From 3625a4e5d5c37c55b4cab84fc03c5a1ff181ec3f Mon Sep 17 00:00:00 2001
From: Evgeny <me@jeka.su>
Date: Thu, 23 Apr 2026 23:56:49 +0300
Subject: [PATCH] Restart NAT check when client address changes in INIT_REQUEST

---
 src/etcp_connections.c | 12 ++++++++++++
 src/route_bgp.c        |  1 -
 src/route_bgp.h        |  6 ++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/etcp_connections.c b/src/etcp_connections.c
index 12825a31..4bbe95f4 100644
--- a/src/etcp_connections.c
+++ b/src/etcp_connections.c
@@ -18,6 +18,8 @@
 #include "crc32.h"
 #include "etcp.h"
 #include "route_node.h"
+#include "route_bgp.h"
+#include "route_ping.h"
 #include "../lib/memory_pool.h"
 #include "../lib/u_async.h"
 #include "../lib/debug_config.h"
@@ -1354,6 +1356,12 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
                 DEBUG_ERROR(DEBUG_CATEGORY_CONNECTION, "Failed to reinsert link after addr change");
                 goto ec_fr;
                 }
+                // Cancel pending NAT check and reset status
+                if (link->etcp->instance->bgp) {
+                    route_ping_cancel_for_conn(link->etcp->instance->bgp, link->etcp);
+                }
+                link->nat_check_status = NAT_CHECK_NONE;
+                link->nat_type = NAT_TYPE_UNKNOWN;
             }
 
         // Link exists - reuse it for recovery
@@ -1483,6 +1491,10 @@ void etcp_connections_read_callback_socket(socket_t sock, void* arg) {
     DEBUG_INFO(DEBUG_CATEGORY_CONNECTION, "[%s] Link %p (local_id=%d) initialized and marked as UP (server)", link->etcp->log_name, link, link->local_link_id);
     start_keepalive_timer(link);
     loadbalancer_link_ready(link);
+    // Restart NAT check after link is up (e.g. after address change or reinit)
+    if (link->etcp->instance->bgp) {
+        route_bgp_start_link_nat_check(link->etcp->instance->bgp, link);
+    }
     return;
 
 
diff --git a/src/route_bgp.c b/src/route_bgp.c
index cf583388..bd239e07 100644
--- a/src/route_bgp.c
+++ b/src/route_bgp.c
@@ -113,7 +113,6 @@ static void route_bgp_broadcast_withdraw(struct ROUTE_BGP* bgp, uint64_t node_id
 // Приём пакетов
 // ============================================================================
 
-void route_bgp_start_link_nat_check(struct ROUTE_BGP* bgp, struct ETCP_LINK* link);
 static void route_bgp_handle_nat_info(struct ROUTE_BGP* bgp, struct ETCP_CONN* from_conn, const uint8_t* data, size_t len);
 static void route_bgp_handle_nat_check_req(struct ROUTE_BGP* bgp, struct ETCP_CONN* from_conn, const uint8_t* data, size_t len);
 
diff --git a/src/route_bgp.h b/src/route_bgp.h
index 817ca8c4..7a37a816 100644
--- a/src/route_bgp.h
+++ b/src/route_bgp.h
@@ -78,6 +78,7 @@ struct BGP_NAT_CHECK_REQ {
 } __attribute__((packed));
 
 struct route_ping_pending;
+struct ETCP_LINK;
 
 struct ROUTE_BGP {
     struct UTUN_INSTANCE* instance;
@@ -200,6 +201,11 @@ void route_bgp_set_nat_check_local(struct ROUTE_BGP* bgp, int allow);
  */
 void route_bgp_request_nat_check_all(struct ROUTE_BGP* bgp);
 
+/**
+ * @brief Запускает NAT check для одного линка.
+ */
+void route_bgp_start_link_nat_check(struct ROUTE_BGP* bgp, struct ETCP_LINK* link);
+
 /* Аргумент callback NAT check */
 struct nat_check_arg {
     struct ETCP_LINK* link;