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* [PATCH] Use xattr (Linux) in qcopy-acl.c
@ 2023-01-04 14:34 Ondrej Valousek
  2023-01-04 14:46 ` Bruno Haible
       [not found] ` <TYXPR01MB18544D0A5C213BF0204BF0D4D9FD9@TYXPR01MB1854.jpnprd01.prod.outlook.com>
  0 siblings, 2 replies; 29+ messages in thread
From: Ondrej Valousek @ 2023-01-04 14:34 UTC (permalink / raw)
  To: bug-gnulib, bruno; +Cc: Ondrej Valousek

Hi Bruno,
Please review now.
Ondrej

---
 lib/qcopy-acl.c         | 36 ++++++++++++++++++++++++++++++++++-
 m4/xattr.m4             | 42 +++++++++++++++++++++++++++++++++++++++++
 modules/acl             |  1 +
 modules/acl-tests       |  6 +++---
 modules/copy-file       |  1 +
 modules/copy-file-tests |  2 +-
 modules/qacl            |  3 +++
 modules/qcopy-acl       |  3 +++
 modules/supersede       |  1 +
 modules/supersede-tests |  2 +-
 10 files changed, 91 insertions(+), 6 deletions(-)
 create mode 100644 m4/xattr.m4

diff --git a/lib/qcopy-acl.c b/lib/qcopy-acl.c
index 883bcf7d58..44980b71a4 100644
--- a/lib/qcopy-acl.c
+++ b/lib/qcopy-acl.c
@@ -23,6 +23,20 @@
 
 #include "acl-internal.h"
 
+#if USE_XATTR
+
+# include <attr/libattr.h>
+
+/* Returns 1 if NAME is the name of an extended attribute that is related
+   to permissions, i.e. ACLs.  Returns 0 otherwise.  */
+
+static int
+is_attr_permissions (const char *name, struct error_context *ctx)
+{
+  return attr_copy_action (name, ctx) == ATTR_ACTION_PERMISSIONS;
+}
+
+#endif  /* USE_XATTR */
 
 /* Copy access control lists from one file to another. If SOURCE_DESC is
    a valid file descriptor, use file descriptor operations, else use
@@ -39,13 +53,33 @@ int
 qcopy_acl (const char *src_name, int source_desc, const char *dst_name,
            int dest_desc, mode_t mode)
 {
-  struct permission_context ctx;
   int ret;
 
+#ifdef USE_XATTR
+  /* in case no ACLs present and also to set higher mode bits
+     we chmod before setting ACLs as doing it after could overwrite them 
+     (especially true for NFSv4, posix ACL has that ugly "mask" hack that
+     nobody understands) */
+  ret = chmod_or_fchmod (dst_name, dest_desc, mode);
+  /* Rather than fiddling with acls one by one, we just copy the whole ACL xattrs
+     (Posix or NFSv4). Of course, that won't address ACLs conversion
+     (i.e. posix <-> nfs4) but we can't do it anyway, so for now, we don't care
+     Functions attr_copy_* return 0 in case we copied something OR nothing
+     to copy */
+  if (ret == 0)
+    ret = source_desc <= 0 || dest_desc <= 0
+      ? attr_copy_file (src_name, dst_name, is_attr_permissions, NULL)
+      : attr_copy_fd (src_name, source_desc, dst_name, dest_desc, 
+                      is_attr_permissions, NULL);
+#else
+  /* no XATTR, so we proceed the old dusty way */
+  struct permission_context ctx;
+
   ret = get_permissions (src_name, source_desc, mode, &ctx);
   if (ret != 0)
     return -2;
   ret = set_permissions (&ctx, dst_name, dest_desc);
   free_permission_context (&ctx);
+#endif
   return ret;
 }
diff --git a/m4/xattr.m4 b/m4/xattr.m4
new file mode 100644
index 0000000000..6efdfa475a
--- /dev/null
+++ b/m4/xattr.m4
@@ -0,0 +1,42 @@
+# xattr.m4 - check for Extended Attributes (Linux)
+# serial 4
+
+# Copyright (C) 2003-2021 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_XATTR],
+[
+  AC_ARG_ENABLE([xattr],
+        AS_HELP_STRING([--disable-xattr],
+                       [do not support extended attributes]),
+        [use_xattr=$enableval], [use_xattr=yes])
+
+  LIB_XATTR=
+  AC_SUBST([LIB_XATTR])
+
+  if test "$use_xattr" = "yes"; then
+    AC_CHECK_HEADERS([attr/error_context.h attr/libattr.h])
+    use_xattr=no
+    if test "$ac_cv_header_attr_libattr_h" = yes \
+        && test "$ac_cv_header_attr_error_context_h" = yes; then
+      xattr_saved_LIBS=$LIBS
+      AC_SEARCH_LIBS([attr_copy_file], [attr],
+                     [test "$ac_cv_search_attr_copy_file" = "none required" ||
+                        LIB_XATTR="$ac_cv_search_attr_copy_file"])
+      AC_CHECK_FUNCS([attr_copy_file])
+      LIBS=$xattr_saved_LIBS
+      if test "$ac_cv_func_attr_copy_file" = yes; then
+        use_xattr=yes
+      fi
+    fi
+    if test $use_xattr = no; then
+      AC_MSG_WARN([libattr development library was not found or not usable.])
+      AC_MSG_WARN([AC_PACKAGE_NAME will be built without xattr support.])
+    fi
+  fi
+  if test $use_xattr = yes; then
+    AC_DEFINE_UNQUOTED([USE_XATTR], 1)
+  fi
+])
diff --git a/modules/acl b/modules/acl
index 1a3a14e6c2..7edfb1e77d 100644
--- a/modules/acl
+++ b/modules/acl
@@ -22,6 +22,7 @@ Include:
 
