From 5728ce9ef83f933291d900be262fc4369f988233 Mon Sep 17 00:00:00 2001
From: tv <tv@krebsco.de>
Date: Sun, 1 Nov 2026 19:52:21 +0100
Subject: libp2p: identify leaves out ignored externals

Identify no longer tells peers confirmed external addresses in ignored
ranges, unless they were announced.
---
 src/transport/libp2p/behaviour.rs |  2 ++
 src/transport/libp2p/ignore.rs    | 16 ++++++++++++++--
 src/transport/libp2p/mod.rs       |  2 ++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/transport/libp2p/behaviour.rs b/src/transport/libp2p/behaviour.rs
index a2e8e91..18d8011 100644
--- a/src/transport/libp2p/behaviour.rs
+++ b/src/transport/libp2p/behaviour.rs
@@ -276,6 +276,8 @@ impl Behaviour {
             identify: Identifying {
                 inner: ::libp2p::identify::Behaviour::new(identify),
                 ranges: ignored.clone(),
+                // Set by `Libp2pTransport::start`.
+                announced: Vec::new(),
             },
             relay_client,
             relay: relay.into(),
diff --git a/src/transport/libp2p/ignore.rs b/src/transport/libp2p/ignore.rs
index 6062839..eca9342 100644
--- a/src/transport/libp2p/ignore.rs
+++ b/src/transport/libp2p/ignore.rs
@@ -215,11 +215,21 @@ impl ::libp2p::swarm::NetworkBehaviour for Ignoring {
     }
 }
 
-/// libp2p's identify, not told our listen addresses in the ranges `libp2p-ignore` names:
-/// peers would remember them, show them, and dial them in vain.
+/// libp2p's identify, not told our listen addresses, nor external ones (found by UPnP,
+/// AutoNAT, a relay), in the ranges `libp2p-ignore` names: peers would remember them,
+/// show them, and dial them in vain. Announced addresses (`--libp2p-announce`) are told
+/// whatever range they are in.
 pub(super) struct Identifying {
     pub(super) inner: ::libp2p::identify::Behaviour,
     pub(super) ranges: Vec<IpRange>,
+    pub(super) announced: Vec<Multiaddr>,
+}
+
+impl Identifying {
+    /// An external address identify isn't told: in an ignored range, and not announced.
+    fn left_out(&self, address: &Multiaddr) -> bool {
+        ignored(&self.ranges, address) && !self.announced.contains(address)
+    }
 }
 
 impl ::libp2p::swarm::NetworkBehaviour for Identifying {
@@ -289,6 +299,8 @@ impl ::libp2p::swarm::NetworkBehaviour for Identifying {
         match event {
             FromSwarm::NewListenAddr(new) if ignored(&self.ranges, new.addr) => {}
             FromSwarm::ExpiredListenAddr(expired) if ignored(&self.ranges, expired.addr) => {}
+            FromSwarm::ExternalAddrConfirmed(confirmed) if self.left_out(confirmed.addr) => {}
+            FromSwarm::ExternalAddrExpired(expired) if self.left_out(expired.addr) => {}
             _ => self.inner.on_swarm_event(event),
         }
     }
diff --git a/src/transport/libp2p/mod.rs b/src/transport/libp2p/mod.rs
index 477f1ba..0bbabc7 100644
--- a/src/transport/libp2p/mod.rs
+++ b/src/transport/libp2p/mod.rs
@@ -247,6 +247,8 @@ impl Libp2pTransport {
                 .listen_on(address.clone())
                 .with_context(|| format!("Listening on {address}"))?;
         }
+        // Told peers whatever range they are in (`Identifying`).
+        swarm.behaviour_mut().identify.announced = config.announce.clone();
         for address in &config.announce {
             // Identify tells peers these.
             swarm.add_external_address(address.clone());
-- 
cgit v1.3.1