Keep peer in wg table when updating psk (#6856)

* Keep peer in wg table when updating psk

* Fix unit test

* update handle_update_peer_psk_request

---------

Co-authored-by: Jędrzej Stuczyński <jedrzej.stuczynski@gmail.com>

gateway/src/node/wireguard/new_peer_registration/lp.rs

@@ -15,25 +15,14 @@ use std::time::Instant;
 
 impl PeerRegistrator {
     /// In the case of an already registered WG peer, update its PSK.
+    ///
+    /// The peer controller keeps the active config and the on-disk PSK in sync.
     pub(super) async fn update_peer_psk(
         &self,
         peer: PeerPublicKey,
         psk: Key,
     ) -> Result<(), GatewayWireguardError> {
-        // 1. check if the peer is currently being handled
-        if self.peer_manager.check_active_peer(peer).await? {
-            // 2. if so, force disconnect it (as we're handling new request from the same peer)
-            self.peer_manager.remove_peer(peer).await?;
-        }
-
-        // 3. update the on-disk PSK
-        let encoded_psk = psk.to_lower_hex();
-        self.ecash_verifier
-            .storage()
-            .update_peer_psk(&peer.to_string(), Some(&encoded_psk))
-            .await?;
-
-        Ok(())
+        self.peer_manager.update_peer_psk(peer, psk).await
     }
 
     fn lp_peer_to_final_response(

gateway/src/node/wireguard/peer_manager.rs

@@ -125,6 +125,44 @@ impl PeerManager {
         res
     }
 
+    pub async fn update_peer_psk(
+        &self,
+        pub_key: PeerPublicKey,
+        psk: Key,
+    ) -> Result<(), GatewayWireguardError> {
+        let controller_start = Instant::now();
+        let peer_key = Key::new(pub_key.to_bytes());
+        let (response_tx, response_rx) = oneshot::channel();
+        let msg = PeerControlRequest::UpdatePeerPsk {
+            peer_key,
+            psk,
+            response_tx,
+        };
+        self.wireguard_gateway_data
+            .peer_tx()
+            .send(msg)
+            .await
+            .map_err(|_| GatewayWireguardError::PeerInteractionStopped)?;
+
+        let res = response_rx
+            .await
+            .map_err(|_| GatewayWireguardError::internal("no response for update peer psk"))?
+            .map_err(|err| {
+                GatewayWireguardError::InternalError(format!(
+                    "updating peer psk could not be performed: {err:?}"
+                ))
+            });
+
+        let latency = controller_start.elapsed().as_secs_f64();
+        add_histogram_obs!(
+            "wg_peer_controller_channel_latency_seconds",
+            latency,
+            WG_CONTROLLER_LATENCY_BUCKETS
+        );
+
+        res
+    }
+
     pub async fn remove_peer(&self, pub_key: PeerPublicKey) -> Result<(), GatewayWireguardError> {
         let controller_start = Instant::now();
         let key = Key::new(pub_key.to_bytes());