Trait Packet

pub trait Packet: Sized {
    const MTU: usize;

    // Required methods
    fn allocate() -> Option<NonNull<u8>>;
    fn into_raw_parts(self) -> (NonNull<u8>, usize);
    unsafe fn from_raw_parts(ptr: NonNull<u8>, len: usize) -> Self;
}

A Packet is a byte buffer for packet data. Similar to a Vec<u8> it has a length and a capacity. The capacity however is the fixed value MTU.

You need to implement this trait to give the L2CAP driver a method to allocate and free the space for the packets sent and received on a channel.

Required Associated Constants

const MTU: usize

The maximum size a packet can have.

Required Methods

fn allocate() -> Option<NonNull<u8>>

Allocate a new buffer with space for MTU bytes. Return None when the allocation can’t be fulfilled.

This function is called by the L2CAP driver when it needs space to receive a packet into. It will later call from_raw_parts with the buffer and the amount of bytes it has received.

fn into_raw_parts(self) -> (NonNull<u8>, usize)

Take ownership of the packet buffer. Returns a pointer to the buffer and the number of bytes in the buffer.

To free the memory the driver will call from_raw_parts later and drop the value.

unsafe fn from_raw_parts(ptr: NonNull<u8>, len: usize) -> Self

Construct a Packet from a pointer to a buffer and the number of bytes written to the buffer.

SAFETY: ptr must be a pointer previously returned by either allocate or ìnto_raw_parts. len must be the number of bytes in the buffer and must not be larger than MTU.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors