ILZCrossChainBridge

Git Source

Title: ILZCrossChainBridge

Interface for the LZ Cross-Chain Bridge facilitator, the user-facing entry point for sending OHM to other chains via LayerZero V2.

It is a periphery contract, as it does not require any privileged access to the Olympus protocol. It transfers OHM from the user to the gateway, which handles burning and sending.

Functions

sendOhm

Sends OHM to a destination chain via the gateway.

The user must approve this contract for the OHM amount before calling. OHM is transferred from the user to the gateway, then the gateway burns and sends via LayerZero. The caller must send the native token with the call to cover the LayerZero messaging fee; excess is refunded to msg.sender. Use estimateSendFee() to determine the required fee.

function sendOhm(uint32 dstEid_, address to_, uint256 amount_) external payable;

Parameters

Name	Type	Description
dstEid_	uint32	The LayerZero destination endpoint ID.
to_	address	The recipient address on the destination chain.
amount_	uint256	The amount of OHM to send.

setGateway

Sets the gateway address.

Only callable by the address pinned in configurator, which is expected to be an LZBridgeAndDelegateConfig instance (the timelock policy).

function setGateway(address gateway_) external;

Parameters

Name	Type	Description
gateway_	address	The new gateway address.

setReEnabler

Sets the address authorized to call reEnable().

Only callable by the address pinned in configurator, which is expected to be an LZBridgeAndDelegateConfig instance (the timelock policy). The zero address is permitted and effectively disables the reEnable() entry point until a non-zero address is set.

function setReEnabler(address reEnabler_) external;

Parameters

Name	Type	Description
reEnabler_	address	The new re-enabler address, or address(0) to clear.

setConfigurator

Sets the configurator address.

Bootstrap: when configurator is the zero address, only the owner may set the first non-zero configurator. After bootstrap, rotation is only allowed by the current configurator. The configurator is expected to be an LZBridgeAndDelegateConfig instance (the timelock policy).

In both cases the new configurator must implement ILZBridgeAndDelegateConfig via ERC-165 to prevent the bridge from being bricked by an incompatible address.

function setConfigurator(address newConfigurator_) external;

Parameters

Name	Type	Description
newConfigurator_	address	The new configurator address.

validateSetGateway

Validates the payload that would be passed to setGateway.

Mirrors the input invariants enforced by setGateway so that callers (for instance, a timelock policy) can fail early at queue time rather than at execution time.

function validateSetGateway(address gateway_) external pure;

Parameters

Name	Type	Description
gateway_	address	The candidate gateway address.

validateSetConfigurator

Validates the payload that would be passed to setConfigurator.

Mirrors the payload invariants enforced by setConfigurator: the zero-address check and the ERC-165 ILZBridgeAndDelegateConfig guard.

function validateSetConfigurator(address newConfigurator_) external view;

Parameters

Name	Type	Description
newConfigurator_	address	The candidate configurator address.

gateway

Returns the LZBridgeGateway address.

function gateway() external view returns (address);

Returns

Name	Type	Description
<none>	address

reEnabler

Returns the address authorized to call reEnable().

Returns address(0) when no re-enabler has been configured.

function reEnabler() external view returns (address);

Returns

Name	Type	Description
<none>	address

configurator

Returns the configurator address (an LZBridgeAndDelegateConfig instance).

Returns address(0) before the owner has performed the bootstrap call.

function configurator() external view returns (address);

Returns

Name	Type	Description
<none>	address

OHM

Returns the OHM token address.

function OHM() external view returns (address);

Returns

Name	Type	Description
<none>	address

estimateSendFee

Estimates the fee for sending OHM to a destination chain.

function estimateSendFee(
        uint32 dstEid_,
        address to_,
        uint256 amount_
    ) external view returns (MessagingFee memory fee);

Parameters

Name	Type	Description
dstEid_	uint32	The LayerZero destination endpoint ID.
to_	address	The recipient address on the destination chain.
amount_	uint256	The amount of OHM to send.

Returns

Name	Type	Description
fee	MessagingFee	The estimated messaging fee (native + lzToken (unused)).

sendable

Returns the current outbound capacity for a destination endpoint, with the in-flight amount decayed against the current timestamp.

function sendable(uint32 dstEid_) external view returns (uint256 inFlight, uint256 available);

Parameters

Name	Type	Description
dstEid_	uint32	The LayerZero destination endpoint ID.

Returns

Name	Type	Description
inFlight	uint256	The decayed outbound in-flight amount at the current timestamp.
available	uint256	The amount that may still be sent to the destination before the outbound rate limit is exceeded.

receivable

Returns the current inbound capacity for a source endpoint, with the in-flight amount decayed against the current timestamp.

function receivable(uint32 srcEid_) external view returns (uint256 inFlight, uint256 available);

Parameters

Name	Type	Description
srcEid_	uint32	The LayerZero source endpoint ID.

Returns

Name	Type	Description
inFlight	uint256	The decayed inbound in-flight amount at the current timestamp.
available	uint256	The amount that may still be received from the source before the inbound rate limit is exceeded.

Events

Bridged

Emitted when OHM is sent to another chain.

event Bridged(
        address indexed sender,
        uint256 amount,
        uint32 indexed dstEid,
        uint256 nativeFee,
        uint256 msgValue
    );

Parameters

Name	Type	Description
sender	address	The address that initiated the bridge transfer.
amount	uint256	The amount of OHM bridged.
dstEid	uint32	The LayerZero destination endpoint ID.
nativeFee	uint256	The native token fee actually charged by LayerZero, read from MessagingReceipt. May be less than msgValue when the caller overpays; the excess is refunded to the sender by the LayerZero endpoint.
msgValue	uint256	The native value the caller supplied with the transaction.

GatewaySet

Emitted when the gateway address is updated.

event GatewaySet(address indexed gateway);

Parameters

Name	Type	Description
gateway	address	The new gateway address.

ReEnablerSet

Emitted when the re-enabler address is updated.

Setting the re-enabler to the zero address effectively disables the reEnable() entry point until a non-zero address is configured again.

event ReEnablerSet(address indexed reEnabler);

Parameters

Name	Type	Description
reEnabler	address	The new re-enabler address, or address(0) to clear.

ConfiguratorSet

Emitted when the configurator address is updated.

event ConfiguratorSet(address indexed configurator);

Parameters

Name	Type	Description
configurator	address	The new configurator address.

Errors

LZCrossChainBridge_InvalidAddress

Thrown when an address argument is the zero address.

error LZCrossChainBridge_InvalidAddress(string parameter);

Parameters

Name	Type	Description
parameter	string	The name of the invalid parameter.

LZCrossChainBridge_InsufficientAmount

Thrown when the send amount is zero.

error LZCrossChainBridge_InsufficientAmount();

LZCrossChainBridge_InvalidConfigurator

Thrown when setConfigurator is supplied a contract that does not implement the ILZBridgeAndDelegateConfig interface via ERC-165.

error LZCrossChainBridge_InvalidConfigurator(address newConfigurator);

Parameters

Name	Type	Description
newConfigurator	address	The unsupported new configurator address.