feat: support disabling relay data forwarding (#2188)

- add a disable_relay_data runtime/config patch option
- reuse the existing avoid_relay_data feature flag when relay data forwarding is disabled

easytier/src/common/config.rs

@@ -71,6 +71,7 @@ pub fn gen_default_flags() -> Flags {
         need_p2p: false,
         instance_recv_bps_limit: u64::MAX,
         disable_upnp: false,
+        disable_relay_data: false,
     }
 }
 

easytier/src/common/global_ctx.rs

@@ -217,6 +217,12 @@ pub struct GlobalCtx {
 
     flags: ArcSwap<Flags>,
 
+    // Runtime/base advertised feature flags before config-owned fields are
+    // overlaid by set_flags. Keep this separate so config patches do not erase
+    // runtime state such as public-server role, IPv6 provider status, or the
+    // non-whitelist avoid-relay preference.
+    base_feature_flags: AtomicCell<PeerFeatureFlag>,
+
     feature_flags: AtomicCell<PeerFeatureFlag>,
 
     token_bucket_manager: TokenBucketManager,
@@ -247,8 +253,17 @@ impl std::fmt::Debug for GlobalCtx {
 pub type ArcGlobalCtx = std::sync::Arc<GlobalCtx>;
 
 impl GlobalCtx {
-    fn derive_feature_flags(flags: &Flags, current: Option<PeerFeatureFlag>) -> PeerFeatureFlag {
+    fn apply_disable_relay_data_flag(
-        let mut feature_flags = current.unwrap_or_default();
+        flags: &Flags,
+        mut feature_flags: PeerFeatureFlag,
+    ) -> PeerFeatureFlag {
+        if flags.disable_relay_data {
+            feature_flags.avoid_relay_data = true;
+        }
+        feature_flags
+    }
+
+    fn derive_feature_flags(flags: &Flags, mut feature_flags: PeerFeatureFlag) -> PeerFeatureFlag {
         feature_flags.kcp_input = !flags.disable_kcp_input;
         feature_flags.no_relay_kcp = flags.disable_relay_kcp;
         feature_flags.support_conn_list_sync = true;
@@ -256,7 +271,7 @@ impl GlobalCtx {
         feature_flags.no_relay_quic = flags.disable_relay_quic;
         feature_flags.need_p2p = flags.need_p2p;
         feature_flags.disable_p2p = flags.disable_p2p;
-        feature_flags
+        Self::apply_disable_relay_data_flag(flags, feature_flags)
     }
 
     pub fn new(config_fs: impl ConfigLoader + 'static) -> Self {
@@ -285,7 +300,8 @@ impl GlobalCtx {
 
         let flags = config_fs.get_flags();
 
-        let feature_flags = Self::derive_feature_flags(&flags, None);
+        let base_feature_flags = PeerFeatureFlag::default();
+        let feature_flags = Self::derive_feature_flags(&flags, base_feature_flags);
 
         let credential_storage_path = config_fs.get_credential_file();
         let credential_manager = Arc::new(CredentialManager::new(credential_storage_path));
@@ -318,6 +334,8 @@ impl GlobalCtx {
 
             flags: ArcSwap::new(Arc::new(flags)),
 
+            base_feature_flags: AtomicCell::new(base_feature_flags),
+
             feature_flags: AtomicCell::new(feature_flags),
 
             token_bucket_manager: TokenBucketManager::new(),
@@ -513,7 +531,7 @@ impl GlobalCtx {
         self.config.set_flags(flags.clone());
         self.feature_flags.store(Self::derive_feature_flags(
             &flags,
-            Some(self.feature_flags.load()),
+            self.base_feature_flags.load(),
         ));
         self.flags.store(Arc::new(flags));
     }
@@ -578,8 +596,53 @@ impl GlobalCtx {
         self.feature_flags.load()
     }
 
-    pub fn set_feature_flags(&self, flags: PeerFeatureFlag) {
+    /// Replace the runtime/base advertised flags as a complete snapshot.
-        self.feature_flags.store(flags);
+    ///
+    /// This is intended for foreign scoped contexts that inherit an already
+    /// computed feature-flag snapshot from their parent. Most callers should use
+    /// a narrower setter so they do not accidentally overwrite unrelated runtime
+    /// state.
+    pub fn set_base_advertised_feature_flags(&self, feature_flags: PeerFeatureFlag) {
+        self.base_feature_flags.store(feature_flags);
+        let flags = self.flags.load();
+        self.feature_flags
+            .store(Self::apply_disable_relay_data_flag(
+                flags.as_ref(),
+                feature_flags,
+            ));
+    }
+
+    /// Set the avoid-relay preference that is independent of disable_relay_data.
+    ///
+    /// disable_relay_data still forces the effective advertised flag to true,
+    /// but this base preference is preserved when that config flag is toggled.
+    pub fn set_avoid_relay_data_preference(&self, avoid_relay_data: bool) -> bool {
+        let mut base_feature_flags = self.base_feature_flags.load();
+        base_feature_flags.avoid_relay_data = avoid_relay_data;
+        self.base_feature_flags.store(base_feature_flags);
+
+        let mut feature_flags = self.feature_flags.load();
+        let previous = feature_flags.avoid_relay_data;
+        feature_flags.avoid_relay_data = avoid_relay_data || self.flags.load().disable_relay_data;
+        self.feature_flags.store(feature_flags);
+        previous != feature_flags.avoid_relay_data
+    }
+
+    /// Set the runtime IPv6-provider advertised bit without touching
+    /// config-derived feature flags.
+    pub fn set_ipv6_public_addr_provider_feature_flag(&self, enabled: bool) -> bool {
+        let mut base_feature_flags = self.base_feature_flags.load();
+        base_feature_flags.ipv6_public_addr_provider = enabled;
+        self.base_feature_flags.store(base_feature_flags);
+
+        let mut feature_flags = self.feature_flags.load();
+        if feature_flags.ipv6_public_addr_provider == enabled {
+            return false;
+        }
+
+        feature_flags.ipv6_public_addr_provider = enabled;
+        self.feature_flags.store(feature_flags);
+        true
     }
 
