Transaction Hash:
Block:
22398254 at May-02-2025 07:38:59 PM +UTC
Transaction Fee:
0.000033434198460222 ETH
$0.06
Gas Used:
57,218 Gas / 0.584330079 Gwei
Emitted Events:
354 |
Uni.Transfer( from=[Sender] 0x1157a2076b9bb22a85cc2c162f20fab3898f4101, to=Forwarder, amount=1998503055920000000000 )
|
Account State Difference:
Address | Before | After | State Difference | ||
---|---|---|---|---|---|
0x1157A207...3898F4101 | (FalconX: 0x115...101) |
19,622.067490162612471853 Eth
Nonce: 89272
|
19,622.067456728414011631 Eth
Nonce: 89273
| 0.000033434198460222 | |
0x1f9840a8...C4201F984 | |||||
0x95222290...5CC4BAfe5
Miner
| (beaverbuild) | 16.014923000590845619 Eth | 16.014925870113712655 Eth | 0.000002869522867036 |
Execution Trace
Uni.transfer( dst=0x15f1BDD06422B1aA429dEbaeD7351A5fe21D2eAF, rawAmount=1998503055920000000000 ) => ( True )
transfer[Uni (ln:396)]
safe96[Uni (ln:397)]
_transferTokens[Uni (ln:398)]
sub96[Uni (ln:518)]
add96[Uni (ln:519)]
Transfer[Uni (ln:520)]
_moveDelegates[Uni (ln:522)]
sub96[Uni (ln:530)]
_writeCheckpoint[Uni (ln:531)]
safe32[Uni (ln:544)]
Checkpoint[Uni (ln:549)]
DelegateVotesChanged[Uni (ln:553)]
add96[Uni (ln:537)]
_writeCheckpoint[Uni (ln:538)]
safe32[Uni (ln:544)]
Checkpoint[Uni (ln:549)]
DelegateVotesChanged[Uni (ln:553)]
File 1 of 2: Uni
File 2 of 2: Forwarder
/** *Submitted for verification at Etherscan.io on 2020-09-15 */ pragma solidity ^0.5.16; pragma experimental ABIEncoderV2; // From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/Math.sol // Subject to the MIT license. /** * @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 addition of two unsigned integers, reverting with custom message on overflow. * * Counterpart to Solidity's `+` operator. * * Requirements: * - Addition cannot overflow. */ function add(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) { uint256 c = a + b; require(c >= a, errorMessage); return c; } /** * @dev Returns the subtraction of two unsigned integers, reverting on underflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * - Subtraction cannot underflow. */ function sub(uint256 a, uint256 b) internal pure returns (uint256) { return sub(a, b, "SafeMath: subtraction underflow"); } /** * @dev Returns the subtraction of two unsigned integers, reverting with custom message on underflow (when the result is negative). * * Counterpart to Solidity's `-` operator. * * Requirements: * - Subtraction cannot underflow. */ 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 multiplication of two unsigned integers, reverting on overflow. * * Counterpart to Solidity's `*` operator. * * Requirements: * - Multiplication cannot overflow. */ function mul(uint256 a, uint256 b, string memory errorMessage) 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, errorMessage); 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) { // Solidity only automatically asserts when dividing by 0 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; } } contract Uni { /// @notice EIP-20 token name for this token string public constant name = "Uniswap"; /// @notice EIP-20 token symbol for this token string public constant symbol = "UNI"; /// @notice EIP-20 token decimals for this token uint8 public constant decimals = 18; /// @notice Total number of tokens in circulation uint public totalSupply = 1_000_000_000e18; // 1 billion Uni /// @notice Address which may mint new tokens address public minter; /// @notice The timestamp after which minting may occur uint public mintingAllowedAfter; /// @notice Minimum time between mints uint32 public constant minimumTimeBetweenMints = 1 days * 365; /// @notice Cap on the percentage of totalSupply that can be minted at each mint uint8 public constant mintCap = 2; /// @notice Allowance amounts on behalf of others mapping (address => mapping (address => uint96)) internal allowances; /// @notice Official record of token balances for each account mapping (address => uint96) internal balances; /// @notice A record of each accounts delegate mapping (address => address) public delegates; /// @notice A checkpoint for marking number of votes from a given block struct Checkpoint { uint32 fromBlock; uint96 votes; } /// @notice A record of votes checkpoints for each account, by index mapping (address => mapping (uint32 => Checkpoint)) public checkpoints; /// @notice The number of checkpoints for each account mapping (address => uint32) public numCheckpoints; /// @notice The EIP-712 typehash for the contract's domain bytes32 public constant DOMAIN_TYPEHASH = keccak256("EIP712Domain(string name,uint256 chainId,address verifyingContract)"); /// @notice The EIP-712 typehash for the delegation struct used by the contract bytes32 public constant DELEGATION_TYPEHASH = keccak256("Delegation(address delegatee,uint256 nonce,uint256 expiry)"); /// @notice The EIP-712 typehash for the permit struct used by