crossbell-bridge

Contents

• ICrossbellGateway
• IERC20Mintable
• IMainchainGateway
• IValidator

ICrossbellGateway

Git Source

This is the interface for the crossbell bridge gateway contract. You'll find all the events and external functions.

Functions

initialize

Initializes the CrossbellGateway.

function initialize(
    address validator,
    address admin,
    address[] calldata crossbellTokens,
    uint256[] calldata chainIds,
    address[] calldata mainchainTokens,
    uint8[] calldata mainchainTokenDecimals
) external;

Parameters

pause

Pauses interaction with the gateway contract

function pause() external;

unpause

Resumes interaction with the gateway contract

function unpause() external;

mapTokens

Maps mainchain tokens to Crossbell network.

function mapTokens(
    address[] calldata crossbellTokens,
    uint256[] calldata chainIds,
    address[] calldata mainchainTokens,
    uint8[] calldata mainchainTokenDecimals
) external;

Parameters

batchAckDeposit

Tries bulk deposit.

function batchAckDeposit(
    uint256[] calldata chainIds,
    uint256[] calldata depositIds,
    address[] calldata recipients,
    address[] calldata tokens,
    uint256[] calldata amounts,
    bytes32[] calldata depositHashes
) external;

batchSubmitWithdrawalSignatures

Tries bulk submit withdrawal signatures. Note that the caller must be a validator.

function batchSubmitWithdrawalSignatures(
    uint256[] calldata chainIds,
    uint256[] calldata withdrawalIds,
    bytes[] calldata sigs
) external;

ackDeposit

Acknowledges a deposit. Note that the caller must be a validator.

function ackDeposit(
    uint256 chainId,
    uint256 depositId,
    address recipient,
    address token,
    uint256 amount,
    bytes32 depositHash
) external;

Parameters

requestWithdrawal

Locks the assets and request withdrawal.

function requestWithdrawal(uint256 chainId, address recipient, address token, uint256 amount, uint256 fee)
    external
    returns (uint256 withdrawalId);

Parameters

Returns

submitWithdrawalSignature

Submits validator signature for withdrawal. Note that the caller must be a validator.

function submitWithdrawalSignature(uint256 chainId, uint256 withdrawalId, bytes calldata sig) external;

Parameters

getMainchainToken

Returns mapped token on mainchain.

function getMainchainToken(uint256 chainId, address crossbellToken)
    external
    view
    returns (DataTypes.MappedToken memory token);

Parameters

Returns

getValidatorAcknowledgementHash

Returns the acknowledge depositHash by validator.

function getValidatorAcknowledgementHash(uint256 chainId, uint256 id, address validator)
    external
    view
    returns (bytes32);

Parameters

Returns

getAcknowledgementStatus

Returns the acknowledge status of deposit by validators.

function getAcknowledgementStatus(uint256 chainId, uint256 id, bytes32 hash) external view returns (DataTypes.Status);

Parameters

Returns

getAcknowledgementCount

Returns the acknowledge count of deposit by validators.

function getAcknowledgementCount(uint256 chainId, uint256 id, bytes32 hash) external view returns (uint256);

Parameters

Returns

getWithdrawalSignatures

Returns withdrawal signatures.

function getWithdrawalSignatures(uint256 chainId, uint256 withdrawalId)
    external
    view
    returns (address[] memory signers, bytes[] memory sigs);

Parameters

Returns

getValidatorContract

Returns the address of the validator contract.

function getValidatorContract() external view returns (address);

Returns

getDepositEntry

Returns the deposit entry.

function getDepositEntry(uint256 chainId, uint256 depositId) external view returns (DataTypes.DepositEntry memory);

Parameters

Returns

getWithdrawalCount

Returns the withdrawal count of different mainchain networks.

function getWithdrawalCount(uint256 chainId) external view returns (uint256);

Parameters

Returns

getWithdrawalEntry

Returns the withdrawal entry.

function getWithdrawalEntry(uint256 chainId, uint256 withdrawalId)
    external
    view
    returns (DataTypes.WithdrawalEntry memory);

Parameters

Returns

Events

TokenMapped

Emitted when the tokens are mapped.

event TokenMapped(
    address[] crossbellTokens, uint256[] chainIds, address[] mainchainTokens, uint8[] mainchainTokenDecimals
);

Parameters

Deposited

Emitted when the assets are deposited.

event Deposited(
    uint256 indexed chainId, uint256 indexed depositId, address indexed recipient, address token, uint256 amount
);

Parameters

AckDeposit

Emitted when the deposit is acknowledged by a validator.

event AckDeposit(
    uint256 indexed chainId,
    uint256 indexed depositId,
    address indexed validator,
    address recipient,
    address token,
    uint256 amount
);

Parameters

RequestWithdrawal

Emitted when the withdrawal is requested.

event RequestWithdrawal(
    uint256 indexed chainId,
    uint256 indexed withdrawalId,
    address indexed recipient,
    address token,
    uint256 amount,
    uint256 fee
);

Parameters

SubmitWithdrawalSignature

Emitted when a withdrawal signature is submitted by validator.

event SubmitWithdrawalSignature(
    uint256 indexed chainId, uint256 indexed withdrawalId, address indexed validator, bytes signature
);

Parameters

IERC20Mintable

Git Source

Functions

mint

function mint(address to, uint256 amount) external;

IMainchainGateway

Git Source

This is the interface for the crossbell bridge manchain gateway contract. You'll find all the events and external functions.

