Raise original BadNetworkName error on DFS failure (#204)

When attempting to resolve the DFS path on a BadNetworkName error it may
error with a DFS related error message. This error should be ignored if
the error was stating DFS is unavailable. The whole check can also be
avoided entirely if the server does not indicate it supports DFS in the
capabilities it sends back.

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.10.1 - TBD
+
+* Raise the original `BadNetworkName` error if the server doesn't indicate it supports DFS or `FSDriverRequired` was raised trying to lookup the DFS information - https://github.com/jborean93/smbprotocol/issues/196
+
 ## 1.10.0 - 2022-11-07
 
 * Require Python 3.7 or newer (dropped 3.6)

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "smbprotocol"
-version = "1.10.0"
+version = "1.10.1"
 description = "Interact with a server using the SMB 2/3 Protocol"
 readme = "README.md"
 requires-python = ">=3.7"

src/smbclient/_pool.py

@@ -10,15 +10,20 @@
 import warnings
 
 from smbprotocol._text import to_text
-from smbprotocol.connection import Connection
+from smbprotocol.connection import Capabilities, Connection
 from smbprotocol.dfs import (
     DFSReferralEntryFlags,
     DFSReferralRequest,
     DFSReferralResponse,
     DomainEntry,
     ReferralEntry,
 )
-from smbprotocol.exceptions import BadNetworkName, InvalidParameter, ObjectPathNotFound
+from smbprotocol.exceptions import (
+    BadNetworkName,
+    FSDriverRequired,
+    InvalidParameter,
+    ObjectPathNotFound,
+)
 from smbprotocol.ioctl import CtlCode, IOCTLFlags, SMB2IOCTLRequest, SMB2IOCTLResponse
 from smbprotocol.session import Session
 from smbprotocol.tree import TreeConnect
@@ -313,14 +318,29 @@ def get_smb_tree(
         tree = TreeConnect(session, share_path)
         try:
             tree.connect(require_secure_negotiate=client_config.require_secure_negotiate)
-        except BadNetworkName:
+        except BadNetworkName as err:
+            # If the server doesn't mention it supports DFS then don't try to
+            # resolve the DFS path.
+            if not session.connection.server_capabilities.has_flag(Capabilities.SMB2_GLOBAL_CAP_DFS):
+                raise
+
             ipc_path = "\\\\%s\\IPC$" % server
             if path == ipc_path:  # In case we already tried connecting to IPC$ but that failed.
                 raise
 
             # The share could be a DFS root, issue a root referral request to the hostname and cache the result.
             ipc_tree = get_smb_tree(ipc_path, **get_kwargs)[0]
-            referral = dfs_request(ipc_tree, "\\%s\\%s" % (path_split[0], path_split[1]))
+            try:
+                referral = dfs_request(ipc_tree, "\\%s\\%s" % (path_split[0], path_split[1]))
+            except FSDriverRequired:
+                # If the DFS Request fails with STATUS_FS_DRIVER_REQUIRED then
+                # the server doesn't support DFS requests and the original
+                # BadNetworkName error should be raised instead of this one.
+                # This provides better context as to why a failure occured, i.e.
+                # a bad share path was provided.
+                # https://github.com/jborean93/smbprotocol/issues/196
+                raise err
+
             client_config.cache_referral(referral)
 
             # Sometimes a DFS referral may return 0 referrals, this needs to be checked here to avoid repeats.