Contract Name:
KyberSwapV3
Contract Source Code:
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.7.6;
pragma experimental ABIEncoderV2;
import "./BaseSwap.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@kyber.network/utils-sc/contracts/IERC20Ext.sol";
import "../libraries/BytesLib.sol";
contract KyberSwapV3 is BaseSwap {
using SafeERC20 for IERC20Ext;
using Address for address;
using BytesLib for bytes;
using SafeMath for uint256;
address public router;
constructor(address _admin, address _router) BaseSwap(_admin) {
router = _router;
}
event UpdatedAggregationRouter(address router);
function updateAggregationRouter(address _router) external onlyAdmin {
router = _router;
emit UpdatedAggregationRouter(router);
}
/// @dev get expected return and conversion rate if using a Uni router
function getExpectedReturn(GetExpectedReturnParams calldata params)
external
view
override
onlyProxyContract
returns (uint256 destAmount)
{
require(false, "getExpectedReturn_notSupported");
}
function getExpectedIn(GetExpectedInParams calldata params)
external
view
override
onlyProxyContract
returns (uint256 srcAmount)
{
require(false, "getExpectedIn_notSupported");
}
/// @dev get expected return and conversion rate if using a Uni router
function getExpectedReturnWithImpact(GetExpectedReturnParams calldata params)
external
view
override
onlyProxyContract
returns (uint256 destAmount, uint256 priceImpact)
{
require(false, "getExpectedReturnWithImpact_notSupported");
}
function getExpectedInWithImpact(GetExpectedInParams calldata params)
external
view
override
onlyProxyContract
returns (uint256 srcAmount, uint256 priceImpact)
{
require(false, "getExpectedInWithImpact_notSupported");
}
function swap(SwapParams calldata params)
external
payable
override
onlyProxyContract
returns (uint256 destAmount)
{
safeApproveAllowance(address(router), IERC20Ext(params.tradePath[0]));
bytes memory encodedSwapData = params.extraArgs;
uint256 tradeLen = params.tradePath.length;
IERC20Ext actualSrc = IERC20Ext(params.tradePath[0]);
IERC20Ext actualDest = IERC20Ext(params.tradePath[tradeLen - 1]);
uint256 destBalanceBefore = getBalance(actualDest, params.recipient);
bool etherIn = IERC20Ext(actualSrc) == ETH_TOKEN_ADDRESS;
uint256 callValue = etherIn ? params.srcAmount : 0;
(bool success, bytes memory returnDestAmount) = payable(router).call{value: callValue}(
encodedSwapData
);
require(success, "swapByKyberSwapV3: failed");
destAmount = decodeSwapResponse(returnDestAmount);
}
function decodeSwapResponse(bytes memory data)
internal
pure
returns (uint256 decodedResponse)
{
decodedResponse = abi.decode(data, (uint256));
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.7.6;
pragma abicoder v2;
import "@kyber.network/utils-sc/contracts/Withdrawable.sol";
import "@kyber.network/utils-sc/contracts/Utils.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "./ISwap.sol";
abstract contract BaseSwap is ISwap, Withdrawable, Utils {
using SafeERC20 for IERC20Ext;
using SafeMath for uint256;
uint256 internal constant MAX_AMOUNT = type(uint256).max;
address public proxyContract;
event UpdatedproxyContract(address indexed _oldProxyImpl, address indexed _newProxyImpl);
modifier onlyProxyContract() {
require(msg.sender == proxyContract, "only swap impl");
_;
}
constructor(address _admin) Withdrawable(_admin) {}
receive() external payable {}
function updateProxyContract(address _proxyContract) external onlyAdmin {
require(_proxyContract != address(0), "invalid swap impl");
emit UpdatedproxyContract(proxyContract, _proxyContract);
proxyContract = _proxyContract;
}
// Swap contracts don't keep funds. It's safe to set the max allowance
function safeApproveAllowance(address spender, IERC20Ext token) internal {
if (token != ETH_TOKEN_ADDRESS && token.allowance(address(this), spender) == 0) {
token.safeApprove(spender, MAX_ALLOWANCE);
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
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 <0.8.0;
/**
* @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 v3.4._
*/
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) {
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 0.7.6;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
/**
* @dev Interface extending ERC20 standard to include decimals() as
* it is optional in the OpenZeppelin IERC20 interface.
