smb: client: fix smbdirect keep alive handling to match the documentation

smb: client: fix smbdirect keep alive handling to match the documentation

We setup the first timer with the negotiate timeout and set
KEEP_ALIVE_PENDING, so that the expired timer disconnects.

On every incoming message we need to reset the timer to the keepalive
interval (120s).

On SMBDIRECT_FLAG_RESPONSE_REQUESTED we need to schedule a response
instead of setting KEEP_ALIVE_PENDING. Doing both would mean
we would also set SMBDIRECT_FLAG_RESPONSE_REQUESTED in that
response. If both ends would do that we'd play ping pong in
a busy loop.

If we move to KEEP_ALIVE_SENT and send the keepalive request
with SMBDIRECT_FLAG_RESPONSE_REQUESTED, we need to setup the
timer with keepalive timeout (5s) in order to disconnect
if no incoming message reset the timer.

The fired timer sets KEEP_ALIVE_PENDING and also
setup timer with keepalive timeout (5s) in order to disconnect
if no incoming message reset the timer.
We do that before queueing the send_immediate_work
and have that timer in case we didn't reach the send code
that typically sets the timer to keepalive timeout.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>