Add NetlinkEvent type

A Netlink event is an unsolicited event from netlink. In most cases, it
will be a Netlink message, but it may also be an overrun notification.

Author: Tuetuopay

src/message.rs

@@ -10,6 +10,15 @@ use crate::{
     NetlinkSerializable, Parseable,
 };
 
+/// Represent a Netlink event
+#[derive(Debug, PartialEq, Eq, Clone)]
+pub enum NetlinkEvent<M> {
+    /// An actual message was received from Netlink
+    Message(M),
+    /// The socket receive buffer filled up
+    Overrun,
+}
+
 /// Represent a netlink message.
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub struct NetlinkMessage<I> {