access-control: Introduce new translator

The access control translator is required for performing permission
checks on files and directories in line with posix conformance.
This is required to be kept separate from storage/posix so that
ACL support can also be later integrated into this translator.

Signed-off-by: Shehjar Tikoo <shehjart@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 400 (Support auxiliary gids in GlusterFS)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=400

configure.ac

@@ -105,6 +105,8 @@ AC_CONFIG_FILES([Makefile
                 extras/volgen/glusterfs-volgen
 		contrib/Makefile
 		contrib/fuse-util/Makefile
+                xlators/features/access-control/Makefile
+                xlators/features/access-control/src/Makefile
 		glusterfs.spec])
 
 AC_CANONICAL_HOST

xlators/features/Makefile.am

@@ -1,3 +1,3 @@
-SUBDIRS = locks trash quota read-only #path-converter # filter 
+SUBDIRS = locks trash quota read-only access-control #path-converter # filter
 
 CLEANFILES = 

xlators/features/access-control/Makefile.am

@@ -0,0 +1,3 @@
+SUBDIRS = src
+
+CLEANFILES =

xlators/features/access-control/src/Makefile.am

@@ -0,0 +1,13 @@
+xlator_LTLIBRARIES = access-control.la
+xlatordir = $(libdir)/glusterfs/$(PACKAGE_VERSION)/xlator/features
+access_control_la_LDFLAGS = -module -avoidversion
+access_control_la_SOURCES = access-control.c
+access_control_la_LIBADD = $(top_builddir)/libglusterfs/src/libglusterfs.la
+
+noinst_HEADERS = access-control.h
+
+AM_CFLAGS = -fPIC -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -Wall -D$(GF_HOST_OS)\
+	-I$(top_srcdir)/libglusterfs/src -shared -nostartfiles $(GF_CFLAGS)\
+	-L$(xlatordir)/
+
+CLEANFILES =

xlators/features/access-control/src/access-control.h

@@ -0,0 +1,55 @@
+/*
+  Copyright (c) 2010 Gluster, Inc. <http://www.gluster.com>
+  This file is part of GlusterFS.
+
+  GlusterFS 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.
+
+  GlusterFS 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 __ACCESS_CONTROL_H_
+#define __ACCESS_CONTROL_H_
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#define ACTRL                   "access-control"
+#define ACCTEST_READ            0x1
+#define ACCTEST_WRITE           0x2
+#define ACCTEST_EXEC            0x4
+#define ACCTEST_DONTCARE        0x8
+
+/* Note if the caller is only interested in ownership test i.e. one of the below
++ * in combination with GF_ACCTEST_DONTCARE, then only one type of user's owner
++ * ship can be tested with one call to gf_test_access, i.e. we can only
++ * check of either owner and group, if both need to be tested for a specific
++ * (uid, gid) pair then two calls will be needed.
++ */
+#define ACCTEST_OWNER           0x1
+#define ACCTEST_GROUP           0x2
+#define ACCTEST_OTHER           0x4
+
+/* Signifies any user, as long as we get access. */
+#define ACCTEST_ANY             (ACCTEST_OWNER | ACCTEST_GROUP | ACCTEST_OTHER)
+
+#define ac_test_owner(acc)      ((acc) & ACCTEST_OWNER)
+#define ac_test_group(acc)      ((acc) & ACCTEST_GROUP)
+#define ac_test_other(acc)      ((acc) & ACCTEST_OTHER)
+#define ac_test_dontcare(acc)   ((acc) & ACCTEST_DONTCARE)
+#define ac_test_read(acc)       ((acc) & ACCTEST_READ)
+#define ac_test_write(acc)      ((acc) & ACCTEST_WRITE)
+#define ac_test_exec(acc)       ((acc) & ACCTEST_EXEC)
+#endif