1 files changed, 39 insertions, 0 deletions
diff --git a/third_party/rust/mio/src/sys/unix/udp.rs b/third_party/rust/mio/src/sys/unix/udp.rs
new file mode 100644
index 0000000000..5a97cbd897
--- /dev/null
+++ b/third_party/rust/mio/src/sys/unix/udp.rs
@@ -0,0 +1,39 @@
+use crate::sys::unix::net::{new_ip_socket, socket_addr};
+
+use std::io;
+use std::mem;
+use std::net::{self, SocketAddr};
+use std::os::unix::io::{AsRawFd, FromRawFd};
+
+pub fn bind(addr: SocketAddr) -> io::Result<net::UdpSocket> {
+    // Gives a warning for non Apple platforms.
+    #[allow(clippy::let_and_return)]
+    let socket = new_ip_socket(addr, libc::SOCK_DGRAM);
+
+    socket.and_then(|socket| {
+        let (raw_addr, raw_addr_length) = socket_addr(&addr);
+        syscall!(bind(socket, raw_addr.as_ptr(), raw_addr_length))
+            .map_err(|err| {
+                // Close the socket if we hit an error, ignoring the error
+                // from closing since we can't pass back two errors.
+                let _ = unsafe { libc::close(socket) };
+                err
+            })
+            .map(|_| unsafe { net::UdpSocket::from_raw_fd(socket) })
+    })
+}
+
+pub(crate) fn only_v6(socket: &net::UdpSocket) -> io::Result<bool> {
+    let mut optval: libc::c_int = 0;
+    let mut optlen = mem::size_of::<libc::c_int>() as libc::socklen_t;
+
+    syscall!(getsockopt(
+        socket.as_raw_fd(),
+        libc::IPPROTO_IPV6,
+        libc::IPV6_V6ONLY,
+        &mut optval as *mut _ as *mut _,
+        &mut optlen,
+    ))?;
+
+    Ok(optval != 0)
+}