the contract bytes32 public constant PERMIT_TYPEHASH = keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"); /// @notice A record of states for signing / validating signatures mapping (address => uint) public nonces; /// @notice An event thats emitted when the minter address is changed event MinterChanged(address minter, address newMinter); /// @notice An event thats emitted when an account changes its delegate event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate); /// @notice An event thats emitted when a delegate account's vote balance changes event DelegateVotesChanged(address indexed delegate, uint previousBalance, uint newBalance); /// @notice The standard EIP-20 transfer event event Transfer(address indexed from, address indexed to, uint256 amount); /// @notice The standard EIP-20 approval event event Approval(address indexed owner, address indexed spender, uint256 amount); /** * @notice Construct a new Uni token * @param account The initial account to grant all the tokens * @param minter_ The account with minting ability * @param mintingAllowedAfter_ The timestamp after which minting may occur */ constructor(address account, address minter_, uint mintingAllowedAfter_) public { require(mintingAllowedAfter_ >= block.timestamp, "Uni::constructor: minting can only begin after deployment"); balances[account] = uint96(totalSupply); emit Transfer(address(0), account, totalSupply); minter = minter_; emit MinterChanged(address(0), minter); mintingAllowedAfter = mintingAllowedAfter_; } /** * @notice Change the minter address * @param minter_ The address of the new minter */ function setMinter(address minter_) external { require(msg.sender == minter, "Uni::setMinter: only the minter can change the minter address"); emit MinterChanged(minter, minter_); minter = minter_; } /** * @notice Mint new tokens * @param dst The address of the destination account * @param rawAmount The number of tokens to be minted */ function mint(address dst, uint rawAmount) external { require(msg.sender == minter, "Uni::mint: only the minter can mint"); require(block.timestamp >= mintingAllowedAfter, "Uni::mint: minting not allowed yet"); require(dst != address(0), "Uni::mint: cannot transfer to the zero address"); // record the mint mintingAllowedAfter = SafeMath.add(block.timestamp, minimumTimeBetweenMints); // mint the amount uint96 amount = safe96(rawAmount, "Uni::mint: amount exceeds 96 bits"); require(amount <= SafeMath.div(SafeMath.mul(totalSupply, mintCap), 100), "Uni::mint: exceeded mint cap"); totalSupply = safe96(SafeMath.add(totalSupply, amount), "Uni::mint: totalSupply exceeds 96 bits"); // transfer the amount to the recipient balances[dst] = add96(balances[dst], amount, "Uni::mint: transfer amount overflows"); emit Transfer(address(0), dst, amount); // move delegates _moveDelegates(address(0), delegates[dst], amount); } /** * @notice Get the number of tokens `spender` is approved to spend on behalf of `account` * @param account The address of the account holding the funds * @param spender The address of the account spending the funds * @return The number of tokens approved */ function allowance(address account, address spender) external view returns (uint) { return allowances[account][spender]; } /** * @notice Approve `spender` to transfer up to `amount` from `src` * @dev This will overwrite the approval amount for `spender` * and is subject to issues noted [here](https://eips.ethereum.org/EIPS/eip-20#approve) * @param spender The address of the account which may transfer tokens * @param rawAmount The number of tokens that are approved (2^256-1 means infinite) * @return Whether or not the approval succeeded */ function approve(address spender, uint rawAmount) external returns (bool) { uint96 amount; if (rawAmount == uint(-1)) { amount = uint96(-1); } else { amount = safe96(rawAmount, "Uni::approve: amount exceeds 96 bits"); } allowances[msg.sender][spender] = amount; emit Approval(msg.sender, spender, amount); return true; } /** * @notice Triggers an approval from owner to spends * @param owner The address to approve from * @param spender The address to be approved * @param rawAmount The number of tokens that are approved (2^256-1 means infinite) * @param deadline The time at which to expire the signature * @param v The recovery byte of the signature * @param r Half of the ECDSA signature pair * @param s Half of the ECDSA signature pair */ function permit(address owner, address spender, uint rawAmount, uint deadline, uint8 v, bytes32 r, bytes32 s) external { uint96 amount; if (rawAmount == uint(-1)) { amount = uint96(-1); } else { amount = safe96(rawAmount, "Uni::permit: amount exceeds 96 bits"); } bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), getChainId(), address(this))); bytes32 structHash = keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, rawAmount, nonces[owner]++, deadline)); bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash)); address signatory = ecrecover(digest, v, r, s); require(signatory != address(0), "Uni::permit: invalid signature"); require(signatory == owner, "Uni::permit: unauthorized"); require(now <= deadline, "Uni::permit: signature expired"); allowances[owner][spender] = amount; emit Approval(owner, spender, amount); } /** * @notice Get the number of tokens held by the `account` * @param account The address of the account to get the balance of * @return The number of tokens held */ function balanceOf(address account) external view returns (uint) { return balances[account]; } /** * @notice Transfer `amount` tokens from `msg.sender` to `dst` * @param dst The address of the destination account * @param rawAmount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transfer(address dst, uint rawAmount) external returns (bool) { uint96 amount = safe96(rawAmount, "Uni::transfer: amount exceeds 96 bits"); _transferTokens(msg.sender, dst, amount); return true; } /** * @notice Transfer `amount` tokens from `src` to `dst` * @param src The address of the source account * @param dst The address of the destination account * @param rawAmount The number of tokens to transfer * @return Whether or not the transfer succeeded */ function transferFrom(address src, address dst, uint rawAmount) external returns (bool) { address spender = msg.sender; uint96 spenderAllowance = allowances[src][spender]; uint96 amount = safe96(rawAmount, "Uni::approve: amount exceeds 96 bits"); if (spender != src && spenderAllowance != uint96(-1)) { uint96 newAllowance = sub96(spenderAllowance, amount, "Uni::transferFrom: transfer amount exceeds spender allowance"); allowances[src][spender] = newAllowance; emit Approval(src, spender, newAllowance); } _transferTokens(src, dst, amount); return true; } /** * @notice Delegate votes from `msg.sender` to `delegatee` * @param delegatee The address to delegate votes to */ function delegate(address delegatee) public { return _delegate(msg.sender, delegatee); } /** * @notice Delegates votes from signatory to `delegatee` * @param delegatee The address to delegate votes to * @param nonce The contract state required to match the signature * @param expiry The time at which to expire the signature * @param v The recovery byte of the signature * @param r Half of the ECDSA signature pair * @param s Half of the ECDSA signature pair */ function delegateBySig(address delegatee, uint nonce, uint expiry, uint8 v, bytes32 r, bytes32 s) public { bytes32 domainSeparator = keccak256(abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name)), getChainId(), address(this))); bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry)); bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash)); address signatory = ecrecover(digest, v, r, s); require(signatory != address(0), "Uni::delegateBySig: invalid signature"); require(nonce == nonces[signatory]++, "Uni::delegateBySig: invalid nonce"); require(now <= expiry, "Uni::delegateBySig: signature expired"); return _delegate(signatory, delegatee); } /** * @notice Gets the current votes balance for `account` * @param account The address to get votes balance * @return The number of current votes for `account` */ function getCurrentVotes(address account) external view returns (uint96) { uint32 nCheckpoints = numCheckpoints[account]; return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0; } /** * @notice Determine the prior number of votes for an account as of a block number * @dev Block number must be a finalized block or else this function will revert to prevent misinformation. * @param account The address of the account to check * @param blockNumber The block number to get the vote balance at * @return The number of votes the account had as of the given block */ function getPriorVotes(address account, uint blockNumber) public view returns (uint96) { require(blockNumber < block.number, "Uni::getPriorVotes: not yet determined"); uint32 nCheckpoints = numCheckpoints[account]; if (nCheckpoints == 0) { return 0; } // First check most recent balance if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) { return checkpoints[account][nCheckpoints - 1].votes; } // Next check implicit zero balance if (checkpoints[account][0].fromBlock > blockNumber) { return 0; } uint32 lower = 0; uint32 upper = nCheckpoints - 1; while (upper > lower) { uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow Checkpoint memory cp = checkpoints[account][center]; if (cp.fromBlock == blockNumber) { return cp.votes; } else if (cp.fromBlock < blockNumber) { lower = center; } else { upper = center - 1; } } return checkpoints[account][lower].votes; } function _delegate(address delegator, address delegatee) internal { address currentDelegate = delegates[delegator]; uint96 delegatorBalance = balances[delegator]; delegates[delegator] = delegatee; emit DelegateChanged(delegator, currentDelegate, delegatee); _moveDelegates(currentDelegate, delegatee, delegatorBalance); } function _transferTokens(address src, address dst, uint96 amount) internal { require(src != address(0), "Uni::_transferTokens: cannot transfer from the zero address"); require(dst != address(0), "Uni::_transferTokens: cannot transfer to the zero address"); balances[src] = sub96(balances[src], amount, "Uni::_transferTokens: transfer amount exceeds balance"); balances[dst] = add96(balances[dst], amount, "Uni::_transferTokens: transfer amount overflows"); emit Transfer(src, dst, amount); _moveDelegates(delegates[src], delegates[dst], amount); } function _moveDelegates(address srcRep, address dstRep, uint96 amount) internal { if (srcRep != dstRep && amount > 0) { if (srcRep != address(0)) { uint32 srcRepNum = numCheckpoints[srcRep]; uint96 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0; uint96 srcRepNew = sub96(srcRepOld, amount, "Uni::_moveVotes: vote amount underflows"); _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew); } if (dstRep != address(0)) { uint32 dstRepNum = numCheckpoints[dstRep]; uint96 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0; uint96 dstRepNew = add96(dstRepOld, amount, "Uni::_moveVotes: vote amount overflows"); _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew); } } } function _writeCheckpoint(address delegatee, uint32 nCheckpoints, uint96 oldVotes, uint96 newVotes) internal { uint32 blockNumber = safe32(block.number, "Uni::_writeCheckpoint: block number exceeds 32 bits"); if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) { checkpoints[delegatee][nCheckpoints - 1].votes = newVotes; } else { checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes); numCheckpoints[delegatee] = nCheckpoints + 1; } emit DelegateVotesChanged(delegatee, oldVotes, newVotes); } function safe32(uint n, string memory errorMessage) internal pure returns (uint32) { require(n < 2**32, errorMessage); return uint32(n); } function safe96(uint n, string memory errorMessage) internal pure returns (uint96) { require(n < 2**96, errorMessage); return uint96(n); } function add96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) { uint96 c = a + b; require(c >= a, errorMessage); return c; } function sub96(uint96 a, uint96 b, string memory errorMessage) internal pure returns (uint96) { require(b <= a, errorMessage); return a - b; } function getChainId() internal pure returns (uint) { uint256 chainId; assembly { chainId := chainid() } return chainId; } }
File 2 of 2: Forwarder
pragma solidity 0.7.5; /* The MIT License (MIT) Copyright (c) 2018 Murray Software, LLC. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ //solhint-disable max-line-length //solhint-disable no-inline-assembly contract CloneFactory { function createClone(address target, bytes32 salt) internal returns (address payable result) { bytes20 targetBytes = bytes20(target); assembly { // load the next free memory slot as a place to store the clone contract data let clone := mload(0x40) // The bytecode block below is responsible for contract initialization // during deployment, it is worth noting the proxied contract constructor will not be called during // the cloning procedure and that is why an initialization function needs to be called after the // clone is created mstore( clone, 0x3d602d80600a3d3981f3363d3d373d3d3d363d73000000000000000000000000 ) // This stores the address location of the implementation contract // so that the proxy knows where to delegate call logic to mstore(add(clone, 0x14), targetBytes) // The bytecode block is the actual code that is deployed for each clone created. // It forwards all calls to the already deployed implementation via a delegatecall mstore( add(clone, 0x28), 0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000 ) // deploy the contract using the CREATE2 opcode // this deploys the minimal proxy defined above, which will proxy all // calls to use the logic defined in the implementation contract `target` result := create2(0, clone, 0x37, salt) } } function isClone(address target, address query) internal view returns (bool result) { bytes20 targetBytes = bytes20(target); assembly { // load the next free memory slot as a place to store the comparison clone let clone := mload(0x40) // The next three lines store the expected bytecode for a miniml proxy // that targets `target` as its implementation contract mstore( clone, 0x363d3d373d3d3d363d7300000000000000000000000000000000000000000000 ) mstore(add(clone, 0xa), targetBytes) mstore( add(clone, 0x1e), 0x5af43d82803e903d91602b57fd5bf30000000000000000000000000000000000 ) // the next two lines store the bytecode of the contract that we are checking in memory let other := add(clone, 0x40) extcodecopy(query, other, 0, 