Contract Name:
ProtocolFeesCollector
Contract Source Code:
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
pragma experimental ABIEncoderV2;
import "../lib/openzeppelin/IERC20.sol";
import "../lib/helpers/InputHelpers.sol";
import "../lib/helpers/Authentication.sol";
import "../lib/openzeppelin/ReentrancyGuard.sol";
import "../lib/openzeppelin/SafeERC20.sol";
import "./interfaces/IVault.sol";
import "./interfaces/IAuthorizer.sol";
/**
* @dev This an auxiliary contract to the Vault, deployed by it during construction. It offloads some of the tasks the
* Vault performs to reduce its overall bytecode size.
*
* The current values for all protocol fee percentages are stored here, and any tokens charged as protocol fees are
* sent to this contract, where they may be withdrawn by authorized entities. All authorization tasks are delegated
* to the Vault's own authorizer.
*/
contract ProtocolFeesCollector is Authentication, ReentrancyGuard {
using SafeERC20 for IERC20;
// Absolute maximum fee percentages (1e18 = 100%, 1e16 = 1%).
uint256 private constant _MAX_PROTOCOL_SWAP_FEE_PERCENTAGE = 50e16; // 50%
uint256 private constant _MAX_PROTOCOL_FLASH_LOAN_FEE_PERCENTAGE = 1e16; // 1%
IVault public immutable vault;
// All fee percentages are 18-decimal fixed point numbers.
// The swap fee is charged whenever a swap occurs, as a percentage of the fee charged by the Pool. These are not
// actually charged on each individual swap: the `Vault` relies on the Pools being honest and reporting fees due
// when users join and exit them.
uint256 private _swapFeePercentage;
// The flash loan fee is charged whenever a flash loan occurs, as a percentage of the tokens lent.
uint256 private _flashLoanFeePercentage;
event SwapFeePercentageChanged(uint256 newSwapFeePercentage);
event FlashLoanFeePercentageChanged(uint256 newFlashLoanFeePercentage);
constructor(IVault _vault)
// The ProtocolFeesCollector is a singleton, so it simply uses its own address to disambiguate action
// identifiers.
Authentication(bytes32(uint256(address(this))))
{
vault = _vault;
}
function withdrawCollectedFees(
IERC20[] calldata tokens,
uint256[] calldata amounts,
address recipient
) external nonReentrant authenticate {
InputHelpers.ensureInputLengthMatch(tokens.length, amounts.length);
for (uint256 i = 0; i < tokens.length; ++i) {
IERC20 token = tokens[i];
uint256 amount = amounts[i];
token.safeTransfer(recipient, amount);
}
}
function setSwapFeePercentage(uint256 newSwapFeePercentage) external authenticate {
_require(newSwapFeePercentage <= _MAX_PROTOCOL_SWAP_FEE_PERCENTAGE, Errors.SWAP_FEE_PERCENTAGE_TOO_HIGH);
_swapFeePercentage = newSwapFeePercentage;
emit SwapFeePercentageChanged(newSwapFeePercentage);
}
function setFlashLoanFeePercentage(uint256 newFlashLoanFeePercentage) external authenticate {
_require(
newFlashLoanFeePercentage <= _MAX_PROTOCOL_FLASH_LOAN_FEE_PERCENTAGE,
Errors.FLASH_LOAN_FEE_PERCENTAGE_TOO_HIGH
);
_flashLoanFeePercentage = newFlashLoanFeePercentage;
emit FlashLoanFeePercentageChanged(newFlashLoanFeePercentage);
}
function getSwapFeePercentage() external view returns (uint256) {
return _swapFeePercentage;
}
function getFlashLoanFeePercentage() external view returns (uint256) {
return _flashLoanFeePercentage;
}
function getCollectedFeeAmounts(IERC20[] memory tokens) external view returns (uint256[] memory feeAmounts) {
feeAmounts = new uint256[](tokens.length);
for (uint256 i = 0; i < tokens.length; ++i) {
feeAmounts[i] = tokens[i].balanceOf(address(this));
}
}
function getAuthorizer() external view returns (IAuthorizer) {
return _getAuthorizer();
}
function _canPerform(bytes32 actionId, address account) internal view override returns (bool) {
return _getAuthorizer().canPerform(actionId, account, address(this));
}
function _getAuthorizer() internal view returns (IAuthorizer) {
return vault.getAuthorizer();
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.7.0;
/**
* @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: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../openzeppelin/IERC20.sol";
import "./BalancerErrors.sol";
import "../../vault/interfaces/IAsset.sol";
library InputHelpers {
function ensureInputLengthMatch(uint256 a, uint256 b) internal pure {
_require(a == b, Errors.INPUT_LENGTH_MISMATCH);
}
function ensureInputLengthMatch(
uint256 a,
uint256 b,
uint256 c
) internal pure {
_require(a == b && b == c, Errors.INPUT_LENGTH_MISMATCH);
}
function ensureArrayIsSorted(IAsset[] memory array) internal pure {
address[] memory addressArray;
// solhint-disable-next-line no-inline-assembly
assembly {
addressArray := array
}
ensureArrayIsSorted(addressArray);
}
function ensureArrayIsSorted(IERC20[] memory array) internal pure {
address[] memory addressArray;
// solhint-disable-next-line no-inline-assembly
assembly {
addressArray := array
}
ensureArrayIsSorted(addressArray);
}
function ensureArrayIsSorted(address[] memory array) internal pure {
if (array.length < 2) {
return;
}
address previous = array[0];
for (uint256 i = 1; i < array.length; ++i) {
address current = array[i];
_require(previous < current, Errors.UNSORTED_ARRAY);
previous = current;
}
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "./BalancerErrors.sol";
import "./IAuthentication.sol";
/**
* @dev Building block for performing access control on external functions.
*
* This contract is used via the `authenticate` modifier (or the `_authenticateCaller` function), which can be applied
* to external functions to only make them callable by authorized accounts.
*
* Derived contracts must implement the `_canPerform` function, which holds the actual access control logic.
*/
abstract contract Authentication is IAuthentication {
bytes32 private immutable _actionIdDisambiguator;
/**
* @dev The main purpose of the `actionIdDisambiguator` is to prevent accidental function selector collisions in
* multi contract systems.
*
* There are two main uses for it:
* - if the contract is a singleton, any unique identifier can be used to make the associated action identifiers
* unique. The contract's own address is a good option.
* - if the contract belongs to a family that shares action identifiers for the same functions, an identifier
* shared by the entire family (and no other contract) should be used instead.
*/
constructor(bytes32 actionIdDisambiguator) {
_actionIdDisambiguator = actionIdDisambiguator;
}
/**
* @dev Reverts unless the caller is allowed to call this function. Should only be applied to external functions.
