From 6bf5e24d48077db58b389e90558100fc121b8134 Mon Sep 17 00:00:00 2001

From: Kamil Dudka <kdudka@redhat.com>

Date: Mon, 4 Apr 2011 12:43:39 +0200

Subject: [PATCH 1/2] libacl: Add acl_extended_file_nofollow()

This function calls lgetxattr() instead of getxattr(), which helps ls(1)

to prevent unnecessary automatic mounts, which acl_extended_file()

triggers.  See the following bug report for more details:

https://bugzilla.redhat.com/692982

---

 exports                             |    1 +

 include/libacl.h                    |    1 +

 libacl/Makefile                     |    3 +-

 libacl/__acl_extended_file.c        |   49 +++++++++++++++++++++++++++++++++++

 libacl/__acl_extended_file.h        |    4 +++

 libacl/acl_extended_file.c          |   20 ++------------

 libacl/acl_extended_file_nofollow.c |   34 ++++++++++++++++++++++++

 man/man3/acl_extended_file.3        |   11 +++++++-

 man/man5/acl.5                      |    1 +

 9 files changed, 105 insertions(+), 19 deletions(-)

 create mode 100644 libacl/__acl_extended_file.c

 create mode 100644 libacl/__acl_extended_file.h

 create mode 100644 libacl/acl_extended_file_nofollow.c

diff --git a/exports b/exports

index ef02842..b368c22 100644

--- a/exports

+++ b/exports

@@ -82,4 +82,5 @@ ACL_1.1 {

 	# Linux specific extensions

 	perm_copy_fd;

 	perm_copy_file;

+	acl_extended_file_nofollow;

 } ACL_1.0;

diff --git a/include/libacl.h b/include/libacl.h

index 41ec48e..d6a6650 100644

--- a/include/libacl.h

+++ b/include/libacl.h

@@ -59,6 +59,7 @@ extern int acl_check(acl_t acl, int *last);

 extern acl_t acl_from_mode(mode_t mode);

 extern int acl_equiv_mode(acl_t acl, mode_t *mode_p);

 int acl_extended_file(const char *path_p);

+int acl_extended_file_nofollow(const char *path_p);

 int acl_extended_fd(int fd);

 extern int acl_entries(acl_t acl);

 extern const char *acl_error(int code);

diff --git a/libacl/Makefile b/libacl/Makefile

index 1224b65..cfe3d3a 100644

--- a/libacl/Makefile

+++ b/libacl/Makefile

@@ -47,7 +47,8 @@ POSIX_CFILES = \

 LIBACL_CFILES = \

 	acl_to_any_text.c acl_entries.c acl_check.c acl_error.c acl_cmp.c \

-	acl_extended_fd.c acl_extended_file.c acl_equiv_mode.c acl_from_mode.c

+	acl_extended_fd.c acl_extended_file.c acl_equiv_mode.c acl_from_mode.c \

+	acl_extended_file_nofollow.c __acl_extended_file.c

 INTERNAL_CFILES = \

 	__acl_to_any_text.c __acl_to_xattr.c __acl_from_xattr.c \

diff --git a/libacl/__acl_extended_file.c b/libacl/__acl_extended_file.c

new file mode 100644

index 0000000..629afe9

--- /dev/null

+++ b/libacl/__acl_extended_file.c

@@ -0,0 +1,49 @@

+/*

+  File: acl_extended_file.c

+

+  Copyright (C) 2000, 2011

+  Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

+

+  This program is free software; you can redistribute it and/or

+  modify it under the terms of the GNU Lesser General Public

+  License as published by the Free Software Foundation; either

+  version 2.1 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

+  Lesser General Public License for more details.

+

+  You should have received a copy of the GNU Lesser General Public

+  License along with this library; if not, write to the Free Software

+  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

+*/

+

+#include <unistd.h>

+#include <attr/xattr.h>

+#include "libacl.h"

+

+#include "byteorder.h"

+#include "acl_ea.h"

+#include "__acl_extended_file.h"

+

+

+int

+__acl_extended_file(const char *path_p, getxattr_t fun)

+{

+	int base_size = sizeof(acl_ea_header) + 3 * sizeof(acl_ea_entry);

+	int retval;

+

+	retval = fun(path_p, ACL_EA_ACCESS, NULL, 0);

+	if (retval < 0 && errno != ENOATTR && errno != ENODATA)

+		return -1;

+	if (retval > base_size)

+		return 1;

+	retval = fun(path_p, ACL_EA_DEFAULT, NULL, 0);

+	if (retval < 0 && errno != ENOATTR && errno != ENODATA)

+		return -1;

+	if (retval >= base_size)

+		return 1;

+	return 0;

