Contract Name:
OpynPerpVault
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.7.2;
pragma experimental ABIEncoderV2;
import '@openzeppelin/contracts/access/Ownable.sol';
import '@openzeppelin/contracts/token/ERC20/ERC20.sol';
import '@openzeppelin/contracts/utils/ReentrancyGuard.sol';
import { SafeMath } from '@openzeppelin/contracts/math/SafeMath.sol';
import { IERC20 } from '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import { SafeERC20 } from '@openzeppelin/contracts/token/ERC20/SafeERC20.sol';
import { IAction } from '../interfaces/IAction.sol';
import { ICurve } from '../interfaces/ICurve.sol';
import { IStakeDao } from '../interfaces/IStakeDao.sol';
/**
* Error Codes
* O1: actions for the vault have not been initialized
* O2: cannot execute transaction, vault is in emergency state
* O3: cannot call setActions, actions have already been initialized
* O4: action being set is using an invalid address
* O5: action being set is a duplicated action
* O6: deposited ETH (msg.value) must be greater than 0
* O7: cannot accept ETH deposit, total sdecrv controlled by the vault would exceed vault cap
* O8: unable to withdraw ETH, sdecrv to withdraw would exceed or be equal to the current vault sdecrv balance
* O9: unable to withdraw ETH, ETH fee transfer to fee recipient (feeRecipient) failed
* O10: unable to withdraw ETH, ETH withdrawal to user (msg.sender) failed
* O11: cannot close vault positions, vault is not in locked state (VaultState.Locked)
* O12: unable to rollover vault, length of allocation percentages (_allocationPercentages) passed is not equal to the initialized actions length
* O13: unable to rollover vault, vault is not in unlocked state (VaultState.Unlocked)
* O14: unable to rollover vault, the calculated percentage sum (sumPercentage) is greater than the base (BASE)
* O15: unable to rollover vault, the calculated percentage sum (sumPercentage) is not equal to the base (BASE)
* O16: withdraw reserve percentage must be less than 50% (5000)
* O17: cannot call emergencyPause, vault is already in emergency state
* O18: cannot call resumeFromPause, vault is not in emergency state
* O19: cannot receive ETH from any address other than the curve pool address (curvePool)
*/
/**
* @title OpynPerpVault
* @author Opyn Team
* @dev implementation of the Opyn Perp Vault contract that works with stakedao's ETH strategy.
* Note that this implementation is meant to only specifically work for the stakedao ETH strategy and is not
* a generalized contract. Stakedao's ETH strategy currently accepts curvePool LP tokens called ecrv from the
* sETH-ETH curvePool pool. This strategy allows users to convert their ETH into yield earning sdecrv tokens
* and use the sdecrv tokens as collateral to sell ETH call options on Opyn.
*/
contract OpynPerpVault is ERC20, ReentrancyGuard, Ownable {
using SafeERC20 for IERC20;
using SafeMath for uint256;
enum VaultState {
Emergency,
Locked,
Unlocked
}
/// @dev actions that build up this strategy (vault)
address[] public actions;
/// @dev address to which all fees are sent
address public feeRecipient;
/// @dev stake dao sdecrvAddress
address public sdecrvAddress;
uint256 public constant BASE = 10000; // 100%
/// @dev Cap for the vault. hardcoded at 1000 for initial release
uint256 public cap = 1000 ether;
/// @dev withdrawal fee percentage. 50 being 0.5%
uint256 public withdrawalFeePercentage = 50;
/// @dev how many percentage should be reserved in vault for withdraw. 1000 being 10%
uint256 public withdrawReserve = 0;
/// @dev curvePool ETH/sETH stableswap
ICurve public curvePool;
VaultState public state;
VaultState public stateBeforePause;
/*=====================
* Events *
*====================*/
event CapUpdated(uint256 newCap);
event Deposit(address account, uint256 amountDeposited, uint256 shareMinted);
event Rollover(uint256[] allocations);
event StateUpdated(VaultState state);
event Withdraw(address account, uint256 amountWithdrawn, uint256 fee, uint256 shareBurned);
/*=====================
* Modifiers *
*====================*/
/**
* @dev can only be called if actions are initialized
*/
function actionsInitialized() private view {
require(actions.length > 0, "O1");
}
/**
* @dev can only be executed if vault is not in emergency state
*/
function notEmergency() private view {
require(state != VaultState.Emergency, "O2");
}
/*=====================
* external function *
*====================*/
constructor (
address _sdecrvAddress,
address _curvePool,