     pub fn token_bucket_manager(&self) -> &TokenBucketManager {
@@ -796,7 +859,7 @@ pub mod tests {
         let mut feature_flags = global_ctx.get_feature_flags();
         feature_flags.avoid_relay_data = true;
         feature_flags.is_public_server = true;
-        global_ctx.set_feature_flags(feature_flags);
+        global_ctx.set_base_advertised_feature_flags(feature_flags);
 
         let mut flags = global_ctx.get_flags().clone();
         flags.disable_kcp_input = true;
@@ -820,6 +883,83 @@ pub mod tests {
         assert!(!feature_flags.ipv6_public_addr_provider);
     }
 
+    #[tokio::test]
+    async fn set_base_advertised_feature_flags_applies_current_values() {
+        let config = TomlConfigLoader::default();
+        let global_ctx = GlobalCtx::new(config);
+
+        let feature_flags = PeerFeatureFlag {
+            kcp_input: false,
+            no_relay_kcp: true,
+            quic_input: false,
+            no_relay_quic: true,
+            is_public_server: true,
+            ..Default::default()
+        };
+        global_ctx.set_base_advertised_feature_flags(feature_flags);
+
+        assert_eq!(global_ctx.get_feature_flags(), feature_flags);
+    }
+
+    #[tokio::test]
+    async fn set_base_advertised_feature_flags_keeps_disable_relay_data_effective() {
+        let config = TomlConfigLoader::default();
+        let global_ctx = GlobalCtx::new(config);
+
+        let mut flags = global_ctx.get_flags().clone();
+        flags.disable_relay_data = true;
+        global_ctx.set_flags(flags);
+
+        let mut feature_flags = global_ctx.get_feature_flags();
+        feature_flags.avoid_relay_data = false;
+        feature_flags.is_public_server = true;
+        global_ctx.set_base_advertised_feature_flags(feature_flags);
+
+        let advertised_feature_flags = global_ctx.get_feature_flags();
+        assert!(advertised_feature_flags.avoid_relay_data);
+        assert!(advertised_feature_flags.is_public_server);
+
+        let mut flags = global_ctx.get_flags().clone();
+        flags.disable_relay_data = false;
+        global_ctx.set_flags(flags);
+
+        let advertised_feature_flags = global_ctx.get_feature_flags();
+        assert!(!advertised_feature_flags.avoid_relay_data);
+        assert!(advertised_feature_flags.is_public_server);
+    }
+
+    #[tokio::test]
+    async fn disable_relay_data_sets_avoid_relay_feature_flag() {
+        let config = TomlConfigLoader::default();
+        let global_ctx = GlobalCtx::new(config);
+
+        let mut flags = global_ctx.get_flags().clone();
+        flags.disable_relay_data = true;
+        global_ctx.set_flags(flags);
+
+        assert!(global_ctx.get_feature_flags().avoid_relay_data);
+
+        let mut flags = global_ctx.get_flags().clone();
+        flags.disable_relay_data = false;
+        global_ctx.set_flags(flags);
+
+        assert!(!global_ctx.get_feature_flags().avoid_relay_data);
+
+        global_ctx.set_avoid_relay_data_preference(true);
+
+        let mut flags = global_ctx.get_flags().clone();
+        flags.disable_relay_data = true;
+        global_ctx.set_flags(flags);
+
+        assert!(global_ctx.get_feature_flags().avoid_relay_data);
+
+        let mut flags = global_ctx.get_flags().clone();
+        flags.disable_relay_data = false;
+        global_ctx.set_flags(flags);
+
+        assert!(global_ctx.get_feature_flags().avoid_relay_data);
+    }
+
     #[tokio::test]
     async fn should_deny_proxy_for_process_wide_rpc_port() {
         protected_port::clear_protected_tcp_ports_for_test();

easytier/src/instance/instance.rs

@@ -340,6 +340,11 @@ impl InstanceConfigPatcher {
             global_ctx.set_ipv6(Some(ipv6.into()));
             global_ctx.config.set_ipv6(Some(ipv6.into()));
         }
+        if let Some(disable_relay_data) = patch.disable_relay_data {
+            let mut flags = global_ctx.get_flags();
+            flags.disable_relay_data = disable_relay_data;
+            global_ctx.set_flags(flags);
+        }
         if let Some(enabled) = patch.ipv6_public_addr_provider {
             global_ctx.config.set_ipv6_public_addr_provider(enabled);
             provider_config_changed = true;

