[PATCH v2 4/9] Add access_mask_to_str() helper to nfs4.0/nfs4acl.py

[Chuck Lever <cel@kernel.org>]

From: Chuck Lever <chuck.lever@oracle.com>

I'm about to add several new ACL-related tests. Introduce
access_mask_to_str() to convert ACE access_mask values to human-
readable symbolic strings for the display output in these new
tests.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 nfs4.0/nfs4acl.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/nfs4.0/nfs4acl.py b/nfs4.0/nfs4acl.py
index 62193123ef7c..0fabd0860cff 100644
--- a/nfs4.0/nfs4acl.py
+++ b/nfs4.0/nfs4acl.py
@@ -268,6 +268,26 @@ def acl2mode_rfc8881(acl):
 
     return mode
 
+def access_mask_to_str(mask):
+    """Convert an ACE access_mask to a symbolic string representation"""
+    perms = [
+        (ACE4_READ_DATA, "READ_DATA"),
+        (ACE4_WRITE_DATA, "WRITE_DATA"),
+        (ACE4_APPEND_DATA, "APPEND_DATA"),
+        (ACE4_READ_NAMED_ATTRS, "READ_NAMED_ATTRS"),
+        (ACE4_WRITE_NAMED_ATTRS, "WRITE_NAMED_ATTRS"),
+        (ACE4_EXECUTE, "EXECUTE"),
+        (ACE4_DELETE_CHILD, "DELETE_CHILD"),
+        (ACE4_READ_ATTRIBUTES, "READ_ATTRIBUTES"),
+        (ACE4_WRITE_ATTRIBUTES, "WRITE_ATTRIBUTES"),
+        (ACE4_DELETE, "DELETE"),
+        (ACE4_READ_ACL, "READ_ACL"),
+        (ACE4_WRITE_ACL, "WRITE_ACL"),
+        (ACE4_WRITE_OWNER, "WRITE_OWNER"),
+        (ACE4_SYNCHRONIZE, "SYNCHRONIZE"),
+    ]
+    return " | ".join(name for bit, name in perms if mask & bit) or "(none)"
+
 def printableacl(acl):
     type_str = ["ACCESS", "DENY"]
     out = ""
-- 
2.51.1