Fix: setuid/setgid daemons should not get sensitive env. var./args

[lttng-tools.git] / src / common / compat / getenv.h

diff --git a/src/common/compat/getenv.h b/src/common/compat/getenv.h
new file mode 100644 (file)
index 0000000..23a6dfe
--- /dev/null
+++ b/src/common/compat/getenv.h
@@ -0,0 +1,43 @@
+#ifndef _COMPAT_GETENV_H
+#define _COMPAT_GETENV_H
+
+/*
+ * Copyright (C) 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <common/error.h>
+
+static inline
+int lttng_is_setuid_setgid(void)
+{
+       return geteuid() != getuid() || getegid() != getgid();
+}
+
+static inline
+char *lttng_secure_getenv(const char *name)
+{
+       if (lttng_is_setuid_setgid()) {
+               WARN("Getting environment variable '%s' from setuid/setgid binary refused for security reasons.",
+                       name);
+               return NULL;
+       }
+       return getenv(name);
+}
+
+#endif /* _COMPAT_GETENV_H */