diff options
Diffstat (limited to '')
-rw-r--r-- | lib/util/close_low_fd.c | 65 |
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; +} |