TokenBridge
Contract to manage cross-chain ERC20 bridging.
CONTRACT_VERSION​
string CONTRACT_VERSION
This is the ABI version and not the reinitialize version.
SET_MESSAGE_SERVICE_ROLE​
bytes32 SET_MESSAGE_SERVICE_ROLE
Role used for setting the message service address.
SET_REMOTE_TOKENBRIDGE_ROLE​
bytes32 SET_REMOTE_TOKENBRIDGE_ROLE
Role used for setting the remote token bridge address.
SET_RESERVED_TOKEN_ROLE​
bytes32 SET_RESERVED_TOKEN_ROLE
Role used for setting a reserved token address.
REMOVE_RESERVED_TOKEN_ROLE​
bytes32 REMOVE_RESERVED_TOKEN_ROLE
Role used for removing a reserved token address.
SET_CUSTOM_CONTRACT_ROLE​
bytes32 SET_CUSTOM_CONTRACT_ROLE
Role used for setting a custom token contract address.
EMPTY​
address EMPTY
EMPTY means a token is not present in the mapping.
RESERVED_STATUS​
address RESERVED_STATUS
RESERVED means a token is reserved and cannot be bridged.
NATIVE_STATUS​
address NATIVE_STATUS
NATIVE means a token is native to the current local chain.
DEPLOYED_STATUS​
address DEPLOYED_STATUS
DEPLOYED means the bridged token contract has been deployed on the remote chain.
_PERMIT_SELECTOR​
bytes4 _PERMIT_SELECTOR
The permit selector to be used when decoding the permit.
tokenBeacon​
address tokenBeacon
The token beacon for deployed tokens.
nativeToBridgedToken​
mapping(uint256 => mapping(address => address)) nativeToBridgedToken
The chainId mapped to a native token address which is then mapped to the bridged token address.
bridgedToNativeToken​
mapping(address => address) bridgedToNativeToken
The bridged token address mapped to the native token address.
sourceChainId​
uint256 sourceChainId
The current layer's chainId from where the bridging is triggered.
targetChainId​
uint256 targetChainId
The targeted layer's chainId where the bridging is received.
isNewToken​
modifier isNewToken(address _token)
Ensures the token has not been bridged before.
nonZeroAddress​
modifier nonZeroAddress(address _addr)
Ensures the address is not address(0).
Parameters​
| Name | Type | Description |
|---|---|---|
| _addr | address | Address to check. |
nonZeroAmount​
modifier nonZeroAmount(uint256 _amount)
Ensures the amount is not 0.
Parameters​
| Name | Type | Description |
|---|---|---|
| _amount | uint256 | amount to check. |
constructor​
constructor() public
Disable constructor for safety
initialize​
function initialize(struct ITokenBridge.InitializationData _initializationData) external
Initializes TokenBridge and underlying service dependencies - used for new networks only.
Contract will be used as proxy implementation.
Parameters​
| Name | Type | Description |
|---|---|---|
| _initializationData | struct ITokenBridge.InitializationData | The initial data used for initializing the TokenBridge contract. |
reinitializePauseTypesAndPermissions​
function reinitializePauseTypesAndPermissions(address _defaultAdmin, struct IPermissionsManager.RoleAddress[] _roleAddresses, struct IPauseManager.PauseTypeRole[] _pauseTypeRoles, struct IPauseManager.PauseTypeRole[] _unpauseTypeRoles) external
Sets permissions for a list of addresses and their roles as well as initialises the PauseManager pauseType:role mappings.
This function is a reinitializer and can only be called once per version. Should be called using an upgradeAndCall transaction to the ProxyAdmin.
Parameters​
| Name | Type | Description |
|---|---|---|
| _defaultAdmin | address | The default admin account's address. |
| _roleAddresses | struct IPermissionsManager.RoleAddress[] | The list of addresses and roles to assign permissions to. |
| _pauseTypeRoles | struct IPauseManager.PauseTypeRole[] | The list of pause types to associate with roles. |
| _unpauseTypeRoles | struct IPauseManager.PauseTypeRole[] | The list of unpause types to associate with roles. |
bridgeToken​
function bridgeToken(address _token, uint256 _amount, address _recipient) public payable
This function is the single entry point to bridge tokens to the other chain, both for native and already bridged tokens. You can use it to bridge any ERC20. If the token is bridged for the first time an ERC20 (BridgedToken.sol) will be automatically deployed on the target chain.
User should first allow the bridge to transfer tokens on his behalf. Alternatively, you can use BridgeTokenWithPermit to do so in a single transaction. If you want the transfer to be automatically executed on the destination chain. You should send enough ETH to pay the postman fees. Note that Linea can reserve some tokens (which use a dedicated bridge). In this case, the token cannot be bridged. Linea can only reserve tokens that have not been bridged yet. Linea can pause the bridge for security reason. In this case new bridge transaction would revert. Note: If, when bridging an unbridged token and decimals are unknown, the call will revert to prevent mismatched decimals. Only those ERC20s, with a decimals function are supported.
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | The address of the token to be bridged. |
| _amount | uint256 | The amount of the token to be bridged. |
| _recipient | address | The address that will receive the tokens on the other chain. |
bridgeTokenWithPermit​
function bridgeTokenWithPermit(address _token, uint256 _amount, address _recipient, bytes _permitData) external payable
Similar to bridgeToken function but allows to pass additional
permit data to do the ERC20 approval in a single transaction.
_permit can fail silently, don't rely on this function passing as a form
of authentication
There is no need for validation at this level as the validation on pausing, and empty values exists on the "bridgeToken" call.
