Re: PPP LCP configuration issue

[Marcel Holtmann <marcel@holtmann.org>]

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Hi Kristen,

> > so I added some debug code to actually print the options during the
> > configuration stage. And something seems to be wrong here.
> > 
> > lcp: pppcp_open_event: current state 0:INITIAL
> > lcp: pppcp_up_event: current state 1:STARTING
> > lcp: pppcp_initialize_restart_count: current state 1:STARTING
> > lcp: pppcp_send_configure_request: current state 1:STARTING
> > lcp: option 2 len 6 (Async-Control-Character-Map) 00 00 00 00
> > lcp: pppcp_process_configure_request: current state 6:REQSENT
> > lcp: option 2 len 6 (Async-Control-Character-Map) 00 00 00 00
> > lcp: option 3 len 5 (Authentication-Protocol) c2 23 05
> > lcp: option 5 len 6 (Magic-Number) 01 ff ef e0
> > lcp: option 7 len 2 (Protocol-Field-Compression)
> > lcp: option 8 len 2 (Address-and-Control-Field-Compression)
> > lcp: pppcp_rcr_plus_event: current state 6:REQSENT
> > lcp: pppcp_send_configure_ack: current state 6:REQSENT
> > lcp: option 2 len 6 (Async-Control-Character-Map) 00 00 00 00
> > lcp: option 3 len 5 (Authentication-Protocol) c2 23 05
> > lcp: option 5 len 6 (Magic-Number) 01 ff ef e0
> > lcp: option 7 len 2 (Protocol-Field-Compression)
> > lcp: option 8 len 2 (Address-and-Control-Field-Compression)
> > lcp: pppcp_process_configure_ack: current state 8:ACKSENT
> > lcp: option 2 len 6 (Async-Control-Character-Map) 00 00 00 00
> > oops -- found acked option 2 we didn't request
> > lcp: pppcp_rca_event: current state 8:ACKSENT
> > lcp: pppcp_initialize_restart_count: current state 8:ACKSENT
> > 
> > I see the oops comment here, but we clearly requested the async control
> > character map. So why does it get recognized as not requested? This is
> > clearly a bug and needs to be fixed.
> 
> what is happening is that we are first send a Config-Request with 
> the accm option as our only option.  We then receive a Config-Request
> from the modem, with accm along with several other options requested.
> We ack the modem's Config-Request and apply the options, and then delete
> them from the list of options that we need to have.  Then the modem
> response to our original Config-Request with an ack to our accm option.
> Because we already applied this option and removed it from the list of
> things we care about, it shows up as an option we didn't request.
> I think I could just delete the error message, and silently ignore 
> this condition. 

are these options really negotiated for both sides in common. Or is the
negotiation process for each side individual?

Personally I like to keep such error messages. We need to cope with
these cases nicely.

Regards

Marcel