address _feeRecipient,
string memory _tokenName,
string memory _tokenSymbol
) ERC20(_tokenName, _tokenSymbol) {
sdecrvAddress = _sdecrvAddress;
feeRecipient = _feeRecipient;
curvePool = ICurve(_curvePool);
state = VaultState.Unlocked;
}
function setActions(address[] memory _actions) external onlyOwner {
require(actions.length == 0, "O3");
// assign actions
for(uint256 i = 0 ; i < _actions.length; i++ ) {
// check all items before actions[i], does not equal to action[i]
require(_actions[i] != address(0), "O4");
for(uint256 j = 0; j < i; j++) {
require(_actions[i] != _actions[j], "O5");
}
actions.push(_actions[i]);
}
}
/**
* @notice allows owner to change the cap
*/
function setCap(uint256 _newCap) external onlyOwner {
cap = _newCap;
emit CapUpdated(_newCap);
}
/**
* @notice total sdecrv controlled by this vault
*/
function totalStakedaoAsset() public view returns (uint256) {
uint256 debt = 0;
uint256 length = actions.length;
for (uint256 i = 0; i < length; i++) {
debt = debt.add(IAction(actions[i]).currentValue());
}
return _balance().add(debt);
}
/**
* total eth value of the sdecrv controlled by this vault
*/
function totalETHControlled() external view returns (uint256) {
IStakeDao sdecrv = IStakeDao(sdecrvAddress);
// hard coded to 36 because ecrv and sdecrv are both 18 decimals.
return totalStakedaoAsset().mul(sdecrv.getPricePerFullShare()).mul(curvePool.get_virtual_price()).div(10**36);
}
/**
* @dev return how many sdecrv you can get if you burn the number of shares, after charging the fee.
*/
function getWithdrawAmountByShares(uint256 _shares) external view returns (uint256) {
uint256 withdrawAmount = _getWithdrawAmountByShares(_shares);
return withdrawAmount.sub(_getWithdrawFee(withdrawAmount));
}
/**
* @notice Deposits ETH into the contract and mint vault shares.
* @dev deposit into the curvePool, then into stakedao, then mint the shares to depositor, and emit the deposit event
* @param minEcrv minimum amount of ecrv to get out from adding liquidity.
*/
function depositETH(uint256 minEcrv) external payable nonReentrant {
notEmergency();
actionsInitialized();
uint256 amount = msg.value;
require(amount > 0, 'O6');
// the sdecrv is already deposited into the contract at this point, need to substract it from total
uint256[2] memory amounts;
amounts[0] = amount;
amounts[1] = 0; // not depositing any seth
// deposit ETH to curvePool
curvePool.add_liquidity{value:amount}(amounts, minEcrv);
// keep track of balance before
uint256 totalSdecrvBalanceBeforeDeposit = totalStakedaoAsset();
// deposit ecrv to stakedao
address cacheSdecrvAddress = sdecrvAddress;
IStakeDao sdecrv = IStakeDao(cacheSdecrvAddress);
IERC20 ecrv = sdecrv.token();
uint256 ecrvToDeposit = ecrv.balanceOf(address(this));
ecrv.safeIncreaseAllowance(cacheSdecrvAddress, ecrvToDeposit);
sdecrv.deposit(ecrvToDeposit);
// mint shares and emit event
uint256 totalWithDepositedAmount = totalStakedaoAsset();
require(totalWithDepositedAmount < cap, 'O7');
uint256 sdecrvDeposited = totalWithDepositedAmount.sub(totalSdecrvBalanceBeforeDeposit);
uint256 share = _getSharesByDepositAmount(sdecrvDeposited, totalSdecrvBalanceBeforeDeposit);
emit Deposit(msg.sender, amount, share);
_mint(msg.sender, share);
}
/**
* @notice Withdraws ETH from vault using vault shares
* @dev burns shares, withdraws ecrv from stakdao, withdraws ETH from curvePool
* @param _share is the number of vault shares to be burned
*/
function withdrawETH(uint256 _share, uint256 minEth) external nonReentrant {
notEmergency();
actionsInitialized();
uint256 currentSdecrvBalance = _balance();
uint256 sdecrvToWithdraw = _getWithdrawAmountByShares(_share);
require(sdecrvToWithdraw <= currentSdecrvBalance, 'O8');
_burn(msg.sender, _share);
// withdraw from stakedao and curvePool
IStakeDao sdecrv = IStakeDao(sdecrvAddress);
sdecrv.withdraw(sdecrvToWithdraw);
uint256 ecrvBalance = sdecrv.token().balanceOf(address(this));
uint256 ethReceived = curvePool.remove_liquidity_one_coin(ecrvBalance, 0, minEth);
// calculate fees
uint256 fee = _getWithdrawFee(ethReceived);
uint256 ethOwedToUser = ethReceived.sub(fee);
// send fee to recipient
(bool success1, ) = feeRecipient.call{ value: fee }('');
require(success1, 'O9');
// send ETH to user
(bool success2, ) = msg.sender.call{ value: ethOwedToUser }('');
require(success2, 'O10');
emit Withdraw(msg.sender, ethOwedToUser, fee, _share);
}
/**
* @notice anyone can call this to close out the previous round by calling "closePositions" on all actions.
