Enhance NAT handling and connection deduplication by introducing node…

.gitmodules

@@ -1,7 +1,7 @@
 [submodule "thirdparty/fc"]
 	path = thirdparty/fc
-	url = https://github.com/VIZ-Blockchain/fc.git
-	branch = update
+	url = https://github.com/m0ssa99/fc.git
+	branch = windows_suport_fc
 [submodule "thirdparty/chainbase"]
 	path = thirdparty/chainbase
 	url = https://github.com/VIZ-Blockchain/chainbase.git

libraries/network/include/graphene/network/dlt_p2p_messages.hpp

@@ -81,6 +81,10 @@ struct dlt_hello_message {
     bool          has_emergency_key = false;
     uint8_t       fork_status = DLT_FORK_STATUS_NORMAL;
     uint8_t       node_status = DLT_NODE_STATUS_SYNC;
+    // Persistent node identity key — used to deduplicate connections from nodes
+    // sharing the same NAT IP (different ports).  Each node generates a random
+    // keypair at startup.  Zero-value means "unknown" (old protocol peer).
+    node_id_t     node_id;
 };
 
 // ── DLT Hello Reply ─────────────────────────────────────────────────
@@ -269,7 +273,7 @@ FC_REFLECT_ENUM(graphene::network::dlt_peer_lifecycle_state,
 FC_REFLECT((graphene::network::dlt_hello_message),
     (protocol_version)(head_block_id)(head_block_num)(lib_block_id)(lib_block_num)
     (dlt_earliest_block)(dlt_latest_block)(emergency_active)(has_emergency_key)
-    (fork_status)(node_status))
+    (fork_status)(node_status)(node_id))
 
 FC_REFLECT((graphene::network::dlt_hello_reply_message),
     (exchange_enabled)(fork_alignment)(initiator_head_seen)(initiator_lib_seen)

libraries/network/include/graphene/network/dlt_p2p_node.hpp

@@ -286,7 +286,7 @@ class dlt_p2p_node {
     bool is_same_subnet(const fc::ip::address& a, const fc::ip::address& b) const;
 
     // ── Per-IP dedup ─────────────────────────────────────────────
-    peer_id find_active_peer_by_ip(const fc::ip::address& addr) const;
+    peer_id find_active_peer_by_node_id(const node_id_t& nid) const;
 
 private:
     dlt_p2p_delegate*               _delegate = nullptr;
@@ -344,6 +344,7 @@ class dlt_p2p_node {
     fc::thread*                     _thread = nullptr;
     bool                            _running = false;
     std::map<peer_id, fc::future<void>> _read_fibers;
+    std::vector<fc::future<void>> _dead_fibers;
     fc::future<void>                _accept_fiber;
     fc::future<void>                _periodic_fiber;
 
@@ -443,6 +444,9 @@ class dlt_p2p_node {
     std::map<uint32_t, fc::time_point>  _blocked_ips;
     static constexpr uint32_t           BLOCKED_IP_DURATION_SEC = 3600; // 1 hour
     void                                block_incoming_ip(uint32_t ip, const std::string& reason);
+    // Last time a peer exchange request was sent — used by periodic_peer_exchange()
+    // to dynamically throttle based on the number of active peers (see impl).
+    fc::time_point                      _last_peer_exchange_time;
     bool                                is_ip_blocked(uint32_t ip);
 
     // ── Diagnostics ───────────────────────────────────────────────

plugins/validator/validator.cpp

@@ -1685,7 +1685,12 @@ namespace graphene {
                     {
                         int64_t ntp_us = 0;
                         try { ntp_us = graphene::time::ntp_error().count(); } catch (...) {}
-                        if (ntp_us > 250000) { // local clock >250ms behind NTP
+                        #if defined(_WIN32)
+                            constexpr int64_t NTP_WARN_THRESHOLD_US = 2000000; // 2s pe Windows
+                        #else
+                            constexpr int64_t NTP_WARN_THRESHOLD_US = 250000;  // 250ms pe Linux/macOS
+                        #endif
+                            if (ntp_us > NTP_WARN_THRESHOLD_US) { // local clock >250ms behind NTP
                             static fc::time_point _last_ntp_drift_log;
                             auto _now_nd = fc::time_point::now();
                             if ((_now_nd - _last_ntp_drift_log).count() > 10000000) {