error of dialback with im.apinc.org, standard compliance problem ?

[Brad Fitzpatrick]

Perhaps psa can reply with an analysis of who's doing the wrong thing?


On Sat, 22 Sep 2007, Michael Scherer wrote:

>
> > Hi,
> >
> > it seems the dialback code is quite buggy as i cannot connect to people on
> > im.apinc.org
> >
> > Here is the trace ( edited to be more readable ):
> >
> > Me :
> > <?xml version="1.0" encoding="UTF-8"?>
> > <stream:stream to='im.apinc.org'
> > xmlns:stream='http://etherx.jabber.org/streams'
> > xmlns='jabber:server'
> > xml:lang='en'
> > xmlns:db='jabber:server:dialback'
> > version='1.0'>
> >
> >
> > Apinc :
> > <?xml version='1.0'?>
> > <stream:stream xmlns:stream='http://etherx.jabber.org/streams'
> > id='db1a6b6ff7193a90ec62d4d3e21313a8bba291c6'
> > from='im.apinc.org'
> > version='1.0'
> > xmlns='jabber:server'
> > xmlns:db='jabber:server:dialback'>
> >   <stream:features xmlns:stream='http://etherx.jabber.org/streams'>
> >      <starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>
> >   </stream:features>
> >
> > Me :
> > <stream:features></stream:features>
> >
> > Apinc :
> > <stream:error>
> >    <improper-addressing xmlns='urn:ietf:params:xml:ns:xmpp-streams'/>
> >    <text xml:lang='en' xmlns='urn:ietf:params:xml:ns:xmpp-streams'>
> >      Invalid Packets Recieved!
> >    </text>
> > </stream:error>
> >
> > Me :
> > <db:result to='im.apinc.org'
> > from='ephaone.org'>i-87bbc9ad5749f6fbc27a4f00e2c7ec3286ec3632</db:result>
> >
> > After reading rfc 3920, I suspect the problem comes from a missing attribute
> > in
> > the stream:features stanza sent by djabberd.
> >
> > "In the 'jabber:server' namespace, a stanza MUST possess a 'from'
> > attribute; if a server receives a stanza that does not meet this
> > restriction, it MUST generate an <improper-addressing/> stream error
> > condition."
> >
> > Adding to, from, version and xmlns solved the problem ( in fact, it showed a
> > different problem related to a dns migration ).
> >
> > Is the patch enclosed ok or is the server on im.apinc.org is having problem ?
> >
> > It seems ejabberd do not have the same behavior as I can access to some other
> > server without trouble.
> > According to a admin of apinc.org, they are running jabberd14 1.6.1.1
> >
> > As I am waiting on dns propagation, I couldn't check with other servers
> > except
> > google's one, which seems to be ok.
>
> ok, so now, the dns was propagated and the problem was still there, i was seeing
> "invalid-from" error instead. And I was also seeing this from other server as
> well.
>
> So I dug into jabberd code in order to see what was wrong. And in fact, the
> problem was not at all what I thought. I wonder even how I could be so wrong.
> Dialback code on djabberd is correct but there is just one thing, the timing of
> the various stanzas.
>
> If we look back at the trace, we can see :
> 1) me send <stream>
> 2) apinc answer <stream><stream:features/>
> 3) me answer <stream:features/>
> 4) apinc answer error
>
> In fact, the apinc server was thinking that <stream:features/> is the dialback
> answer, which is wrong. My current fix is to not send this at all, and so I can
> connect to the server without troubles.
>
> However, I think that's quite a hack and that's a part of xmpp I am not
> comfortable with.
>
> What would be the proper fix ?
>
> 1) send <stream> + <stream:features /> in one shot ?
> 2) not send <stream:features> ?
> 3) fix jabberd to do more check about this and not assuming that
> everything coming on this socket is a dialback result ?
>
>
> --
> Michael Scherer
>