*/
modifier authenticate() {
_authenticateCaller();
_;
}
/**
* @dev Reverts unless the caller is allowed to call the entry point function.
*/
function _authenticateCaller() internal view {
bytes32 actionId = getActionId(msg.sig);
_require(_canPerform(actionId, msg.sender), Errors.SENDER_NOT_ALLOWED);
}
function getActionId(bytes4 selector) public view override returns (bytes32) {
// Each external function is dynamically assigned an action identifier as the hash of the disambiguator and the
// function selector. Disambiguation is necessary to avoid potential collisions in the function selectors of
// multiple contracts.
return keccak256(abi.encodePacked(_actionIdDisambiguator, selector));
}
function _canPerform(bytes32 actionId, address user) internal view virtual returns (bool);
}
// SPDX-License-Identifier: MIT
// Based on the ReentrancyGuard library from OpenZeppelin Contracts, altered to reduce bytecode size.
// Modifier code is inlined by the compiler, which causes its code to appear multiple times in the codebase. By using
// private functions, we achieve the same end result with slightly higher runtime gas costs, but reduced bytecode size.
pragma solidity ^0.7.0;
import "../helpers/BalancerErrors.sol";
/**
* @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() {
_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() {
_enterNonReentrant();
_;
_exitNonReentrant();
}
function _enterNonReentrant() private {
// On the first call to nonReentrant, _status will be _NOT_ENTERED
_require(_status != _ENTERED, Errors.REENTRANCY);
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
}
function _exitNonReentrant() private {
// 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
// Based on the ReentrancyGuard library from OpenZeppelin Contracts, altered to reduce gas costs.
// The `safeTransfer` and `safeTransferFrom` functions assume that `token` is a contract (an account with code), and
// work differently from the OpenZeppelin version if it is not.
pragma solidity ^0.7.0;
import "../helpers/BalancerErrors.sol";
import "./IERC20.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 {
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(address(token), abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(address(token), abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @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).
*
* WARNING: `token` is assumed to be a contract: calls to EOAs will *not* revert.
*/
function _callOptionalReturn(address 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.
(bool success, bytes memory returndata) = token.call(data);
// If the low-level call didn't succeed we return whatever was returned from it.
assembly {
if eq(success, 0) {
returndatacopy(0, 0, returndatasize())
revert(0, returndatasize())
}
}
// Finally we check the returndata size is either zero or true - note that this check will always pass for EOAs
_require(returndata.length == 0 || abi.decode(returndata, (bool)), Errors.SAFE_ERC20_CALL_FAILED);
}
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma experimental ABIEncoderV2;
import "../../lib/openzeppelin/IERC20.sol";
import "./IWETH.sol";
import "./IAsset.sol";
import "./IAuthorizer.sol";
import "./IFlashLoanRecipient.sol";
import "../ProtocolFeesCollector.sol";
import "../../lib/helpers/ISignaturesValidator.sol";
import "../../lib/helpers/ITemporarilyPausable.sol";
pragma solidity ^0.7.0;
/**
* @dev Full external interface for the Vault core contract - no external or public methods exist in the contract that
* don't override one of these declarations.
*/
interface IVault is ISignaturesValidator, ITemporarilyPausable {
// Generalities about the Vault:
//
// - Whenever documentation refers to 'tokens', it strictly refers to ERC20-compliant token contracts. Tokens are
// transferred out of the Vault by calling the `IERC20.transfer` function, and transferred in by calling
// `IERC20.transferFrom`. In these cases, the sender must have previously allowed the Vault to use their tokens by
// calling `IERC20.approve`. The only deviation from the ERC20 standard that is supported is functions not returning
// a boolean value: in these scenarios, a non-reverting call is assumed to be successful.
//
// - All non-view functions in the Vault are non-reentrant: calling them while another one is mid-execution (e.g.
// while execution control is transferred to a token contract during a swap) will result in a revert. View
// functions can be called in a re-reentrant way, but doing so might cause them to return inconsistent results.
// Contracts calling view functions in the Vault must make sure the Vault has not already been entered.
//
// - View functions revert if referring to either unregistered Pools, or unregistered tokens for registered Pools.
// Authorizer
//
// Some system actions are permissioned, like setting and collecting protocol fees. This permissioning system exists
// outside of the Vault in the Authorizer contract: the Vault simply calls the Authorizer to check if the caller
// can perform a given action.
/**
* @dev Returns the Vault's Authorizer.
*/
function getAuthorizer() external view returns (IAuthorizer);
/**
* @dev Sets a new Authorizer for the Vault. The caller must be allowed by the current Authorizer to do this.
*
* Emits an `AuthorizerChanged` event.
*/
function setAuthorizer(IAuthorizer newAuthorizer) external;
/**
* @dev Emitted when a new authorizer is set by `setAuthorizer`.
*/
event AuthorizerChanged(IAuthorizer indexed newAuthorizer);
// Relayers
//
// Additionally, it is possible for an account to perform certain actions on behalf of another one, using their
// Vault ERC20 allowance and Internal Balance. These accounts are said to be 'relayers' for these Vault functions,
// and are expected to be smart contracts with sound authentication mechanisms. For an account to be able to wield
// this power, two things must occur:
// - The Authorizer must grant the account the permission to be a relayer for the relevant Vault function. This
// means that Balancer governance must approve each individual contract to act as a relayer for the intended
// functions.
// - Each user must approve the relayer to act on their behalf.
// This double protection means users cannot be tricked into approving malicious relayers (because they will not
// have been allowed by the Authorizer via governance), nor can malicious relayers approved by a compromised
// Authorizer or governance drain user funds, since they would also need to be approved by each individual user.
/**
* @dev Returns true if `user` has approved `relayer` to act as a relayer for them.
*/
function hasApprovedRelayer(address user, address relayer) external view returns (bool);
/**
* @dev Allows `relayer` to act as a relayer for `sender` if `approved` is true, and disallows it otherwise.
*
* Emits a `RelayerApprovalChanged` event.
*/
function setRelayerApproval(
address sender,
address relayer,
bool approved
) external;
/**
* @dev Emitted every time a relayer is approved or disapproved by `setRelayerApproval`.
*/
event RelayerApprovalChanged(address indexed relayer, address indexed sender, bool approved);
// Internal Balance
//
// Users can deposit tokens into the Vault, where they are allocated to their Internal Balance, and later
// transferred or withdrawn. It can also be used as a source of tokens when joining Pools, as a destination
// when exiting them, and as either when performing swaps. This usage of Internal Balance results in greatly reduced
// gas costs when compared to relying on plain ERC20 transfers, leading to large savings for frequent users.
//
// Internal Balance management features batching, which means a single contract call can be used to perform multiple
// operations of different kinds, with different senders and recipients, at once.
