From c718835585379dfd0e72e4359695450ce5100ae9 Mon Sep 17 00:00:00 2001
From: stormshield-frb <144998884+stormshield-frb@users.noreply.github.com>
Date: Wed, 22 Nov 2023 21:40:26 +0100
Subject: [PATCH] fix(mdns): don't suspend task forever upon reading non-mDNS
 packet

Fixes: #4860.

Pull-Request: #4861.
---
 protocols/mdns/CHANGELOG.md           | 2 ++
 protocols/mdns/src/behaviour/iface.rs | 6 +++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/protocols/mdns/CHANGELOG.md b/protocols/mdns/CHANGELOG.md
index 6f5aa6945fd..cfd02232b07 100644
--- a/protocols/mdns/CHANGELOG.md
+++ b/protocols/mdns/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 - Ensure `Multiaddr` handled and returned by `Behaviour` are `/p2p` terminated.
   See [PR 4596](https://github.com/libp2p/rust-libp2p/pull/4596).
+- Fix a bug in the `Behaviour::poll` method causing missed mdns packets.
+  See [PR 4861](https://github.com/libp2p/rust-libp2p/pull/4861).
 
 ## 0.45.0
 
diff --git a/protocols/mdns/src/behaviour/iface.rs b/protocols/mdns/src/behaviour/iface.rs
index 7fe97c38381..9302065cde2 100644
--- a/protocols/mdns/src/behaviour/iface.rs
+++ b/protocols/mdns/src/behaviour/iface.rs
@@ -312,14 +312,18 @@ where
                 }
                 Poll::Ready(Err(err)) if err.kind() == std::io::ErrorKind::WouldBlock => {
                     // No more bytes available on the socket to read
+                    continue;
                 }
                 Poll::Ready(Err(err)) => {
                     tracing::error!("failed reading datagram: {}", err);
+                    return Poll::Ready(());
                 }
                 Poll::Ready(Ok(Err(err))) => {
                     tracing::debug!("Parsing mdns packet failed: {:?}", err);
+                    continue;
                 }
-                Poll::Ready(Ok(Ok(None))) | Poll::Pending => {}
+                Poll::Ready(Ok(Ok(None))) => continue,
+                Poll::Pending => {}
             }
 
             return Poll::Pending;