 Link:
 $(LIB_MBRTOWC)
+$(LIB_XATTR)
 
 License:
 GPL
diff --git a/modules/acl-tests b/modules/acl-tests
index e4173fe9ae..1d8d84d299 100644
--- a/modules/acl-tests
+++ b/modules/acl-tests
@@ -25,6 +25,6 @@ TESTS += \
   test-copy-acl.sh test-copy-acl-1.sh test-copy-acl-2.sh
 TESTS_ENVIRONMENT += USE_ACL=$(USE_ACL)
 check_PROGRAMS += test-set-mode-acl test-copy-acl test-sameacls
-test_set_mode_acl_LDADD = $(LDADD) $(LIB_ACL) @LIBINTL@ $(LIB_MBRTOWC)
-test_copy_acl_LDADD = $(LDADD) $(LIB_ACL) @LIBINTL@ $(LIB_MBRTOWC)
-test_sameacls_LDADD = $(LDADD) $(LIB_ACL) @LIBINTL@ $(LIB_MBRTOWC)
+test_set_mode_acl_LDADD = $(LDADD) $(LIB_ACL) $(LIB_XATTR) @LIBINTL@ $(LIB_MBRTOWC)
+test_copy_acl_LDADD = $(LDADD) $(LIB_ACL) $(LIB_XATTR) @LIBINTL@ $(LIB_MBRTOWC)
+test_sameacls_LDADD = $(LDADD) $(LIB_ACL) $(LIB_XATTR) @LIBINTL@ $(LIB_MBRTOWC)
diff --git a/modules/copy-file b/modules/copy-file
index 6140c72fa1..0a86a15889 100644
--- a/modules/copy-file
+++ b/modules/copy-file
@@ -37,6 +37,7 @@ Include:
 
 Link:
 $(LIB_MBRTOWC)
+$(LIB_XATTR)
 
 License:
 GPL
diff --git a/modules/copy-file-tests b/modules/copy-file-tests
index a0788755f1..dc598b24f3 100644
--- a/modules/copy-file-tests
+++ b/modules/copy-file-tests
@@ -18,4 +18,4 @@ Makefile.am:
 TESTS += test-copy-file.sh test-copy-file-1.sh test-copy-file-2.sh
 TESTS_ENVIRONMENT += USE_ACL=$(USE_ACL)
 check_PROGRAMS += test-copy-file
-test_copy_file_LDADD = $(LDADD) $(LIB_ACL) $(LIB_CLOCK_GETTIME) @LIBINTL@ $(LIB_MBRTOWC)
+test_copy_file_LDADD = $(LDADD) $(LIB_ACL) $(LIB_XATTR) $(LIB_CLOCK_GETTIME) @LIBINTL@ $(LIB_MBRTOWC)
diff --git a/modules/qacl b/modules/qacl
index 45753c7623..7cfd9f3fbc 100644
--- a/modules/qacl
+++ b/modules/qacl
@@ -15,6 +15,9 @@ Makefile.am:
 
 Include:
 
+Link:
+$(LIB_XATTR)
+
 License:
 GPL
 
diff --git a/modules/qcopy-acl b/modules/qcopy-acl
index c0e5b6a8f8..dcd610464b 100644
--- a/modules/qcopy-acl
+++ b/modules/qcopy-acl
@@ -3,11 +3,13 @@ Copy access control list from one file to another.  (Unportable.)
 
