Add (set_)so_bindany for target_os=openbsd

Author: cavivie

src/sys/unix.rs

@@ -3309,6 +3309,40 @@ impl crate::Socket {
             )
         }
     }
+
+    /// Set the value of the `SO_BINDANY` option on this socket.
+    ///
+    /// SO_BINDANY allows the socket to be bound to addresses which are not
+    /// local to the machine, so it can be used to make a transparent proxy.
+    /// Note that this option is limited to the superuser. In order to
+    /// receive packets for these addresses, SO_BINDANY needs to be combined
+    /// with matching outgoing pf(4) rules with the divert-reply parameter.
+    #[cfg(all(feature = "all", target_os = "openbsd"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "openbsd"))))]
+    pub fn set_so_bindany(&self, bindany: bool) -> io::Result<()> {
+        unsafe {
+            setsockopt(
+                self.as_raw(),
+                libc::IPPROTO_IP,
+                libc::SO_BINDANY,
+                bindany as c_int,
+            )
+        }
+    }
+
+    /// Get the value of the `IP_BINDANY` option on this socket.
+    ///
+    /// For more information about this option, see [`set_ip_bindany`].
+    ///
+    /// [`set_ip_bindany`]: crate::Socket::set_ip_bindany
+    #[cfg(all(feature = "all", target_os = "freebsd"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "freebsd"))))]
+    pub fn ip_bindany(&self) -> io::Result<bool> {
+        unsafe {
+            getsockopt::<c_int>(self.as_raw(), libc::IPPROTO_IP, libc::IP_BINDANY)
+                .map(|bindany| bindany != 0)
+        }
+    }
 }
 
 /// See [`Socket::dccp_available_ccids`].

tests/socket.rs

@@ -1399,6 +1399,12 @@ test!(
     ip_bindany_v6,
     set_ip_bindany_v6(true)
 );
+#[cfg(all(feature = "all", target_os = "openbsd"))]
+test!(
+    #[ignore = "setting `SO_BINDANY` is limited to the superuser"]
+    so_bindany,
+    set_so_bindany(true)
+);
 #[cfg(all(feature = "all", any(target_os = "fuchsia", target_os = "linux")))]
 test!(
     #[ignore = "setting `SO_MARK` requires the `CAP_NET_ADMIN` capability (works when running as root)"]