/**
* @dev Returns `user`'s Internal Balance for a set of tokens.
*/
function getInternalBalance(address user, IERC20[] memory tokens) external view returns (uint256[] memory);
/**
* @dev Performs a set of user balance operations, which involve Internal Balance (deposit, withdraw or transfer)
* and plain ERC20 transfers using the Vault's allowance. This last feature is particularly useful for relayers, as
* it lets integrators reuse a user's Vault allowance.
*
* For each operation, if the caller is not `sender`, it must be an authorized relayer for them.
*/
function manageUserBalance(UserBalanceOp[] memory ops) external payable;
/**
* @dev Data for `manageUserBalance` operations, which include the possibility for ETH to be sent and received
without manual WETH wrapping or unwrapping.
*/
struct UserBalanceOp {
UserBalanceOpKind kind;
IAsset asset;
uint256 amount;
address sender;
address payable recipient;
}
// There are four possible operations in `manageUserBalance`:
//
// - DEPOSIT_INTERNAL
// Increases the Internal Balance of the `recipient` account by transferring tokens from the corresponding
// `sender`. The sender must have allowed the Vault to use their tokens via `IERC20.approve()`.
//
// ETH can be used by passing the ETH sentinel value as the asset and forwarding ETH in the call: it will be wrapped
// and deposited as WETH. Any ETH amount remaining will be sent back to the caller (not the sender, which is
// relevant for relayers).
//
// Emits an `InternalBalanceChanged` event.
//
//
// - WITHDRAW_INTERNAL
// Decreases the Internal Balance of the `sender` account by transferring tokens to the `recipient`.
//
// ETH can be used by passing the ETH sentinel value as the asset. This will deduct WETH instead, unwrap it and send
// it to the recipient as ETH.
//
// Emits an `InternalBalanceChanged` event.
//
//
// - TRANSFER_INTERNAL
// Transfers tokens from the Internal Balance of the `sender` account to the Internal Balance of `recipient`.
//
// Reverts if the ETH sentinel value is passed.
//
// Emits an `InternalBalanceChanged` event.
//
//
// - TRANSFER_EXTERNAL
// Transfers tokens from `sender` to `recipient`, using the Vault's ERC20 allowance. This is typically used by
// relayers, as it lets them reuse a user's Vault allowance.
//
// Reverts if the ETH sentinel value is passed.
//
// Emits an `ExternalBalanceTransfer` event.
enum UserBalanceOpKind { DEPOSIT_INTERNAL, WITHDRAW_INTERNAL, TRANSFER_INTERNAL, TRANSFER_EXTERNAL }
/**
* @dev Emitted when a user's Internal Balance changes, either from calls to `manageUserBalance`, or through
* interacting with Pools using Internal Balance.
*
* Because Internal Balance works exclusively with ERC20 tokens, ETH deposits and withdrawals will use the WETH
* address.
*/
event InternalBalanceChanged(address indexed user, IERC20 indexed token, int256 delta);
/**
* @dev Emitted when a user's Vault ERC20 allowance is used by the Vault to transfer tokens to an external account.
*/
event ExternalBalanceTransfer(IERC20 indexed token, address indexed sender, address recipient, uint256 amount);
// Pools
//
// There are three specialization settings for Pools, which allow for cheaper swaps at the cost of reduced
// functionality:
//
// - General: no specialization, suited for all Pools. IGeneralPool is used for swap request callbacks, passing the
// balance of all tokens in the Pool. These Pools have the largest swap costs (because of the extra storage reads),
// which increase with the number of registered tokens.
//
// - Minimal Swap Info: IMinimalSwapInfoPool is used instead of IGeneralPool, which saves gas by only passing the
// balance of the two tokens involved in the swap. This is suitable for some pricing algorithms, like the weighted
// constant product one popularized by Balancer V1. Swap costs are smaller compared to general Pools, and are
// independent of the number of registered tokens.
//
// - Two Token: only allows two tokens to be registered. This achieves the lowest possible swap gas cost. Like
// minimal swap info Pools, these are called via IMinimalSwapInfoPool.
enum PoolSpecialization { GENERAL, MINIMAL_SWAP_INFO, TWO_TOKEN }
/**
* @dev Registers the caller account as a Pool with a given specialization setting. Returns the Pool's ID, which
* is used in all Pool-related functions. Pools cannot be deregistered, nor can the Pool's specialization be
* changed.
*
* The caller is expected to be a smart contract that implements either `IGeneralPool` or `IMinimalSwapInfoPool`,
* depending on the chosen specialization setting. This contract is known as the Pool's contract.
*
* Note that the same contract may register itself as multiple Pools with unique Pool IDs, or in other words,
* multiple Pools may share the same contract.
*
* Emits a `PoolRegistered` event.
*/
function registerPool(PoolSpecialization specialization) external returns (bytes32);
/**
* @dev Emitted when a Pool is registered by calling `registerPool`.
*/
event PoolRegistered(bytes32 indexed poolId, address indexed poolAddress, PoolSpecialization specialization);
/**
* @dev Returns a Pool's contract address and specialization setting.
*/
function getPool(bytes32 poolId) external view returns (address, PoolSpecialization);
/**
* @dev Registers `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
*
* Pools can only interact with tokens they have registered. Users join a Pool by transferring registered tokens,
* exit by receiving registered tokens, and can only swap registered tokens.
*
* Each token can only be registered once. For Pools with the Two Token specialization, `tokens` must have a length
* of two, that is, both tokens must be registered in the same `registerTokens` call, and they must be sorted in
* ascending order.
*
* The `tokens` and `assetManagers` arrays must have the same length, and each entry in these indicates the Asset
* Manager for the corresponding token. Asset Managers can manage a Pool's tokens via `managePoolBalance`,
* depositing and withdrawing them directly, and can even set their balance to arbitrary amounts. They are therefore
* expected to be highly secured smart contracts with sound design principles, and the decision to register an
* Asset Manager should not be made lightly.
*
* Pools can choose not to assign an Asset Manager to a given token by passing in the zero address. Once an Asset
* Manager is set, it cannot be changed except by deregistering the associated token and registering again with a
* different Asset Manager.
*
* Emits a `TokensRegistered` event.
*/
function registerTokens(
bytes32 poolId,
IERC20[] memory tokens,
address[] memory assetManagers
) external;
/**
* @dev Emitted when a Pool registers tokens by calling `registerTokens`.
*/
event TokensRegistered(bytes32 indexed poolId, IERC20[] tokens, address[] assetManagers);
/**
* @dev Deregisters `tokens` for the `poolId` Pool. Must be called by the Pool's contract.
