Prepare for implementing extended attribute support.

This patch adds *xattr() stubs in case extended attribute support is
not present and implements the *attrat() family of functions.  Based
on the patch by Pavel Raiskup <[email protected]> for gnulib.

* acinclude.m4 (TAR_HEADERS_ATTR_XATTR_H): New defun.
* configure.ac: Call TAR_HEADERS_ATTR_XATTR_H
* lib/Makefile.am: Add xattr-at.[ch], distribute attr-xattr.in.h
[!TAR_COND_XATTR_H]: Build attr/xattr.h
* lib/attr-xattr.in.h: New file.
* lib/xattr-at.c: New file.
* lib/xattr-at.h: New file.

acinclude.m4

@@ -24,3 +24,29 @@ AC_DEFUN([TAR_COMPR_PROGRAM],[
 	     [tar_compr_var=m4_if($2,,$1,$2)])
  AC_DEFINE_UNQUOTED(tar_compr_define, "$tar_compr_var",
                     [Define to the program name of ]$1[ compressor program])])
+
+# Provide <attr/xattr.h>, if necessary
+
+AC_DEFUN([TAR_HEADERS_ATTR_XATTR_H],
+[
+  AC_ARG_WITH([xattrs],
+    AS_HELP_STRING([--without-xattrs], [don't use linux extended attributes]),
+    [], [with_xattrs=maybe]
+  )
+
+  AC_CHECK_HEADERS([attr/xattr.h])
+  AM_CONDITIONAL([TAR_COND_XATTR_H],[test "$ac_cv_header_attr_xattr_h" = yes])
+  if test "$ac_cv_header_attr_xattr_h" = yes; then
+    AC_CHECK_FUNCS(getxattr  fgetxattr  lgetxattr \
+                   setxattr  fsetxattr  lsetxattr \
+                   listxattr flistxattr llistxattr,
+        # only when functions are present
+        AC_DEFINE([HAVE_ATTR_XATTR_H], [1],
+                    [define to 1 if we have <attr/xattr.h> header])
+        if test "$with_xattrs" != no; then
+          AC_DEFINE([HAVE_XATTRS],,[Define when we have working linux xattrs.])
+        fi
+    )
+  fi
+])
+		    

configure.ac

@@ -90,6 +90,8 @@ gl_INIT
 # paxutils modules
 tar_PAXUTILS
 
+TAR_HEADERS_ATTR_XATTR_H
+
 AC_CHECK_FUNCS_ONCE([fchmod fchown fsync lstat mkfifo readlink symlink])
 AC_CHECK_DECLS([getgrgid],,, [#include <grp.h>])
 AC_CHECK_DECLS([getpwuid],,, [#include <pwd.h>])

lib/Makefile.am

@@ -28,11 +28,24 @@ BUILT_SOURCES = rmt-command.h
 CLEANFILES = rmt-command.h rmt-command.h-t
 INCLUDES = -I$(top_srcdir)/gnu -I../ -I../gnu
 
-noinst_HEADERS = system.h system-ioctl.h rmt.h paxlib.h stdopen.h
+noinst_HEADERS = system.h system-ioctl.h rmt.h paxlib.h stdopen.h xattr-at.h
 libtar_a_SOURCES = \
   paxerror.c paxexit-status.c paxlib.h paxnames.c \
   prepargs.c prepargs.h \
   rtapelib.c \
   rmt.h \
   stdopen.c stdopen.h \
-  system.h system-ioctl.h
+  system.h system-ioctl.h \
+  xattr-at.c
+
+if !TAR_COND_XATTR_H
+BUILT_SOURCES += attr/xattr.h
+attr/xattr.h: attr-xattr.in.h $(top_builddir)/config.status
+	$(AM_V_at)$(MKDIR_P) attr
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	 cp $(srcdir)/attr-xattr.in.h attr/xattr.h
+
+MOSTLYCLEANFILES = attr/xattr.h attr/xattr.h
+endif
+
+EXTRA_DIST = attr-xattr.in.h

