[Xastir] {Disarmed} Re: objects getting scrambled

[Tom Russo]

On Fri, Sep 16, 2011 at 09:14:48PM -0700, we recorded a bogon-computron collision of the <aa9vi at yahoo.com> flavor, containing:
> Tom (and Curt),
> FYI, TNC is in serial mode.? But no logging or snapshots are checked under the File menu.

Ugh.  Well, there goes that theory.

> There appears to be a bug.? I had to restart Xastir again today.? I thought I could workaround the bug by putting the objects into the TNC and not using Xastir, but it ends up sending the objects twice, even though I don't tell Xastir to send them.? Seems Xastir has some smarts to take objects originated from the TNC and put it into it's Xastir object file and then sends out its own version.

If you tell the TNC to send the objects from the same callsign/ssid as 
Xastir is using, yeah --- Xastir will hear an object with its callsign and
adopt it.  

> Here are some examples object name Shmbg-DMR that get sent out due to this bug:
>  Shkbg-DMR Shkbg-lMR Shmbg-$MR Shmbg-BMR Shmbg-DMQ Shmng-BMR Shmng.DMR ShmRg-DMR Shmzg-DKR
> 
> The actual text of the object is considerably messed up too like the object name.

I have never, ever seen this behavior --- and I have several objects beaconing
24/7/365.

Does Xastir have multiple objects with bad names, or does the name get scrambled
and appear as a duplicate of another object?

I ask, because if a digi out there is running a TNC with PASSALL turned on
(or if you are), then a scrambled *received* packet (due to noise or whatever)
could then be getting digipeated in its scrambled form, and then adopted
by Xastir because the callsign matches.

To test this, Try turning TNC logging on (and only TNC logging), restarting 
Xastir, and creating an object.  Then, as soon as you see a scrambled-name
object, look in the TNC log and see if it's Xastir that's originating the
scrambled object, or if Xastir heard it on the RF port and *then* started
beaconing it.

That's the only thing I can even begin to guess at. 

Oh, and are you by any chance running a network port as well as a TNC port?
I ask *that* because if your local IGate is the one with PASSALL on, then
you could be getting bad data through the network port rather than the 
TNC.  
 
> Message: 1
> Date: Thu, 15 Sep 2011 13:06:51 -0600
> From: Tom Russo <russo at bogodyn.org>
> To: Xastir - APRS client software discussion <xastir at lists.xastir.org>
> Subject: Re: [Xastir] objects getting scrambled
> Message-ID: <20110915190651.GA50642 at bogodyn.org>
> Content-Type: text/plain; charset=us-ascii
> 
> On Thu, Sep 15, 2011 at 08:51:38AM -0700, we recorded a bogon-computron collision of the <aa9vi at yahoo.com> flavor, containing:
> >
>  I am having issues on 2.0.1 with my objects from AA9VI-13 getting all 
> scrambled from time to time.? Sometimes the object name gets funny 
> characters, sometimes the object text gets some wrong characters or 
> loses characters all together.? Any idea why this is happening?? I use a
>  KPC3+ and I am running Debian 6.
> > 
> > A shutdown and 
> restart of Xastir cleans this up for a short period of time.? It's like 
> the .cnf file or whatever stores the object info is getting fouled up.? 
> Weird.? Should I just blow the installation away and go to stable 
> v2.0.0? Thanks for your feedback.? 
> 
> 
> I've not seen this, but I have seen something similar and perplexing.? Perhaps
> they are related.
> 
> Do you have multiple check boxes under the File menu set, e.g. for PNG 
> snapshots, logging, etc.?
> 
> When I had both PNG snaphots and TNC logging turned on, I found that some
> configuration did indeed get scrambled --- in my case, it was the path names
> for snapshots, which would become completely corrupted.? If I attempted to quit
> Xastir, it would give error messages about not being able to write the .cnf
> file out (because the path was corrupted).? My guess is that there
> is some non-thread-safe code that scribbles into arrays, and when there are
> multiple timed writes like snapshots and logging, the two acts corrupt each 
> other in some instances.? I was never able to track it down, but the behavior
> went away when I turned off TNC logging (I run PNG snapshots continuously,
> which I upload to a web site every 5-10 mins).
> 
> So, if you have two or more logging/snapshot options selected, try shutting
> off all but one of them and see if the behavior changes.? If so, then it may
> be the same issue that bit me.
> 
> I wish I could have tracked it down, but since it's a random event it was 
> pretty much impossible to work through in finite time.
> 
> -- 
> Tom Russo? ? KM5VY???SAR502???DM64ux? ? ? ? ? http://www.swcp.com/~russo/
> Tijeras, NM? QRPL#1592 K2#398? SOC#236? ? ? ? http://kevan.org/brain.cgi?DDTNM
>  "One man alone can be pretty dumb sometimes, but for real bona fide
>  stupidity, there ain't nothin' can beat teamwork." - Edward Abbey
> 
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-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236        http://kevan.org/brain.cgi?DDTNM
 "One man alone can be pretty dumb sometimes, but for real bona fide
 stupidity, there ain't nothin' can beat teamwork." - Edward Abbey