Contract Name:
L2WethGateway
Contract Source Code:
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2020, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.6.11;
import "./L2ArbitrumGateway.sol";
import "../../libraries/IWETH9.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
contract L2WethGateway is L2ArbitrumGateway {
using SafeERC20 for IERC20;
address public l1Weth;
address public l2Weth;
function initialize(
address _l1Counterpart,
address _router,
address _l1Weth,
address _l2Weth
) public {
L2ArbitrumGateway._initialize(_l1Counterpart, _router);
require(_l1Weth != address(0), "INVALID_L1WETH");
require(_l2Weth != address(0), "INVALID_L2WETH");
l1Weth = _l1Weth;
l2Weth = _l2Weth;
}
/**
* @notice internal utility function used to handle when no contract is deployed at expected address
* @param l1ERC20 L1 address of ERC20
*/
function handleNoContract(
address l1ERC20,
address, /* expectedL2Address */
address _from,
address, /* _to */
uint256 _amount,
bytes memory /* deployData */
) internal override returns (bool shouldHalt) {
// it is assumed that the custom token is deployed in the L2 before deposits are made
// trigger withdrawal
// this codepath should only be hit if the system is setup incorrectly
// this withdrawal is for error recovery, not composing with L2 dapps, so we ignore the return value
triggerWithdrawal(l1ERC20, address(this), _from, _amount, "");
return true;
}
/**
* @notice Calculate the address used when bridging an ERC20 token
* @dev the L1 and L2 address oracles may not always be in sync.
* For example, a custom token may have been registered but not deploy or the contract self destructed.
* @param l1ERC20 address of L1 token
* @return L2 address of a bridged ERC20 token
*/
function calculateL2TokenAddress(address l1ERC20) public view override returns (address) {
if (l1ERC20 != l1Weth) {
// invalid L1 weth address
return address(0);
}
return l2Weth;
}
function inboundEscrowTransfer(
address _l2TokenAddress,
address _dest,
uint256 _amount
) internal override {
IWETH9(_l2TokenAddress).deposit{ value: _amount }();
IERC20(_l2TokenAddress).safeTransfer(_dest, _amount);
}
function createOutboundTx(
address _from,
uint256 _tokenAmount,
bytes memory _outboundCalldata
) internal override returns (uint256) {
return
sendTxToL1(
// we send the amount of weth withdrawn as callvalue to the L1 gateway
_tokenAmount,
_from,
counterpartGateway,
_outboundCalldata
);
}
receive() external payable {}
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2020, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.6.11;
import "@openzeppelin/contracts/utils/Address.sol";
import "arb-bridge-eth/contracts/libraries/BytesLib.sol";
import "arb-bridge-eth/contracts/libraries/ProxyUtil.sol";
import "arb-bridge-eth/contracts/libraries/AddressAliasHelper.sol";
import "../IArbToken.sol";
import "../L2ArbitrumMessenger.sol";
import "../../libraries/gateway/GatewayMessageHandler.sol";
import "../../libraries/gateway/TokenGateway.sol";
/**
* @title Common interface for gatways on Arbitrum messaging to L1.
*/
abstract contract L2ArbitrumGateway is L2ArbitrumMessenger, TokenGateway {
using Address for address;
uint256 public exitNum;
event DepositFinalized(
address indexed l1Token,
address indexed _from,
address indexed _to,
uint256 _amount
);
event WithdrawalInitiated(
address l1Token,
address indexed _from,
address indexed _to,
uint256 indexed _l2ToL1Id,
uint256 _exitNum,
uint256 _amount
);
modifier onlyCounterpartGateway() override {
require(
msg.sender == AddressAliasHelper.applyL1ToL2Alias(counterpartGateway),
"ONLY_COUNTERPART_GATEWAY"
);
_;
}
function postUpgradeInit() external {
// it is assumed the L2 Arbitrum Gateway contract is behind a Proxy controlled by a proxy admin
// this function can only be called by the proxy admin contract
address proxyAdmin = ProxyUtil.getProxyAdmin();
require(msg.sender == proxyAdmin, "NOT_FROM_ADMIN");
// this has no other logic since the current upgrade doesn't require this logic
}
function _initialize(address _l1Counterpart, address _router) internal override {
TokenGateway._initialize(_l1Counterpart, _router);
// L1 gateway must have a router
require(_router != address(0), "BAD_ROUTER");
}
function createOutboundTx(
address _from,
uint256, /* _tokenAmount */
bytes memory _outboundCalldata
) internal virtual returns (uint256) {
// We make this function virtual since outboundTransfer logic is the same for many gateways
// but sometimes (ie weth) you construct the outgoing message differently.