easytier/src/instance/public_ipv6_provider.rs

@@ -361,16 +361,8 @@ fn apply_public_ipv6_provider_runtime_state(
     let prefix_changed = global_ctx.set_advertised_ipv6_public_addr_prefix(next_prefix);
 
     let next_provider_enabled = matches!(state, PublicIpv6ProviderRuntimeState::Active(_));
-    let feature_changed = {
+    let feature_changed =
-        let mut feature_flags = global_ctx.get_feature_flags();
+        global_ctx.set_ipv6_public_addr_provider_feature_flag(next_provider_enabled);
-        if feature_flags.ipv6_public_addr_provider == next_provider_enabled {
-            false
-        } else {
-            feature_flags.ipv6_public_addr_provider = next_provider_enabled;
-            global_ctx.set_feature_flags(feature_flags);
-            true
-        }
-    };
 
     prefix_changed || feature_changed
 }

easytier/src/launcher.rs

@@ -816,6 +816,10 @@ impl NetworkConfig {
             flags.disable_upnp = disable_upnp;
         }
 
+        if let Some(disable_relay_data) = self.disable_relay_data {
+            flags.disable_relay_data = disable_relay_data;
+        }
+
         if let Some(disable_sym_hole_punching) = self.disable_sym_hole_punching {
             flags.disable_sym_hole_punching = disable_sym_hole_punching;
         }
@@ -990,6 +994,7 @@ impl NetworkConfig {
         result.disable_tcp_hole_punching = Some(flags.disable_tcp_hole_punching);
         result.disable_udp_hole_punching = Some(flags.disable_udp_hole_punching);
         result.disable_upnp = Some(flags.disable_upnp);
+        result.disable_relay_data = Some(flags.disable_relay_data);
         result.disable_sym_hole_punching = Some(flags.disable_sym_hole_punching);
         result.enable_magic_dns = Some(flags.accept_dns);
         result.mtu = Some(flags.mtu as i32);

easytier/src/peers/foreign_network_manager.rs

@@ -56,7 +56,7 @@ use super::{
     route_trait::NextHopPolicy,
     traffic_metrics::{
         InstanceLabelKind, LogicalTrafficMetrics, TrafficKind, TrafficMetricRecorder,
-        route_peer_info_instance_id, traffic_kind,
+        is_relay_data_packet_type, route_peer_info_instance_id, traffic_kind,
     },
 };
 
@@ -69,11 +69,16 @@ pub trait GlobalForeignNetworkAccessor: Send + Sync + 'static {
 struct ForeignNetworkEntry {
     my_peer_id: PeerId,
 
+    // Node-global runtime flags, such as disable_relay_data, live on the parent
+    // context. The foreign context is scoped to the foreign network's OSPF view.
+    parent_global_ctx: ArcGlobalCtx,
     global_ctx: ArcGlobalCtx,
     network: NetworkIdentity,
     peer_map: Arc<PeerMap>,
     relay_peer_map: Arc<RelayPeerMap>,
     peer_session_store: Arc<PeerSessionStore>,
+    // Static per-network permission from the whitelist check. disable_relay_data
+    // is the node-wide runtime override layered on top of this value.
     relay_data: bool,
     pm_packet_sender: Mutex<Option<PacketRecvChan>>,
 
@@ -205,6 +210,7 @@ impl ForeignNetworkEntry {
         Self {
             my_peer_id,
 
+            parent_global_ctx: global_ctx.clone(),
             global_ctx: foreign_global_ctx,
             network,
             peer_map,
@@ -231,6 +237,27 @@ impl ForeignNetworkEntry {
         }
     }
 
+    fn desired_avoid_relay_data_feature_flag(
+        parent_global_ctx: &ArcGlobalCtx,
+        relay_data: bool,
+    ) -> bool {
+        !relay_data || parent_global_ctx.get_feature_flags().avoid_relay_data
+    }
+
+    fn sync_parent_relay_data_feature_flag(
+        parent_global_ctx: &ArcGlobalCtx,
+        global_ctx: &ArcGlobalCtx,
+        relay_data: bool,
+    ) -> bool {
+        let avoid_relay_data =
+            Self::desired_avoid_relay_data_feature_flag(parent_global_ctx, relay_data);
+        if global_ctx.get_feature_flags().avoid_relay_data == avoid_relay_data {
+            return false;
+        }
+
+        global_ctx.set_avoid_relay_data_preference(avoid_relay_data)
+    }
+
     fn build_foreign_global_ctx(
         network: &NetworkIdentity,
         global_ctx: ArcGlobalCtx,
@@ -258,10 +285,9 @@ impl ForeignNetworkEntry {
 
         let mut feature_flag = global_ctx.get_feature_flags();
         feature_flag.is_public_server = true;
-        if !relay_data {
+        feature_flag.avoid_relay_data =
-            feature_flag.avoid_relay_data = true;
+            Self::desired_avoid_relay_data_feature_flag(&global_ctx, relay_data);
-        }
+        foreign_global_ctx.set_base_advertised_feature_flags(feature_flag);
-        foreign_global_ctx.set_feature_flags(feature_flag);
 
