Function getsockopt

pub unsafe fn getsockopt(
    sockfd: i32,
    level: i32,
    opt_name: i32,
    opt_val: *mut c_void,
    opt_len: &mut u32,
) -> Result<(), i32> 

Available on crate feature dep_nc only.

Get options on sockets

Examples

use std::mem::size_of_val;

fn main() -> Result<(), nc::Errno> {
    let socket_fd = unsafe { nc::socket(nc::AF_INET, nc::SOCK_STREAM, 0)? };

    let set_queue_len: i32 = 5;
    {
        let buf_len = size_of_val(&set_queue_len) as nc::socklen_t;
        let ret = unsafe {
            nc::setsockopt(
                socket_fd,
                nc::IPPROTO_TCP,
                nc::TCP_FASTOPEN,
                &set_queue_len as *const i32 as *const _,
                buf_len,
            )
        };
        assert!(ret.is_ok());
    }

    let mut get_queue_len: i32 = 0;
    {
        let mut buf_len = size_of_val(&get_queue_len) as nc::socklen_t;
        let ret = unsafe {
            nc::getsockopt(
                socket_fd,
                nc::IPPROTO_TCP,
                nc::TCP_FASTOPEN,
                &mut get_queue_len as *mut i32 as *mut _,
                &mut buf_len,
            )
        };
        assert!(ret.is_ok());
        println!("queue len: {get_queue_len}");
    }
    assert_eq!(set_queue_len, get_queue_len);

    unsafe { nc::close(socket_fd) }
}