lib/attr-xattr.in.h

@@ -0,0 +1,58 @@
+/* Replacement <attr/xattr.h> for platforms that lack it.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+
+   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 TAR_ATTR_XATTR_H
+#define TAR_ATTR_XATTR_H
+#include <errno.h>
+
+/* setting */
+static inline int setxattr (const char *path, const char *name, const void
+                            *value, size_t size, int flags)
+{ errno = ENOTSUP; return -1; }
+
+static inline int lsetxattr (const char *path, const char *name, const void
+                             *value, size_t size, int flags)
+{ errno = ENOTSUP; return -1; }
+
+static inline int fsetxattr (int filedes, const char *name, const void *value,
+                             size_t size, int flags)
+{ errno = ENOTSUP; return -1; }
+
+
+/* getting */
+static inline ssize_t getxattr (const char *path, const char *name, void *value,
+                                size_t size)
+{ errno = ENOTSUP; return -1; }
+static inline ssize_t lgetxattr (const char *path, const char *name, void
+                                 *value, size_t size)
+{ errno = ENOTSUP; return -1; }
+static inline ssize_t fgetxattr (int filedes, const char *name, void *value,
+                                 size_t size)
+{ errno = ENOTSUP; return -1; }
+
+
+/* listing */
+static inline ssize_t listxattr (const char *path, char *list, size_t size)
+{ errno = ENOTSUP; return -1; }
+
+static inline ssize_t llistxattr (const char *path, char *list, size_t size)
+{ errno = ENOTSUP; return -1; }
+
+static inline ssize_t flistxattr (int filedes, char *list, size_t size)
+{ errno = ENOTSUP; return -1; }
+
+#endif
+

lib/xattr-at.c

@@ -0,0 +1,110 @@
+/* openat-style fd-relative functions for operating with extended file
+   attributes.
+
+   Copyright (C) 2012 Free Software Foundation, Inc.
+
+   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 <config.h>
+
+#include "xattr-at.h"
+#include "openat.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
+#include "save-cwd.h"
+
+#include "openat-priv.h"
+
+/* setxattrat */
+#define AT_FUNC_NAME setxattrat
+#define AT_FUNC_F1 setxattr
+#define AT_FUNC_POST_FILE_PARAM_DECLS   , const char *name, const void *value \
+                                        , size_t size, int flags
+#define AT_FUNC_POST_FILE_ARGS          , name, value, size, flags
+#include "at-func.c"
+#undef AT_FUNC_NAME
+#undef AT_FUNC_F1
+#undef AT_FUNC_POST_FILE_PARAM_DECLS
+#undef AT_FUNC_POST_FILE_ARGS
+
+/* lsetxattrat */
+#define AT_FUNC_NAME lsetxattrat
+#define AT_FUNC_F1 lsetxattr
+#define AT_FUNC_POST_FILE_PARAM_DECLS   , const char *name, const void *value \
+                                        , size_t size, int flags
+#define AT_FUNC_POST_FILE_ARGS          , name, value, size, flags
+#include "at-func.c"
+#undef AT_FUNC_NAME
+#undef AT_FUNC_F1
+#undef AT_FUNC_POST_FILE_PARAM_DECLS
+#undef AT_FUNC_POST_FILE_ARGS
+
+/* getxattrat */
+#define AT_FUNC_NAME getxattrat
+#define AT_FUNC_RESULT ssize_t
+#define AT_FUNC_F1 getxattr
+#define AT_FUNC_POST_FILE_PARAM_DECLS   , const char *name, void *value \
+                                        , size_t size
+#define AT_FUNC_POST_FILE_ARGS          , name, value, size
+#include "at-func.c"
+#undef AT_FUNC_NAME
+#undef AT_FUNC_F1
+#undef AT_FUNC_RESULT
+#undef AT_FUNC_POST_FILE_PARAM_DECLS
+#undef AT_FUNC_POST_FILE_ARGS
+
+/* lgetxattrat */
+#define AT_FUNC_NAME lgetxattrat
+#define AT_FUNC_RESULT ssize_t
+#define AT_FUNC_F1 lgetxattr
+#define AT_FUNC_POST_FILE_PARAM_DECLS   , const char *name, void *value \
+                                        , size_t size
+#define AT_FUNC_POST_FILE_ARGS          , name, value, size
+#include "at-func.c"
+#undef AT_FUNC_NAME
+#undef AT_FUNC_F1
+#undef AT_FUNC_RESULT
+#undef AT_FUNC_POST_FILE_PARAM_DECLS
+#undef AT_FUNC_POST_FILE_ARGS
+
+/* listxattrat */
+#define AT_FUNC_NAME listxattrat
+#define AT_FUNC_RESULT ssize_t
+#define AT_FUNC_F1 listxattr
+#define AT_FUNC_POST_FILE_PARAM_DECLS   , char *list , size_t size
+#define AT_FUNC_POST_FILE_ARGS          , list , size
+#include "at-func.c"
+#undef AT_FUNC_NAME
+#undef AT_FUNC_F1
+#undef AT_FUNC_RESULT
+#undef AT_FUNC_POST_FILE_PARAM_DECLS
+#undef AT_FUNC_POST_FILE_ARGS
+
+/* llistxattrat */
+#define AT_FUNC_NAME llistxattrat
+#define AT_FUNC_RESULT ssize_t
+#define AT_FUNC_F1 llistxattr
+#define AT_FUNC_POST_FILE_PARAM_DECLS   , char *list , size_t size
+#define AT_FUNC_POST_FILE_ARGS          , list , size
+#include "at-func.c"
+#undef AT_FUNC_NAME
+#undef AT_FUNC_F1
+#undef AT_FUNC_RESULT
+#undef AT_FUNC_POST_FILE_PARAM_DECLS
+#undef AT_FUNC_POST_FILE_ARGS