         for u in global_ctx.get_running_listeners().into_iter() {
             foreign_global_ctx.add_running_listener(u);
@@ -412,6 +438,7 @@ impl ForeignNetworkEntry {
         let peer_map = self.peer_map.clone();
         let relay_peer_map = self.relay_peer_map.clone();
         let traffic_metrics = self.traffic_metrics.clone();
+        let parent_global_ctx = self.parent_global_ctx.clone();
         let relay_data = self.relay_data;
         let pm_sender = self.pm_packet_sender.lock().await.take().unwrap();
         let network_name = self.network.network_name.clone();
@@ -497,11 +524,16 @@ impl ForeignNetworkEntry {
                         "ignore packet in foreign network"
                     );
                 } else {
-                    if packet_type == PacketType::Data as u8
+                    if is_relay_data_packet_type(packet_type) {
-                        || packet_type == PacketType::KcpSrc as u8
+                        let disable_relay_data = parent_global_ctx.flags_arc().disable_relay_data;
-                        || packet_type == PacketType::KcpDst as u8
+                        if !relay_data || disable_relay_data {
-                    {
+                            tracing::debug!(
-                        if !relay_data {
+                                ?from_peer_id,
+                                ?to_peer_id,
+                                packet_type,
+                                disable_relay_data,
+                                "drop foreign network relay data"
+                            );
                             continue;
                         }
                         if !bps_limiter.try_consume(len.into()) {
@@ -589,10 +621,31 @@ impl ForeignNetworkEntry {
         });
     }
 
+    async fn run_parent_feature_flag_sync_routine(&self) {
+        let parent_global_ctx = self.parent_global_ctx.clone();
+        let global_ctx = self.global_ctx.clone();
+        let relay_data = self.relay_data;
+        self.tasks.lock().await.spawn(async move {
+            let mut parent_events = parent_global_ctx.subscribe();
+            loop {
+                ForeignNetworkEntry::sync_parent_relay_data_feature_flag(
+                    &parent_global_ctx,
+                    &global_ctx,
+                    relay_data,
+                );
+
+                if parent_events.recv().await.is_err() {
+                    parent_events = parent_global_ctx.subscribe();
+                }
+            }
+        });
+    }
+
     async fn prepare(&self, accessor: Box<dyn GlobalForeignNetworkAccessor>) {
         self.prepare_route(accessor).await;
         self.start_packet_recv().await;
         self.run_relay_session_gc_routine().await;
+        self.run_parent_feature_flag_sync_routine().await;
         self.peer_rpc.run();
         self.peer_center.init().await;
     }
@@ -1397,6 +1450,92 @@ pub mod tests {
         );
     }
 
+    #[tokio::test]
+    async fn disable_relay_data_blocks_foreign_network_transit_data() {
+        let pm_center = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
+        let pma_net1 = create_mock_peer_manager_for_foreign_network("net1").await;
+        let pmb_net1 = create_mock_peer_manager_for_foreign_network("net1").await;
+
+        connect_peer_manager(pma_net1.clone(), pm_center.clone()).await;
+        connect_peer_manager(pmb_net1.clone(), pm_center.clone()).await;
+        wait_route_appear(pma_net1.clone(), pmb_net1.clone())
+            .await
+            .unwrap();
+
+        let mut flags = pm_center.get_global_ctx().get_flags();
+        flags.disable_relay_data = true;
+        pm_center.get_global_ctx().set_flags(flags);
+        pm_center
+            .get_global_ctx()
+            .issue_event(GlobalCtxEvent::ConfigPatched(Default::default()));
+
+        let center_peer_id = pm_center
+            .get_foreign_network_manager()
+            .get_network_peer_id("net1")
+            .unwrap();
+        wait_for_condition(
+            || {
+                let pma_net1 = pma_net1.clone();
+                async move {
+                    pma_net1.list_routes().await.iter().any(|route| {
+                        route.peer_id == center_peer_id
+                            && route
+                                .feature_flag
+                                .as_ref()
+                                .map(|flag| flag.avoid_relay_data)
+                                .unwrap_or(false)
+                    })
+                }
+            },
+            Duration::from_secs(5),
+        )
+        .await;
+
+        let network_labels =
+            LabelSet::new().with_label_type(LabelType::NetworkName("net1".to_string()));
+        let forwarded_bytes_before = metric_value(
+            &pm_center,
+            MetricName::TrafficBytesForwarded,
+            network_labels.clone(),
+        );
+        let forwarded_packets_before = metric_value(
+            &pm_center,
+            MetricName::TrafficPacketsForwarded,
+            network_labels.clone(),
+        );
+
+        let mut transit_pkt = ZCPacket::new_with_payload(b"foreign-transit-disabled");
+        transit_pkt.fill_peer_manager_hdr(
+            pma_net1.my_peer_id(),
+            pmb_net1.my_peer_id(),
+            PacketType::Data as u8,
+        );
+        pma_net1
+            .get_foreign_network_client()
+            .send_msg(transit_pkt, center_peer_id)
+            .await
+            .unwrap();
+
+        tokio::time::sleep(Duration::from_millis(300)).await;
+
+        assert_eq!(
+            metric_value(
+                &pm_center,
+                MetricName::TrafficBytesForwarded,
+                network_labels.clone()
+            ),
+            forwarded_bytes_before
+        );
+        assert_eq!(
+            metric_value(
+                &pm_center,
+                MetricName::TrafficPacketsForwarded,
+                network_labels
+            ),
+            forwarded_packets_before
+        );
+    }
+
     #[tokio::test]
     async fn foreign_network_transit_control_forwarding_records_control_forwarded_metrics() {
         let pm_center = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
@@ -1409,6 +1548,10 @@ pub mod tests {
             .await
             .unwrap();
 
