Function sendto 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn sendto(
    socket: c_int,
    message: *const c_void,
    length: size_t,
    flags: c_int,
    dest_addr: *const sockaddr,
    dest_len: socklen_t,
) -> ssize_t

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/sendto.html.