*
* Only registered tokens (via `registerTokens`) can be deregistered. Additionally, they must have zero total
* balance. For Pools with the Two Token specialization, `tokens` must have a length of two, that is, both tokens
* must be deregistered in the same `deregisterTokens` call.
*
* A deregistered token can be re-registered later on, possibly with a different Asset Manager.
*
* Emits a `TokensDeregistered` event.
*/
function deregisterTokens(bytes32 poolId, IERC20[] memory tokens) external;
/**
* @dev Emitted when a Pool deregisters tokens by calling `deregisterTokens`.
*/
event TokensDeregistered(bytes32 indexed poolId, IERC20[] tokens);
/**
* @dev Returns detailed information for a Pool's registered token.
*
* `cash` is the number of tokens the Vault currently holds for the Pool. `managed` is the number of tokens
* withdrawn and held outside the Vault by the Pool's token Asset Manager. The Pool's total balance for `token`
* equals the sum of `cash` and `managed`.
*
* Internally, `cash` and `managed` are stored using 112 bits. No action can ever cause a Pool's token `cash`,
* `managed` or `total` balance to be greater than 2^112 - 1.
*
* `lastChangeBlock` is the number of the block in which `token`'s total balance was last modified (via either a
* join, exit, swap, or Asset Manager update). This value is useful to avoid so-called 'sandwich attacks', for
* example when developing price oracles. A change of zero (e.g. caused by a swap with amount zero) is considered a
* change for this purpose, and will update `lastChangeBlock`.
*
* `assetManager` is the Pool's token Asset Manager.
*/
function getPoolTokenInfo(bytes32 poolId, IERC20 token)
external
view
returns (
uint256 cash,
uint256 managed,
uint256 lastChangeBlock,
address assetManager
);
/**
* @dev Returns a Pool's registered tokens, the total balance for each, and the latest block when *any* of
* the tokens' `balances` changed.
*
* The order of the `tokens` array is the same order that will be used in `joinPool`, `exitPool`, as well as in all
* Pool hooks (where applicable). Calls to `registerTokens` and `deregisterTokens` may change this order.
*
* If a Pool only registers tokens once, and these are sorted in ascending order, they will be stored in the same
* order as passed to `registerTokens`.
*
* Total balances include both tokens held by the Vault and those withdrawn by the Pool's Asset Managers. These are
* the amounts used by joins, exits and swaps. For a detailed breakdown of token balances, use `getPoolTokenInfo`
* instead.
*/
function getPoolTokens(bytes32 poolId)
external
view
returns (
IERC20[] memory tokens,
uint256[] memory balances,
uint256 lastChangeBlock
);
/**
* @dev Called by users to join a Pool, which transfers tokens from `sender` into the Pool's balance. This will
* trigger custom Pool behavior, which will typically grant something in return to `recipient` - often tokenized
* Pool shares.
*
* If the caller is not `sender`, it must be an authorized relayer for them.
*
* The `assets` and `maxAmountsIn` arrays must have the same length, and each entry indicates the maximum amount
* to send for each asset. The amounts to send are decided by the Pool and not the Vault: it just enforces
* these maximums.
*
* If joining a Pool that holds WETH, it is possible to send ETH directly: the Vault will do the wrapping. To enable
* this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead of the
* WETH address. Note that it is not possible to combine ETH and WETH in the same join. Any excess ETH will be sent
* back to the caller (not the sender, which is important for relayers).
*
* `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
* interacting with Pools that register and deregister tokens frequently. If sending ETH however, the array must be
* sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the final
* `assets` array might not be sorted. Pools with no registered tokens cannot be joined.
*
* If `fromInternalBalance` is true, the caller's Internal Balance will be preferred: ERC20 transfers will only
* be made for the difference between the requested amount and Internal Balance (if any). Note that ETH cannot be
* withdrawn from Internal Balance: attempting to do so will trigger a revert.
*
* This causes the Vault to call the `IBasePool.onJoinPool` hook on the Pool's contract, where Pools implement
* their own custom logic. This typically requires additional information from the user (such as the expected number
* of Pool shares). This can be encoded in the `userData` argument, which is ignored by the Vault and passed
* directly to the Pool's contract, as is `recipient`.
*
* Emits a `PoolBalanceChanged` event.
*/
function joinPool(
bytes32 poolId,
address sender,
address recipient,
JoinPoolRequest memory request
) external payable;
struct JoinPoolRequest {
IAsset[] assets;
uint256[] maxAmountsIn;
bytes userData;
bool fromInternalBalance;
}
/**
* @dev Called by users to exit a Pool, which transfers tokens from the Pool's balance to `recipient`. This will
* trigger custom Pool behavior, which will typically ask for something in return from `sender` - often tokenized
* Pool shares. The amount of tokens that can be withdrawn is limited by the Pool's `cash` balance (see
* `getPoolTokenInfo`).
*
* If the caller is not `sender`, it must be an authorized relayer for them.
*
* The `tokens` and `minAmountsOut` arrays must have the same length, and each entry in these indicates the minimum
* token amount to receive for each token contract. The amounts to send are decided by the Pool and not the Vault:
* it just enforces these minimums.
*
* If exiting a Pool that holds WETH, it is possible to receive ETH directly: the Vault will do the unwrapping. To
* enable this mechanism, the IAsset sentinel value (the zero address) must be passed in the `assets` array instead
* of the WETH address. Note that it is not possible to combine ETH and WETH in the same exit.
*
* `assets` must have the same length and order as the array returned by `getPoolTokens`. This prevents issues when
* interacting with Pools that register and deregister tokens frequently. If receiving ETH however, the array must
* be sorted *before* replacing the WETH address with the ETH sentinel value (the zero address), which means the
* final `assets` array might not be sorted. Pools with no registered tokens cannot be exited.
*
* If `toInternalBalance` is true, the tokens will be deposited to `recipient`'s Internal Balance. Otherwise,
* an ERC20 transfer will be performed. Note that ETH cannot be deposited to Internal Balance: attempting to
* do so will trigger a revert.
*
* `minAmountsOut` is the minimum amount of tokens the user expects to get out of the Pool, for each token in the
* `tokens` array. This array must match the Pool's registered tokens.
*
* This causes the Vault to call the `IBasePool.onExitPool` hook on the Pool's contract, where Pools implement
* their own custom logic. This typically requires additional information from the user (such as the expected number
* of Pool shares to return). This can be encoded in the `userData` argument, which is ignored by the Vault and
* passed directly to the Pool's contract.
*
* Emits a `PoolBalanceChanged` event.
*/
function exitPool(
bytes32 poolId,
address sender,
address payable recipient,
ExitPoolRequest memory request
) external;
struct ExitPoolRequest {
IAsset[] assets;
uint256[] minAmountsOut;
bytes userData;
bool toInternalBalance;
}
/**
* @dev Emitted when a user joins or exits a Pool by calling `joinPool` or `exitPool`, respectively.