+        let mut flags = pm_center.get_global_ctx().get_flags();
+        flags.disable_relay_data = true;
+        pm_center.get_global_ctx().set_flags(flags);
+
         let center_peer_id = pm_center
             .get_foreign_network_manager()
             .get_network_peer_id("net1")
@@ -1657,6 +1800,81 @@ pub mod tests {
         ));
     }
 
+    #[tokio::test]
+    async fn foreign_entry_feature_flag_tracks_parent_disable_relay_data_toggle() {
+        let global_ctx = get_mock_global_ctx_with_network(Some(NetworkIdentity::new(
+            "__access__".to_string(),
+            "access_secret".to_string(),
+        )));
+        let foreign_network = NetworkIdentity::new("net1".to_string(), "net1_secret".to_string());
+        let (pm_packet_sender, _pm_packet_recv) = create_packet_recv_chan();
+        let entry = ForeignNetworkEntry::new(
+            foreign_network,
+            1,
+            global_ctx.clone(),
+            true,
+            Arc::new(PeerSessionStore::new()),
+            pm_packet_sender,
+        );
+        assert!(!entry.global_ctx.get_feature_flags().avoid_relay_data);
+
+        entry.run_parent_feature_flag_sync_routine().await;
+
+        let mut flags = global_ctx.get_flags();
+        flags.disable_relay_data = true;
+        global_ctx.set_flags(flags);
+        global_ctx.issue_event(GlobalCtxEvent::ConfigPatched(Default::default()));
+
+        wait_for_condition(
+            || async { entry.global_ctx.get_feature_flags().avoid_relay_data },
+            Duration::from_secs(2),
+        )
+        .await;
+
+        let mut flags = global_ctx.get_flags();
+        flags.disable_relay_data = false;
+        global_ctx.set_flags(flags);
+        global_ctx.issue_event(GlobalCtxEvent::ConfigPatched(Default::default()));
+
+        wait_for_condition(
+            || async { !entry.global_ctx.get_feature_flags().avoid_relay_data },
+            Duration::from_secs(2),
+        )
+        .await;
+    }
+
+    #[tokio::test]
+    async fn foreign_entry_without_relay_data_keeps_avoid_feature_flag() {
+        let global_ctx = get_mock_global_ctx_with_network(Some(NetworkIdentity::new(
+            "__access__".to_string(),
+            "access_secret".to_string(),
+        )));
+        let foreign_network = NetworkIdentity::new("net1".to_string(), "net1_secret".to_string());
+        let (pm_packet_sender, _pm_packet_recv) = create_packet_recv_chan();
+        let entry = ForeignNetworkEntry::new(
+            foreign_network,
+            1,
+            global_ctx.clone(),
+            false,
+            Arc::new(PeerSessionStore::new()),
+            pm_packet_sender,
+        );
+
+        assert!(entry.global_ctx.get_feature_flags().avoid_relay_data);
+
+        let mut flags = global_ctx.get_flags();
+        flags.disable_relay_data = false;
+        global_ctx.set_flags(flags);
+
+        ForeignNetworkEntry::sync_parent_relay_data_feature_flag(
+            &global_ctx,
+            &entry.global_ctx,
+            entry.relay_data,
+        );
+
+        assert!(entry.global_ctx.get_feature_flags().avoid_relay_data);
+    }
+
     #[test]
     fn credential_trust_path_rejects_admin_identity() {
         assert!(ForeignNetworkManager::should_reject_credential_trust_path(

easytier/src/peers/peer_manager.rs

@@ -38,7 +38,7 @@ use crate::{
         route_trait::{ForeignNetworkRouteInfoMap, MockRoute, NextHopPolicy, RouteInterface},
         traffic_metrics::{
             InstanceLabelKind, LogicalTrafficMetrics, TrafficKind, TrafficMetricRecorder,
-            route_peer_info_instance_id, traffic_kind,
+            is_relay_data_packet_type, route_peer_info_instance_id, traffic_kind,
         },
     },
     proto::{
@@ -263,9 +263,7 @@ impl PeerManager {
             .is_err()
         {
             // if local network is not in whitelist, avoid relay data when exist any other route path
-            let mut f = global_ctx.get_feature_flags();
+            global_ctx.set_avoid_relay_data_preference(true);
-            f.avoid_relay_data = true;
-            global_ctx.set_feature_flags(f);
         }
 
         let is_secure_mode_enabled = global_ctx
@@ -774,6 +772,7 @@ impl PeerManager {
         my_peer_id: PeerId,
         peer_map: &PeerMap,
         foreign_network_mgr: &ForeignNetworkManager,
+        disable_relay_data: bool,
     ) -> Result<(), ZCPacket> {
         let pm_header = packet.peer_manager_header().unwrap();
         if pm_header.packet_type != PacketType::ForeignNetworkPacket as u8 {
@@ -783,6 +782,16 @@ impl PeerManager {
         let from_peer_id = pm_header.from_peer_id.get();
         let to_peer_id = pm_header.to_peer_id.get();
 
