testhelper/smbclient: set different client guids

The smbclient high level calls make use of a global configuration which
ends up reusing the client guid. This doesn't work for us in our multi
client testing.

Make use of some low level calls at the point of setting up the
connection so that we use different client guids for each connection.

This particular workaround requires setting the connection cache
bypassing the methods available in the smbclient module. Setting this as
a separate commit to highlight the part which may break if the
underlying implementation is changed in the future.

Signed-off-by: Sachin Prabhu <sp@spui.uk>

testhelper/smbclient.py

@@ -1,6 +1,8 @@
 from smbprotocol.exceptions import SMBException  # type: ignore
 import smbclient  # type: ignore
+from smbprotocol.connection import Connection  # type: ignore
 import typing
+import uuid
 
 rw_chunk_size = 1 << 21  # 2MB
 
@@ -19,10 +21,11 @@ def __init__(
         self.server = hostname
         self.share = share
         self.port = port
+        self.connection_cache: dict = {}
         self.client_params = {
             "username": username,
             "password": passwd,
-            "connection_cache": {},
+            "connection_cache": self.connection_cache,
         }
         self.prepath = f"\\\\{self.server}\\{self.share}\\"
         self.connected = False
@@ -36,6 +39,12 @@ def connect(self) -> None:
         if self.connected:
             return
         try:
+            # Manually setup connection to avoid re-using guid through
+            # the global configuration
+            connection_key = f"{self.server.lower()}:{self.port}"
+            connection = Connection(uuid.uuid4(), self.server, self.port)
+            connection.connect()
+            self.connection_cache[connection_key] = connection
             smbclient.register_session(
                 self.server, port=self.port, **self.client_params
             )
@@ -46,7 +55,7 @@ def connect(self) -> None:
     def disconnect(self) -> None:
         self.connected = False
         smbclient.reset_connection_cache(
-            connection_cache=self.client_params["connection_cache"]
+            connection_cache=self.connection_cache
         )
 
     def _check_connected(self, action: str) -> None: