PPP LCP configuration issue

[Kristen Carlson Accardi]

On Thu, 01 Apr 2010 00:25:45 -0700
Marcel Holtmann <marcel at holtmann.org> wrote:

> 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.