Make libsmbclient more fail-safe

[Jeremy Allison]

On Wed, Nov 28, 2001 at 11:41:17PM +0100, Tom Jansen wrote:
> Hi Richard,
> 
> I've been working on a patch for libsmbclient that makes it even more reliable
> regarding to server restarts, network failures etc.
> 
> Now I've run into the following problem: How can I verify if a connection to a
> SMB server is still operational? I can check if cli_state->fd != -1 but that is
> not enough. I want to make sure a server is operational when I give back a
> server from the server cache LL inside libsmbclient. I'm looking for a way to
> send some sort of ping to the server. Is there a way to do this?

Use a SMBkeepalive NetBIOS packet. Look at the send_keepalive()
code in Samba.

> I've got yet another question. Recently, Jeremy removed the "reestablish" code
> from libsmb/clientgen.c. I would like to use a slighty modified version of this
> code to recover from possible server-side disconnects or connection failures.
> Can I move it back in the tree if my patch gets accepted ? 

Doing client re-establishment doesn't make sense in the 
client library (IMHO). It has no knowledge of the state
needed (file open, locks held etc.). That belongs in the
application.

Jeremy.