Add (set_)ip_bindany_v4 for target_os=freebsd

Author: cavivie

src/sys/unix.rs

@@ -3239,6 +3239,41 @@ impl crate::Socket {
             )
         }
     }
+
+    /// Get the value of the `IP_BINDANY` option on this socket.
+    ///
+    /// For more information about this option, see [`set_ip_bindany_v4`].
+    ///
+    /// [`set_ip_bindany_v4`]: crate::Socket::set_ip_bindany_v4
+    #[cfg(all(feature = "all", target_os = "freebsd"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "freebsd"))))]
+    pub fn ip_bindany_v4(&self) -> io::Result<bool> {
+        unsafe {
+            getsockopt::<c_int>(self.as_raw(), libc::IPPROTO_IP, libc::IP_BINDANY)
+                .map(|bindany| bindany != 0)
+        }
+    }
+
+    /// Set the value of the `IP_BINDANY` option on this socket.
+    ///
+    /// If the IP_BINDANY option is enabled on a SOCK_STREAM, SOCK_DGRAM or a
+    /// SOCK_RAW socket, one can bind(2) to any	address, even one not bound to
+    /// any available network interface in the system. This functionality (in
+    /// conjunction with special firewall rules) can be used for implementing a
+    /// transparent proxy. The PRIV_NETINET_BINDANY privilege is needed	to set
+    /// this option.
+    #[cfg(all(feature = "all", target_os = "freebsd"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "all", target_os = "freebsd"))))]
+    pub fn set_ip_bindany_v4(&self, bindany: bool) -> io::Result<()> {
+        unsafe {
+            setsockopt(
+                self.as_raw(),
+                libc::IPPROTO_IP,
+                libc::IP_BINDANY,
+                bindany as c_int,
+            )
+        }
+    }
 }
 
 /// See [`Socket::dccp_available_ccids`].

tests/socket.rs

@@ -1378,6 +1378,12 @@ test!(
     ip_transparent_v6,
     set_ip_transparent_v6(true)
 );
+#[cfg(all(feature = "all", target_os = "freebsd"))]
+test!(
+    #[ignore = "setting `IP_BINDANY` requires the `PRIV_NETINET_BINDANY` privilege (works when running as root)"]
+    ip_bindany_v4,
+    set_ip_bindany_v4(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)"]