Fix TCP announce flood: adaptive filter, TCP backpressure, aligned table caps

- Enhanced announce filter: adaptive rate (3/sec boot, 5/sec normal),
  skip re-validation of known paths unless hop count improved or 5min
  revalidation window expired
- Skip TCP reads when RNS loop exceeds 200ms to prevent UI starvation
- Lower MAX_ANNOUNCES_PER_SEC from 8 to 5
- Align build flag table caps (256/128) with runtime values

platformio.ini

@@ -24,10 +24,10 @@ build_flags =
     -DRNS_CONTAINER_ALLOCATOR=RNS_PSRAM_POOL_ALLOCATOR
     -DRNS_PSRAM_POOL_BUFFER_SIZE=2048000
     ; Raise microReticulum table caps — all containers go to 2MB PSRAM pool
-    -DRNS_KNOWN_DESTINATIONS_MAX=500
-    -DRNS_HASHLIST_MAX=500
-    -DRNS_PATH_TABLE_MAX=500
-    -DRNS_ANNOUNCE_TABLE_MAX=500
+    -DRNS_KNOWN_DESTINATIONS_MAX=256
+    -DRNS_HASHLIST_MAX=256
+    -DRNS_PATH_TABLE_MAX=256
+    -DRNS_ANNOUNCE_TABLE_MAX=128
     -DRNS_RECEIPTS_MAX=64
     -DRNS_QUEUED_ANNOUNCES_MAX=64
     -DRNS_RANDOM_BLOBS_MAX=128

src/config/Config.h

@@ -47,7 +47,7 @@
 #define TCP_CONNECT_TIMEOUT_MS      5000
 
 // --- Announce Flood Defense ---
-#define RATDECK_MAX_ANNOUNCES_PER_SEC 8     // Transport-level rate limit (before Ed25519 verify)
+#define RATDECK_MAX_ANNOUNCES_PER_SEC 5     // Transport-level rate limit (before Ed25519 verify)
 
 // --- Limits ---
 #define RATDECK_MAX_NODES             200   // PSRAM allows more

src/main.cpp

@@ -895,12 +895,15 @@ void loop() {
     }
 
     // 4. Reticulum loop (radio RX via LoRaInterface) — throttle to ~100Hz
+    unsigned long rnsDuration = 0;
     {
         static unsigned long lastRNS = 0;
         unsigned long now = millis();
         if (now - lastRNS >= 10) {
             lastRNS = now;
+            unsigned long rnsStart = millis();
             rns.loop();
+            rnsDuration = millis() - rnsStart;
         }
     }
 
@@ -973,14 +976,17 @@ void loop() {
         }
     }
 
-    // 8. WiFi + TCP loops (with global budget)
-    if (wifiImpl) wifiImpl->loop();
+    // 8. WiFi + TCP loops (with global budget) — skip if RNS was overloaded
     {
-        unsigned long tcpBudgetStart = millis();
-        for (auto* tcp : tcpClients) {
-            if (millis() - tcpBudgetStart >= TCP_GLOBAL_BUDGET_MS) break;
-            tcp->loop();
-            yield();
+        bool skipTcp = (rnsDuration > 200);
+        if (!skipTcp && wifiImpl) wifiImpl->loop();
+        if (!skipTcp) {
+            unsigned long tcpBudgetStart = millis();
+            for (auto* tcp : tcpClients) {
+                if (millis() - tcpBudgetStart >= TCP_GLOBAL_BUDGET_MS) break;
+                tcp->loop();
+                yield();
+            }
         }
     }
 

src/reticulum/ReticulumManager.cpp

@@ -3,6 +3,8 @@
 #include "config/Config.h"
 #include <LittleFS.h>
 #include <Preferences.h>
+#include <map>
+#include <string>
 
 bool LittleFSFileSystem::init() { return true; }
 bool LittleFSFileSystem::file_exists(const char* p) { return LittleFS.exists(p); }
@@ -98,15 +100,38 @@ bool ReticulumManager::begin(SX1262* radio, FlashStore* flash) {
     _reticulum.start();
     Serial.println("[RNS] Reticulum started (Endpoint)");
 
-    // Layer 1: Transport-level announce rate limiter — filters BEFORE Ed25519 verify
+    // Layer 1: Transport-level announce filter — runs BEFORE Ed25519 verify
     RNS::Transport::set_filter_packet_callback([](const RNS::Packet& packet) -> bool {
-        if (packet.packet_type() == RNS::Type::Packet::ANNOUNCE) {
-            static unsigned long windowStart = 0;
-            static unsigned int count = 0;
-            unsigned long now = millis();
-            if (now - windowStart >= 1000) { windowStart = now; count = 0; }
-            if (++count > RATDECK_MAX_ANNOUNCES_PER_SEC) return false;
+        if (packet.packet_type() != RNS::Type::Packet::ANNOUNCE) return true;
+
+        unsigned long now = millis();
+
+        // Rate limit window (per-second)
+        static unsigned long windowStart = 0;
+        static unsigned int count = 0;
+        if (now - windowStart >= 1000) { windowStart = now; count = 0; }
+
+        // Adaptive rate: tighter during first 60s boot flood, then normal
+        unsigned int maxRate = (now < 60000) ? 3 : RATDECK_MAX_ANNOUNCES_PER_SEC;
+        if (++count > maxRate) return false;
+
+        // Skip re-validation of known paths (saves ~100ms Ed25519 per announce)
+        // Allow through if hop count improved, or once per 5 min for name/ratchet updates
+        if (RNS::Transport::has_path(packet.destination_hash())) {
+            static std::map<std::string, unsigned long> lastRevalidate;
+            std::string destHex = packet.destination_hash().toHex();
+
+            uint8_t existingHops = RNS::Transport::hops_to(packet.destination_hash());
+            if (packet.hops() < existingHops) return true;  // Better path, allow
+
+            auto it = lastRevalidate.find(destHex);
+            if (it != lastRevalidate.end() && (now - it->second) < 300000) return false;
+            lastRevalidate[destHex] = now;
+
+            // Cap map size to prevent unbounded growth
+            if (lastRevalidate.size() > 300) lastRevalidate.clear();
         }
+
         return true;
     });