1 files changed, 65 insertions, 0 deletions
diff --git a/lib/util/close_low_fd.c b/lib/util/close_low_fd.c
new file mode 100644
index 0000000..5e74918
--- /dev/null
+++ b/lib/util/close_low_fd.c
@@ -0,0 +1,65 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * Samba utility functions
+ * Copyright (C) Volker Lendecke 2014
+ *
+ * This program 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.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "replace.h"
+#include "system/filesys.h"
+#include "close_low_fd.h"
+
+_PUBLIC_ int close_low_fd(int fd)
+{
+#ifndef VALGRIND
+	int ret, dev_null;
+
+	dev_null = open("/dev/null", O_RDWR, 0);
+
+	if ((dev_null == -1) && (errno == ENFILE)) {
+		/*
+		 * Try to free up an fd
+		 */
+		ret = close(fd);
+		if (ret != 0) {
+			return errno;
+		}
+	}
+
+	dev_null = open("/dev/null", O_RDWR, 0);
+	if (dev_null == -1) {
+		dev_null = open("/dev/null", O_WRONLY, 0);
+	}
+	if (dev_null == -1) {
+		return errno;
+	}
+
+	if (dev_null == fd) {
+		/*
+		 * This can happen in the ENFILE case above
+		 */
+		return 0;
+	}
+
+	ret = dup2(dev_null, fd);
+	if (ret == -1) {
+		int err = errno;
+		close(dev_null);
+		return err;
+	}
+	close(dev_null);
+#endif
+	return 0;
+}