Crate roam_fdpass 

Cross-platform file descriptor / handle passing for roam.

This crate provides a unified API for passing file descriptors (Unix) or socket handles (Windows) between processes over IPC channels.

Platform implementations

• Unix: Uses SCM_RIGHTS to pass raw file descriptors over Unix domain sockets
• Windows: Uses WSADuplicateSocket to serialize socket state, sends it over a named pipe, and recreates the socket with WSASocket on the receiving end

Usage

Unix

use roam_fdpass::{send_fd, recv_fd};
use tokio::net::UnixStream;

// Sender
let tcp_listener = std::net::TcpListener::bind("127.0.0.1:0")?;
let fd = tcp_listener.into_raw_fd();
send_fd(&unix_stream, fd).await?;

// Receiver
let fd = recv_fd(&unix_stream).await?;
let listener = unsafe { std::net::TcpListener::from_raw_fd(fd) };

Windows

use roam_fdpass::{send_socket, recv_socket};
use tokio::net::windows::named_pipe::{NamedPipeServer, NamedPipeClient};

// Sender (needs receiver's process ID)
let tcp_listener = std::net::TcpListener::bind("127.0.0.1:0")?;
send_socket(&pipe, &tcp_listener, receiver_pid).await?;

// Receiver
let listener: std::net::TcpListener = recv_socket(&pipe).await?;

Functions

recv_fd

Receive a file descriptor from a Unix stream.

recv_fds

Receive exactly expected fds from one SCM_RIGHTS message.

send_fd

Send a file descriptor over a Unix stream.

send_fds

Send multiple file descriptors over a Unix stream in one SCM_RIGHTS message.