* @dev iterrate through each action, close position and withdraw funds
*/
function closePositions() public {
actionsInitialized();
require(state == VaultState.Locked, "O11");
state = VaultState.Unlocked;
address cacheAddress = sdecrvAddress;
for (uint8 i = 0; i < actions.length; i = i + 1) {
// 1. close position. this should revert if any position is not ready to be closed.
IAction(actions[i]).closePosition();
// 2. withdraw sdecrv
uint256 actionBalance = IERC20(cacheAddress).balanceOf(actions[i]);
if (actionBalance > 0)
IERC20(cacheAddress).safeTransferFrom(actions[i], address(this), actionBalance);
}
emit StateUpdated(VaultState.Unlocked);
}
/**
* @notice can only be called when the vault is unlocked. It sets the state to locked and distributes funds to each action.
*/
function rollOver(uint256[] calldata _allocationPercentages) external onlyOwner nonReentrant {
actionsInitialized();
require(_allocationPercentages.length == actions.length, 'O12');
require(state == VaultState.Unlocked, "O13");
state = VaultState.Locked;
uint256 cacheTotalAsset = totalStakedaoAsset();
uint256 cacheBase = BASE;
// keep track of total percentage to make sure we're summing up to 100%
uint256 sumPercentage = withdrawReserve;
address cacheAddress = sdecrvAddress;
for (uint8 i = 0; i < _allocationPercentages.length; i = i + 1) {
sumPercentage = sumPercentage.add(_allocationPercentages[i]);
require(sumPercentage <= cacheBase, 'O14');
uint256 newAmount = cacheTotalAsset.mul(_allocationPercentages[i]).div(cacheBase);
if (newAmount > 0) IERC20(cacheAddress).safeTransfer(actions[i], newAmount);
IAction(actions[i]).rolloverPosition();
}
require(sumPercentage == cacheBase, 'O15');
emit Rollover(_allocationPercentages);
emit StateUpdated(VaultState.Locked);
}
/**
* @dev set the vault withdrawal fee recipient
*/
function setWithdrawalFeeRecipient(address _newWithdrawalFeeRecipient) external onlyOwner {
feeRecipient = _newWithdrawalFeeRecipient;
}
/**
* @dev set the percentage that should be reserved in vault for withdraw
*/
function setWithdrawalFeePercentage(uint256 _newWithdrawalFeePercentage) external onlyOwner {
withdrawalFeePercentage = _newWithdrawalFeePercentage;
}
/**
* @dev set the percentage that should be reserved in vault for withdraw
*/
function setWithdrawReserve(uint256 _reserve) external onlyOwner {
require(_reserve < 5000, "O16");
withdrawReserve = _reserve;
}
/**
* @dev set the state to "Emergency", which disable all withdraw and deposit
*/
function emergencyPause() external onlyOwner {
require(state != VaultState.Emergency, "O17");
stateBeforePause = state;
state = VaultState.Emergency;
emit StateUpdated(VaultState.Emergency);
}
/**
* @dev set the state from "Emergency", which disable all withdraw and deposit
*/
function resumeFromPause() external onlyOwner {
require(state == VaultState.Emergency, "O18");
state = stateBeforePause;
emit StateUpdated(stateBeforePause);
}
/**
* @dev return how many shares you can get if you deposit {_amount} sdecrv
* @param _amount amount of token depositing
*/
function getSharesByDepositAmount(uint256 _amount) external view returns (uint256) {
return _getSharesByDepositAmount(_amount, totalStakedaoAsset());
}
/*=====================
* Internal functions *
*====================*/
/**
* @dev returns remaining sdecrv balance in the vault.
*/
function _balance() internal view returns (uint256) {
return IERC20(sdecrvAddress).balanceOf(address(this));
}
/**
* @dev return how many shares you can get if you deposit {_amount} sdecrv
* @param _amount amount of token depositing
* @param _totalAssetAmount amont of sdecrv already in the pool before deposit
*/
function _getSharesByDepositAmount(uint256 _amount, uint256 _totalAssetAmount) internal view returns (uint256) {
uint256 shareSupply = totalSupply();
// share amount
return shareSupply == 0 ? _amount : _amount.mul(shareSupply).div(_totalAssetAmount);
}
/**
* @dev return how many sdecrv you can get if you burn the number of shares
*/
function _getWithdrawAmountByShares(uint256 _share) internal view returns (uint256) {
// withdrawal amount
return _share.mul(totalStakedaoAsset()).div(totalSupply());
}
/**
* @dev get amount of fee charged based on total amount of weth withdrawing.
*/
function _getWithdrawFee(uint256 _withdrawAmount) internal view returns (uint256) {
return _withdrawAmount.mul(withdrawalFeePercentage).div(BASE);
}
/**
* @notice the receive ether function is called whenever the call data is empty
*/
receive() external payable {
require(msg.sender == address(curvePool), "O19");
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
abstract contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () internal {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(owner() == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
import "../../utils/Context.sol";
import "./IERC20.sol";
import "../../math/SafeMath.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of ERC20 applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20 {
using SafeMath for uint256;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
uint8 private _decimals;
/**
* @dev Sets the values for {name} and {symbol}, initializes {decimals} with
* a default value of 18.
*
* To select a different value for {decimals}, use {_setupDecimals}.
*
* All three of these values are immutable: they can only be set once during
* construction.
*/
constructor (string memory name_, string memory symbol_) public {
_name = name_;
_symbol = symbol_;
_decimals = 18;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
* called.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
return true;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(address sender, address recipient, uint256 amount) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Sets {decimals} to a value other than the default one of 18.
*
* WARNING: This function should only be called from the constructor. Most
* applications that interact with token contracts will not expect
* {decimals} to ever change, and may work incorrectly if it does.
*/
function _setupDecimals(uint8 decimals_) internal virtual {
_decimals = decimals_;
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor () internal {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
// 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;
}
}
// 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;
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 >=0.7.2;
interface IAction {
/**
* The function used to determin how much asset the current action is controlling.
* this will impact the withdraw and deposit amount calculated from the vault.
*/
function currentValue() external view returns (uint256);
/**
* The function for the vault to call at the end of each vault's round.
* after calling this function, the vault will try to pull assets back from the action and enable withdraw.
*/
function closePosition() external;
/**
* The function for the vault to call when the vault is ready to start the next round.
* the vault will push assets to action before calling this function, but the amount can change compare to
* the last round. So each action should check their asset balance instead of using any cached balance.
*
* Each action can also add additional checks and revert the `rolloverPosition` call if the action
* is not ready to go into the next round.
*/
function rolloverPosition() external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.2;
pragma experimental ABIEncoderV2;
interface ICurve {
function add_liquidity(uint256[2] memory amounts, uint256 minAmount) external payable returns (uint256);
function remove_liquidity_one_coin(uint256 _token_amount, int128 i, uint256 _minAmount) external returns (uint256);
function get_virtual_price() external view returns (uint256);
}
// SPDX-License-Identifier: MIT
import { IERC20 } from '@openzeppelin/contracts/token/ERC20/IERC20.sol';
pragma solidity ^0.7.2;
pragma experimental ABIEncoderV2;
interface IStakeDao {
function depositAll() external;
function deposit(uint256 amount) external;
function withdrawAll() external;
function withdraw(uint256 _shares) external;
function token() external returns (IERC20);
function balanceOf(address account) external view returns (uint256);
function approve(address spender, uint256 amount) external returns (bool);
function transfer(address recipient, uint256 amount) external returns (bool);
function getPricePerFullShare() external view returns (uint256);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;
/*
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with GSN meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address payable) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// 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);
}
}
}
}