v1.1.7 - Add per-connection database query tracking for abuse detection

Implemented comprehensive database query tracking to identify clients causing
high CPU usage through excessive database queries. The relay now tracks and
displays query statistics per WebSocket connection in the admin UI.

Features Added:
- Track db_queries_executed and db_rows_returned per connection
- Calculate query rate (queries/minute) and row rate (rows/minute)
- Display stats in admin UI grouped by IP address and WebSocket
- Show: IP, Subscriptions, Queries, Rows, Query Rate, Duration

Implementation:
- Added tracking fields to per_session_data structure
- Increment counters in handle_req_message() and handle_count_message()
- Extract stats from pss in query_subscription_details()
- Updated admin UI to display IP address and query metrics

Use Case:
Admins can now identify abusive clients by monitoring:
- High query rates (>50 queries/min indicates polling abuse)
- High row counts (>10K rows/min indicates broad filter abuse)
- Query patterns (high queries + low rows = targeted, high both = crawler)

This enables informed decisions about which IPs to blacklist based on
actual resource consumption rather than just connection count.

api/index.js

@@ -4324,6 +4324,12 @@ function populateSubscriptionDetailsTable(subscriptionsData) {
         const oldestDuration = Math.max(...subscriptions.map(s => now - s.created_at));
         const oldestDurationStr = formatDuration(oldestDuration);
 
+        // Calculate total query stats for this connection
+        const totalQueries = subscriptions.reduce((sum, s) => sum + (s.db_queries_executed || 0), 0);
+        const totalRows = subscriptions.reduce((sum, s) => sum + (s.db_rows_returned || 0), 0);
+        const avgQueryRate = subscriptions.length > 0 ? (subscriptions[0].query_rate_per_min || 0) : 0;
+        const clientIp = subscriptions.length > 0 ? (subscriptions[0].client_ip || 'unknown') : 'unknown';
+
         // Create header row (summary)
         const headerRow = document.createElement('tr');
         headerRow.className = 'subscription-group-header';
@@ -4334,9 +4340,14 @@ function populateSubscriptionDetailsTable(subscriptionsData) {
         headerRow.innerHTML = `
             <td colspan="4" style="padding: 8px;">
                 <span class="expand-icon" style="display: inline-block; width: 20px; transition: transform 0.2s;">▶</span>
-                <strong style="font-family: 'Courier New', monospace; font-size: 12px;">Websocket: ${wsiPointer}</strong>
-                <span style="color: #666; margin-left: 15px;">
-                    Subscriptions: ${subCount} | Oldest: ${oldestDurationStr}
+                <strong style="font-family: 'Courier New', monospace; font-size: 12px;">IP: ${clientIp}</strong>
+                <span style="color: #666; margin-left: 10px; font-size: 11px;">
+                    WS: ${wsiPointer} |
+                    Subs: ${subCount} |
+                    Queries: ${totalQueries.toLocaleString()} |
+                    Rows: ${totalRows.toLocaleString()} |
+                    Rate: ${avgQueryRate.toFixed(1)} q/min |
+                    Duration: ${oldestDurationStr}
                 </span>
             </td>
         `;

relay.pid

@@ -1 +1 @@
-1979749
+1987115

src/api.c

@@ -287,6 +287,46 @@ cJSON* query_subscription_details(void) {
         cJSON_AddBoolToObject(sub_obj, "active", 1);  // All from this view are active
         cJSON_AddStringToObject(sub_obj, "wsi_pointer", wsi_pointer ? wsi_pointer : "N/A");
 