lib/xattr-at.h

@@ -0,0 +1,66 @@
+/* Prototypes for openat-style fd-relative functions for operating with
+   extended file attributes.
+
+   Copyright (C) 2012 Free Software Foundation, Inc.
+
+   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 XATTRS_AT_H
+#define XATTRS_AT_H
+
+#include <sys/types.h>
+#include <attr/xattr.h>
+
+/* These are the dir-fd-relative variants of the functions without the
+   "at" suffix.  For example, setxattrat (AT_FDCWD, path, name, value, size,
+   flags &c) is usually equivalent to setxattr (file, name, value, size,
+   flags).  For more info use the setxattr(2), getxattr(2) or listxattr(2)
+   manpages. */
+
+/* dir-fd-relative setxattr.  Operation sets the VALUE of the extended
+   attribute identified by NAME and associated with the given PATH in the
+   filesystem relatively to directory identified by DIR_FD.  See the
+   setxattr(2) manpage for the description of all parameters. */
+int setxattrat (int dir_fd, const char *path, const char *name,
+                const void *value, size_t size, int flags);
+
+/* dir-fd-relative lsetxattr.  This function is just like setxattrat,
+   except when DIR_FD and FILE specify a symlink:  lsetxattrat operates on the
+   symlink, while the setxattrat operates on the referent of the symlink.  */
+int lsetxattrat (int dir_fd, const char *path, const char *name,
+                 const void *value, size_t size, int flags);
+
+/* dir-fd-relative getxattr.  Operation gets the VALUE of the extended
+   attribute idenfified by NAME and associated with the given PATH in the
+   filesystem relatively to directory identified by DIR_FD.  For more info
+   about all parameters see the getxattr(2) manpage. */
+ssize_t getxattrat (int dir_fd, const char *path, const char *name,
+                    void *value, size_t size);
+
+/* dir-fd-relative lgetxattr.  This function is just like getxattrat,
+   except when DIR_FD and FILE specify a symlink:  lgetxattrat operates on the
+   symlink, while the getxattrat operates on the referent of the symlink.  */
+ssize_t lgetxattrat (int dir_fd, const char *path, const char *name,
+                     void *value, size_t size);
+
+/* dir-fd-relative listxattr.  Obtain the list of extended attrubtes names.  For
+   more info see the listxattr(2) manpage. */
+ssize_t listxattrat (int dir_fd, const char *path, char *list, size_t size);
+
+/* dir-fd-relative llistxattr.  This function is just like listxattrat,
+   except when DIR_FD and FILE specify a symlink:  llistxattr operates on the
+   symlink, while the listxattrat operates on the referent of the symlink.  */
+ssize_t llistxattrat (int dir_fd, const char *path, char *list, size_t size);
+
+#endif /* XATTRS_AT_H */

tests/capabs_raw01.at

@@ -0,0 +1,51 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright (C) 2012 Free Software Foundation, Inc.
+#
+# 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, 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/>.
+#
+# Test description:  Test if file capabilities are archived/restored correctly
+# using just the default xattr support (capabilities are stored/restored in
+# binary format -> system dependant).
+
+AT_SETUP([capabilities: binary store/restore])
+AT_KEYWORDS([xattrs capabilities capabs_raw01])
+
+AT_TAR_CHECK([
+AT_PRIVILEGED_PREREQ
+AT_XATTRS_PREREQ
+AT_CAPABILITIES_UTILS_PREREQ
+
+mkdir dir
+genfile --file dir/file
+
+setcap "= cap_chown=ei" dir/file
+
+# archive whole directory including binary xattrs
+tar --xattrs -cf archive.tar dir
+
+# clear the directory
+rm -rf dir
+
+# restore _all_ xattrs (not just the user.* domain)
+tar --xattrs --xattrs-include='*' -xf archive.tar
+
+getcap dir/file
+],
+[0],
+[dir/file = cap_chown+ei
+])
+
+AT_CLEANUP

