Crate async_send_fd

async-send-fd is a library for sending and receiving Unix file descriptors over async UnixStream connections. You can either transfer

• RawFd;
• Tokio UnixStream if tokio feature enabled;
• or Smol UnixStream if smol feature enabled;

Examles

See test_raw_fd.rs, test_smol_stream.rs or test_tokio_stream.rs for examples.

Creating a Tokio UnixStream from RawFd

If you make a Tokio UnixStream from a raw file descriptor made by an OS call (e.g. UnixStream::pair), you must make it set_nonblocking(true), otherwise receivers scheduler will block writing into the socket ⚠️

Smol UnixStream makes it automatically if created using UnixStream::from(Async::new(stream))

Transfering socket pair ownership

Sending a descriptor doesn’t close the local copy, which leads to having the socket being opened by the sender until it shuts down. If you want socket pair receivers to detect peer shutdown, you have to close local sockets after sending them.

Use close Posix call for Tokio streams, or UnixStream::shutdown() for Smol.

Features

• tokio - for Tokio support
• smol - for Smol support

Traits

• AsyncRecvFd
  A trait to receive raw file descriptors
• AsyncSendFd
  A trait to send raw file descriptors