1  use std::io;
2  use std::mem::{self, MaybeUninit};
3  use std::net::{self, SocketAddr};
4  use std::os::windows::io::{AsRawSocket, FromRawSocket};
5  use std::os::windows::raw::SOCKET as StdSocket; // windows-sys uses usize, stdlib uses u32/u64.
6  
7  use crate::sys::windows::net::{new_ip_socket, socket_addr};
8  use windows_sys::Win32::Networking::WinSock::{
9      bind as win_bind, getsockopt, IPPROTO_IPV6, IPV6_V6ONLY, SOCKET_ERROR, SOCK_DGRAM,
10  };
11  
bind(addr: SocketAddr) -> io::Result<net::UdpSocket>12  pub fn bind(addr: SocketAddr) -> io::Result<net::UdpSocket> {
13      let raw_socket = new_ip_socket(addr, SOCK_DGRAM)?;
14      let socket = unsafe { net::UdpSocket::from_raw_socket(raw_socket as StdSocket) };
15  
16      let (raw_addr, raw_addr_length) = socket_addr(&addr);
17      syscall!(
18          win_bind(raw_socket, raw_addr.as_ptr(), raw_addr_length),
19          PartialEq::eq,
20          SOCKET_ERROR
21      )?;
22  
23      Ok(socket)
24  }
25  
only_v6(socket: &net::UdpSocket) -> io::Result<bool>26  pub(crate) fn only_v6(socket: &net::UdpSocket) -> io::Result<bool> {
27      let mut optval: MaybeUninit<i32> = MaybeUninit::uninit();
28      let mut optlen = mem::size_of::<i32>() as i32;
29  
30      syscall!(
31          getsockopt(
32              socket.as_raw_socket() as usize,
33              IPPROTO_IPV6 as i32,
34              IPV6_V6ONLY as i32,
35              optval.as_mut_ptr().cast(),
36              &mut optlen,
37          ),
38          PartialEq::eq,
39          SOCKET_ERROR
40      )?;
41  
42      debug_assert_eq!(optlen as usize, mem::size_of::<i32>());
43      // Safety: `getsockopt` initialised `optval` for us.
44      let optval = unsafe { optval.assume_init() };
45      Ok(optval != 0)
46  }
47