*/
event PoolBalanceChanged(
bytes32 indexed poolId,
address indexed liquidityProvider,
IERC20[] tokens,
int256[] deltas,
uint256[] protocolFeeAmounts
);
enum PoolBalanceChangeKind { JOIN, EXIT }
// Swaps
//
// Users can swap tokens with Pools by calling the `swap` and `batchSwap` functions. To do this,
// they need not trust Pool contracts in any way: all security checks are made by the Vault. They must however be
// aware of the Pools' pricing algorithms in order to estimate the prices Pools will quote.
//
// The `swap` function executes a single swap, while `batchSwap` can perform multiple swaps in sequence.
// In each individual swap, tokens of one kind are sent from the sender to the Pool (this is the 'token in'),
// and tokens of another kind are sent from the Pool to the recipient in exchange (this is the 'token out').
// More complex swaps, such as one token in to multiple tokens out can be achieved by batching together
// individual swaps.
//
// There are two swap kinds:
// - 'given in' swaps, where the amount of tokens in (sent to the Pool) is known, and the Pool determines (via the
// `onSwap` hook) the amount of tokens out (to send to the recipient).
// - 'given out' swaps, where the amount of tokens out (received from the Pool) is known, and the Pool determines
// (via the `onSwap` hook) the amount of tokens in (to receive from the sender).
//
// Additionally, it is possible to chain swaps using a placeholder input amount, which the Vault replaces with
// the calculated output of the previous swap. If the previous swap was 'given in', this will be the calculated
// tokenOut amount. If the previous swap was 'given out', it will use the calculated tokenIn amount. These extended
// swaps are known as 'multihop' swaps, since they 'hop' through a number of intermediate tokens before arriving at
// the final intended token.
//
// In all cases, tokens are only transferred in and out of the Vault (or withdrawn from and deposited into Internal
// Balance) after all individual swaps have been completed, and the net token balance change computed. This makes
// certain swap patterns, such as multihops, or swaps that interact with the same token pair in multiple Pools, cost
// much less gas than they would otherwise.
//
// It also means that under certain conditions it is possible to perform arbitrage by swapping with multiple
// Pools in a way that results in net token movement out of the Vault (profit), with no tokens being sent in (only
// updating the Pool's internal accounting).
//
// To protect users from front-running or the market changing rapidly, they supply a list of 'limits' for each token
// involved in the swap, where either the maximum number of tokens to send (by passing a positive value) or the
// minimum amount of tokens to receive (by passing a negative value) is specified.
//
// Additionally, a 'deadline' timestamp can also be provided, forcing the swap to fail if it occurs after
// this point in time (e.g. if the transaction failed to be included in a block promptly).
//
// If interacting with Pools that hold WETH, it is possible to both send and receive ETH directly: the Vault will do
// the wrapping and unwrapping. To enable this mechanism, the IAsset sentinel value (the zero address) must be
// passed in the `assets` array instead of the WETH address. Note that it is possible to combine ETH and WETH in the
// same swap. Any excess ETH will be sent back to the caller (not the sender, which is relevant for relayers).
//
// Finally, Internal Balance can be used when either sending or receiving tokens.
enum SwapKind { GIVEN_IN, GIVEN_OUT }
/**
* @dev Performs a swap with a single Pool.
*
* If the swap is 'given in' (the number of tokens to send to the Pool is known), it returns the amount of tokens
* taken from the Pool, which must be greater than or equal to `limit`.
*
* If the swap is 'given out' (the number of tokens to take from the Pool is known), it returns the amount of tokens
* sent to the Pool, which must be less than or equal to `limit`.
*
* Internal Balance usage and the recipient are determined by the `funds` struct.
*
* Emits a `Swap` event.
*/
function swap(
SingleSwap memory singleSwap,
FundManagement memory funds,
uint256 limit,
uint256 deadline
) external payable returns (uint256);
/**
* @dev Data for a single swap executed by `swap`. `amount` is either `amountIn` or `amountOut` depending on
* the `kind` value.
*
* `assetIn` and `assetOut` are either token addresses, or the IAsset sentinel value for ETH (the zero address).
* Note that Pools never interact with ETH directly: it will be wrapped to or unwrapped from WETH by the Vault.
*
* The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
* used to extend swap behavior.
*/
struct SingleSwap {
bytes32 poolId;
SwapKind kind;
IAsset assetIn;
IAsset assetOut;
uint256 amount;
bytes userData;
}
/**
* @dev Performs a series of swaps with one or multiple Pools. In each individual swap, the caller determines either
* the amount of tokens sent to or received from the Pool, depending on the `kind` value.
*
* Returns an array with the net Vault asset balance deltas. Positive amounts represent tokens (or ETH) sent to the
* Vault, and negative amounts represent tokens (or ETH) sent by the Vault. Each delta corresponds to the asset at
* the same index in the `assets` array.
*
* Swaps are executed sequentially, in the order specified by the `swaps` array. Each array element describes a
* Pool, the token to be sent to this Pool, the token to receive from it, and an amount that is either `amountIn` or
* `amountOut` depending on the swap kind.
*
* Multihop swaps can be executed by passing an `amount` value of zero for a swap. This will cause the amount in/out
* of the previous swap to be used as the amount in for the current one. In a 'given in' swap, 'tokenIn' must equal
* the previous swap's `tokenOut`. For a 'given out' swap, `tokenOut` must equal the previous swap's `tokenIn`.
*
* The `assets` array contains the addresses of all assets involved in the swaps. These are either token addresses,
* or the IAsset sentinel value for ETH (the zero address). Each entry in the `swaps` array specifies tokens in and
* out by referencing an index in `assets`. Note that Pools never interact with ETH directly: it will be wrapped to
* or unwrapped from WETH by the Vault.
*
* Internal Balance usage, sender, and recipient are determined by the `funds` struct. The `limits` array specifies
* the minimum or maximum amount of each token the vault is allowed to transfer.
*
* `batchSwap` can be used to make a single swap, like `swap` does, but doing so requires more gas than the
* equivalent `swap` call.
*
* Emits `Swap` events.
*/
function batchSwap(
SwapKind kind,
BatchSwapStep[] memory swaps,
IAsset[] memory assets,
FundManagement memory funds,
int256[] memory limits,
uint256 deadline
) external payable returns (int256[] memory);
/**
* @dev Data for each individual swap executed by `batchSwap`. The asset in and out fields are indexes into the
* `assets` array passed to that function, and ETH assets are converted to WETH.
*
* If `amount` is zero, the multihop mechanism is used to determine the actual amount based on the amount in/out
* from the previous swap, depending on the swap kind.
