From 4925058fdda69f4c8db0eac886b828a4adfae73c Mon Sep 17 00:00:00 2001
From: Emilia Hane <elsaemiliaevahane@gmail.com>
Date: Mon, 15 Jan 2024 23:33:25 +0100
Subject: [PATCH] Add implementation feature to protocol id

---
 src/packet/mod.rs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/packet/mod.rs b/src/packet/mod.rs
index f071263bd..ef7ad63c0 100644
--- a/src/packet/mod.rs
+++ b/src/packet/mod.rs
@@ -29,16 +29,25 @@ pub const MESSAGE_NONCE_LENGTH: usize = 12;
 /// The Id nonce length (in bytes).
 pub const ID_NONCE_LENGTH: usize = 16;
 
+pub struct Nat;
+
+impl ProtocolIdentity<3> for Nat {
+    const PROTOCOL_ID_BYTES: [u8; 6] = *b"discv5";
+    const PROTOCOL_VERSION_BYTES: [u8; 2] = 0x0001_u16.to_be_bytes();
+    const IMPLEMENTATION_FEATURES: [u8; 3] = *b"nat";
+}
 pub struct DefaultProtocolId {}
 
 impl ProtocolIdentity for DefaultProtocolId {
     const PROTOCOL_ID_BYTES: [u8; 6] = *b"discv5";
     const PROTOCOL_VERSION_BYTES: [u8; 2] = 0x0001_u16.to_be_bytes();
+    const IMPLEMENTATION_FEATURES: [u8; 0] = *b"";
 }
 
-pub trait ProtocolIdentity {
+pub trait ProtocolIdentity<const N: usize = 0>: Sync + Send {
     const PROTOCOL_ID_BYTES: [u8; 6];
     const PROTOCOL_VERSION_BYTES: [u8; 2];
+    const IMPLEMENTATION_FEATURES: [u8; N];
 }
 
 pub(crate) const MAX_PACKET_SIZE: usize = 1280;