[ovs-dev] [PATCH v2] ovs-ofctl: Fixed the "snoop" command of ovs-ofctl

Ashish Varma ashishvarma.ovs at gmail.com
Fri Apr 20 00:03:35 UTC 2018


Sure, I will update the comment in the code to explain the effect of using:
 "use_names = 0".
Also, would change the comment in the commit back to the original message.
Thanks,

On Wed, Apr 18, 2018 at 4:29 PM, Ben Pfaff <blp at ovn.org> wrote:

> On Tue, Apr 17, 2018 at 06:40:46PM -0700, Ashish Varma wrote:
> > In normal ovs-ofctl commands (e.g. add-flow), ovs-ofctl connects to
> > ovs-vswitchd process on “<ovs_rundir()>/<bridge_name>.mgmt” unix socket.
> > In an output that contains a port or table, port name or table name can
> be
> > displayed, instead of their numbers, if the user turns on this feature.
> > (by -—names option) Also, this feature is enabled when interacting with
> a user
> > on console.  To fetch the names, ovs-ofctl sends TABLE FEATURE /
> > PORT DESCRIPTION request message to ovs-vswitchd process and expects a
> reply
> > on the connection.
> > When ovs-ofctl runs the snoop command, it connects to
> > “<ovs_rundir()>/<bridge_name>.snoop” unix socket. ovs-vswitchd process
> would
> > not reply to the TABLE FEATURE / PORT DESCRIPTION request message on this
> > connection. It would only send any open flow message it receives from the
> > controller.
> > When using port/table name feature with snoop command, the print of open
> flow
> > message would call ‘tables_to_show()’/‘ports_to_show()’ which in turn
> would
> > send the request message on the snoop connection. ovs-vswitchd would not
> reply
> > back on this connection, but instead would keep sending the open flow
> messages
> > received from controller. ‘table_iterator_next()/port_iterator_next()’
> function
> > would loop for ever waiting for response.
> > The fix for this is to turn off display of table/port names when running
> > snoop command.
> >
> > Signed-off-by: Ashish Varma <ashishvarma.ovs at gmail.com>
> > ---
> > v1-v2
> >
> > Added more description to the cause of the issue and reason to add the
> fix.
>
> Thanks for the update.
>
> I think I didn't describe my request on v1 very well.  I thought that
> the commit message was fine; it described the problem and the solution
> well.  I was asking for the comment in the code to describe the problem
> that it solved.  As is, the following comment:
> > +    use_names = 0; /* don't show port and table names */
> explains the immediate effect, but not why.  The "why" is more important
> than the immediate effect, because the effect is pretty easy to
> understand if the reader looks at the comments on the definition of
> "use_names", but the reason is nonobvious.
>
> Thanks,
>
> Ben.
>


More information about the dev mailing list