// exitNum incremented after being included in _outboundCalldata
exitNum++;
return
sendTxToL1(
// default to sending no callvalue to the L1
0,
_from,
counterpartGateway,
_outboundCalldata
);
}
function getOutboundCalldata(
address _token,
address _from,
address _to,
uint256 _amount,
bytes memory _data
) public view override returns (bytes memory outboundCalldata) {
outboundCalldata = abi.encodeWithSelector(
ITokenGateway.finalizeInboundTransfer.selector,
_token,
_from,
_to,
_amount,
GatewayMessageHandler.encodeFromL2GatewayMsg(exitNum, _data)
);
return outboundCalldata;
}
function outboundTransfer(
address _l1Token,
address _to,
uint256 _amount,
bytes calldata _data
) public payable returns (bytes memory) {
return outboundTransfer(_l1Token, _to, _amount, 0, 0, _data);
}
/**
* @notice Initiates a token withdrawal from Arbitrum to Ethereum
* @param _l1Token l1 address of token
* @param _to destination address
* @param _amount amount of tokens withdrawn
* @return res encoded unique identifier for withdrawal
*/
function outboundTransfer(
address _l1Token,
address _to,
uint256 _amount,
uint256, /* _maxGas */
uint256, /* _gasPriceBid */
bytes calldata _data
) public payable override returns (bytes memory res) {
// This function is set as public and virtual so that subclasses can override
// it and add custom validation for callers (ie only whitelisted users)
// the function is marked as payable to conform to the inheritance setup
// this particular code path shouldn't have a msg.value > 0
// TODO: remove this invariant for execution markets
require(msg.value == 0, "NO_VALUE");
address _from;
bytes memory _extraData;
{
if (isRouter(msg.sender)) {
(_from, _extraData) = GatewayMessageHandler.parseFromRouterToGateway(_data);
} else {
_from = msg.sender;
_extraData = _data;
}
}
// the inboundEscrowAndCall functionality has been disabled, so no data is allowed
require(_extraData.length == 0, "EXTRA_DATA_DISABLED");
uint256 id;
{
address l2Token = calculateL2TokenAddress(_l1Token);
require(l2Token.isContract(), "TOKEN_NOT_DEPLOYED");
require(IArbToken(l2Token).l1Address() == _l1Token, "NOT_EXPECTED_L1_TOKEN");
_amount = outboundEscrowTransfer(l2Token, _from, _amount);
id = triggerWithdrawal(_l1Token, _from, _to, _amount, _extraData);
}
return abi.encode(id);
}
function triggerWithdrawal(
address _l1Token,
address _from,
address _to,
uint256 _amount,
bytes memory _data
) internal returns (uint256) {
// exit number used for tradeable exits
uint256 currExitNum = exitNum;
// unique id used to identify the L2 to L1 tx
uint256 id = createOutboundTx(
_from,
_amount,
getOutboundCalldata(_l1Token, _from, _to, _amount, _data)
);
emit WithdrawalInitiated(_l1Token, _from, _to, id, currExitNum, _amount);
return id;
}
function outboundEscrowTransfer(
address _l2Token,
address _from,
uint256 _amount
) internal virtual returns (uint256 amountBurnt) {
// this method is virtual since different subclasses can handle escrow differently
// user funds are escrowed on the gateway using this function
// burns L2 tokens in order to release escrowed L1 tokens
IArbToken(_l2Token).bridgeBurn(_from, _amount);
// by default we assume that the amount we send to bridgeBurn is the amount burnt
// this might not be the case for every token
return _amount;
}
function inboundEscrowTransfer(
address _l2Address,
address _dest,
uint256 _amount
) internal virtual {
// this method is virtual since different subclasses can handle escrow differently
IArbToken(_l2Address).bridgeMint(_dest, _amount);
}
/**
* @notice Mint on L2 upon L1 deposit.
