Prefer declared external IP instead of observed address

p2p/src/connection/outgoing/mod.rs

@@ -6,11 +6,13 @@ pub use p2p_connection_outgoing_actions::*;
 
 mod p2p_connection_outgoing_reducer;
 
+use std::net::IpAddr;
 #[cfg(feature = "p2p-libp2p")]
 use std::net::SocketAddr;
 use std::{fmt, str::FromStr};
 
 use binprot_derive::{BinProtRead, BinProtWrite};
+use multiaddr::{Multiaddr, Protocol};
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
@@ -44,6 +46,42 @@ pub struct P2pConnectionOutgoingInitLibp2pOpts {
     pub port: u16,
 }
 
+impl P2pConnectionOutgoingInitLibp2pOpts {
+    /// If the current host is local and there is a better host among the `addrs`,
+    /// replace the current one with the better one.
+    pub fn update_host_if_needed<'a>(&mut self, mut addrs: impl Iterator<Item = &'a Multiaddr>) {
+        fn is_local(ip: impl Into<IpAddr>) -> bool {
+            match ip.into() {
+                IpAddr::V4(ip) => ip.is_loopback() || ip.is_private(),
+                IpAddr::V6(ip) => ip.is_loopback(),
+            }
+        }
+
+        // if current dial opts is not good enough
+        let update = match &self.host {
+            Host::Domain(_) => false,
+            Host::Ipv4(ip) => is_local(*ip),
+            Host::Ipv6(ip) => is_local(*ip),
+        };
+        if update {
+            // if new options is better
+            let new = addrs.find_map(|x| {
+                x.iter().find_map(|x| match x {
+                    Protocol::Dns4(hostname) | Protocol::Dns6(hostname) => {
+                        Some(Host::Domain(hostname.into_owned()))
+                    }
+                    Protocol::Ip4(ip) if !is_local(ip) => Some(Host::Ipv4(ip)),
+                    Protocol::Ip6(ip) if !is_local(ip) => Some(Host::Ipv6(ip)),
+                    _ => None,
+                })
+            });
+            if let Some(new) = new {
+                self.host = new;
+            }
+        }
+    }
+}
+
 pub(crate) mod libp2p_opts {
     use std::net::{IpAddr, SocketAddr};
 

p2p/src/identify/p2p_identify_reducer.rs

@@ -2,6 +2,7 @@ use openmina_core::{bug_condition, Substate};
 use redux::ActionWithMeta;
 
 use crate::{
+    connection::outgoing::P2pConnectionOutgoingInitOpts,
     disconnection::{P2pDisconnectionAction, P2pDisconnectionReason},
     token::{BroadcastAlgorithm, DiscoveryAlgorithm, IdentifyAlgorithm, RpcAlgorithm, StreamKind},
     P2pNetworkConnectionMuxState, P2pNetworkKadRequestAction, P2pNetworkKadState,
@@ -60,6 +61,9 @@ impl P2pState {
                 let info = *info;
                 if let Some(peer) = p2p_state.peers.get_mut(&peer_id) {
                     peer.identify = Some(info.clone());
+                    if let Some(P2pConnectionOutgoingInitOpts::LibP2P(opts)) = &mut peer.dial_opts {
+                        opts.update_host_if_needed(info.listen_addrs.iter());
+                    }
                 } else {
                     bug_condition!(
                         "Peer state not found for `P2pIdentifyAction::UpdatePeerInformation`"