*/
interface IERC20Ext is IERC20 {
/**
* @dev This function is required as Kyber requires to interact
* with token.decimals() with many of its operations.
*/
function decimals() external view returns (uint8 digits);
}
pragma solidity 0.7.6;
library BytesLib {
function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
require(_start + 20 >= _start, "toAddress_overflow");
require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
address tempAddress;
assembly {
tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
}
return tempAddress;
}
function toUint24(bytes memory _bytes, uint256 _start) internal pure returns (uint24) {
require(_start + 3 >= _start, "toUint24_overflow");
require(_bytes.length >= _start + 3, "toUint24_outOfBounds");
uint24 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x3), _start))
}
return tempUint;
}
function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
require(_start + 32 >= _start, "toUint256_overflow");
require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
uint256 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x20), _start))
}
return tempUint;
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.6;
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "./IERC20Ext.sol";
import "./PermissionAdmin.sol";
abstract contract Withdrawable is PermissionAdmin {
using SafeERC20 for IERC20Ext;
event TokenWithdraw(IERC20Ext token, uint256 amount, address sendTo);
event EtherWithdraw(uint256 amount, address sendTo);
constructor(address _admin) PermissionAdmin(_admin) {}
/**
* @dev Withdraw all IERC20Ext compatible tokens
* @param token IERC20Ext The address of the token contract
*/
function withdrawToken(
IERC20Ext token,
uint256 amount,
address sendTo
) external onlyAdmin {
token.safeTransfer(sendTo, amount);
emit TokenWithdraw(token, amount, sendTo);
}
/**
* @dev Withdraw Ethers
*/
function withdrawEther(uint256 amount, address payable sendTo) external onlyAdmin {
(bool success, ) = sendTo.call{value: amount}("");
require(success, "withdraw failed");
emit EtherWithdraw(amount, sendTo);
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.6;
import "./IERC20Ext.sol";
/**
* @title Kyber utility file
* mostly shared constants and rate calculation helpers
* inherited by most of kyber contracts.
* previous utils implementations are for previous solidity versions.
*/
abstract contract Utils {
// Declared constants below to be used in tandem with
// getDecimalsConstant(), for gas optimization purposes
// which return decimals from a constant list of popular
// tokens.
IERC20Ext internal constant ETH_TOKEN_ADDRESS = IERC20Ext(
0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE
);
IERC20Ext internal constant USDT_TOKEN_ADDRESS = IERC20Ext(
0xdAC17F958D2ee523a2206206994597C13D831ec7
);
IERC20Ext internal constant DAI_TOKEN_ADDRESS = IERC20Ext(
0x6B175474E89094C44Da98b954EedeAC495271d0F
);
IERC20Ext internal constant USDC_TOKEN_ADDRESS = IERC20Ext(
0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
);
IERC20Ext internal constant WBTC_TOKEN_ADDRESS = IERC20Ext(
0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599
);
IERC20Ext internal constant KNC_TOKEN_ADDRESS = IERC20Ext(
0xdd974D5C2e2928deA5F71b9825b8b646686BD200
);
uint256 public constant BPS = 10000; // Basic Price Steps. 1 step = 0.01%
uint256 internal constant PRECISION = (10**18);
uint256 internal constant MAX_QTY = (10**28); // 10B tokens
uint256 internal constant MAX_RATE = (PRECISION * 10**7); // up to 10M tokens per eth
uint256 internal constant MAX_DECIMALS = 18;
uint256 internal constant ETH_DECIMALS = 18;
uint256 internal constant MAX_ALLOWANCE = uint256(-1); // token.approve inifinite
mapping(IERC20Ext => uint256) internal decimals;
/// @dev Sets the decimals of a token to storage if not already set, and returns
/// the decimals value of the token. Prefer using this function over
/// getDecimals(), to avoid forgetting to set decimals in local storage.
