Type Route Cutovers + Reduce IP Tracker cleanup pressure

src/proxy/direct_relay.rs

@@ -18,8 +18,7 @@ use crate::error::{ProxyError, Result};
 use crate::protocol::constants::*;
 use crate::proxy::handshake::{HandshakeSuccess, encrypt_tg_nonce_with_ciphers, generate_tg_nonce};
 use crate::proxy::route_mode::{
-    ROUTE_SWITCH_ERROR_MSG, RelayRouteMode, RouteCutoverState, affected_cutover_state,
-    cutover_stagger_delay,
+    RelayRouteMode, RouteCutoverState, affected_cutover_state, cutover_stagger_delay,
 };
 use crate::proxy::shared_state::{
     ConntrackCloseEvent, ConntrackClosePublishResult, ConntrackCloseReason, ProxySharedState,
@@ -360,7 +359,7 @@ where
                 "Cutover affected direct session, closing client connection"
             );
             tokio::time::sleep(delay).await;
-            break Err(ProxyError::Proxy(ROUTE_SWITCH_ERROR_MSG.to_string()));
+            break Err(ProxyError::RouteSwitched);
         }
         tokio::select! {
             result = &mut relay_result => {

src/proxy/middle_relay.rs

@@ -23,8 +23,7 @@ use crate::error::{ProxyError, Result};
 use crate::protocol::constants::{secure_padding_len, *};
 use crate::proxy::handshake::HandshakeSuccess;
 use crate::proxy::route_mode::{
-    ROUTE_SWITCH_ERROR_MSG, RelayRouteMode, RouteCutoverState, affected_cutover_state,
-    cutover_stagger_delay,
+    RelayRouteMode, RouteCutoverState, affected_cutover_state, cutover_stagger_delay,
 };
 use crate::proxy::shared_state::{
     ConntrackCloseEvent, ConntrackClosePublishResult, ConntrackCloseReason, ProxySharedState,
@@ -1188,7 +1187,7 @@ where
         tokio::time::sleep(delay).await;
         let _ = me_pool.send_close(conn_id).await;
         me_pool.registry().unregister(conn_id).await;
-        return Err(ProxyError::Proxy(ROUTE_SWITCH_ERROR_MSG.to_string()));
+        return Err(ProxyError::RouteSwitched);
     }
 
     // Per-user ad_tag from access.user_ad_tags; fallback to general.ad_tag (hot-reloadable)
@@ -1690,7 +1689,7 @@ where
                 stats.as_ref(),
             )
             .await;
-            main_result = Err(ProxyError::Proxy(ROUTE_SWITCH_ERROR_MSG.to_string()));
+            main_result = Err(ProxyError::RouteSwitched);
             break;
         }
 

src/proxy/route_mode.rs

@@ -4,8 +4,6 @@ use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
 use tokio::sync::watch;
 
-pub(crate) const ROUTE_SWITCH_ERROR_MSG: &str = "Session terminated";
-
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 #[repr(u8)]
 pub(crate) enum RelayRouteMode {

src/proxy/tests/client_security_tests.rs

@@ -661,7 +661,7 @@ async fn integration_route_cutover_and_quota_overlap_fails_closed_and_releases_s
 
     assert!(
         matches!(relay_result, Err(ProxyError::DataQuotaExceeded { .. }))
-            || matches!(relay_result, Err(ProxyError::Proxy(ref msg)) if msg == crate::proxy::route_mode::ROUTE_SWITCH_ERROR_MSG),
+            || matches!(relay_result, Err(ProxyError::RouteSwitched)),
         "overlap race must fail closed via quota enforcement or generic cutover termination"
     );
 

src/proxy/tests/direct_relay_security_tests.rs

@@ -1491,7 +1491,7 @@ async fn direct_relay_cutover_midflight_releases_route_gauge() {
     assert!(
         matches!(
             relay_result,
-            Err(ProxyError::Proxy(ref msg)) if msg == ROUTE_SWITCH_ERROR_MSG
+            Err(ProxyError::RouteSwitched)
         ),
         "client-visible cutover error must stay generic and avoid route-internal metadata"
     );
@@ -1631,7 +1631,7 @@ async fn direct_relay_cutover_storm_multi_session_keeps_generic_errors_and_relea
         assert!(
             matches!(
                 relay_result,
-                Err(ProxyError::Proxy(ref msg)) if msg == ROUTE_SWITCH_ERROR_MSG
+                Err(ProxyError::RouteSwitched)
             ),
             "storm-cutover termination must remain generic for all direct sessions"
         );
@@ -1937,7 +1937,7 @@ async fn adversarial_direct_relay_cutover_integrity() {
     assert!(
         matches!(
             result,
-            Err(ProxyError::Proxy(ref msg)) if msg == ROUTE_SWITCH_ERROR_MSG
+            Err(ProxyError::RouteSwitched)
         ),
         "Session must terminate with route switch error on cutover"
     );