acls: bugfix for default ACLs extraction

When --acls option is on (regardless of tarball contents or
tarball format), we should explicitly set OR delete default ACLs
for extracted directories.  Prior to this update, we always
created arbitrary default ACLs based standard file permissions.

* configure.ac (with_posix_acls): Check also for acl_free and
acl_delete_def_file to mark IEEE 1003.1e ACLs as supported.
* src/xattrs.c (acl_delete_def_file_at): New function.
(xattrs__acls_set): Do not treat acls_option at all;  Delete
default ACLs if appropriate.

References:
http://www.mail-archive.com/bug-tar@gnu.org/msg04355.html
Thanks: Juan J. Martínez and Mark Steinborn

diff --git a/configure.ac b/configure.ac
index 08bed2b18273b30b359f2db17fc6a4f7e2955ab4..d39387654ec7d6c53413bf2d30efa701409521bb 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -74,7 +74,8 @@ AC_ARG_WITH([posix-acls],
 if test "x$with_posix_acls" != "xno"; then
   AC_CHECK_HEADERS(sys/acl.h,, [with_posix_acls=no])
   for tar_acl_func in acl_get_file acl_get_fd acl_set_file acl_set_fd \
-                     acl_to_text acl_from_text; do \
+                     acl_to_text acl_from_text acl_delete_def_file \
+                     acl_free; do \
     test "x$with_posix_acls" = xno && break
     AC_SEARCH_LIBS([$tar_acl_func], [acl pacl], [], [with_posix_acls=no])
   done

diff --git a/src/xattrs.c b/src/xattrs.c
index dbaa2092f5a208a280c3cb5b26f819701db235eb..307ee380fab183f8b02915f1d585ba80b1d0684b 100644 (file)
--- a/src/xattrs.c
+++ b/src/xattrs.c
@@ -61,6 +61,7 @@ static struct
 static acl_t acl_get_file_at (int, const char *, acl_type_t);
 static int acl_set_file_at (int, const char *, acl_type_t, acl_t);
 static int file_has_acl_at (int, char const *, struct stat const *);
+static int acl_delete_def_file_at (int, char const *);
 
 /* acl_get_file_at */
 #define AT_FUNC_NAME acl_get_file_at
@@ -88,6 +89,17 @@ static int file_has_acl_at (int, char const *, struct stat const *);
 #undef AT_FUNC_POST_FILE_PARAM_DECLS
 #undef AT_FUNC_POST_FILE_ARGS
 
+/* acl_delete_def_file_at */
+#define AT_FUNC_NAME acl_delete_def_file_at
+#define AT_FUNC_F1 acl_delete_def_file
+#define AT_FUNC_POST_FILE_PARAM_DECLS
+#define AT_FUNC_POST_FILE_ARGS
+#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
+
 /* gnulib file_has_acl_at */
 #define AT_FUNC_NAME file_has_acl_at
 #define AT_FUNC_F1 file_has_acl
@@ -187,7 +199,8 @@ fixup_extra_acl_fields (char *ptr)
   return ptr;
 }
 
-/* "system.posix_acl_access" */
+/* Set the "system.posix_acl_access/system.posix_acl_default" extended
+   attribute.  Called only when acls_option > 0. */
 static void
 xattrs__acls_set (struct tar_stat_info const *st,
                   char const *file_name, int type,
@@ -199,15 +212,23 @@ xattrs__acls_set (struct tar_stat_info const *st,
     {
       /* assert (strlen (ptr) == len); */
       ptr = fixup_extra_acl_fields (ptr);
-
       acl = acl_from_text (ptr);
-      acls_option = 1;
     }
-  else if (acls_option > 0)
-    acl = perms2acl (st->stat.st_mode);
+  else if (def)
+    {
+      /* No "default" IEEE 1003.1e ACL set for directory.  At this moment,
+         FILE_NAME may already have inherited default acls from parent
+         directory;  clean them up. */
+      if (acl_delete_def_file_at (chdir_fd, file_name))
+        WARNOPT (WARN_XATTR_WRITE,
+                (0, errno,
+                 _("acl_delete_def_file_at: Cannot drop default POSIX ACLs "
+                   "for file '%s'"),
+                 file_name));
+      return;
+    }
   else
-    return;  /* don't call acl functions unless we first hit an ACL, or
-               --acls was passed explicitly */
+    acl = perms2acl (st->stat.st_mode);
 
   if (!acl)
     {