+        if disable_relay_data && Self::is_relay_data_zc_packet(&packet) {
+            tracing::debug!(
+                ?from_peer_id,
+                ?to_peer_id,
+                inner_packet_type = ?packet.foreign_network_inner_packet_type(),
+                "drop foreign network relay data while relay data is disabled"
+            );
+            return Ok(());
+        }
+
         let foreign_hdr = packet.foreign_network_hdr().unwrap();
         let foreign_network_name = foreign_hdr.get_network_name(packet.payload());
         let foreign_peer_id = foreign_hdr.get_dst_peer_id();
@@ -872,6 +881,29 @@ impl PeerManager {
         }
     }
 
+    fn is_relay_data_packet(packet_type: u8) -> bool {
+        is_relay_data_packet_type(packet_type)
+    }
+
+    fn is_relay_data_zc_packet(packet: &ZCPacket) -> bool {
+        let Some(hdr) = packet.peer_manager_header() else {
+            return false;
+        };
+
+        if hdr.packet_type == PacketType::ForeignNetworkPacket as u8 {
+            let inner_packet_type = packet.foreign_network_inner_packet_type();
+            if inner_packet_type.is_none() {
+                tracing::warn!(
+                    ?hdr,
+                    "foreign network packet has unparseable inner peer manager header"
+                );
+            }
+            return inner_packet_type.is_none_or(Self::is_relay_data_packet);
+        }
+
+        Self::is_relay_data_packet(hdr.packet_type)
+    }
+
     async fn start_peer_recv(&self) {
         let mut recv = self.packet_recv.lock().await.take().unwrap();
         let my_peer_id = self.my_peer_id;
@@ -925,14 +957,21 @@ impl PeerManager {
         self.tasks.lock().await.spawn(async move {
             tracing::trace!("start_peer_recv");
             while let Ok(ret) = recv_packet_from_chan(&mut recv).await {
-                let Err(mut ret) =
+                let disable_relay_data = global_ctx.flags_arc().disable_relay_data;
-                    Self::try_handle_foreign_network_packet(ret, my_peer_id, &peers, &foreign_mgr)
+                let Err(mut ret) = Self::try_handle_foreign_network_packet(
-                        .await
+                    ret,
+                    my_peer_id,
+                    &peers,
+                    &foreign_mgr,
+                    disable_relay_data,
+                )
+                .await
                 else {
                     continue;
                 };
 
                 let buf_len = ret.buf_len();
+                let is_relay_data_packet = Self::is_relay_data_zc_packet(&ret);
                 let Some(hdr) = ret.mut_peer_manager_header() else {
                     tracing::warn!(?ret, "invalid packet, skip");
                     continue;
@@ -944,6 +983,16 @@ impl PeerManager {
                 let packet_type = hdr.packet_type;
                 let is_encrypted = hdr.is_encrypted();
                 if to_peer_id != my_peer_id {
+                    if disable_relay_data && is_relay_data_packet {
+                        tracing::debug!(
+                            ?from_peer_id,
+                            ?to_peer_id,
+                            packet_type,
+                            "drop forwarded relay data while relay data is disabled"
+                        );
+                        continue;
+                    }
+
                     if hdr.forward_counter > 7 {
                         tracing::warn!(?hdr, "forward counter exceed, drop packet");
                         continue;
@@ -2080,7 +2129,7 @@ mod tests {
             },
         },
         proto::{
-            common::{CompressionAlgoPb, NatType, PeerFeatureFlag},
+            common::{CompressionAlgoPb, NatType},
             peer_rpc::SecureAuthLevel,
         },
         tunnel::{
@@ -2224,6 +2273,84 @@ mod tests {
         assert_eq!(signal.version(), initial_version + 2);
     }
 
