Network discovery: store the remote address of the peer after finishi…

…ng a successful handshake.

This remote address can later by used for various tasks, like banning.

Network connection pool: only look at a part of a Multiaddr to determine if an address is banned.

network-libp2p/src/connection_pool/behaviour.rs

@@ -28,7 +28,7 @@ use rand::{seq::IteratorRandom, thread_rng};
 use void::Void;
 
 use super::Error;
-use crate::discovery::peer_contacts::PeerContactBook;
+use crate::discovery::{handler, peer_contacts::PeerContactBook};
 
 /// Current state of connections and peers for connection limits
 #[derive(Clone, Debug)]
@@ -625,12 +625,11 @@ impl Behaviour {
         self.peer_ids.mark_banned(peer_id);
         debug!(%peer_id, "Banned peer");
 
-        // Mark its addresses as banned if we have them
+        // Mark its outer protocol address as banned if we have it
         if let Some(contact) = self.contacts.read().get(&peer_id) {
-            let addresses = contact.addresses();
-            for address in addresses {
-                self.addresses.mark_banned(address.clone());
-                debug!(%address, "Banned address");
+            if let Some(outer_protocol_address) = contact.get_outer_protocol_address() {
+                debug!(address = %outer_protocol_address, "Banned address");
+                self.addresses.mark_banned(outer_protocol_address);
             }
         }
     }
@@ -893,9 +892,11 @@ impl NetworkBehaviour for Behaviour {
         _local_addr: &Multiaddr,
         remote_addr: &Multiaddr,
     ) -> Result<(), ConnectionDenied> {
-        if self.addresses.is_banned(remote_addr.clone()) {
-            debug!(%remote_addr, "Address is banned");
-            return Err(ConnectionDenied::new(Error::BannedIp));
+        if let Some(outer_protocol_address) = handler::outer_protocol_address(remote_addr) {
+            if self.addresses.is_banned(outer_protocol_address) {
+                debug!(%remote_addr, "Address is banned");
+                return Err(ConnectionDenied::new(Error::BannedIp));
+            }
         }
 
         // Get IP from multiaddress if it exists.

network-libp2p/src/discovery/handler.rs

@@ -10,6 +10,7 @@ use futures_timer::Delay;
 use instant::Instant;
 use libp2p::{
     identity::Keypair,
+    multiaddr::Protocol,
     swarm::{
         handler::{
             ConnectionEvent, DialUpgradeError, FullyNegotiatedInbound, FullyNegotiatedOutbound,
@@ -173,6 +174,12 @@ impl Handler {
         peer_contact_book: Arc<RwLock<PeerContactBook>>,
         peer_address: Multiaddr,
     ) -> Self {
+        if let Some(peer_contact) = peer_contact_book.write().get(&peer_id) {
+            if let Some(outer_protocol_address) = outer_protocol_address(&peer_address) {
+                peer_contact.set_outer_protocol_address(outer_protocol_address);
+            }
+        }
+
         Self {
             peer_id,
             config,
@@ -244,6 +251,23 @@ impl Handler {
     }
 }
 
+/// Extract the `/ip4/`,`/ip6/`, `/dns4/` or `/dns6/` protocol part from a `Multiaddr`
+pub(crate) fn outer_protocol_address(addr: &Multiaddr) -> Option<Multiaddr> {
+    addr.iter()
+        .find(|p| {
+            matches!(
+                p,
+                Protocol::Dns(_)
+                    | Protocol::Dns4(_)
+                    | Protocol::Dns6(_)
+                    | Protocol::Ip4(_)
+                    | Protocol::Ip6(_)
+            )
+        })
+        .map(|p| Some(p.into()))
+        .unwrap_or(None)
+}
+
 impl ConnectionHandler for Handler {
     type FromBehaviour = ();
     type ToBehaviour = HandlerOutEvent;

network-libp2p/src/discovery/peer_contacts.rs

@@ -185,6 +185,7 @@ impl SignedPeerContact {
 /// Meta information attached to peer contact info objects. This is meant to be mutable and change over time.
 #[derive(Clone, Debug, Serialize, Deserialize)]
 struct PeerContactMeta {
+    outer_protocol_address: Option<Multiaddr>,
     score: f64,
 }
 
@@ -209,7 +210,10 @@ impl From<SignedPeerContact> for PeerContactInfo {
         Self {
             peer_id,
             contact,
-            meta: RwLock::new(PeerContactMeta { score: 0. }),
+            meta: RwLock::new(PeerContactMeta {
+                score: 0.,
+                outer_protocol_address: None,
+            }),
         }
     }
 }
@@ -273,6 +277,22 @@ impl PeerContactInfo {
     pub fn set_score(&self, score: f64) {
         self.meta.write().score = score;
     }
+
+    /// Gets the outer protocol address of the peer. For example `/ip4/x.x.x.x` or `/dns4/foo.bar`
+    pub fn get_outer_protocol_address(&self) -> Option<Multiaddr> {
+        self.meta.read().outer_protocol_address.clone()
+    }
+
+    /// Sets the outer protocol address of the peer once
+    pub fn set_outer_protocol_address(&self, addr: Multiaddr) {
+        self.meta
+            .write()
+            .outer_protocol_address
+            .get_or_insert_with(|| {
+                trace!(peer_id = %self.peer_id, %addr, "Set outer protocol address for peer");
+                addr
+            });
+    }
 }
 
 /// Main structure that holds the peer information that has been obtained or