*
* The `userData` field is ignored by the Vault, but forwarded to the Pool in the `onSwap` hook, and may be
* used to extend swap behavior.
*/
struct BatchSwapStep {
bytes32 poolId;
uint256 assetInIndex;
uint256 assetOutIndex;
uint256 amount;
bytes userData;
}
/**
* @dev Emitted for each individual swap performed by `swap` or `batchSwap`.
*/
event Swap(
bytes32 indexed poolId,
IERC20 indexed tokenIn,
IERC20 indexed tokenOut,
uint256 amountIn,
uint256 amountOut
);
/**
* @dev All tokens in a swap are either sent from the `sender` account to the Vault, or from the Vault to the
* `recipient` account.
*
* If the caller is not `sender`, it must be an authorized relayer for them.
*
* If `fromInternalBalance` is true, the `sender`'s Internal Balance will be preferred, performing an ERC20
* transfer for the difference between the requested amount and the User's Internal Balance (if any). The `sender`
* must have allowed the Vault to use their tokens via `IERC20.approve()`. This matches the behavior of
* `joinPool`.
*
* If `toInternalBalance` is true, tokens will be deposited to `recipient`'s internal balance instead of
* transferred. This matches the behavior of `exitPool`.
*
* Note that ETH cannot be deposited to or withdrawn from Internal Balance: attempting to do so will trigger a
* revert.
*/
struct FundManagement {
address sender;
bool fromInternalBalance;
address payable recipient;
bool toInternalBalance;
}
/**
* @dev Simulates a call to `batchSwap`, returning an array of Vault asset deltas. Calls to `swap` cannot be
* simulated directly, but an equivalent `batchSwap` call can and will yield the exact same result.
*
* Each element in the array corresponds to the asset at the same index, and indicates the number of tokens (or ETH)
* the Vault would take from the sender (if positive) or send to the recipient (if negative). The arguments it
* receives are the same that an equivalent `batchSwap` call would receive.
*
* Unlike `batchSwap`, this function performs no checks on the sender or recipient field in the `funds` struct.
* This makes it suitable to be called by off-chain applications via eth_call without needing to hold tokens,
* approve them for the Vault, or even know a user's address.
*
* Note that this function is not 'view' (due to implementation details): the client code must explicitly execute
* eth_call instead of eth_sendTransaction.
*/
function queryBatchSwap(
SwapKind kind,
BatchSwapStep[] memory swaps,
IAsset[] memory assets,
FundManagement memory funds
) external returns (int256[] memory assetDeltas);
// Flash Loans
/**
* @dev Performs a 'flash loan', sending tokens to `recipient`, executing the `receiveFlashLoan` hook on it,
* and then reverting unless the tokens plus a proportional protocol fee have been returned.
*
* The `tokens` and `amounts` arrays must have the same length, and each entry in these indicates the loan amount
* for each token contract. `tokens` must be sorted in ascending order.
*
* The 'userData' field is ignored by the Vault, and forwarded as-is to `recipient` as part of the
* `receiveFlashLoan` call.
*
* Emits `FlashLoan` events.
*/
function flashLoan(
IFlashLoanRecipient recipient,
IERC20[] memory tokens,
uint256[] memory amounts,
bytes memory userData
) external;
/**
* @dev Emitted for each individual flash loan performed by `flashLoan`.
*/
event FlashLoan(IFlashLoanRecipient indexed recipient, IERC20 indexed token, uint256 amount, uint256 feeAmount);
// Asset Management
//
// Each token registered for a Pool can be assigned an Asset Manager, which is able to freely withdraw the Pool's
// tokens from the Vault, deposit them, or assign arbitrary values to its `managed` balance (see
// `getPoolTokenInfo`). This makes them extremely powerful and dangerous. Even if an Asset Manager only directly
// controls one of the tokens in a Pool, a malicious manager could set that token's balance to manipulate the
// prices of the other tokens, and then drain the Pool with swaps. The risk of using Asset Managers is therefore
// not constrained to the tokens they are managing, but extends to the entire Pool's holdings.
//
// However, a properly designed Asset Manager smart contract can be safely used for the Pool's benefit,
// for example by lending unused tokens out for interest, or using them to participate in voting protocols.
//
// This concept is unrelated to the IAsset interface.
/**
* @dev Performs a set of Pool balance operations, which may be either withdrawals, deposits or updates.
*
* Pool Balance management features batching, which means a single contract call can be used to perform multiple
* operations of different kinds, with different Pools and tokens, at once.
*
* For each operation, the caller must be registered as the Asset Manager for `token` in `poolId`.
*/
function managePoolBalance(PoolBalanceOp[] memory ops) external;
struct PoolBalanceOp {
PoolBalanceOpKind kind;
bytes32 poolId;
IERC20 token;
uint256 amount;
}
/**
* Withdrawals decrease the Pool's cash, but increase its managed balance, leaving the total balance unchanged.
*
* Deposits increase the Pool's cash, but decrease its managed balance, leaving the total balance unchanged.
*
* Updates don't affect the Pool's cash balance, but because the managed balance changes, it does alter the total.
* The external amount can be either increased or decreased by this call (i.e., reporting a gain or a loss).
*/
enum PoolBalanceOpKind { WITHDRAW, DEPOSIT, UPDATE }
/**
* @dev Emitted when a Pool's token Asset Manager alters its balance via `managePoolBalance`.
*/
event PoolBalanceManaged(
bytes32 indexed poolId,
address indexed assetManager,
IERC20 indexed token,
int256 cashDelta,
int256 managedDelta
);
// Protocol Fees
//
// Some operations cause the Vault to collect tokens in the form of protocol fees, which can then be withdrawn by
// permissioned accounts.
//
// There are two kinds of protocol fees:
//
// - flash loan fees: charged on all flash loans, as a percentage of the amounts lent.
//
// - swap fees: a percentage of the fees charged by Pools when performing swaps. For a number of reasons, including
// swap gas costs and interface simplicity, protocol swap fees are not charged on each individual swap. Rather,
// Pools are expected to keep track of how much they have charged in swap fees, and pay any outstanding debts to the
// Vault when they are joined or exited. This prevents users from joining a Pool with unpaid debt, as well as
// exiting a Pool in debt without first paying their share.
/**
* @dev Returns the current protocol fee module.
*/
function getProtocolFeesCollector() external view returns (ProtocolFeesCollector);
/**
* @dev Safety mechanism to pause most Vault operations in the event of an emergency - typically detection of an
* error in some part of the system.
*
* The Vault can only be paused during an initial time period, after which pausing is forever disabled.
*
* While the contract is paused, the following features are disabled:
* - depositing and transferring internal balance
* - transferring external balance (using the Vault's allowance)
* - swaps
* - joining Pools
* - Asset Manager interactions
*
* Internal Balance can still be withdrawn, and Pools exited.