+    #[test]
+    fn disable_relay_data_classifies_data_plane_packets_only() {
+        for packet_type in [
+            PacketType::Data,
+            PacketType::KcpSrc,
+            PacketType::KcpDst,
+            PacketType::QuicSrc,
+            PacketType::QuicDst,
+            PacketType::DataWithKcpSrcModified,
+            PacketType::DataWithQuicSrcModified,
+            PacketType::RelayHandshake,
+            PacketType::RelayHandshakeAck,
+            PacketType::ForeignNetworkPacket,
+        ] {
+            assert!(PeerManager::is_relay_data_packet(packet_type as u8));
+        }
+
+        for packet_type in [
+            PacketType::RpcReq,
+            PacketType::RpcResp,
+            PacketType::Ping,
+            PacketType::Pong,
+            PacketType::HandShake,
+            PacketType::NoiseHandshakeMsg1,
+            PacketType::NoiseHandshakeMsg2,
+            PacketType::NoiseHandshakeMsg3,
+        ] {
+            assert!(!PeerManager::is_relay_data_packet(packet_type as u8));
+        }
+    }
+
+    #[test]
+    fn disable_relay_data_inspects_foreign_network_inner_packet_type() {
+        let network_name = "net1".to_string();
+
+        let mut rpc_packet = ZCPacket::new_with_payload(b"rpc");
+        rpc_packet.fill_peer_manager_hdr(1, 2, PacketType::RpcReq as u8);
+        let mut foreign_rpc_packet =
+            ZCPacket::new_for_foreign_network(&network_name, 2, &rpc_packet);
+        foreign_rpc_packet.fill_peer_manager_hdr(10, 20, PacketType::ForeignNetworkPacket as u8);
+
+        assert_eq!(
+            foreign_rpc_packet.foreign_network_inner_packet_type(),
+            Some(PacketType::RpcReq as u8)
+        );
+        assert!(!PeerManager::is_relay_data_zc_packet(&foreign_rpc_packet));
+
+        let mut data_packet = ZCPacket::new_with_payload(b"data");
+        data_packet.fill_peer_manager_hdr(1, 2, PacketType::Data as u8);
+        let mut foreign_data_packet =
+            ZCPacket::new_for_foreign_network(&network_name, 2, &data_packet);
+        foreign_data_packet.fill_peer_manager_hdr(10, 20, PacketType::ForeignNetworkPacket as u8);
+
+        assert_eq!(
+            foreign_data_packet.foreign_network_inner_packet_type(),
+            Some(PacketType::Data as u8)
+        );
+        assert!(PeerManager::is_relay_data_zc_packet(&foreign_data_packet));
+    }
+
+    #[tokio::test]
+    async fn non_whitelisted_network_avoid_relay_survives_disable_relay_data_toggle() {
+        let global_ctx = get_mock_global_ctx();
+        let mut flags = global_ctx.get_flags();
+        flags.disable_relay_data = true;
+        flags.relay_network_whitelist = "other-network".to_string();
+        global_ctx.set_flags(flags);
+
+        let (packet_send, _packet_recv) = create_packet_recv_chan();
+        let _peer_mgr = PeerManager::new(RouteAlgoType::Ospf, global_ctx.clone(), packet_send);
+
+        let mut flags = global_ctx.get_flags();
+        flags.disable_relay_data = false;
+        global_ctx.set_flags(flags);
+
+        assert!(global_ctx.get_feature_flags().avoid_relay_data);
+    }
+
     #[tokio::test]
     async fn send_msg_internal_does_not_record_tx_metrics_on_failed_delivery() {
         let peer_mgr = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
@@ -3121,10 +3248,7 @@ mod tests {
         // when b's avoid_relay_data is true, a->c should route through d and e, cost is 3
         peer_mgr_b
             .get_global_ctx()
-            .set_feature_flags(PeerFeatureFlag {
+            .set_avoid_relay_data_preference(true);
-                avoid_relay_data: true,
-                ..Default::default()
-            });
         tokio::time::sleep(Duration::from_secs(2)).await;
         if wait_route_appear_with_cost(peer_mgr_a.clone(), peer_mgr_c.my_peer_id, Some(3))
             .await

easytier/src/peers/traffic_metrics.rs

@@ -241,6 +241,13 @@ pub(crate) fn traffic_kind(packet_type: u8) -> TrafficKind {
     }
 }
 
+pub(crate) fn is_relay_data_packet_type(packet_type: u8) -> bool {
+    traffic_kind(packet_type) == TrafficKind::Data
+        || packet_type == PacketType::RelayHandshake as u8
+        || packet_type == PacketType::RelayHandshakeAck as u8
+        || packet_type == PacketType::ForeignNetworkPacket as u8
+}
+
 #[derive(Clone)]
 struct TrafficMetricGroup {
     data: Arc<LogicalTrafficMetrics>,

easytier/src/proto/api_config.proto

@@ -27,6 +27,7 @@ message InstanceConfigPatch {
   optional bool ipv6_public_addr_provider = 11;
   optional bool ipv6_public_addr_auto = 12;
   optional string ipv6_public_addr_prefix = 13;
+  optional bool disable_relay_data = 14;
 }
 
 message PortForwardPatch {

easytier/src/proto/api_manage.proto

@@ -99,6 +99,7 @@ message NetworkConfig {
   optional bool ipv6_public_addr_provider = 62;
   optional bool ipv6_public_addr_auto = 63;
   optional string ipv6_public_addr_prefix = 64;
+  optional bool disable_relay_data = 65;
 }
 
 message PortForwardConfig {

easytier/src/proto/common.proto

@@ -75,6 +75,7 @@ message FlagsInConfig {
   bool need_p2p = 38;
   uint64 instance_recv_bps_limit = 39;
   bool disable_upnp = 40;
+  bool disable_relay_data = 41;
 }
 
 message RpcDescriptor {

easytier/src/tests/credential_tests.rs

@@ -501,10 +501,10 @@ async fn credential_relay_capability(#[case] allow_relay: bool) {
     // Create admin node
     let admin_config = create_admin_config("admin", Some("ns_adm"), "10.144.144.1", "fd00::1/64");
     let mut admin_inst = Instance::new(admin_config);
-    let mut ff = admin_inst.get_global_ctx().get_feature_flags();
     // if cred c allow relay, we set admin inst avoid relay (if other same-cost path available, admin will not relay data)
-    ff.avoid_relay_data = allow_relay;
+    admin_inst
-    admin_inst.get_global_ctx().set_feature_flags(ff);
+        .get_global_ctx()
+        .set_avoid_relay_data_preference(allow_relay);
     admin_inst.run().await.unwrap();
 
     let admin_peer_id = admin_inst.peer_id();

easytier/src/tests/three_node.rs

@@ -3730,6 +3730,153 @@ pub async fn config_patch_test() {
     drop_insts(insts).await;
 }
 
