More advanced DFS compatibility checks

Avoid setting the SMB2_FLAGS_DFS_OPERATIONS flag in the SMB header if
the server did not report it as supporting DFS operations during the
negotiation phase. This should hopefully fix up some problems when the
server errors in the case it doesn't support DFS operations.

CHANGELOG.md

@@ -6,6 +6,7 @@
   * This avoid having to call `stat()` to retrieve data like the file attributes or datetime fields that is already available
 * Ensure `DateTimeField` values are set to `UTC` timezones as FILETIME values are in UTC
 * Stop using `datetime.datetime.utcfromtimestamp()` as it has been deprecated
+* Avoid setting DFS request when the server does not report it is capable of DFS operations.
 
 ## 1.12.0 - 2023-11-09
 

src/smbprotocol/connection.py

@@ -1198,7 +1198,7 @@ def _send(
             if tree_id not in session.tree_connect_table:
                 raise SMBException("Cannot find Tree with the ID %d in the session tree table" % tree_id)
             tree = session.tree_connect_table[tree_id]
-            is_dfs = tree.is_dfs_share
+            is_dfs = self.server_capabilities.has_flag(Capabilities.SMB2_GLOBAL_CAP_DFS) and tree.is_dfs_share
 
         total_requests = len(messages)
         for i, message in enumerate(messages):