint256);
function poolAmounts(address _token) external view returns (uint256);
function bufferAmounts(address _token) external view returns (uint256);
function reservedAmounts(address _token) external view returns (uint256);
function usdnAmounts(address _token) external view returns (uint256);
function maxUsdnAmounts(address _token) external view returns (uint256);
function getRedemptionAmount(address _token, uint256 _usdnAmount) external view returns (uint256);
function getMaxPrice(address _token) external view returns (uint256);
function getMinPrice(address _token) external view returns (uint256);
function getDelta(address _indexToken, uint256 _size, uint256 _averagePrice, bool _isLong, uint256 _lastIncreasedTime) external view returns (bool, uint256);
function getPosition(address _account, address _collateralToken, address _indexToken, bool _isLong) external view returns (uint256, uint256, uint256, uint256, uint256, uint256, bool, uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
interface IVaultUtils {
function updateCumulativeFundingRate(address _collateralToken, address _indexToken) external returns (bool);
function validateIncreasePosition(address _account, address _collateralToken, address _indexToken, uint256 _sizeDelta, bool _isLong) external view;
function validateDecreasePosition(address _account, address _collateralToken, address _indexToken, uint256 _collateralDelta, uint256 _sizeDelta, bool _isLong, address _receiver) external view;
function validateLiquidation(address _account, address _collateralToken, address _indexToken, bool _isLong, bool _raise) external view returns (uint256, uint256);
function getEntryFundingRate(address _collateralToken, address _indexToken, bool _isLong) external view returns (uint256);
function getPositionFee(address _account, address _collateralToken, address _indexToken, bool _isLong, uint256 _sizeDelta) external view returns (uint256);
function getFundingFee(address _account, address _collateralToken, address _indexToken, bool _isLong, uint256 _size, uint256 _entryFundingRate) external view returns (uint256);
function getBuyUsdnFeeBasisPoints(address _token, uint256 _usdnAmount) external view returns (uint256);
function getSellUsdnFeeBasisPoints(address _token, uint256 _usdnAmount) external view returns (uint256);
function getSwapFeeBasisPoints(address _tokenIn, address _tokenOut, uint256 _usdnAmount) external view returns (uint256);
function getFeeBasisPoints(address _token, uint256 _usdnDelta, uint256 _feeBasisPoints, uint256 _taxBasisPoints, bool _increment) external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.12;
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
/**
* @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 0.6.12;
import "./IERC20.sol";
import "../math/SafeMath.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 SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
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'
// solhint-disable-next-line max-line-length
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));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @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");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.2;
/**
* @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
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 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://diligence.consensys.net/posts/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/v0.5.11/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");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(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 functionCall(target, data, "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");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: value }(data);
return _verifyCallResult(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) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.3._
*/
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 v3.3._
*/
function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
if (success) {
return returndata;
} else {
// 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
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
//SPDX-License-Identifier: MIT
pragma solidity 0.6.12;
interface IWETH {
function deposit() external payable;
function transfer(address to, uint value) external returns (bool);
function withdraw(uint) external;
}