+#[rstest::rstest]
+#[tokio::test]
+#[serial_test::serial]
+pub async fn config_patch_disable_relay_data_test() {
+    use crate::proto::api::config::InstanceConfigPatch;
+
+    let insts = init_three_node_ex(
+        "udp",
+        |cfg| {
+            cfg.set_ipv6(None);
+            cfg
+        },
+        false,
+    )
+    .await;
+
+    let relay_peer_id = insts[1].peer_id();
+    let dst_peer_id = insts[2].peer_id();
+    assert!(!insts[1].get_global_ctx().get_flags().disable_relay_data);
+    assert!(
+        !insts[1]
+            .get_global_ctx()
+            .get_feature_flags()
+            .avoid_relay_data
+    );
+
+    check_route_ex(
+        insts[0].get_peer_manager().list_routes().await,
+        dst_peer_id,
+        |route| {
+            assert_eq!(route.next_hop_peer_id, relay_peer_id);
+            true
+        },
+    );
+
+    wait_for_condition(
+        || async { ping_test("net_a", "10.144.144.3", None).await },
+        Duration::from_secs(5),
+    )
+    .await;
+
+    insts[1]
+        .get_config_patcher()
+        .apply_patch(InstanceConfigPatch {
+            disable_relay_data: Some(true),
+            ..Default::default()
+        })
+        .await
+        .unwrap();
+
+    assert!(insts[1].get_global_ctx().get_flags().disable_relay_data);
+    assert!(
+        insts[1]
+            .get_global_ctx()
+            .config
+            .get_flags()
+            .disable_relay_data
+    );
+    assert!(
+        insts[1]
+            .get_global_ctx()
+            .get_feature_flags()
+            .avoid_relay_data
+    );
+
+    wait_for_condition(
+        || {
+            let peer_mgr = insts[0].get_peer_manager().clone();
+            async move {
+                peer_mgr.list_routes().await.iter().any(|route| {
+                    route.peer_id == relay_peer_id
+                        && route
+                            .feature_flag
+                            .as_ref()
+                            .map(|flag| flag.avoid_relay_data)
+                            .unwrap_or(false)
+                })
+            }
+        },
+        Duration::from_secs(5),
+    )
+    .await;
+
+    check_route_ex(
+        insts[0].get_peer_manager().list_routes().await,
+        dst_peer_id,
+        |route| {
+            assert_eq!(route.next_hop_peer_id, relay_peer_id);
+            true
+        },
+    );
+    assert!(
+        !ping_test("net_a", "10.144.144.3", None).await,
+        "traffic from inst1 to inst3 should be blocked while inst2 relay data is disabled"
+    );
+
+    insts[1]
+        .get_config_patcher()
+        .apply_patch(InstanceConfigPatch {
+            disable_relay_data: Some(false),
+            ..Default::default()
+        })
+        .await
+        .unwrap();
+
+    assert!(!insts[1].get_global_ctx().get_flags().disable_relay_data);
+    assert!(
+        !insts[1]
+            .get_global_ctx()
+            .config
+            .get_flags()
+            .disable_relay_data
+    );
+    assert!(
+        !insts[1]
+            .get_global_ctx()
+            .get_feature_flags()
+            .avoid_relay_data
+    );
+
+    wait_for_condition(
+        || {
+            let peer_mgr = insts[0].get_peer_manager().clone();
+            async move {
+                peer_mgr.list_routes().await.iter().any(|route| {
+                    route.peer_id == relay_peer_id
+                        && route
+                            .feature_flag
+                            .as_ref()
+                            .map(|flag| !flag.avoid_relay_data)
+                            .unwrap_or(false)
+                })
+            }
+        },
+        Duration::from_secs(5),
+    )
+    .await;
+
+    wait_for_condition(
+        || async { ping_test("net_a", "10.144.144.3", None).await },
+        Duration::from_secs(5),
+    )
+    .await;
+
+    drop_insts(insts).await;
+}
+
 /// Generate SecureModeConfig with specified x25519 private key
 pub fn generate_secure_mode_config_with_key(
     private_key: &x25519_dalek::StaticSecret,

easytier/src/tunnel/packet_def.rs

@@ -730,6 +730,17 @@ impl ZCPacket {
         }
     }
 
+    pub fn foreign_network_inner_packet_type(&self) -> Option<u8> {
+        if self.peer_manager_header()?.packet_type != PacketType::ForeignNetworkPacket as u8 {
+            return None;
+        }
+
+        let payload = self.payload();
+        let hdr = ForeignNetworkPacketHeader::ref_from_prefix(payload)?;
+        let inner_packet = payload.get(hdr.get_header_len()..)?;
+        PeerManagerHeader::ref_from_prefix(inner_packet).map(|hdr| hdr.packet_type)
+    }
+
     pub fn foreign_network_packet(mut self) -> Self {
         let hdr = self.foreign_network_hdr().unwrap();
         let foreign_hdr_len = hdr.get_header_len();