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | The address of the token to be bridged. |
| _amount | uint256 | The amount of the token to be bridged. |
| _recipient | address | The address that will receive the tokens on the other chain. |
| _permitData | bytes | The permit data for the token, if applicable. |
completeBridging​
function completeBridging(address _nativeToken, uint256 _amount, address _recipient, uint256 _chainId, bytes _tokenMetadata) external
It can only be called from the Message Service. To finalize the bridging
process, a user or postman needs to use the claimMessage function of the
Message Service to trigger the transaction.
Parameters​
| Name | Type | Description |
|---|---|---|
| _nativeToken | address | The address of the token on its native chain. |
| _amount | uint256 | The amount of the token to be received. |
| _recipient | address | The address that will receive the tokens. |
| _chainId | uint256 | The token's origin layer chaindId |
| _tokenMetadata | bytes | Additional data used to deploy the bridged token if it doesn't exist already. |
setMessageService​
function setMessageService(address _messageService) external
Change the address of the Message Service. SET_MESSAGE_SERVICE_ROLE is required to execute.
Parameters​
| Name | Type | Description |
|---|---|---|
| _messageService | address | The address of the new Message Service. |
confirmDeployment​
function confirmDeployment(address[] _tokens) external payable
Change the status to DEPLOYED to the tokens passed in parameter Will call the method setDeployed on the other chain using the message Service
Parameters​
| Name | Type | Description |
|---|---|---|
| _tokens | address[] | Array of bridged tokens that have been deployed. |
setDeployed​
function setDeployed(address[] _nativeTokens) external
Change the status of tokens to DEPLOYED. New bridge transaction will not
contain token metadata, which save gas.
Can only be called from the Message Service. A user or postman needs to use
the claimMessage function of the Message Service to trigger the transaction.
Parameters​
| Name | Type | Description |
|---|---|---|
| _nativeTokens | address[] | Array of native tokens for which the DEPLOYED status must be set. |
setRemoteTokenBridge​
function setRemoteTokenBridge(address _remoteTokenBridge) external
Sets the address of the remote token bridge. Can only be called once. SET_REMOTE_TOKENBRIDGE_ROLE is required to execute.
Parameters​
| Name | Type | Description |
|---|---|---|
| _remoteTokenBridge | address | The address of the remote token bridge to be set. |
deployBridgedToken​
function deployBridgedToken(address _nativeToken, bytes _tokenMetadata, uint256 _chainId) internal returns (address bridgedTokenAddress)
Deploy a new EC20 contract for bridged token using a beacon proxy pattern. To adapt to future requirements, Linea can update the implementation of all (existing and future) contracts by updating the beacon. This update is subject to a delay by a time lock. Contracts are deployed using CREATE2 so deployment address is deterministic.
Parameters​
| Name | Type | Description |
|---|---|---|
| _nativeToken | address | The address of the native token on the source chain. |
| _tokenMetadata | bytes | The encoded metadata for the token. |
| _chainId | uint256 | The chain id on which the token will be deployed, used to calculate the salt |
Return Values​
| Name | Type | Description |
|---|---|---|
| bridgedTokenAddress | address | The address of the newly deployed BridgedToken contract. |
setReserved​
function setReserved(address _token) external
Make sure that _token is native to the current chain where you are calling this function from
Linea can reserve tokens. In this case, the token cannot be bridged. Linea can only reserve tokens that have not been bridged before. SET_RESERVED_TOKEN_ROLE is required to execute.
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | The address of the token to be set as reserved. |
removeReserved​
function removeReserved(address _token) external
Removes a token from the reserved list. REMOVE_RESERVED_TOKEN_ROLE is required to execute.
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | The address of the token to be removed from the reserved list. |
setCustomContract​
function setCustomContract(address _nativeToken, address _targetContract) external
Linea can set a custom ERC20 contract for specific ERC20. For security purpose, Linea can only call this function if the token has not been bridged yet. SET_CUSTOM_CONTRACT_ROLE is required to execute.
Parameters​
| Name | Type | Description |
|---|---|---|
| _nativeToken | address | The address of the token on the source chain. |
| _targetContract | address | The address of the custom contract. |
_safeName​
function _safeName(address _token) internal view returns (string tokenName)
Provides a safe ERC20.name version which returns 'NO_NAME' as fallback string.
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | The address of the ERC-20 token contract |
Return Values​
| Name | Type | Description |
|---|---|---|
| tokenName | string | Returns the string of the token name. |
_safeSymbol​
function _safeSymbol(address _token) internal view returns (string symbol)
Provides a safe ERC20.symbol version which returns 'NO_SYMBOL' as fallback string
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | The address of the ERC-20 token contract |
Return Values​
| Name | Type | Description |
|---|---|---|
| symbol | string | Returns the string of the symbol. |
_safeDecimals​
function _safeDecimals(address _token) internal view returns (uint8)
Provides a safe ERC20.decimals version which reverts when decimals are unknown Note Tokens with (decimals > 255) are not supported
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | The address of the ERC-20 token contract |
Return Values​
| Name | Type | Description |
|---|---|---|
| [0] | uint8 | Returns the token's decimals value. |
_returnDataToString​
function _returnDataToString(bytes _data) internal pure returns (string decodedString)
Converts returned data to string. Returns 'NOT_VALID_ENCODING' as fallback value.
Parameters​
| Name | Type | Description |
|---|---|---|
| _data | bytes | returned data. |
Return Values​
| Name | Type | Description |
|---|---|---|
| decodedString | string | The decoded string data. |
_permit​
function _permit(address _token, bytes _permitData) internal
Call the token permit method of extended ERC20 Only support tokens implementing ERC-2612
Parameters​
| Name | Type | Description |
|---|---|---|
| _token | address | ERC20 token address |
| _permitData | bytes | Raw data of the call permit of the token |