From a7ae23ccb79d557bdb013d03753bff47254811fb Mon Sep 17 00:00:00 2001
From: Dave Huseby <dwh@linuxprogrammer.org>
Date: Wed, 16 Aug 2023 20:34:31 -0600
Subject: [PATCH] added behavior event when local protocols change

Signed-off-by: Dave Huseby <dwh@linuxprogrammer.org>
---
 protocols/identify/src/behaviour.rs | 13 ++++++++++-
 protocols/identify/src/handler.rs   | 35 ++++++++++++++++++-----------
 2 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/protocols/identify/src/behaviour.rs b/protocols/identify/src/behaviour.rs
index f572b937d38..a7eb68ae9b0 100644
--- a/protocols/identify/src/behaviour.rs
+++ b/protocols/identify/src/behaviour.rs
@@ -26,7 +26,7 @@ use libp2p_identity::PublicKey;
 use libp2p_swarm::behaviour::{ConnectionClosed, ConnectionEstablished, DialFailure, FromSwarm};
 use libp2p_swarm::{
     ConnectionDenied, DialError, ExternalAddresses, ListenAddresses, NetworkBehaviour,
-    NotifyHandler, PollParameters, StreamUpgradeError, THandlerInEvent, ToSwarm,
+    NotifyHandler, PollParameters, StreamProtocol, StreamUpgradeError, THandlerInEvent, ToSwarm,
 };
 use libp2p_swarm::{ConnectionId, THandler, THandlerOutEvent};
 use lru::LruCache;
@@ -309,6 +309,10 @@ impl NetworkBehaviour for Behaviour {
                 self.events
                     .push_back(ToSwarm::GenerateEvent(Event::Error { peer_id, error }));
             }
+            handler::Event::LocalProtocolsChanged(protocols) => {
+                self.events
+                    .push_back(ToSwarm::GenerateEvent(Event::LocalProtocolsChanged { peer_id, protocols }));
+            }
         }
     }
 
@@ -439,6 +443,13 @@ pub enum Event {
         /// The error that occurred.
         error: StreamUpgradeError<UpgradeError>,
     },
+    /// Local protocols have changed.
+    LocalProtocolsChanged {
+        /// The peer we are advertising protocols to.
+        peer_id: PeerId,
+        /// The list of local supported protocols we are advertising to the peer.
+        protocols: Vec<StreamProtocol>,
+    },
 }
 
 /// If there is a given peer_id in the multiaddr, make sure it is the same as
diff --git a/protocols/identify/src/handler.rs b/protocols/identify/src/handler.rs
index 5a1712e8c3d..a6a99194e6f 100644
--- a/protocols/identify/src/handler.rs
+++ b/protocols/identify/src/handler.rs
@@ -104,6 +104,8 @@ pub enum Event {
     IdentificationPushed,
     /// Failed to identify the remote, or to reply to an identification request.
     IdentificationError(StreamUpgradeError<UpgradeError>),
+    /// Local supported protocols changed
+    LocalProtocolsChanged(Vec<StreamProtocol>),
 }
 
 impl Handler {
@@ -370,20 +372,27 @@ impl ConnectionHandler for Handler {
                     .then(|| self.local_protocols_to_string())
                     .unwrap_or_default();
 
-                if protocols_changed && self.exchanged_one_periodic_identify {
-                    log::debug!(
-                        "Supported listen protocols changed from [{before}] to [{after}], pushing to {}",
-                        self.remote_peer_id
-                    );
-
-                    let info = self.build_info();
+                if protocols_changed {
                     self.events
-                        .push(ConnectionHandlerEvent::OutboundSubstreamRequest {
-                            protocol: SubstreamProtocol::new(
-                                Either::Right(Push::outbound(info)),
-                                (),
-                            ),
-                        });
+                        .push(ConnectionHandlerEvent::NotifyBehaviour(Event::LocalProtocolsChanged(
+                            Vec::from_iter(self.local_supported_protocols.iter().cloned())
+                        )));
+
+                    if self.exchanged_one_periodic_identify {
+                        log::debug!(
+                            "Supported listen protocols changed from [{before}] to [{after}], pushing to {}",
+                            self.remote_peer_id
+                        );
+
+                        let info = self.build_info();
+                        self.events
+                            .push(ConnectionHandlerEvent::OutboundSubstreamRequest {
+                                protocol: SubstreamProtocol::new(
+                                    Either::Right(Push::outbound(info)),
+                                    (),
+                                ),
+                            });
+                    }
                 }
             }
         }