/// @param token The token type
/// @return tokenDecimals The decimals of the token
function getSetDecimals(IERC20Ext token) internal returns (uint256 tokenDecimals) {
tokenDecimals = getDecimalsConstant(token);
if (tokenDecimals > 0) return tokenDecimals;
tokenDecimals = decimals[token];
if (tokenDecimals == 0) {
tokenDecimals = token.decimals();
decimals[token] = tokenDecimals;
}
}
/// @dev Get the balance of a user
/// @param token The token type
/// @param user The user's address
/// @return The balance
function getBalance(IERC20Ext token, address user) internal view returns (uint256) {
if (token == ETH_TOKEN_ADDRESS) {
return user.balance;
} else {
return token.balanceOf(user);
}
}
/// @dev Get the decimals of a token, read from the constant list, storage,
/// or from token.decimals(). Prefer using getSetDecimals when possible.
/// @param token The token type
/// @return tokenDecimals The decimals of the token
function getDecimals(IERC20Ext token) internal view returns (uint256 tokenDecimals) {
// return token decimals if has constant value
tokenDecimals = getDecimalsConstant(token);
if (tokenDecimals > 0) return tokenDecimals;
// handle case where token decimals is not a declared decimal constant
tokenDecimals = decimals[token];
// moreover, very possible that old tokens have decimals 0
// these tokens will just have higher gas fees.
return (tokenDecimals > 0) ? tokenDecimals : token.decimals();
}
function calcDestAmount(
IERC20Ext src,
IERC20Ext dest,
uint256 srcAmount,
uint256 rate
) internal view returns (uint256) {
return calcDstQty(srcAmount, getDecimals(src), getDecimals(dest), rate);
}
function calcSrcAmount(
IERC20Ext src,
IERC20Ext dest,
uint256 destAmount,
uint256 rate
) internal view returns (uint256) {
return calcSrcQty(destAmount, getDecimals(src), getDecimals(dest), rate);
}
function calcDstQty(
uint256 srcQty,
uint256 srcDecimals,
uint256 dstDecimals,
uint256 rate
) internal pure returns (uint256) {
require(srcQty <= MAX_QTY, "srcQty > MAX_QTY");
require(rate <= MAX_RATE, "rate > MAX_RATE");
if (dstDecimals >= srcDecimals) {
require((dstDecimals - srcDecimals) <= MAX_DECIMALS, "dst - src > MAX_DECIMALS");
return (srcQty * rate * (10**(dstDecimals - srcDecimals))) / PRECISION;
} else {
require((srcDecimals - dstDecimals) <= MAX_DECIMALS, "src - dst > MAX_DECIMALS");
return (srcQty * rate) / (PRECISION * (10**(srcDecimals - dstDecimals)));
}
}
function calcSrcQty(
uint256 dstQty,
uint256 srcDecimals,
uint256 dstDecimals,
uint256 rate
) internal pure returns (uint256) {
require(dstQty <= MAX_QTY, "dstQty > MAX_QTY");
require(rate <= MAX_RATE, "rate > MAX_RATE");
//source quantity is rounded up. to avoid dest quantity being too low.
