Function nc::setsockopt

source · 
pub unsafe fn setsockopt(
    sockfd: i32,
    level: i32,
    optname: i32,
    optval: usize,
    optlen: socklen_t
) -> Result<(), Errno>
Expand description

Set options on sockets.

§Example

let socket_fd = unsafe { nc::socket(nc::AF_INET, nc::SOCK_STREAM, 0) };
assert!(socket_fd.is_ok());
let socket_fd = socket_fd.unwrap();

// Enable tcp fast open.
let queue_len: i32 = 5;
let queue_len_ptr = &queue_len as *const i32 as usize;
let ret = unsafe {
    nc::setsockopt(
        socket_fd,
        nc::IPPROTO_TCP,
        nc::TCP_FASTOPEN,
        queue_len_ptr,
        std::mem::size_of_val(&queue_len) as u32,
    )
};
assert!(ret.is_ok());
let ret = unsafe { nc::close(socket_fd) };
assert!(ret.is_ok());
Examples found in repository?
examples/bind_device.rs (lines 9-15)
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fn main() -> Result<(), nc::Errno> {
    let socket_fd = unsafe { nc::socket(nc::AF_INET, nc::SOCK_STREAM, 0)? };
    let interface_name = "lo";
    let ret = unsafe {
        nc::setsockopt(
            socket_fd,
            nc::SOL_SOCKET,
            nc::SO_BINDTODEVICE,
            interface_name.as_ptr() as usize,
            interface_name.len() as nc::socklen_t,
        )
    };
    match ret {
        Err(errno) => eprintln!("socket() err: {}", nc::strerror(errno)),
        Ok(_) => println!("Now socket is bind to {}", interface_name),
    }
    let ret = unsafe { nc::close(socket_fd) };
    assert!(ret.is_ok());
    Ok(())
}
More examples
Hide additional examples
examples/tcp_fast_open.rs (lines 18-24)
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fn main() -> Result<(), nc::Errno> {
    let socket_fd = unsafe { nc::socket(nc::AF_INET, nc::SOCK_STREAM, 0)? };

    // For Linux, value is the queue length of pending packets.
    // See https://github.com/rust-lang/socket2/issues/49
    #[cfg(any(target_os = "linux", target_os = "android"))]
    let queue_len: i32 = 5;
    // For the others, just a boolean value for enable and disable.
    #[cfg(target_os = "freebsd")]
    let queue_len: i32 = 1;
    let queue_len_ptr = &queue_len as *const i32 as usize;

    let ret = unsafe {
        nc::setsockopt(
            socket_fd,
            nc::IPPROTO_TCP,
            nc::TCP_FASTOPEN,
            queue_len_ptr,
            std::mem::size_of_val(&queue_len) as u32,
        )
    };
    assert!(ret.is_ok());

    unsafe { nc::close(socket_fd) }
}