Functions

initialize

Initializes the MainchainGateway. Note that the thresholds contains:

• thresholds[1]:

function initialize(
    address validator,
    address admin,
    address[] calldata mainchainTokens,
    uint256[] calldata dailyWithdrawalMaxQuota,
    address[] calldata crossbellTokens,
    uint8[] calldata crossbellTokenDecimals
) external;

Parameters

pause

Pauses interaction with the gateway contract. Requirements:

• The caller must have the ADMIN_ROLE.

function pause() external;

unpause

Resumes interaction with the gateway contract. Requirements:

• The caller must have the ADMIN_ROLE.

function unpause() external;

mapTokens

Maps Crossbell tokens to mainchain. Emits the TokenMapped event. Requirements:

• The caller must have the ADMIN_ROLE.

function mapTokens(
    address[] calldata mainchainTokens,
    address[] calldata crossbellTokens,
    uint8[] calldata crossbellTokenDecimals
) external;

Parameters

requestDeposit

Requests deposit to crossbell chain. Emits the RequestDeposit event.

function requestDeposit(address recipient, address token, uint256 amount) external returns (uint256 depositId);

Parameters

Returns

withdraw

Withdraws based on the validator signatures. Emits the Withdrew event. Requirements:

• The signatures should be sorted by signing addresses of validators in ascending order.

function withdraw(
    uint256 chainId,
    uint256 withdrawalId,
    address recipient,
    address token,
    uint256 amount,
    uint256 fee,
    DataTypes.Signature[] calldata signatures
) external;

Parameters

setDailyWithdrawalMaxQuotas

Sets daily max quotas for the withdrawals. Emits the DailyWithdrawalMaxQuotasUpdated event. Requirements:

• The caller must have the ADMIN_ROLE.
• The arrays have the same length.

function setDailyWithdrawalMaxQuotas(address[] calldata tokens, uint256[] calldata quotas) external;

Parameters

getDomainSeparator

Returns the domain separator for this contract.

function getDomainSeparator() external view returns (bytes32);

Returns

getValidatorContract

Returns the address of the validator contract.

function getValidatorContract() external view returns (address);

Returns

getDepositCount

Returns the deposit count of the gateway contract.

function getDepositCount() external view returns (uint256);

Returns

getWithdrawalHash

Returns the withdrawal hash by withdrawal id.

function getWithdrawalHash(uint256 withdrawalId) external view returns (bytes32);

Parameters

Returns

getDailyWithdrawalMaxQuota

Returns the daily withdrawal max quota.

function getDailyWithdrawalMaxQuota(address token) external view returns (uint256);

Parameters

getDailyWithdrawalRemainingQuota

Returns today's withdrawal remaining quota.

function getDailyWithdrawalRemainingQuota(address token) external view returns (uint256 remainingQuota);

Parameters

Returns

getCrossbellToken

Returns mapped tokens from crossbell chain.

function getCrossbellToken(address mainchainToken) external view returns (DataTypes.MappedToken memory token);

Parameters

Returns

Events

TokenMapped

Emitted when the tokens are mapped

event TokenMapped(address[] mainchainTokens, address[] crossbellTokens, uint8[] crossbellTokenDecimals);

Parameters

RequestDeposit

Emitted when the deposit is requested.

event RequestDeposit(
    uint256 indexed chainId,
    uint256 indexed depositId,
    address indexed recipient,
    address token,
    uint256 amount,
    bytes32 depositHash
);

Parameters

Withdrew

Emitted when the assets are withdrawn on mainchain.

event Withdrew(
    uint256 indexed chainId,
    uint256 indexed withdrawalId,
    address indexed recipient,
    address token,
    uint256 amount,
    uint256 fee
);

Parameters

DailyWithdrawalMaxQuotasUpdated

Emitted when the daily quota thresholds are updated.

event DailyWithdrawalMaxQuotasUpdated(address[] tokens, uint256[] quotas);

IValidator

Git Source

This is the interface for the validator contract. You'll find all the events and external functions.

