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

5 files changed, 92 insertions, 18 deletions

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);
+}
+