v1.2.3 - Handle rate limiting properly on kind 99999 request

src/main.c

@@ -844,58 +844,117 @@ cJSON* retrieve_event(const char* event_id) {
 /////////////////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////////////////
 
+/**
+ * Check if filters contain only kind 99999 (NDK ping)
+ * Returns 1 if all filters only request kind 99999, 0 otherwise
+ */
+static int is_only_kind_99999_request(cJSON* filters) {
+    if (!filters || !cJSON_IsArray(filters)) {
+        return 0;
+    }
+    
+    int filter_count = cJSON_GetArraySize(filters);
+    if (filter_count == 0) {
+        return 0;
+    }
+    
+    for (int i = 0; i < filter_count; i++) {
+        cJSON* filter = cJSON_GetArrayItem(filters, i);
+        if (!filter || !cJSON_IsObject(filter)) {
+            return 0;
+        }
+        
+        cJSON* kinds = cJSON_GetObjectItem(filter, "kinds");
+        if (!kinds || !cJSON_IsArray(kinds)) {
+            // Filter has no kinds or kinds is not an array - not a pure 99999 request
+            return 0;
+        }
+        
+        int kinds_count = cJSON_GetArraySize(kinds);
+        if (kinds_count == 0) {
+            return 0;
+        }
+        
+        for (int j = 0; j < kinds_count; j++) {
+            cJSON* kind_item = cJSON_GetArrayItem(kinds, j);
+            if (!cJSON_IsNumber(kind_item)) {
+                return 0;
+            }
+            int kind_val = (int)cJSON_GetNumberValue(kind_item);
+            if (kind_val != 99999) {
+                return 0;
+            }
+        }
+    }
+    
+    return 1; // All filters only contain kind 99999
+}
+
 int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, struct per_session_data *pss) {
     if (!cJSON_IsArray(filters)) {
         DEBUG_ERROR("REQ filters is not an array");
         return 0;
     }
 
+    // Check if this is a kind 99999 (NDK ping) request - these should never count toward rate limiting
+    int is_ndk_ping = is_only_kind_99999_request(filters);
+
     // EARLY SUBSCRIPTION LIMIT CHECK - Check limits BEFORE any processing
     if (pss) {
         time_t current_time = time(NULL);
 
         // Check if client is currently rate limited due to excessive failed attempts
         if (pss->rate_limit_until > current_time) {
-            char rate_limit_msg[256];
-            int remaining_seconds = (int)(pss->rate_limit_until - current_time);
-            snprintf(rate_limit_msg, sizeof(rate_limit_msg),
-                    "Rate limited due to excessive failed subscription attempts. Try again in %d seconds.", remaining_seconds);
+            // NDK ping (kind 99999) should not be blocked by rate limiting at all
+            if (is_ndk_ping) {
+                // Allow the request through - it will be handled normally and get a proper response
+                // The subscription will be created but no events will match (which is correct)
+                DEBUG_TRACE("Allowing kind 99999 NDK ping through despite rate limit");
+                // Fall through to normal processing (skip rate limit block)
+            } else {
+                char rate_limit_msg[256];
+                int remaining_seconds = (int)(pss->rate_limit_until - current_time);
+                snprintf(rate_limit_msg, sizeof(rate_limit_msg),
+                        "Rate limited due to excessive failed subscription attempts. Try again in %d seconds.", remaining_seconds);
 
-            // Send CLOSED notice for rate limiting
-            cJSON* closed_msg = cJSON_CreateArray();
-            cJSON_AddItemToArray(closed_msg, cJSON_CreateString("CLOSED"));
-            cJSON_AddItemToArray(closed_msg, cJSON_CreateString(sub_id));
-            cJSON_AddItemToArray(closed_msg, cJSON_CreateString("error: rate limited"));
-            cJSON_AddItemToArray(closed_msg, cJSON_CreateString(rate_limit_msg));
+                // Send CLOSED notice for rate limiting
+                cJSON* closed_msg = cJSON_CreateArray();
+                cJSON_AddItemToArray(closed_msg, cJSON_CreateString("CLOSED"));
+                cJSON_AddItemToArray(closed_msg, cJSON_CreateString(sub_id));
+                cJSON_AddItemToArray(closed_msg, cJSON_CreateString("error: rate limited"));
+                cJSON_AddItemToArray(closed_msg, cJSON_CreateString(rate_limit_msg));
 
-            char* closed_str = cJSON_Print(closed_msg);
-            if (closed_str) {
-                size_t closed_len = strlen(closed_str);
-                unsigned char* buf = malloc(LWS_PRE + closed_len);
-                if (buf) {
-                    memcpy(buf + LWS_PRE, closed_str, closed_len);
-                    lws_write(wsi, buf + LWS_PRE, closed_len, LWS_WRITE_TEXT);
-                    free(buf);
+                char* closed_str = cJSON_Print(closed_msg);
+                if (closed_str) {
+                    size_t closed_len = strlen(closed_str);
+                    unsigned char* buf = malloc(LWS_PRE + closed_len);
+                    if (buf) {
+                        memcpy(buf + LWS_PRE, closed_str, closed_len);
+                        lws_write(wsi, buf + LWS_PRE, closed_len, LWS_WRITE_TEXT);
+                        free(buf);
+                    }
+                    free(closed_str);
                 }
-                free(closed_str);
+                cJSON_Delete(closed_msg);
+
+                // Do NOT increment rate limiting counters here - the client is already rate limited.
+                // Incrementing counters while already blocked would extend the punishment indefinitely,
+                // especially for benign requests like NDK's kind 99999 pings.
+
+                return 0;
             }
-            cJSON_Delete(closed_msg);
-
-            // Update rate limiting counters
-            pss->failed_subscription_attempts++;
-            pss->last_failed_attempt = current_time;
-
-            return 0;
         }
 
         // Check session subscription limits
         if (pss->subscription_count >= g_subscription_manager.max_subscriptions_per_client) {
             DEBUG_ERROR("Maximum subscriptions per client exceeded");
 
-            // Update rate limiting counters for failed attempt
-            pss->failed_subscription_attempts++;
-            pss->last_failed_attempt = current_time;
-            pss->consecutive_failures++;
+            // Update rate limiting counters for failed attempt (but not for NDK ping)
+            if (!is_ndk_ping) {
+                pss->failed_subscription_attempts++;
+                pss->last_failed_attempt = current_time;
+                pss->consecutive_failures++;
+            }
 
             // Implement progressive backoff: 1s, 5s, 30s, 300s (5min) based on consecutive failures
             int backoff_seconds = 1;
@@ -1010,7 +1069,8 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
         cJSON_Delete(closed_msg);
 
         // Update rate limiting counters for failed attempt (global limit reached)
-        if (pss) {
+        // Do not count NDK ping (kind 99999) toward rate limiting
+        if (pss && !is_ndk_ping) {
             time_t current_time = time(NULL);
             pss->failed_subscription_attempts++;
             pss->last_failed_attempt = current_time;

src/main.h

@@ -13,8 +13,8 @@
 // Using CRELAY_ prefix to avoid conflicts with nostr_core_lib VERSION macros
 #define CRELAY_VERSION_MAJOR 1
 #define CRELAY_VERSION_MINOR 2
-#define CRELAY_VERSION_PATCH 2
-#define CRELAY_VERSION "v1.2.2"
+#define CRELAY_VERSION_PATCH 3
+#define CRELAY_VERSION "v1.2.3"
 
 // Relay metadata (authoritative source for NIP-11 information)
 #define RELAY_NAME "C-Relay"