Re: [reSIProcate] NULL Pointer crash with resip 1.3.3

["Aron Rosenberg" <arosenberg@xxxxxxxxxxxxxx>]

Scott,

 

I’ll test your patch out and also combine it with my patch for removing the use of mRemoteTarget as the new To when onRequestRetry is properly called.

 

If I understand your changes correctly, onRequestRetry should now only be called for timeouts/errors of the initial SUBSCRIBE and any reSUBSCRIBE messages.

 

-Aron

 

From: Scott Godin [mailto:slgodin@xxxxxxxxxxxx]
Sent: Wednesday, July 23, 2008 9:06 AM
To: Aron Rosenberg; 'resiprocate-devel'
Subject: RE: [reSIProcate] NULL Pointer crash with resip 1.3.3

 

I’m not sure I fully understand yet why the crash is happening.  The logs seem to indicated that the ClientSubscription is handling two 408 responses????  For some reason the two 408’s have the same TID, but a different to tag – very strange.

 

SIP: [.\ClientSubscription.cxx:59] ClientSubscription::dispatch SipResp: 408 tid=151dd73cc5746622 cseq=SUBSCRIBE / 2 from(wire)

SIP: [.\ClientSubscription.cxx:114] processing client subscription response

SIP: [.\ClientSubscription.cxx:168] Received 408 to SUBSCRIBE <sip:kristie.lomond@xxxxxxxxxxxxxxxxxx>;tag=10.11374.1216071735.678374

…

SIP: [.\ClientSubscription.cxx:59] ClientSubscription::dispatch SipResp: 408 tid=151dd73cc5746622 cseq=SUBSCRIBE / 2 from(wire)

SIP: [.\ClientSubscription.cxx:114] processing client subscription response

SIP: [.\ClientSubscription.cxx:168] Received 408 to SUBSCRIBE <sip:kristie.lomond@xxxxxxxxxxxxxxxxxx>;tag=10.11385.1216071758.680732

 

 

But I did find another issue with ClientSubscriptions, and the fix for this may end up stopping the crash as well.

 

The problem is that when ClientSubscription::end is called, an un-subscribe message is sent out.  Normally if this is successful, then we wait for a Notify to arrive with subscription-state terminated, before destroying the ClientSubscription.  However if this un-subscribe request fails, then the whole AppDialogSet reuse and ClientSubscription retry logic kicks in.  However the retry request generated is not an unsubscribe request, it is a new subscription that is retried.  I’ve attached a patch that will just terminate the ClientSubscription, if we call end() then receive an error response to the unsubscribe.

 

It seems that the whole ClientSubscription usage needs a makeover.  : )

 

Scott

 

From: resiprocate-devel-bounces@xxxxxxxxxxxxxxx [mailto:resiprocate-devel-bounces@xxxxxxxxxxxxxxx] On Behalf Of Aron Rosenberg
Sent: July 14, 2008 7:20 PM
To: resiprocate-devel
Subject: Re: [reSIProcate] NULL Pointer crash with resip 1.3.3

 

I  was finally able to get a working pcap, resip log and debug crash at the same time. Here is what is going on

 

1.       Client makes subscription

2.       Client ends the subscription by invoking end() on the handle

3.       This end results in a local 408 error, which calls onRequestRetry

4.       Our code returns 0 to onRequestRetry(ClientSubscriptionHandle) to retry the request since we want the server to know we ended the sub

5.       "Application requested immediate retry on Retry-After" is printed to log

6.       Crash happens in the else statement in ClientSubscription.cxx:198 when trying to call getAppDialogSet()->reuse().

 

I have a full log (over 100MB of resip data which I can send to a developer who wants to look at it along with the matching pcap error file

 

-Aron

 

 

From: resiprocate-devel-bounces@xxxxxxxxxxxxxxx [mailto:resiprocate-devel-bounces@xxxxxxxxxxxxxxx] On Behalf Of Aron Rosenberg
Sent: Monday, July 14, 2008 2:17 PM
To: resiprocate-devel
Subject: Re: [reSIProcate] NULL Pointer crash with resip 1.3.3

 

Here is a little bit more information gleaned from a pcap trace.

 

The stack seems to be crashing when dealing with a 400 error where the “From:” header looks like this

 

“From: <sip:>;tag=5b461e50”

 

I was able to find the outbound SUBSCRIBE request and it also has an empty From address so something strange is going on in the stack. Still working on getting the resip logs.

 

-Aron

 

From: resiprocate-devel-bounces@xxxxxxxxxxxxxxx [mailto:resiprocate-devel-bounces@xxxxxxxxxxxxxxx] On Behalf Of Aron Rosenberg
Sent: Monday, July 14, 2008 11:50 AM
To: resiprocate-devel
Subject: [reSIProcate] NULL Pointer crash with resip 1.3.3

 

Resip ver: SVN rev 8128 on 1.3 branch

 

Call Stack:

resip::AppDialogSet::getHandle() Line 22 + 0x3 bytes C++
resip::DialogUsage::getAppDialogSet() Line 38 + 0x18 bytes C++
resip::ClientSubscription::processResponse(const resip::SipMessage & msg={...}) Line 198 + 0x12 bytes C++
resip::ClientSubscription::dispatch(const resip::SipMessage & msg={...}) Line 117 C++
resip::Dialog::dispatch(const resip::SipMessage & msg={...}) Line 651 + 0x1a bytes C++
resip::DialogSet::dispatchToAllDialogs(const resip::SipMessage & msg={...}) Line 1028 C++
resip::DialogSet::dispatch(const resip::SipMessage & msg={...}) Line 608 C++
resip::DialogUsageManager::processResponse(const resip::SipMessage & response={...}) Line 1810 C++
resip::DialogUsageManager::incomingProcess(std::auto_ptr<resip::Message> msg=auto_ptr {tu=??? }) Line 1363 C++
resip::DialogUsageManager::internalProcess(std::auto_ptr<resip::Message> msg=auto_ptr {tu=??? }) Line 1190 C++
resip::DialogUsageManager::process(resip::RWMutex * mutex=0x00000000) Line 1390 + 0x49 bytes C++
SipEP::run() Line 3408 + 0xa bytes C++

 

The crash is because the appDialogSet returned in DialogUsage::getAppDialogSet() is NULL.

 

It came from our production client and is reasonable repeatable, so I am working on getting the resip logs that would go with it.

 

-Aron

 

 

---------------------------------------------

Aron Rosenberg

Founder and CTO

SightSpeed - http://www.sightspeed.com/

 

918 Parker St, Suite A14

Berkeley, CA 94710

 

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