Functions

addValidators

Adds new validators. This function can only be called by the owner of validator contract. Note that this reverts if new validators to add are already validators.

function addValidators(address[] calldata validators) external;

Parameters

removeValidators

Removes exist validators. This function can only be called by the owner of validator contract. Note that this reverts if validators to remove are not validators.

function removeValidators(address[] calldata validators) external;

Parameters

changeRequiredNumber

Change the required number of validators. Requirements::

1. the caller is owner of validator contract.
2. new required number > validators length.
3. new required number is zero.

function changeRequiredNumber(uint256 newRequiredNumber) external;

Parameters

isValidator

Returns whether an address is validator or not.

function isValidator(address addr) external view returns (bool);

Parameters

getValidators

Returns all the validators.

function getValidators() external view returns (address[] memory validators);

getRequiredNumber

Returns current required number.

function getRequiredNumber() external view returns (uint256);

checkThreshold

Checks whether the voteCount passes the threshold.

function checkThreshold(uint256 voteCount) external view returns (bool);

Events

ValidatorAdded

Emitted when a new validator is added.

event ValidatorAdded(address indexed validator);

Parameters

ValidatorRemoved

Emitted when a validator is removed.

event ValidatorRemoved(address indexed validator);

Parameters

RequirementChanged

Emitted when a new required number is set.

event RequirementChanged(uint256 indexed requirement, uint256 indexed previousRequired);

Parameters

Contents

• DataTypes

DataTypes

Git Source

A standard library of data types.

Structs

MappedToken

struct MappedToken {
    address token;
    uint8 decimals;
}

DepositEntry

A struct containing deposit data.

struct DepositEntry {
    uint256 chainId;
    address recipient;
    address token;
    uint256 amount;
}

Properties

WithdrawalEntry

A struct containing withdrawal data.

struct WithdrawalEntry {
    uint256 chainId;
    address recipient;
    address token;
    uint256 amount;
    uint256 fee;
}

Properties

Signature

A struct containing a validator signature for the withdrawal.

struct Signature {
    uint8 v;
    bytes32 r;
    bytes32 s;
}

Enums

Status

Acknowledge status, once the acknowledgements reach the threshold the 1st time, it can take effect to the system. Acknowledgments after that should not have any effects.

enum Status {
    NotApproved,
    FirstApproved,
    AlreadyApproved
}

Contents

• CrossbellGatewayStorage
• MainchainGatewayStorage

CrossbellGatewayStorage

Git Source

Storage of deposit and withdraw information.

State Variables

_deposits

Mapping from chainId => depositId => DepositEntry

mapping(uint256 => mapping(uint256 => DataTypes.DepositEntry)) internal _deposits;

_withdrawalCounter

Mapping from chainId => withdrawCount

mapping(uint256 => uint256) internal _withdrawalCounter;

_withdrawals

Mapping from chainId => withdrawalId => WithdrawalEntry

mapping(uint256 => mapping(uint256 => DataTypes.WithdrawalEntry)) internal _withdrawals;

_withdrawalSig

Mapping from chainId => withdrawalId => signature

mapping(uint256 => mapping(uint256 => mapping(address => bytes))) internal _withdrawalSig;

_withdrawalSigners

Mapping from chainId => withdrawalId => address[]

mapping(uint256 => mapping(uint256 => address[])) internal _withdrawalSigners;

_mainchainTokens

Mapping from token address => chain id => mainchain token address

mapping(address => mapping(uint256 => DataTypes.MappedToken)) internal _mainchainTokens;

_validator

address internal _validator;

_validatorAck

Mapping from chainId => id => validator => data hash

mapping(uint256 => mapping(uint256 => mapping(address => bytes32))) internal _validatorAck;

_ackCount

Mapping from chainId => id => data hash => ack count

mapping(uint256 => mapping(uint256 => mapping(bytes32 => uint256))) internal _ackCount;

_ackStatus

Mapping from chainId => id => data hash => ack status

mapping(uint256 => mapping(uint256 => mapping(bytes32 => DataTypes.Status))) internal _ackStatus;

MainchainGatewayStorage

Git Source

Storage of deposit and withdraw information.

State Variables

_domainSeparator

Domain separator

bytes32 internal _domainSeparator;

_validator

Validator contract address

address internal _validator;

_depositCounter

Total deposit count

uint256 internal _depositCounter;

_withdrawalHash

Mapping from withdrawal id => withdrawal hash

mapping(uint256 => bytes32) internal _withdrawalHash;

_dailyWithdrawalMaxQuota

for withdrawal restriction

Mapping from mainchain token => daily max amount for withdrawal

mapping(address => uint256) internal _dailyWithdrawalMaxQuota;

_lastSyncedWithdrawal

Mapping from token address => today withdrawal amount

mapping(address => uint256) internal _lastSyncedWithdrawal;

_lastDateSynced

Mapping from token address => last date synced to record the _lastSyncedWithdrawal

mapping(address => uint256) internal _lastDateSynced;

_crossbellTokens

Mapping from mainchain token => token address on crossbell network

mapping(address => DataTypes.MappedToken) internal _crossbellTokens;