lib: Make close_low_fd() independently linkable

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

6 files changed, 101 insertions, 51 deletions

diff --git a/lib/util/become_daemon.c b/lib/util/become_daemon.c
index d940cd7d33..17e0bafe16 100644
--- a/lib/util/become_daemon.c
+++ b/lib/util/become_daemon.c
@@ -27,54 +27,12 @@
 #if HAVE_SYSTEMD
 #include <systemd/sd-daemon.h>
 #endif
+#include "lib/util/close_low_fd.h"
 
 /*******************************************************************
  Close the low 3 fd's and open dev/null in their place.
 ********************************************************************/
 
-_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;
-}
-
 _PUBLIC_ void close_low_fds(bool stdin_too, bool stdout_too, bool stderr_too)
 {
 
diff --git a/lib/util/close_low_fd.c b/lib/util/close_low_fd.c
new file mode 100644
index 0000000000..b11d25f657
--- /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;
+}
diff --git a/lib/util/close_low_fd.h b/lib/util/close_low_fd.h
new file mode 100644
index 0000000000..954d1d2668
--- /dev/null
+++ b/lib/util/close_low_fd.h
@@ -0,0 +1,28 @@
+/*
+ * 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/>.
+ */
+
+#ifndef _CLOSE_LOW_FD_H
+#define _CLOSE_LOW_FD_H
+
+/*
+ * Redirect "fd" to /dev/null
+ */
+int close_low_fd(int fd);
+
+#endif
diff --git a/lib/util/debug.c b/lib/util/debug.c
index f83b14cf02..2779dd3df8 100644
--- a/lib/util/debug.c
+++ b/lib/util/debug.c
@@ -23,6 +23,7 @@
 #include "system/filesys.h"
 #include "system/syslog.h"
 #include "lib/util/time_basic.h"
+#include "lib/util/close_low_fd.h"
 
 /* define what facility to use for syslog */
 #ifndef SYSLOG_FACILITY
diff --git a/lib/util/samba_util.h b/lib/util/samba_util.h
index b31ee1f8f0..233b5fd8cb 100644
--- a/lib/util/samba_util.h
+++ b/lib/util/samba_util.h
@@ -836,13 +836,6 @@ _PUBLIC_ void *idr_find(struct idr_context *idp, int id);
 */
 _PUBLIC_ int idr_remove(struct idr_context *idp, int id);
 
-/* The following definitions come from lib/util/become_daemon.c  */
-
-/**
- Close a fd and open dev/null in its place
-**/
-_PUBLIC_ int close_low_fd(int fd);
-
 /**
  Close the low 3 fd's and open dev/null in their place
 **/
diff --git a/lib/util/wscript_build b/lib/util/wscript_build
index 8be2c2ec4a..6f625dc061 100755
--- a/lib/util/wscript_build
+++ b/lib/util/wscript_build
@@ -5,6 +5,11 @@ bld.SAMBA_SUBSYSTEM('time-basic',
                     deps='replace',
                     local_include=False)
 
+bld.SAMBA_SUBSYSTEM('close-low-fd',
+                    source='close_low_fd.c',
+                    deps='replace',
+                    local_include=False)
+
 bld.SAMBA_LIBRARY('samba-util',
                   source='''talloc_stack.c smb_threads.c xfile.c data_blob.c
                     util_file.c time.c rbtree.c rfc1738.c select.c getpass.c
@@ -14,7 +19,7 @@ bld.SAMBA_LIBRARY('samba-util',
                     util_str.c util_str_common.c substitute.c ms_fnmatch.c
                     server_id.c dprintf.c parmlist.c bitmap.c pidfile.c
                     tevent_debug.c util_process.c memcache.c''',
-                  deps='DYNCONFIG time-basic',
+                  deps='DYNCONFIG time-basic close-low-fd',
                   public_deps='talloc tevent execinfo pthread LIBCRYPTO charset util_setid systemd-daemon',
                   public_headers='debug.h attr.h byteorder.h data_blob.h memory.h safe_string.h time.h talloc_stack.h xfile.h dlinklist.h samba_util.h string_wrappers.h',
                   header_path= [ ('dlinklist.h samba_util.h', '.'), ('*', 'util') ],