Make sure XDP program has attached at least once.

src/loader/prog.c

@@ -187,6 +187,7 @@ int main(int argc, char *argv[])
     }
 
     int if_idx[MAX_INTERFACES] = {0};
+    int attach_success = 0;
 
     // Attach XDP program to interface(s).
     for (int i = 0; i < cfg.interfaces_cnt; i++)
@@ -228,6 +229,18 @@ int main(int argc, char *argv[])
         {
             log_msg(&cfg, 1, 0, "Attached XDP program to interface '%s' using mode '%s'...", interface, mode_used);
         }
+
+        if (!attach_success)
+        {
+            attach_success = 1;
+        }
+    }
+
+    if (!attach_success)
+    {
+        log_msg(&cfg, 0, 1, "[ERROR] Failed to attach XDP program to any configured interfaces.");
+
+        return EXIT_FAILURE;
     }
 
     log_msg(&cfg, 2, 0, "Retrieving BPF map FDs...");

src/loader/utils/logging.c

@@ -11,7 +11,7 @@
  * 
  * @return void
  */
-static void log_msgRaw(int req_lvl, int cur_lvl, int error, const char* log_path, const char* msg, va_list args)
+static void log_msg_raw(int req_lvl, int cur_lvl, int error, const char* log_path, const char* msg, va_list args)
 {
     if (cur_lvl < req_lvl)
     {
@@ -86,7 +86,7 @@ static void log_msgRaw(int req_lvl, int cur_lvl, int error, const char* log_path
 }
 
 /**
- * Prints a log message using log_msgRaw().
+ * Prints a log message using log_msg_raw().
  * 
  * @param cfg A pointer to the config structure.
  * @param req_lvl The required level for this message.
@@ -100,7 +100,7 @@ void log_msg(config__t* cfg, int req_lvl, int error, const char* msg, ...)
     va_list args;
     va_start(args, msg);
 
-    log_msgRaw(req_lvl, cfg->verbose, error, (const char*)cfg->log_file, msg, args);
+    log_msg_raw(req_lvl, cfg->verbose, error, (const char*)cfg->log_file, msg, args);
 
     va_end(args);
 }