testcase.rs

use nix::sys::socket::{
    recvmmsg, sendmmsg, socket, AddressFamily, MsgFlags, MultHdrs, SockFlag, SockProtocol,
    SockType, SockaddrIn,
};
use std::io::{IoSlice, IoSliceMut};
use std::str::FromStr;

fn main() {
    let sock_addr = SockaddrIn::from_str("127.0.0.1:6790").unwrap();

    let ssock = socket(
        AddressFamily::Inet,
        SockType::Datagram,
        SockFlag::empty(),
        SockProtocol::Udp,
    )
    .unwrap();
    let rsock = socket(
        AddressFamily::Inet,
        SockType::Datagram,
        SockFlag::empty(),
        SockProtocol::Udp,
    )
    .unwrap();
    nix::sys::socket::bind(rsock, &sock_addr).unwrap();

    let sbufs = [[0xaau8; 1]; 1];
    let flags = MsgFlags::empty();

    sendmmsg(
        ssock,
        &mut MultHdrs::preallocate(1, None),
        sbufs.iter().map(|buf| [IoSlice::new(buf)]),
        vec![Some(sock_addr); 1],
        &[],
        flags,
    )
    .unwrap();

    let mut rbuf = [[0x55u8; 1]; 1];
    let mut hdrs = MultHdrs::preallocate(1, None);
    let recvs = recvmmsg::<'_, _, (), _>(
        rsock,
        &mut hdrs,
        rbuf.iter_mut().map(|buf| [IoSliceMut::new(buf)]),
        flags,
        None,
    )
    .unwrap();

    for (recv, sbuf) in recvs.zip(sbufs) {
        assert_eq!(recv.iovs().next().unwrap(), sbuf);
    }
}