Lightning Wire Messages

A crate defining serialization and deserialization for lightning wire messages into rust structs.

Usage

This crate defines the following traits:

WireItem

Implemented for any type that can be included in a wire message. Requires encode and decode. Provides methods for TLV serialization and deserialization.

WireMessage

Implemented for any struct that is a lightning wire message type. Has methods for serialization and deserialization. If check_type is false for read_from, it is expecting the message without the first 2 bytes indicating the message type. If it is true, it will read in the first 2 bytes and verify it matches the message type, otherwise it will return std::io::ErrorKind::InvalidData.

AnyWireMessage

Can be derived for any enum that is an arbitrary subset of all types that implement WireMessage. It will use the first 2 bytes of the message to determine which variant to deserialize into.

Contributing

Most lightning messages can be trivially implemented using the following derive macros:

WireMessage

Requirements

• Requires attribute: #[msg_type = 123] which defines the 2 byte number used to uniquely identify the message type.
• The type of each field must implement WireItem.
• Fields can be tagged with the #[tlv_type = 123] attribute.
• TLV field numbers must be monotonically increasing.
• TLV fields must be after non-TLV fields.
• TLV fields must be Optional.

Result

Given a struct named MessageName:

• Defines an enum called MessageNameItem which is a tagged union between all WireItem types within the message.
• Defines a type called MessageNameIter which is an iterator over the messages fields wrapped in MessageNameItem.
• Implements IntoIterator for &MessageName which converts it to MessageNameIter.
• Implements WireMessage for MessageName

AnyWireMessage

Requirements

• Must be an enum.
• Each variant must contain a single unnamed field that implements WireMessage.

Result

• Implements AnyWireMessage for the enum.