uint256 numerator;
uint256 denominator;
if (srcDecimals >= dstDecimals) {
require((srcDecimals - dstDecimals) <= MAX_DECIMALS, "src - dst > MAX_DECIMALS");
numerator = (PRECISION * dstQty * (10**(srcDecimals - dstDecimals)));
denominator = rate;
} else {
require((dstDecimals - srcDecimals) <= MAX_DECIMALS, "dst - src > MAX_DECIMALS");
numerator = (PRECISION * dstQty);
denominator = (rate * (10**(dstDecimals - srcDecimals)));
}
return (numerator + denominator - 1) / denominator; //avoid rounding down errors
}
function calcRateFromQty(
uint256 srcAmount,
uint256 destAmount,
uint256 srcDecimals,
uint256 dstDecimals
) internal pure returns (uint256) {
require(srcAmount <= MAX_QTY, "srcAmount > MAX_QTY");
require(destAmount <= MAX_QTY, "destAmount > MAX_QTY");
if (dstDecimals >= srcDecimals) {
require((dstDecimals - srcDecimals) <= MAX_DECIMALS, "dst - src > MAX_DECIMALS");
return ((destAmount * PRECISION) / ((10**(dstDecimals - srcDecimals)) * srcAmount));
} else {
require((srcDecimals - dstDecimals) <= MAX_DECIMALS, "src - dst > MAX_DECIMALS");
return ((destAmount * PRECISION * (10**(srcDecimals - dstDecimals))) / srcAmount);
}
}
/// @dev save storage access by declaring token decimal constants
/// @param token The token type
/// @return token decimals
function getDecimalsConstant(IERC20Ext token) internal pure returns (uint256) {
if (token == ETH_TOKEN_ADDRESS) {
return ETH_DECIMALS;
} else if (token == USDT_TOKEN_ADDRESS) {
return 6;
} else if (token == DAI_TOKEN_ADDRESS) {
return 18;
} else if (token == USDC_TOKEN_ADDRESS) {
return 6;
} else if (token == WBTC_TOKEN_ADDRESS) {
return 8;
} else if (token == KNC_TOKEN_ADDRESS) {
return 18;
} else {
return 0;
}
}
function minOf(uint256 x, uint256 y) internal pure returns (uint256) {
return x > y ? y : x;
}
}
// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.7.6;
pragma abicoder v2;
interface ISwap {
struct GetExpectedReturnParams {
uint256 srcAmount;
address[] tradePath;
uint256 feeBps;
bytes extraArgs;
}
function getExpectedReturn(GetExpectedReturnParams calldata params)
external
view
returns (uint256 destAmount);
function getExpectedReturnWithImpact(GetExpectedReturnParams calldata params)
external
view
returns (uint256 destAmount, uint256 priceImpact);
struct GetExpectedInParams {
uint256 destAmount;
address[] tradePath;
uint256 feeBps;
bytes extraArgs;
}
function getExpectedIn(GetExpectedInParams calldata params)
external
view
returns (uint256 srcAmount);
function getExpectedInWithImpact(GetExpectedInParams calldata params)
external
view
returns (uint256 srcAmount, uint256 priceImpact);
struct SwapParams {
uint256 srcAmount;
uint256 minDestAmount;
address[] tradePath;
address recipient;
uint256 feeBps;
address payable feeReceiver;
bytes extraArgs;
}
function swap(SwapParams calldata params) external payable returns (uint256 destAmount);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.7.6;
abstract contract PermissionAdmin {
address public admin;
address public pendingAdmin;
event AdminClaimed(address newAdmin, address previousAdmin);
event TransferAdminPending(address pendingAdmin);
constructor(address _admin) {
require(_admin != address(0), "admin 0");
admin = _admin;
}
modifier onlyAdmin() {
require(msg.sender == admin, "only admin");
_;
}
/**
* @dev Allows the current admin to set the pendingAdmin address.
* @param newAdmin The address to transfer ownership to.
*/
function transferAdmin(address newAdmin) public onlyAdmin {
require(newAdmin != address(0), "new admin 0");
emit TransferAdminPending(newAdmin);
pendingAdmin = newAdmin;
}
/**
* @dev Allows the current admin to set the admin in one tx. Useful initial deployment.
* @param newAdmin The address to transfer ownership to.
*/
function transferAdminQuickly(address newAdmin) public onlyAdmin {
require(newAdmin != address(0), "admin 0");
emit TransferAdminPending(newAdmin);
emit AdminClaimed(newAdmin, admin);
admin = newAdmin;
}
/**
* @dev Allows the pendingAdmin address to finalize the change admin process.
*/
function claimAdmin() public {
require(pendingAdmin == msg.sender, "not pending");
emit AdminClaimed(pendingAdmin, admin);
admin = pendingAdmin;
pendingAdmin = address(0);
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @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, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b > a) return (false, 0);
return (true, a - b);
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, 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 (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a / b);
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a % b);
}
/**
* @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) {
require(b <= a, "SafeMath: subtraction overflow");
return a - b;
}
/**
* @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) {
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, reverting 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) {
require(b > 0, "SafeMath: division by zero");
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting 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) {
require(b > 0, "SafeMath: modulo by zero");
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* 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);
return a - b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* 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);
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* 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;
}
}