[optimize] Packet Decode

1. Add a macro to obtain Packet’s encapsulation information (the returned data is an immutable reference to Packet)
    * get_innermost_special_encapsulation!()
    * get_outermost_special_encapsulation!()

    Example: let icmp_encapsulation : Option<&Encapsulation> = get_innermost_special_encapsulation!(&Packet, ICMP);
    Example: let l4_encapsulation   : Option<&Encapsulation> = get_innermost_special_encapsulation!(&Packet, TCP | UDP);

2. Clean up the Clone/Copy Trait of PacketDecode to avoid memory copies caused by improper use by users.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/event/event.rs b/src/event/event.rs
index 830bdda..476ddce 100644
--- a/src/event/event.rs
+++ b/src/event/event.rs
@@ -1,4 +1,4 @@
-#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub enum Event {
     L2Event,
     L3Event,