Re: Memoryleak in SSL.Connection

On Mon, 5 Apr 2004 23:08:07 +0200
Andre Reitz <[email protected]> wrote:

> On Mon, 5 Apr 2004 22:36:37 +0800
> Ng Pheng Siong <[email protected]> wrote:
> 
> > On Thu, Apr 01, 2004 at 11:25:53PM +0200, Andre Reitz wrote:
> > > I am pretty sure, that since the Connection object
> > > gets garbage collected (and the __del__ method gets called)
> > > the server sometimes hangs completely.
> > > [...]
> > > IN OTHER WORDS:
> > > Is it possible that:
> > >    m2.bio_free(self.sslbio)
> > >    m2.bio_free(self.sockbio)
> > > or self.socket.close()
> > > may hang if the client does not finish the connection completely?
> >
> > Perhaps the server is waiting for SSL connection-close alerts, and
> > OpenSSL isn't allowing the session to be harvested?
> >
> > E.g., running echo.py, see the ALERTs at the end:
> >
> >   INFO: SSL connect: SSL negotiation finished successfully
> >   Host = vista.netmemetic.com
> >   Cipher = DHE-RSA-AES256-SHA
> >   Server = /C=SG/O=M2Crypto/CN=localhost/[email protected]
> >   ALERT: read: warning: close notify
> >   ALERT: write: warning: close notify
> >
> > Before your server calls self.socket.close(), try calling this:
> >
> >   self.socket.set_shutdown(SSL.SSL_SENT_SHUTDOWN|SSL.SSL_RECEIVED_SHUTDOWN)
> >
> Ok I will try it...
> 
> > This says to set the SSL 'shutdown' state to "sent shutdown" and "received
> > shutdown". The precise behaviour is described in the TLS RFC.
> >
> > Are your clients in Python?
> >
> yes. but the clients dont use M2Crypto.
> They use socket.ssl from the standard distribution.
> 
> 

now I have tried it: 
 calling 
    set_shutdown(SSL.SSL_SENT_SHUTDOWN|SSL.SSL_RECEIVED_SHUTDOWN)
 before destructor __del__ comes
 stops my multi-threaded server from hanging.

 if I do not call 
    set_shutdown(SSL.SSL_SENT_SHUTDOWN|SSL.SSL_RECEIVED_SHUTDOWN)
 the complete server sometimes hangs in 
   m2.bio_free(self.sslbio)  of Connection.__del__
 
Why?
  does bio_free still want to communicate with the client?
  (which is already disconnected?)


Thank you very much for your help.
Greetings, Andre'




> 
> >
> > --
> > Ng Pheng Siong <[email protected]>
> >
> > http://firewall.rulemaker.net -+- Firewall Change Management & Version Control
> > http://sandbox.rulemaker.net/ngps -+- Open Source Python Crypto & SSL


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