Add simple interface for busy_poll on Linux

src/sys/unix.rs

@@ -2813,6 +2813,29 @@ impl crate::Socket {
             )
         }
     }
+
+    /// Get the value for the `SO_BUSY_POLL` option on this socket.
+    ///
+    /// On Linux this function requires the `CAP_NET_ADMIN` capability.
+    #[cfg(all(feature = "all", target_os = "linux"))]
+    pub fn busy_poll(&self) -> io::Result<u32> {
+        unsafe { getsockopt(self.as_raw(), libc::SOL_SOCKET, libc::SO_BUSY_POLL) }
+    }
+
+    /// Set the value for the `SO_BUSY_POLL` option on this socket.
+    ///
+    /// On Linux this function requires the `CAP_NET_ADMIN` capability.
+    #[cfg(all(feature = "all", target_os = "linux"))]
+    pub fn set_busy_poll(&self, busy_poll: u32) -> io::Result<()> {
+        unsafe {
+            setsockopt(
+                self.as_raw(),
+                libc::SOL_SOCKET,
+                libc::SO_BUSY_POLL,
+                busy_poll as c_int,
+            )
+        }
+    }
 }
 
 /// Berkeley Packet Filter (BPF).

tests/socket.rs

@@ -1827,3 +1827,16 @@ fn set_priority() {
         assert!(socket.priority().unwrap() == i);
     }
 }
+
+#[cfg(all(feature = "all", target_os = "linux"))]
+#[test]
+fn set_busy_poll() {
+    let socket = Socket::new(Domain::UNIX, Type::DGRAM, None).unwrap();
+    assert!(socket.busy_poll().unwrap() == 0);
+
+    // test busy poll values 0 .. 6; values above 6 require additional priviledges
+    for i in (0..=6).rev() {
+        socket.set_busy_poll(i).unwrap();
+        assert!(socket.busy_poll().unwrap() == i);
+    }
+}