Function listen

pub unsafe fn listen(sockfd: i32, backlog: i32) -> Result<(), i32> 

Available on crate feature dep_nc only.

Listen for connections on a socket.

Examples

use nc::Errno;
use std::mem::{size_of, transmute};
use std::thread;

const SERVER_PORT: u16 = 18086;

#[must_use]
#[inline]
const fn htons(host: u16) -> u16 {
    host.to_be()
}

fn main() -> Result<(), Errno> {
    let listen_fd = unsafe { nc::socket(nc::AF_INET, nc::SOCK_STREAM, 0)? };
    println!("listen fd: {listen_fd}");

    let addr = nc::sockaddr_in_t {
        sin_family: nc::AF_INET as nc::sa_family_t,
        sin_port: htons(SERVER_PORT),
        sin_addr: nc::in_addr_t {
            s_addr: nc::INADDR_ANY as u32,
        },
        ..Default::default()
    };
    println!("addr: {addr:?}");

    let ret = unsafe {
        let addr_alias = transmute::<&nc::sockaddr_in_t, &nc::sockaddr_t>(&addr);
        nc::bind(listen_fd, addr_alias, size_of::<nc::sockaddr_in_t>() as u32)
    };
    assert!(ret.is_ok());

    // Start worker thread
    thread::spawn(|| {
        println!("worker thread started");
        let socket_fd = unsafe { nc::socket(nc::AF_INET, nc::SOCK_STREAM, 0) };
        assert!(socket_fd.is_ok());
        if let Ok(socket_fd) = socket_fd {
            let addr = nc::sockaddr_in_t {
                sin_family: nc::AF_INET as nc::sa_family_t,
                sin_port: htons(SERVER_PORT),
                sin_addr: nc::in_addr_t {
                    s_addr: nc::INADDR_ANY as u32,
                },
                ..Default::default()
            };
            unsafe {
                let addr_alias = transmute::<&nc::sockaddr_in_t, &nc::sockaddr_t>(&addr);
                let ret = nc::connect(socket_fd, addr_alias, size_of::<nc::sockaddr_in_t>() as u32);
                assert_eq!(ret, Ok(()));
            }
        } else {
            eprintln!("Failed to create socket");
        }
    });

    unsafe {
        nc::listen(listen_fd, nc::SOCK_STREAM)?;
    }

    let conn_fd = unsafe {
        nc::accept4(
            listen_fd,
            None,
            None,
            nc::SOCK_CLOEXEC,
        )?
    };
    println!("conn_fd: {conn_fd}");

    unsafe {
        nc::close(listen_fd)?;
    }

    Ok(())
}