 Files:
 lib/qcopy-acl.c
+m4/xattr.m4
 
 Depends-on:
 acl-permissions
 
 configure.ac:
+gl_FUNC_XATTR
 
 Makefile.am:
 lib_SOURCES += qcopy-acl.c
@@ -17,6 +19,7 @@ Include:
 
 Link:
 $(LIB_ACL)
+$(LIB_XATTR)
 
 License:
 GPL
diff --git a/modules/supersede b/modules/supersede
index 70f3fdc482..5c6ccafe5c 100644
--- a/modules/supersede
+++ b/modules/supersede
@@ -38,6 +38,7 @@ Link:
 $(LIB_GETRANDOM)
 $(LIB_CLOCK_GETTIME)
 $(LIBTHREAD)
+$(LIB_XATTR)
 
 License:
 GPL
diff --git a/modules/supersede-tests b/modules/supersede-tests
index 7224d2e31e..dc01a63652 100644
--- a/modules/supersede-tests
+++ b/modules/supersede-tests
@@ -19,4 +19,4 @@ configure.ac:
 Makefile.am:
 TESTS += test-supersede
 check_PROGRAMS += test-supersede
-test_supersede_LDADD = $(LDADD) $(LIB_ACL) $(LIB_CLOCK_GETTIME) $(LIB_GETRANDOM) $(LIBINTL) $(LIBTHREAD)
+test_supersede_LDADD = $(LDADD) $(LIB_ACL) $(LIB_XATTR) $(LIB_CLOCK_GETTIME) $(LIB_GETRANDOM) $(LIBINTL) $(LIBTHREAD)
-- 
2.38.1



^ permalink raw reply related	[flat|nested] 29+ messages in thread
end of thread, other threads:[~2023-01-30 10:19 UTC | newest]

Thread overview: 29+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-01-04 14:34 [PATCH] Use xattr (Linux) in qcopy-acl.c Ondrej Valousek
2023-01-04 14:46 ` Bruno Haible
2023-01-04 19:29   ` Paul Eggert
2023-01-04 20:54     ` Ondrej Valousek
2023-01-05  1:19       ` Paul Eggert
2023-01-13  9:15         ` ACL complexity Bruno Haible
2023-01-13 10:03           ` Ondrej Valousek
2023-01-13 11:05             ` Bruno Haible
2023-01-13 11:22               ` Ondrej Valousek
2023-01-05  9:00       ` [PATCH] Use xattr (Linux) in qcopy-acl.c Bruno Haible
2023-01-05  9:05         ` Ondrej Valousek
2023-01-05 10:32           ` Bruno Haible
2023-01-05 19:06             ` Paul Eggert
2023-01-11  9:11               ` Ondrej Valousek
2023-01-12 20:42                 ` Bruno Haible
2023-01-13  7:51                   ` Bruno Haible
2023-01-13  8:09                     ` Bruno Haible
2023-01-13  8:32                       ` Ondrej Valousek
2023-01-13  8:46                         ` Bruno Haible
2023-01-14  1:52                           ` Paul Eggert
2023-01-14  7:26                             ` Ondrej Valousek
2023-01-14  7:55                               ` Bruno Haible
2023-01-14  8:02                                 ` Ondrej Valousek
2023-01-13  8:33               ` Bruno Haible
2023-01-13  8:50                 ` Bruno Haible
2023-01-30 10:18                 ` Bruno Haible
2023-01-05  8:56     ` Bruno Haible
     [not found] ` <TYXPR01MB18544D0A5C213BF0204BF0D4D9FD9@TYXPR01MB1854.jpnprd01.prod.outlook.com>
     [not found]   ` <c1ddff8c-2734-bfa1-11a3-3279ae9e92cb@cs.ucla.edu>
2023-01-12 20:58     ` Bruno Haible
2023-01-12 22:53       ` Paul Eggert

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