+}

+

diff --git a/libacl/__acl_extended_file.h b/libacl/__acl_extended_file.h

new file mode 100644

index 0000000..f8881a1

--- /dev/null

+++ b/libacl/__acl_extended_file.h

@@ -0,0 +1,4 @@

+typedef ssize_t (*getxattr_t)(const char *, const char *, void *value,

+        size_t size);

+

+int __acl_extended_file(const char *path_p, getxattr_t fun);

diff --git a/libacl/acl_extended_file.c b/libacl/acl_extended_file.c

index d1cb85d..f417784 100644

--- a/libacl/acl_extended_file.c

+++ b/libacl/acl_extended_file.c

@@ -1,7 +1,7 @@

 /*

   File: acl_extended_file.c

-  Copyright (C) 2000

+  Copyright (C) 2011

   Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

   This program is free software; you can redistribute it and/or

@@ -23,26 +23,12 @@

 #include <attr/xattr.h>

 #include "libacl.h"

-#include "byteorder.h"

-#include "acl_ea.h"

+#include "__acl_extended_file.h"

 int

 acl_extended_file(const char *path_p)

 {

-	int base_size = sizeof(acl_ea_header) + 3 * sizeof(acl_ea_entry);

-	int retval;

-

-	retval = getxattr(path_p, ACL_EA_ACCESS, NULL, 0);

-	if (retval < 0 && errno != ENOATTR && errno != ENODATA)

-		return -1;

-	if (retval > base_size)

-		return 1;

-	retval = getxattr(path_p, ACL_EA_DEFAULT, NULL, 0);

-	if (retval < 0 && errno != ENOATTR && errno != ENODATA)

-		return -1;

-	if (retval >= base_size)

-		return 1;

-	return 0;

+	return __acl_extended_file(path_p, getxattr);

 }

diff --git a/libacl/acl_extended_file_nofollow.c b/libacl/acl_extended_file_nofollow.c

new file mode 100644

index 0000000..8f4711f

--- /dev/null

+++ b/libacl/acl_extended_file_nofollow.c

@@ -0,0 +1,34 @@

+/*

+  File: acl_extended_file.c

+

+  Copyright (C) 2011

+  Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

+

+  This program is free software; you can redistribute it and/or

+  modify it under the terms of the GNU Lesser General Public

+  License as published by the Free Software Foundation; either

+  version 2.1 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

+  Lesser General Public License for more details.

+

+  You should have received a copy of the GNU Lesser General Public

+  License along with this library; if not, write to the Free Software

+  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

+*/

+

+#include <unistd.h>

+#include <attr/xattr.h>

+#include "libacl.h"

+

+#include "__acl_extended_file.h"

+

+

+int

+acl_extended_file_nofollow(const char *path_p)

+{

+	return __acl_extended_file(path_p, lgetxattr);

+}

+

diff --git a/man/man3/acl_extended_file.3 b/man/man3/acl_extended_file.3

index 0ca7e0f..1f04331 100644

--- a/man/man3/acl_extended_file.3

+++ b/man/man3/acl_extended_file.3

@@ -25,7 +25,7 @@

 .Dt ACL_EXTENDED_FILE 3

 .Os "Linux ACL"

 .Sh NAME

-.Nm acl_extended_file

+.Nm acl_extended_file, acl_extended_file_nofollow

 .Nd test for information in ACLs by file name

 .Sh LIBRARY

 Linux Access Control Lists library (libacl, \-lacl).

@@ -34,6 +34,8 @@ Linux Access Control Lists library (libacl, \-lacl).

 .In acl/libacl.h

 .Ft int

 .Fn acl_extended_file "const char *path_p"

+.Ft int

+.Fn acl_extended_file_nofollow "const char *path_p"

 .Sh DESCRIPTION

 The

 .Fn acl_extended_file

@@ -61,6 +63,13 @@ mechanisms, such as Mandatory Access Control schemes. The

 .Xr access 2

 system call can be used to check whether a given type of access to a file

 object would be granted.

+.Pp

+.Fn acl_extended_file_nofollow

+is identical to 

+.Fn acl_extended_file ,

+except in the case of a symbolic link, where the link itself is interrogated,

+not the file that it refers to.  Since symbolic links have no ACL themselves,

+the operation is supposed to fail on them.

 .Sh RETURN VALUE

 If successful, the

 .Fn acl_extended_file

diff --git a/man/man5/acl.5 b/man/man5/acl.5

index 6b0f468..aec58aa 100644

--- a/man/man5/acl.5

+++ b/man/man5/acl.5

@@ -497,6 +497,7 @@ These non-portable extensions are available on Linux systems.