*/
function setPaused(bool paused) external;
/**
* @dev Returns the Vault's WETH instance.
*/
function WETH() external view returns (IWETH);
// solhint-disable-previous-line func-name-mixedcase
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
interface IAuthorizer {
/**
* @dev Returns true if `account` can perform the action described by `actionId` in the contract `where`.
*/
function canPerform(
bytes32 actionId,
address account,
address where
) external view returns (bool);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
// solhint-disable
/**
* @dev Reverts if `condition` is false, with a revert reason containing `errorCode`. Only codes up to 999 are
* supported.
*/
function _require(bool condition, uint256 errorCode) pure {
if (!condition) _revert(errorCode);
}
/**
* @dev Reverts with a revert reason containing `errorCode`. Only codes up to 999 are supported.
*/
function _revert(uint256 errorCode) pure {
// We're going to dynamically create a revert string based on the error code, with the following format:
// 'BAL#{errorCode}'
// where the code is left-padded with zeroes to three digits (so they range from 000 to 999).
//
// We don't have revert strings embedded in the contract to save bytecode size: it takes much less space to store a
// number (8 to 16 bits) than the individual string characters.
//
// The dynamic string creation algorithm that follows could be implemented in Solidity, but assembly allows for a
// much denser implementation, again saving bytecode size. Given this function unconditionally reverts, this is a
// safe place to rely on it without worrying about how its usage might affect e.g. memory contents.
assembly {
// First, we need to compute the ASCII representation of the error code. We assume that it is in the 0-999
// range, so we only need to convert three digits. To convert the digits to ASCII, we add 0x30, the value for
// the '0' character.
let units := add(mod(errorCode, 10), 0x30)
errorCode := div(errorCode, 10)
let tenths := add(mod(errorCode, 10), 0x30)
errorCode := div(errorCode, 10)
let hundreds := add(mod(errorCode, 10), 0x30)
// With the individual characters, we can now construct the full string. The "BAL#" part is a known constant
// (0x42414c23): we simply shift this by 24 (to provide space for the 3 bytes of the error code), and add the
// characters to it, each shifted by a multiple of 8.
// The revert reason is then shifted left by 200 bits (256 minus the length of the string, 7 characters * 8 bits
// per character = 56) to locate it in the most significant part of the 256 slot (the beginning of a byte
// array).
let revertReason := shl(200, add(0x42414c23000000, add(add(units, shl(8, tenths)), shl(16, hundreds))))
// We can now encode the reason in memory, which can be safely overwritten as we're about to revert. The encoded
// message will have the following layout:
// [ revert reason identifier ] [ string location offset ] [ string length ] [ string contents ]
// The Solidity revert reason identifier is 0x08c739a0, the function selector of the Error(string) function. We
// also write zeroes to the next 28 bytes of memory, but those are about to be overwritten.
mstore(0x0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
// Next is the offset to the location of the string, which will be placed immediately after (20 bytes away).
mstore(0x04, 0x0000000000000000000000000000000000000000000000000000000000000020)
// The string length is fixed: 7 characters.
mstore(0x24, 7)
// Finally, the string itself is stored.
mstore(0x44, revertReason)
// Even if the string is only 7 bytes long, we need to return a full 32 byte slot containing it. The length of
// the encoded message is therefore 4 + 32 + 32 + 32 = 100.
revert(0, 100)
}
}
library Errors {
// Math
uint256 internal constant ADD_OVERFLOW = 0;
uint256 internal constant SUB_OVERFLOW = 1;
uint256 internal constant SUB_UNDERFLOW = 2;
uint256 internal constant MUL_OVERFLOW = 3;
uint256 internal constant ZERO_DIVISION = 4;
uint256 internal constant DIV_INTERNAL = 5;
uint256 internal constant X_OUT_OF_BOUNDS = 6;
uint256 internal constant Y_OUT_OF_BOUNDS = 7;
uint256 internal constant PRODUCT_OUT_OF_BOUNDS = 8;
uint256 internal constant INVALID_EXPONENT = 9;
// Input
uint256 internal constant OUT_OF_BOUNDS = 100;
uint256 internal constant UNSORTED_ARRAY = 101;
uint256 internal constant UNSORTED_TOKENS = 102;
uint256 internal constant INPUT_LENGTH_MISMATCH = 103;
uint256 internal constant ZERO_TOKEN = 104;
// Shared pools
uint256 internal constant MIN_TOKENS = 200;
uint256 internal constant MAX_TOKENS = 201;
uint256 internal constant MAX_SWAP_FEE_PERCENTAGE = 202;
uint256 internal constant MIN_SWAP_FEE_PERCENTAGE = 203;
uint256 internal constant MINIMUM_BPT = 204;
uint256 internal constant CALLER_NOT_VAULT = 205;
uint256 internal constant UNINITIALIZED = 206;
uint256 internal constant BPT_IN_MAX_AMOUNT = 207;
uint256 internal constant BPT_OUT_MIN_AMOUNT = 208;
uint256 internal constant EXPIRED_PERMIT = 209;
// Pools
uint256 internal constant MIN_AMP = 300;
uint256 internal constant MAX_AMP = 301;
uint256 internal constant MIN_WEIGHT = 302;
uint256 internal constant MAX_STABLE_TOKENS = 303;
uint256 internal constant MAX_IN_RATIO = 304;
uint256 internal constant MAX_OUT_RATIO = 305;
uint256 internal constant MIN_BPT_IN_FOR_TOKEN_OUT = 306;
uint256 internal constant MAX_OUT_BPT_FOR_TOKEN_IN = 307;
uint256 internal constant NORMALIZED_WEIGHT_INVARIANT = 308;
uint256 internal constant INVALID_TOKEN = 309;
uint256 internal constant UNHANDLED_JOIN_KIND = 310;
uint256 internal constant ZERO_INVARIANT = 311;
uint256 internal constant ORACLE_INVALID_SECONDS_QUERY = 312;
uint256 internal constant ORACLE_NOT_INITIALIZED = 313;
uint256 internal constant ORACLE_QUERY_TOO_OLD = 314;
uint256 internal constant ORACLE_INVALID_INDEX = 315;
uint256 internal constant ORACLE_BAD_SECS = 316;
// Lib
uint256 internal constant REENTRANCY = 400;
uint256 internal constant SENDER_NOT_ALLOWED = 401;
uint256 internal constant PAUSED = 402;
