tornado-nova/contracts/bridge/BridgeHelper.sol

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/**
*Submitted for verification at BscScan.com on 2021-03-09
*/
pragma solidity 0.7.6;
/**
* @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;
}
}
interface IOmnibridge {
function relayTokens(
address _token,
address _receiver,
uint256 _value
) external;
/**
* @dev Initiate the bridge operation for some amount of tokens from msg.sender.
* The user should first call Approve method of the ERC677 token.
* @param token bridged token contract address.
* @param _receiver address that will receive the native tokens on the other network.
* @param _value amount of tokens to be transferred to the other network.
* @param _data additional transfer data to be used on the other side.
*/
function relayTokensAndCall(
address token,
address _receiver,
uint256 _value,
bytes memory _data
) external;
}
interface IWETH {
function deposit() external payable;
function withdraw(uint256 _value) external;
function approve(address _to, uint256 _value) external;
}
contract Sacrifice {
constructor(address payable _recipient) payable {
selfdestruct(_recipient);
}
}
/**
* @title AddressHelper
* @dev Helper methods for Address type.
*/
library AddressHelper {
/**
* @dev Try to send native tokens to the address. If it fails, it will force the transfer by creating a selfdestruct contract
* @param _receiver address that will receive the native tokens
* @param _value the amount of native tokens to send
*/
function safeSendValue(address payable _receiver, uint256 _value) internal {
if (!(_receiver).send(_value)) {
new Sacrifice{ value: _value }(_receiver);
}
}
}
/**
* @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) {
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly {
codehash := extcodehash(account)
}
return (codehash != accountHash && codehash != 0x0);
}
/**
* @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");
return _functionCallWithValue(target, data, value, errorMessage);
}
function _functionCallWithValue(
address target,
bytes memory data,
uint256 weiValue,
string memory errorMessage
) private returns (bytes memory) {
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
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);
}
}
}
}
/**
* @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);
}
/**
* @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");
}
}
}
/**
* @title OwnableModule
* @dev Common functionality for multi-token extension non-upgradeable module.
*/
contract OwnableModule {
address public owner;
/**
* @dev Initializes this contract.
* @param _owner address of the owner that is allowed to perform additional actions on the particular module.
*/
constructor(address _owner) {
owner = _owner;
}
/**
* @dev Throws if sender is not the owner of this contract.
*/
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
/**
* @dev Changes the owner of this contract.
* @param _newOwner address of the new owner.
*/
function transferOwnership(address _newOwner) external onlyOwner {
owner = _newOwner;
}
}
/**
* @title Claimable
* @dev Implementation of the claiming utils that can be useful for withdrawing accidentally sent tokens that are not used in bridge operations.
*/
contract Claimable {
using SafeERC20 for IERC20;
/**
* Throws if a given address is equal to address(0)
*/
modifier validAddress(address _to) {
require(_to != address(0));
_;
}
/**
* @dev Withdraws the erc20 tokens or native coins from this contract.
* Caller should additionally check that the claimed token is not a part of bridge operations (i.e. that token != erc20token()).
* @param _token address of the claimed token or address(0) for native coins.
* @param _to address of the tokens/coins receiver.
*/
function claimValues(address _token, address _to) internal validAddress(_to) {
if (_token == address(0)) {
claimNativeCoins(_to);
} else {
claimErc20Tokens(_token, _to);
}
}
/**
* @dev Internal function for withdrawing all native coins from the contract.
* @param _to address of the coins receiver.
*/
function claimNativeCoins(address _to) internal {
uint256 value = address(this).balance;
AddressHelper.safeSendValue(payable(_to), value);
}
/**
* @dev Internal function for withdrawing all tokens of ssome particular ERC20 contract from this contract.
* @param _token address of the claimed ERC20 token.
* @param _to address of the tokens receiver.
*/
function claimErc20Tokens(address _token, address _to) internal {
IERC20 token = IERC20(_token);
uint256 balance = token.balanceOf(address(this));
token.safeTransfer(_to, balance);
}
}
/**
* @title WETHOmnibridgeRouter
* @dev Omnibridge extension for processing native and wrapped native assets.
* Intended to work with WETH/WBNB/WXDAI tokens, see:
* https://etherscan.io/address/0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2
* https://bscscan.com/address/0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c
* https://blockscout.com/poa/xdai/address/0xe91D153E0b41518A2Ce8Dd3D7944Fa863463a97d
*/
contract WETHOmnibridgeRouter is OwnableModule, Claimable {
IOmnibridge public immutable bridge;
IWETH public immutable WETH;
/**
* @dev Initializes this contract.
* @param _bridge address of the HomeOmnibridge/ForeignOmnibridge contract.
* @param _weth address of the WETH token used for wrapping/unwrapping native coins (e.g. WETH/WBNB/WXDAI).
* @param _owner address of the contract owner.
*/
constructor(
IOmnibridge _bridge,
IWETH _weth,
address _owner
) OwnableModule(_owner) {
bridge = _bridge;
WETH = _weth;
_weth.approve(address(_bridge), uint256(-1));
}
/**
* @dev Wraps native assets and relays wrapped ERC20 tokens to the other chain.
* Call msg.sender will receive assets on the other side of the bridge.
*/
function wrapAndRelayTokens() external payable {
wrapAndRelayTokens(msg.sender);
}
/**
* @dev Wraps native assets and relays wrapped ERC20 tokens to the other chain.
* @param _receiver bridged assets receiver on the other side of the bridge.
*/
function wrapAndRelayTokens(address _receiver) public payable {
WETH.deposit{ value: msg.value }();
bridge.relayTokens(address(WETH), _receiver, msg.value);
}
/**
* @dev Wraps native assets and relays wrapped ERC20 tokens to the other chain.
* It also calls receiver on other side with the _data provided.
* @param _receiver bridged assets receiver on the other side of the bridge.
* @param _data data for the call of receiver on other side.
*/
2021-10-04 12:22:13 +02:00
function wrapAndRelayTokens(address _receiver, bytes memory _data) public payable {
WETH.deposit{ value: msg.value }();
bridge.relayTokensAndCall(address(WETH), _receiver, msg.value, _data);
}
/**
* @dev Bridged callback function used for unwrapping received tokens.
* Can only be called by the associated Omnibridge contract.
* @param _token bridged token contract address, should be WETH.
* @param _value amount of bridged/received tokens.
* @param _data extra data passed alongside with relayTokensAndCall on the other side of the bridge.
* Should contain coins receiver address.
*/
function onTokenBridged(
address _token,
uint256 _value,
bytes calldata _data
) external {
require(_token == address(WETH));
require(msg.sender == address(bridge));
require(_data.length == 20);
WETH.withdraw(_value);
address payable receiver;
assembly {
receiver := calldataload(120)
}
AddressHelper.safeSendValue(receiver, _value);
}
/**
* @dev Claims stuck coins/tokens.
* Only contract owner can call this method.
* @param _token address of claimed token contract, address(0) for native coins.
* @param _to address of tokens receiver
*/
function claimTokens(address _token, address _to) external onlyOwner {
claimValues(_token, _to);
}
/**
* @dev Ether receive function.
* Should be only called from the WETH contract when withdrawing native coins. Will revert otherwise.
*/
receive() external payable {
require(msg.sender == address(WETH));
}
}