* If token not yet deployed and symbol/name/decimal data is included, deploys StandardArbERC20
* @dev Callable only by the L1ERC20Gateway.outboundTransfer method. For initial deployments of a token the L1 L1ERC20Gateway
* is expected to include the deployData. If not a L1 withdrawal is automatically triggered for the user
* @param _token L1 address of ERC20
* @param _from account that initiated the deposit in the L1
* @param _to account to be credited with the tokens in the L2 (can be the user's L2 account or a contract)
* @param _amount token amount to be minted to the user
* @param _data encoded symbol/name/decimal data for deploy, in addition to any additional callhook data
*/
function finalizeInboundTransfer(
address _token,
address _from,
address _to,
uint256 _amount,
bytes calldata _data
) external payable override onlyCounterpartGateway {
(bytes memory gatewayData, bytes memory callHookData) = GatewayMessageHandler
.parseFromL1GatewayMsg(_data);
if (callHookData.length != 0) {
// callHookData should always be 0 since inboundEscrowAndCall is disabled
callHookData = bytes("");
}
address expectedAddress = calculateL2TokenAddress(_token);
if (!expectedAddress.isContract()) {
bool shouldHalt = handleNoContract(
_token,
expectedAddress,
_from,
_to,
_amount,
gatewayData
);
if (shouldHalt) return;
}
// ignores gatewayData if token already deployed
{
// validate if L1 address supplied matches that of the expected L2 address
(bool success, bytes memory _l1AddressData) = expectedAddress.staticcall(
abi.encodeWithSelector(IArbToken.l1Address.selector)
);
bool shouldWithdraw;
if (!success || _l1AddressData.length < 32) {
shouldWithdraw = true;
} else {
// we do this in the else branch since we want to avoid reverts
// and `toAddress` reverts if _l1AddressData has a short length
// `_l1AddressData` should be 12 bytes of padding then 20 bytes for the address
address expectedL1Address = BytesLib.toAddress(_l1AddressData, 12);
if (expectedL1Address != _token) {
shouldWithdraw = true;
}
}
if (shouldWithdraw) {
// we don't need the return value from triggerWithdrawal since this is forcing
// a withdrawal back to the L1 instead of composing with a L2 dapp
triggerWithdrawal(_token, address(this), _from, _amount, "");
return;
}
}
inboundEscrowTransfer(expectedAddress, _to, _amount);
emit DepositFinalized(_token, _from, _to, _amount);
return;
}
// returns if function should halt after
function handleNoContract(
address _l1Token,
address expectedL2Address,
address _from,
address _to,
uint256 _amount,
bytes memory gatewayData
) internal virtual returns (bool shouldHalt);
}
// SPDX-License-Identifier: Apache-2.0
// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;
interface IWETH9 {
function deposit() external payable;
function withdraw(uint256 _amount) external;
}
// 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 >=0.6.2 <0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain`call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: value }(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.staticcall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.delegatecall(data);
return _verifyCallResult(success, returndata, errorMessage);
}
function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
/*
* @title Solidity Bytes Arrays Utils
* @author Gonçalo Sá <[email protected]>
*
* @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
* The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
*/
pragma solidity ^0.6.11;
/* solhint-disable no-inline-assembly */
library BytesLib {
function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
require(_bytes.length >= (_start + 20), "Read out of bounds");
address tempAddress;
assembly {
tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
}
return tempAddress;
}
function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
require(_bytes.length >= (_start + 1), "Read out of bounds");
uint8 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x1), _start))
}
return tempUint;
}
function toUint(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
require(_bytes.length >= (_start + 32), "Read out of bounds");
uint256 tempUint;
assembly {
tempUint := mload(add(add(_bytes, 0x20), _start))
}
return tempUint;
}
function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
require(_bytes.length >= (_start + 32), "Read out of bounds");
bytes32 tempBytes32;
assembly {
tempBytes32 := mload(add(add(_bytes, 0x20), _start))
}
return tempBytes32;
}
}
/* solhint-enable no-inline-assembly */
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2021, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.6.11;
library ProxyUtil {
function getProxyAdmin() internal view returns (address admin) {
// https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/proxy/TransparentUpgradeableProxy.sol#L48
// Storage slot with the admin of the proxy contract.
// This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
bytes32 slot = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
assembly {
admin := sload(slot)
}
}
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2019-2021, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.6.11;
library AddressAliasHelper {
uint160 constant offset = uint160(0x1111000000000000000000000000000000001111);
/// @notice Utility function that converts the address in the L1 that submitted a tx to
/// the inbox to the msg.sender viewed in the L2
/// @param l1Address the address in the L1 that triggered the tx to L2
/// @return l2Address L2 address as viewed in msg.sender
function applyL1ToL2Alias(address l1Address) internal pure returns (address l2Address) {
l2Address = address(uint160(l1Address) + offset);
}
/// @notice Utility function that converts the msg.sender viewed in the L2 to the
/// address in the L1 that submitted a tx to the inbox
/// @param l2Address L2 address as viewed in msg.sender
/// @return l1Address the address in the L1 that triggered the tx to L2
function undoL1ToL2Alias(address l2Address) internal pure returns (address l1Address) {
l1Address = address(uint160(l2Address) - offset);
}
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2020, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @title Minimum expected interface for L2 token that interacts with the L2 token bridge (this is the interface necessary
* for a custom token that interacts with the bridge, see TestArbCustomToken.sol for an example implementation).
*/
// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;
interface IArbToken {
/**
* @notice should increase token supply by amount, and should (probably) only be callable by the L1 bridge.
*/
function bridgeMint(address account, uint256 amount) external;
/**
* @notice should decrease token supply by amount, and should (probably) only be callable by the L1 bridge.
*/
function bridgeBurn(address account, uint256 amount) external;
/**
* @return address of layer 1 token
*/
function l1Address() external view returns (address);
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2020, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.6.11;
import "arbos-precompiles/arbos/builtin/ArbSys.sol";
/// @notice L2 utility contract to assist with L1 <=> L2 interactions
/// @dev this is an abstract contract instead of library so the functions can be easily overriden when testing
abstract contract L2ArbitrumMessenger {
address internal constant ARB_SYS_ADDRESS = address(100);
event TxToL1(address indexed _from, address indexed _to, uint256 indexed _id, bytes _data);
function sendTxToL1(
uint256 _l1CallValue,
address _from,
address _to,
bytes memory _data
) internal returns (uint256) {
uint256 _id = ArbSys(ARB_SYS_ADDRESS).sendTxToL1{ value: _l1CallValue }(_to, _data);
emit TxToL1(_from, _to, _id, _data);
return _id;
}
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2021, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.6.11;
/// @notice this library manages encoding and decoding of gateway communication
library GatewayMessageHandler {
// these are for communication from L1 to L2 gateway
function encodeToL2GatewayMsg(bytes memory gatewayData, bytes memory callHookData)
internal
pure
returns (bytes memory res)
{
res = abi.encode(gatewayData, callHookData);
}
function parseFromL1GatewayMsg(bytes calldata _data)
internal
pure
returns (bytes memory gatewayData, bytes memory callHookData)
{
// abi decode may revert, but the encoding is done by L1 gateway, so we trust it
(gatewayData, callHookData) = abi.decode(_data, (bytes, bytes));
}
// these are for communication from L2 to L1 gateway
function encodeFromL2GatewayMsg(uint256 exitNum, bytes memory callHookData)
internal
pure
returns (bytes memory res)
{
res = abi.encode(exitNum, callHookData);
}
function parseToL1GatewayMsg(bytes calldata _data)
internal
pure
returns (uint256 exitNum, bytes memory callHookData)
{
// abi decode may revert, but the encoding is done by L1 gateway, so we trust it
(exitNum, callHookData) = abi.decode(_data, (uint256, bytes));
}
// these are for communication from router to gateway
function encodeFromRouterToGateway(address _from, bytes calldata _data)
internal
pure
returns (bytes memory res)
{
// abi decode may revert, but the encoding is done by L1 gateway, so we trust it
return abi.encode(_from, _data);
}
function parseFromRouterToGateway(bytes calldata _data)
internal
pure
returns (address, bytes memory res)
{
// abi decode may revert, but the encoding is done by L1 gateway, so we trust it
return abi.decode(_data, (address, bytes));
}
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2020, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
pragma solidity ^0.6.11;
import "./ITokenGateway.sol";
import "@openzeppelin/contracts/utils/Address.sol";
abstract contract TokenGateway is ITokenGateway {
using Address for address;
address public counterpartGateway;
address public router;
// This modifier is overriden in gateways to validate the message sender
// For L1 to L2 messages need to be validated against the aliased counterpartGateway
// For L2 to L1 messages need to be validated against the bridge and L2ToL1Sender
// prettier-ignore
modifier onlyCounterpartGateway() virtual;
function _initialize(address _counterpartGateway, address _router) internal virtual {
// This initializes internal variables of the abstract contract it can be chained together with other functions.
// It is virtual so subclasses can override or wrap around this logic.
// An example where this is useful is different subclasses that validate the router address differently
require(_counterpartGateway != address(0), "INVALID_COUNTERPART");
require(counterpartGateway == address(0), "ALREADY_INIT");
counterpartGateway = _counterpartGateway;
router = _router;
}
function isRouter(address _target) internal view returns (bool isTargetRouter) {
return _target == router;
}
/**
* @notice Calculate the address used when bridging an ERC20 token
* @dev the L1 and L2 address oracles may not always be in sync.
* For example, a custom token may have been registered but not deploy or the contract self destructed.
* @param l1ERC20 address of L1 token
* @return L2 address of a bridged ERC20 token
*/
function calculateL2TokenAddress(address l1ERC20)
public
view
virtual
override
returns (address);
}
pragma solidity >=0.6.9 <0.9.0;
/**
* @title Precompiled contract that exists in every Arbitrum chain at address(100), 0x0000000000000000000000000000000000000064. Exposes a variety of system-level functionality.