+        // Extract query stats from per_session_data if wsi is still valid
+        int db_queries = 0;
+        int db_rows = 0;
+        double query_rate = 0.0;
+        double row_rate = 0.0;
+        double avg_rows_per_query = 0.0;
+
+        if (wsi_pointer && strlen(wsi_pointer) > 2) {  // Check for valid pointer string
+            // Parse wsi pointer from hex string
+            struct lws* wsi = NULL;
+            if (sscanf(wsi_pointer, "%p", (void**)&wsi) == 1 && wsi != NULL) {
+                // Get per_session_data from wsi
+                struct per_session_data* pss = (struct per_session_data*)lws_wsi_user(wsi);
+                if (pss) {
+                    db_queries = pss->db_queries_executed;
+                    db_rows = pss->db_rows_returned;
+                    
+                    // Calculate rates (per minute)
+                    time_t connection_duration = current_time - pss->query_tracking_start;
+                    if (connection_duration > 0) {
+                        double minutes = connection_duration / 60.0;
+                        query_rate = db_queries / minutes;
+                        row_rate = db_rows / minutes;
+                    }
+                    
+                    // Calculate average rows per query
+                    if (db_queries > 0) {
+                        avg_rows_per_query = (double)db_rows / (double)db_queries;
+                    }
+                }
+            }
+        }
+
+        // Add query stats to subscription object
+        cJSON_AddNumberToObject(sub_obj, "db_queries_executed", db_queries);
+        cJSON_AddNumberToObject(sub_obj, "db_rows_returned", db_rows);
+        cJSON_AddNumberToObject(sub_obj, "query_rate_per_min", query_rate);
+        cJSON_AddNumberToObject(sub_obj, "row_rate_per_min", row_rate);
+        cJSON_AddNumberToObject(sub_obj, "avg_rows_per_query", avg_rows_per_query);
+
         // Parse and add filter JSON if available
         if (filter_json) {
             cJSON* filters = cJSON_Parse(filter_json);

src/main.c

@@ -1202,6 +1202,11 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
             continue;
         }
 
+        // Track query execution for abuse detection
+        if (pss) {
+            pss->db_queries_executed++;
+        }
+
         // Bind parameters
         for (int i = 0; i < bind_param_count; i++) {
             sqlite3_bind_text(stmt, i + 1, bind_params[i], -1, SQLITE_TRANSIENT);
@@ -1211,6 +1216,11 @@ int handle_req_message(const char* sub_id, cJSON* filters, struct lws *wsi, stru
         while (sqlite3_step(stmt) == SQLITE_ROW) {
             row_count++;
             
+            // Track rows returned for abuse detection
+            if (pss) {
+                pss->db_rows_returned++;
+            }
+            
             // Build event JSON
             cJSON* event = cJSON_CreateObject();
             cJSON_AddStringToObject(event, "id", (char*)sqlite3_column_text(stmt, 0));

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 1
-#define CRELAY_VERSION_PATCH 6
-#define CRELAY_VERSION "v1.1.6"
+#define CRELAY_VERSION_PATCH 7
+#define CRELAY_VERSION "v1.1.7"
 
 // Relay metadata (authoritative source for NIP-11 information)
 #define RELAY_NAME "C-Relay"

src/websockets.c

@@ -391,6 +391,11 @@ static int nostr_relay_callback(struct lws *wsi, enum lws_callback_reasons reaso
             memset(pss, 0, sizeof(*pss));
             pthread_mutex_init(&pss->session_lock, NULL);
 
+            // Initialize database query tracking
+            pss->db_queries_executed = 0;
+            pss->db_rows_returned = 0;
+            pss->query_tracking_start = time(NULL);
+
             // Get real client IP address
             char client_ip[CLIENT_IP_MAX_LENGTH];
             memset(client_ip, 0, sizeof(client_ip));
@@ -2429,7 +2434,7 @@ int process_dm_stats_command(cJSON* dm_event, char* error_message, size_t error_
 
 // Handle NIP-45 COUNT message
 int handle_count_message(const char* sub_id, cJSON* filters, struct lws *wsi, struct per_session_data *pss) {
-    (void)pss; // Suppress unused parameter warning
+    // pss is now used for query tracking, so remove unused warning suppression
 
     if (!cJSON_IsArray(filters)) {
         DEBUG_ERROR("COUNT filters is not an array");

src/websockets.h

@@ -79,6 +79,11 @@ struct per_session_data {
     size_t reassembly_size;                   // Current size of accumulated data
     size_t reassembly_capacity;               // Allocated capacity of reassembly buffer
     int reassembly_active;                    // Flag: 1 if currently reassembling a message
+
+    // Database query tracking for abuse detection and monitoring
+    int db_queries_executed;                  // Total SELECT queries executed by this connection
+    int db_rows_returned;                     // Total rows returned across all queries
+    time_t query_tracking_start;              // When connection was established (for rate calculation)
 };
 
 // NIP-11 HTTP session data structure for managing buffer lifetime