uint256 internal constant PAUSE_WINDOW_EXPIRED = 403;
uint256 internal constant MAX_PAUSE_WINDOW_DURATION = 404;
uint256 internal constant MAX_BUFFER_PERIOD_DURATION = 405;
uint256 internal constant INSUFFICIENT_BALANCE = 406;
uint256 internal constant INSUFFICIENT_ALLOWANCE = 407;
uint256 internal constant ERC20_TRANSFER_FROM_ZERO_ADDRESS = 408;
uint256 internal constant ERC20_TRANSFER_TO_ZERO_ADDRESS = 409;
uint256 internal constant ERC20_MINT_TO_ZERO_ADDRESS = 410;
uint256 internal constant ERC20_BURN_FROM_ZERO_ADDRESS = 411;
uint256 internal constant ERC20_APPROVE_FROM_ZERO_ADDRESS = 412;
uint256 internal constant ERC20_APPROVE_TO_ZERO_ADDRESS = 413;
uint256 internal constant ERC20_TRANSFER_EXCEEDS_ALLOWANCE = 414;
uint256 internal constant ERC20_DECREASED_ALLOWANCE_BELOW_ZERO = 415;
uint256 internal constant ERC20_TRANSFER_EXCEEDS_BALANCE = 416;
uint256 internal constant ERC20_BURN_EXCEEDS_ALLOWANCE = 417;
uint256 internal constant SAFE_ERC20_CALL_FAILED = 418;
uint256 internal constant ADDRESS_INSUFFICIENT_BALANCE = 419;
uint256 internal constant ADDRESS_CANNOT_SEND_VALUE = 420;
uint256 internal constant SAFE_CAST_VALUE_CANT_FIT_INT256 = 421;
uint256 internal constant GRANT_SENDER_NOT_ADMIN = 422;
uint256 internal constant REVOKE_SENDER_NOT_ADMIN = 423;
uint256 internal constant RENOUNCE_SENDER_NOT_ALLOWED = 424;
uint256 internal constant BUFFER_PERIOD_EXPIRED = 425;
// Vault
uint256 internal constant INVALID_POOL_ID = 500;
uint256 internal constant CALLER_NOT_POOL = 501;
uint256 internal constant SENDER_NOT_ASSET_MANAGER = 502;
uint256 internal constant USER_DOESNT_ALLOW_RELAYER = 503;
uint256 internal constant INVALID_SIGNATURE = 504;
uint256 internal constant EXIT_BELOW_MIN = 505;
uint256 internal constant JOIN_ABOVE_MAX = 506;
uint256 internal constant SWAP_LIMIT = 507;
uint256 internal constant SWAP_DEADLINE = 508;
uint256 internal constant CANNOT_SWAP_SAME_TOKEN = 509;
uint256 internal constant UNKNOWN_AMOUNT_IN_FIRST_SWAP = 510;
uint256 internal constant MALCONSTRUCTED_MULTIHOP_SWAP = 511;
uint256 internal constant INTERNAL_BALANCE_OVERFLOW = 512;
uint256 internal constant INSUFFICIENT_INTERNAL_BALANCE = 513;
uint256 internal constant INVALID_ETH_INTERNAL_BALANCE = 514;
uint256 internal constant INVALID_POST_LOAN_BALANCE = 515;
uint256 internal constant INSUFFICIENT_ETH = 516;
uint256 internal constant UNALLOCATED_ETH = 517;
uint256 internal constant ETH_TRANSFER = 518;
uint256 internal constant CANNOT_USE_ETH_SENTINEL = 519;
uint256 internal constant TOKENS_MISMATCH = 520;
uint256 internal constant TOKEN_NOT_REGISTERED = 521;
uint256 internal constant TOKEN_ALREADY_REGISTERED = 522;
uint256 internal constant TOKENS_ALREADY_SET = 523;
uint256 internal constant TOKENS_LENGTH_MUST_BE_2 = 524;
uint256 internal constant NONZERO_TOKEN_BALANCE = 525;
uint256 internal constant BALANCE_TOTAL_OVERFLOW = 526;
uint256 internal constant POOL_NO_TOKENS = 527;
uint256 internal constant INSUFFICIENT_FLASH_LOAN_BALANCE = 528;
// Fees
uint256 internal constant SWAP_FEE_PERCENTAGE_TOO_HIGH = 600;
uint256 internal constant FLASH_LOAN_FEE_PERCENTAGE_TOO_HIGH = 601;
uint256 internal constant INSUFFICIENT_FLASH_LOAN_FEE_AMOUNT = 602;
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
/**
* @dev This is an empty interface used to represent either ERC20-conforming token contracts or ETH (using the zero
* address sentinel value). We're just relying on the fact that `interface` can be used to declare new address-like
* types.
*
* This concept is unrelated to a Pool's Asset Managers.
*/
interface IAsset {
// solhint-disable-previous-line no-empty-blocks
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
interface IAuthentication {
/**
* @dev Returns the action identifier associated with the external function described by `selector`.
*/
function getActionId(bytes4 selector) external view returns (bytes32);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
import "../../lib/openzeppelin/IERC20.sol";
/**
* @dev Interface for the WETH token contract used internally for wrapping and unwrapping, to support
* sending and receiving ETH in joins, swaps, and internal balance deposits and withdrawals.
*/
interface IWETH is IERC20 {
function deposit() external payable;
function withdraw(uint256 amount) external;
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
// Inspired by Aave Protocol's IFlashLoanReceiver.
import "../../lib/openzeppelin/IERC20.sol";
interface IFlashLoanRecipient {
/**
* @dev When `flashLoan` is called on the Vault, it invokes the `receiveFlashLoan` hook on the recipient.
*
* At the time of the call, the Vault will have transferred `amounts` for `tokens` to the recipient. Before this
* call returns, the recipient must have transferred `amounts` plus `feeAmounts` for each token back to the
* Vault, or else the entire flash loan will revert.
*
* `userData` is the same value passed in the `IVault.flashLoan` call.
*/
function receiveFlashLoan(
IERC20[] memory tokens,
uint256[] memory amounts,
uint256[] memory feeAmounts,
bytes memory userData
) external;
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
/**
* @dev Interface for the SignatureValidator helper, used to support meta-transactions.
*/
interface ISignaturesValidator {
/**
* @dev Returns the EIP712 domain separator.
*/
function getDomainSeparator() external view returns (bytes32);
/**
* @dev Returns the next nonce used by an address to sign messages.
*/
function getNextNonce(address user) external view returns (uint256);
}
// SPDX-License-Identifier: GPL-3.0-or-later
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
pragma solidity ^0.7.0;
/**
* @dev Interface for the TemporarilyPausable helper.
*/
interface ITemporarilyPausable {
/**
* @dev Emitted every time the pause state changes by `_setPaused`.
*/
event PausedStateChanged(bool paused);
/**
* @dev Returns the current paused state.
*/
function getPausedState()
external
view
returns (
bool paused,
uint256 pauseWindowEndTime,
uint256 bufferPeriodEndTime
);
}