*/
interface ArbSys {
/**
* @notice Get internal version number identifying an ArbOS build
* @return version number as int
*/
function arbOSVersion() external pure returns (uint256);
function arbChainID() external view returns (uint256);
/**
* @notice Get Arbitrum block number (distinct from L1 block number; Arbitrum genesis block has block number 0)
* @return block number as int
*/
function arbBlockNumber() external view returns (uint256);
/**
* @notice Send given amount of Eth to dest from sender.
* This is a convenience function, which is equivalent to calling sendTxToL1 with empty calldataForL1.
* @param destination recipient address on L1
* @return unique identifier for this L2-to-L1 transaction.
*/
function withdrawEth(address destination) external payable returns (uint256);
/**
* @notice Send a transaction to L1
* @param destination recipient address on L1
* @param calldataForL1 (optional) calldata for L1 contract call
* @return a unique identifier for this L2-to-L1 transaction.
*/
function sendTxToL1(address destination, bytes calldata calldataForL1)
external
payable
returns (uint256);
/**
* @notice get the number of transactions issued by the given external account or the account sequence number of the given contract
* @param account target account
* @return the number of transactions issued by the given external account or the account sequence number of the given contract
*/
function getTransactionCount(address account) external view returns (uint256);
/**
* @notice get the value of target L2 storage slot
* This function is only callable from address 0 to prevent contracts from being able to call it
* @param account target account
* @param index target index of storage slot
* @return stotage value for the given account at the given index
*/
function getStorageAt(address account, uint256 index) external view returns (uint256);
/**
* @notice check if current call is coming from l1
* @return true if the caller of this was called directly from L1
*/
function isTopLevelCall() external view returns (bool);
/**
* @notice check if the caller (of this caller of this) is an aliased L1 contract address
* @return true iff the caller's address is an alias for an L1 contract address
*/
function wasMyCallersAddressAliased() external view returns (bool);
/**
* @notice return the address of the caller (of this caller of this), without applying L1 contract address aliasing
* @return address of the caller's caller, without applying L1 contract address aliasing
*/
function myCallersAddressWithoutAliasing() external view returns (address);
/**
* @notice map L1 sender contract address to its L2 alias
* @param sender sender address
* @param dest destination address
* @return aliased sender address
*/
function mapL1SenderContractAddressToL2Alias(address sender, address dest)
external
pure
returns (address);
/**
* @notice get the caller's amount of available storage gas
* @return amount of storage gas available to the caller
*/
function getStorageGasAvailable() external view returns (uint256);
event L2ToL1Transaction(
address caller,
address indexed destination,
uint256 indexed uniqueId,
uint256 indexed batchNumber,
uint256 indexInBatch,
uint256 arbBlockNum,
uint256 ethBlockNum,
uint256 timestamp,
uint256 callvalue,
bytes data
);
}
// SPDX-License-Identifier: Apache-2.0
/*
* Copyright 2020, Offchain Labs, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// solhint-disable-next-line compiler-version
pragma solidity >=0.6.9 <0.9.0;
interface ITokenGateway {
/// @notice event deprecated in favor of DepositInitiated and WithdrawalInitiated
// event OutboundTransferInitiated(
// address token,
// address indexed _from,
// address indexed _to,
// uint256 indexed _transferId,
// uint256 _amount,
// bytes _data
// );
/// @notice event deprecated in favor of DepositFinalized and WithdrawalFinalized
// event InboundTransferFinalized(
// address token,
// address indexed _from,
// address indexed _to,
// uint256 indexed _transferId,
// uint256 _amount,
// bytes _data
// );
function outboundTransfer(
address _token,
address _to,
uint256 _amount,
uint256 _maxGas,
uint256 _gasPriceBid,
bytes calldata _data
) external payable returns (bytes memory);
function finalizeInboundTransfer(
address _token,
address _from,
address _to,
uint256 _amount,
bytes calldata _data
) external payable;
/**
* @notice Calculate the address used when bridging an ERC20 token
* @dev the L1 and L2 address oracles may not always be in sync.
* For example, a custom token may have been registered but not deploy or the contract self destructed.
* @param l1ERC20 address of L1 token
* @return L2 address of a bridged ERC20 token
*/
function calculateL2TokenAddress(address l1ERC20) external view returns (address);
function getOutboundCalldata(
address _token,
address _from,
address _to,
uint256 _amount,
bytes memory _data
) external view returns (bytes memory);
}
// 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;
}
}