0x2d) // Check if the expected bytecode equals the actual bytecode and return the result result := and( eq(mload(clone), mload(other)), eq(mload(add(clone, 0xd)), mload(add(other, 0xd))) ) } } } /** * Contract that exposes the needed erc20 token functions */ abstract contract ERC20Interface { // Send _value amount of tokens to address _to function transfer(address _to, uint256 _value) public virtual returns (bool success); // Get the account balance of another account with address _owner function balanceOf(address _owner) public virtual view returns (uint256 balance); } // helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false library TransferHelper { function safeApprove( address token, address to, uint256 value ) internal { // bytes4(keccak256(bytes('approve(address,uint256)'))); (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value)); require( success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper::safeApprove: approve failed' ); } function safeTransfer( address token, address to, uint256 value ) internal { // bytes4(keccak256(bytes('transfer(address,uint256)'))); (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value)); require( success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper::safeTransfer: transfer failed' ); } function safeTransferFrom( address token, address from, address to, uint256 value ) internal { // bytes4(keccak256(bytes('transferFrom(address,address,uint256)'))); (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value)); require( success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper::transferFrom: transferFrom failed' ); } function safeTransferETH(address to, uint256 value) internal { (bool success, ) = to.call{value: value}(new bytes(0)); require(success, 'TransferHelper::safeTransferETH: ETH transfer failed'); } } /** * Contract that will forward any incoming Ether to the creator of the contract * */ contract Forwarder { // Address to which any funds sent to this contract will be forwarded address public parentAddress; event ForwarderDeposited(address from, uint256 value, bytes data); /** * Initialize the contract, and sets the destination address to that of the creator */ function init(address _parentAddress) external onlyUninitialized { parentAddress = _parentAddress; uint256 value = address(this).balance; if (value == 0) { return; } (bool success, ) = parentAddress.call{ value: value }(''); require(success, 'Flush failed'); // NOTE: since we are forwarding on initialization, // we don't have the context of the original sender. // We still emit an event about the forwarding but set // the sender to the forwarder itself emit ForwarderDeposited(address(this), value, msg.data); } /** * Modifier that will execute internal code block only if the sender is the parent address */ modifier onlyParent { require(msg.sender == parentAddress, 'Only Parent'); _; } /** * Modifier that will execute internal code block only if the contract has not been initialized yet */ modifier onlyUninitialized { require(parentAddress == address(0x0), 'Already initialized'); _; } /** * Default function; Gets called when data is sent but does not match any other function */ fallback() external payable { flush(); } /** * Default function; Gets called when Ether is deposited with no data, and forwards it to the parent address */ receive() external payable { flush(); } /** * Execute a token transfer of the full balance from the forwarder token to the parent address * @param tokenContractAddress the address of the erc20 token contract */ function flushTokens(address tokenContractAddress) external onlyParent { ERC20Interface instance = ERC20Interface(tokenContractAddress); address forwarderAddress = address(this); uint256 forwarderBalance = instance.balanceOf(forwarderAddress); if (forwarderBalance == 0) { return; } TransferHelper.safeTransfer( tokenContractAddress, parentAddress, forwarderBalance ); } /** * Flush the entire balance of the contract to the parent address. */ function flush() public { uint256 value = address(this).balance; if (value == 0) { return; } (bool success, ) = parentAddress.call{ value: value }(''); require(success, 'Flush failed'); emit ForwarderDeposited(msg.sender, value, msg.data); } } contract ForwarderFactory is CloneFactory { address public implementationAddress; event ForwarderCreated(address newForwarderAddress, address parentAddress); constructor(address _implementationAddress) { implementationAddress = _implementationAddress; } function createForwarder(address parent, bytes32 salt) external { // include the signers in the salt so any contract deployed to a given address must have the same signers bytes32 finalSalt = keccak256(abi.encodePacked(parent, salt)); address payable clone = createClone(implementationAddress, finalSalt); Forwarder(clone).init(parent); emit ForwarderCreated(clone, parent); } }