[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/protocol/codec.rs b/src/protocol/codec.rs
index 7bf2243..575e49d 100644
--- a/src/protocol/codec.rs
+++ b/src/protocol/codec.rs
@@ -2,7 +2,7 @@ use nom::IResult;
 use std::fmt::Debug;
 
 pub trait Decode {
-    type Iterm: Debug;
+    type Iterm: Debug + PartialEq;
     fn decode(input: &[u8]) -> IResult<&[u8], Self::Iterm>;
 }