 .Xr acl_error 3 ,

 .Xr acl_extended_fd 3 ,

 .Xr acl_extended_file 3 ,

+.Xr acl_extended_file_nofollow 3 ,

 .Xr acl_from_mode 3 ,

 .Xr acl_get_perm 3 ,

 .Xr acl_to_any_text 3

-- 

1.7.4

From ad4ca5aaee96e98b2e8e8a4351fa5e6c58d65216 Mon Sep 17 00:00:00 2001

From: Andreas Gruenbacher <agruen@linbit.com>

Date: Mon, 4 Apr 2011 17:18:38 +0200

Subject: [PATCH 2/2] Minor fixes to the previous commit

* Assign the new libacl version ACL_1.2 to acl_extended_file_nofollow

  so that package managers will end up with the appropriate

  dependencies.

* Add a manpage entry for acl_extended_file_nofollow which sources

  ("links to") the acl_extended_file manpage.

* Remove the prototype for getxattr/lgetxattr.

* Whitespace cleanups.

---

 exports                               |    7 ++++++-

 libacl/__acl_extended_file.c          |    7 ++++---

 libacl/__acl_extended_file.h          |    7 +++----

 libacl/acl_extended_file_nofollow.c   |    3 +--

 man/man3/acl_extended_file.3          |    2 +-

 man/man3/acl_extended_file_nofollow.3 |    1 +

 6 files changed, 16 insertions(+), 11 deletions(-)

 create mode 100644 man/man3/acl_extended_file_nofollow.3

diff --git a/exports b/exports

index b368c22..7d8e69e 100644

--- a/exports

+++ b/exports

@@ -82,5 +82,10 @@ ACL_1.1 {

 	# Linux specific extensions

 	perm_copy_fd;

 	perm_copy_file;

-	acl_extended_file_nofollow;

 } ACL_1.0;

+

+ACL_1.2 {

+    global:

+	# Linux specific extensions

+	acl_extended_file_nofollow;

+} ACL_1.1;

diff --git a/libacl/__acl_extended_file.c b/libacl/__acl_extended_file.c

index 629afe9..3e45abd 100644

--- a/libacl/__acl_extended_file.c

+++ b/libacl/__acl_extended_file.c

@@ -1,5 +1,5 @@

 /*

-  File: acl_extended_file.c

+  File: __acl_extended_file.c

   Copyright (C) 2000, 2011

   Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

@@ -29,7 +29,9 @@

 int

-__acl_extended_file(const char *path_p, getxattr_t fun)

+__acl_extended_file(const char *path_p,

+		    ssize_t (*fun)(const char *, const char *,

+				   void *, size_t))

 {

 	int base_size = sizeof(acl_ea_header) + 3 * sizeof(acl_ea_entry);

 	int retval;

@@ -46,4 +48,3 @@ __acl_extended_file(const char *path_p, getxattr_t fun)

 		return 1;

 	return 0;

 }

-

diff --git a/libacl/__acl_extended_file.h b/libacl/__acl_extended_file.h

index f8881a1..0b0da9e 100644

--- a/libacl/__acl_extended_file.h

+++ b/libacl/__acl_extended_file.h

@@ -1,4 +1,3 @@

-typedef ssize_t (*getxattr_t)(const char *, const char *, void *value,

-        size_t size);

-

-int __acl_extended_file(const char *path_p, getxattr_t fun);

+int __acl_extended_file(const char *path_p,

+			ssize_t (*)(const char *, const char *,

+				    void *, size_t));

diff --git a/libacl/acl_extended_file_nofollow.c b/libacl/acl_extended_file_nofollow.c

index 8f4711f..c253e4d 100644

--- a/libacl/acl_extended_file_nofollow.c

+++ b/libacl/acl_extended_file_nofollow.c

@@ -1,5 +1,5 @@

 /*

-  File: acl_extended_file.c

+  File: acl_extended_file_nofollow.c

   Copyright (C) 2011

   Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

@@ -31,4 +31,3 @@ acl_extended_file_nofollow(const char *path_p)

 {

 	return __acl_extended_file(path_p, lgetxattr);

 }

-

diff --git a/man/man3/acl_extended_file.3 b/man/man3/acl_extended_file.3

index 1f04331..fdeef86 100644

--- a/man/man3/acl_extended_file.3

+++ b/man/man3/acl_extended_file.3

@@ -65,7 +65,7 @@ system call can be used to check whether a given type of access to a file

 object would be granted.

 .Pp

 .Fn acl_extended_file_nofollow

-is identical to 

+is identical to

 .Fn acl_extended_file ,

 except in the case of a symbolic link, where the link itself is interrogated,

 not the file that it refers to.  Since symbolic links have no ACL themselves,

diff --git a/man/man3/acl_extended_file_nofollow.3 b/man/man3/acl_extended_file_nofollow.3

new file mode 100644

index 0000000..44fc24f

--- /dev/null

+++ b/man/man3/acl_extended_file_nofollow.3

@@ -0,0 +1 @@

+.so man3/acl_extended_file.3

-- 

1.7.4