tests/xattr01.at

@@ -0,0 +1,47 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# 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, 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/>.
+#
+# Test description:
+#
+# This is basic test for support of extended attributes.
+
+AT_SETUP([xattrs: basic functionality])
+AT_KEYWORDS([xattrs xattr01])
+
+AT_TAR_CHECK([
+AT_XATTRS_PREREQ
+mkdir dir
+genfile --file dir/file
+
+setfattr -n user.test -v OurDirValue dir
+setfattr -n user.test -v OurFileValue dir/file
+
+tar --xattrs -cf archive.tar dir
+
+rm -rf dir
+tar --xattrs -xf archive.tar
+
+getfattr -h -d dir         | grep -v -e '^#' -e ^$
+getfattr -h -d dir/file    | grep -v -e '^#' -e ^$
+],
+[0],
+[user.test="OurDirValue"
+user.test="OurFileValue"
+])
+
+AT_CLEANUP

tests/xattr02.at

@@ -0,0 +1,55 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright (C) 2011 Free Software Foundation, Inc.
+#
+# 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, 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/>.
+#
+# Test description:
+#
+# Cooperation of the '-C' option and storing/restoring extended attributes.
+
+AT_SETUP([xattrs: change directory with -C option])
+AT_KEYWORDS([xattrs xattr02])
+
+AT_TAR_CHECK([
+AT_XATTRS_PREREQ
+
+mkdir dir
+mkdir dir/subdir
+mkdir dir/subdir/subsubdir
+genfile --file dir/file1
+genfile --file dir/subdir/file2
+
+setfattr -n user.test -v OurFile1Value dir/file1
+setfattr -n user.test -v OurFile2Value dir/subdir/file2
+setfattr -n user.test -v OurDirValue   dir/subdir/subsubdir
+
+tar --xattrs -cf archive.tar -C dir file1 -C subdir file2 subsubdir
+
+rm -rf dir
+
+tar --xattrs -xf archive.tar
+
+getfattr -h -d file1        | grep -v -e '^#' -e ^$
+getfattr -h -d file2        | grep -v -e '^#' -e ^$
+getfattr -h -d subsubdir    | grep -v -e '^#' -e ^$
+],
+[0],
+[user.test="OurFile1Value"
+user.test="OurFile2Value"
+user.test="OurDirValue"
+])
+
+AT_CLEANUP

tests/xattr03.at

@@ -0,0 +1,56 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright (C) 2012 Free Software Foundation, Inc.
+#
+# 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, 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/>.
+#
+# Test description:
+#
+# Setup of the trusted.* domain under privileged user.
+
+AT_SETUP([xattrs: trusted.* attributes])
+AT_KEYWORDS([xattrs xattr03])
+
+AT_TAR_CHECK([
+AT_PRIVILEGED_PREREQ
+AT_XATTRS_PREREQ
+
+mkdir dir
+mkdir dir/subdir
+mkdir dir/subdir/subsubdir
+genfile --file dir/file1
+genfile --file dir/subdir/file2
+
+setfattr -n trusted.test -v OurFile1Value dir/file1
+setfattr -n trusted.test -v OurFile2Value dir/subdir/file2
+setfattr -n trusted.test -v OurDirValue   dir/subdir/subsubdir
+
+tar --xattrs -cf archive.tar -C dir file1 -C subdir file2 subsubdir
+
+rm -rf dir
+
+tar --xattrs --xattrs-include=trusted* -xf archive.tar
+
+getfattr -mtrusted. -d file1        | grep -v -e '^#' -e ^$
+getfattr -mtrusted. -d file2        | grep -v -e '^#' -e ^$
+getfattr -mtrusted. -d subsubdir    | grep -v -e '^#' -e ^$
+],
+[0],
+[trusted.test="OurFile1Value"
+trusted.test="OurFile2Value"
+trusted.test="OurDirValue"
+])
+
+AT_CLEANUP

tests/xattr04.at

@@ -0,0 +1,48 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright (C) 2012 Free Software Foundation, Inc.
+#
+# 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, 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/>.
+#
+# Test description:  Test for the regression caused by tar update from 1.23 to
+# 1.26, Red Hat xattr patch was not ready for open->openat conversion.
+#
+# Related commit 4bde4f3.  See the bug: https://bugzilla.redhat.com/717684
+
+AT_SETUP([xattrs: s/open/openat/ regression])
+AT_KEYWORDS([xattrs xattr04])
+
+AT_TAR_CHECK([
+AT_XATTRS_PREREQ
+
+mkdir dir
+mkdir output
+genfile --file dir/file
+
+setfattr -n user.test -v value dir/file
+
+# archive whole directory including binary xattrs
+tar --xattrs -cf archive.tar -C dir .
+
+tar --xattrs -xf archive.tar -C output
+ret=$?
+getfattr -h -d output/file | grep -v -e '^#' -e ^$
+exit $ret
+],
+[0],
+[user.test="value"
+])
+
+AT_CLEANUP