[asterisk-bugs] [Asterisk 0015894]: SIP register via tls causes lock on sip reload

Asterisk Bug Tracker noreply at bugs.digium.com
Thu Oct 22 15:00:25 CDT 2009


The following issue has been ASSIGNED. 
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https://issues.asterisk.org/view.php?id=15894 
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Reported By:                dvossel
Assigned To:                dvossel
====================================================================== 
Project:                    Asterisk
Issue ID:                   15894
Category:                   Channels/chan_sip/TCP-TLS
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     assigned
Asterisk Version:           SVN 
JIRA:                        
Regression:                 No 
Reviewboard Link:           https://reviewboard.asterisk.org/r/380/ 
SVN Branch (only for SVN checkouts, not tarball releases):  trunk 
SVN Revision (number only!): 218430 
Request Review:              
====================================================================== 
Date Submitted:             2009-09-14 17:47 CDT
Last Modified:              2009-10-22 15:00 CDT
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Summary:                    SIP register via tls causes lock on sip reload
Description: 
I ran into this problem because of another issue Asterisk has with TLS.

register => tls://user:1234@mydomain

Given the register line above in sip.conf, I'd expect the register request
to be send via port 5061.  Instead it defaults to port 5060 which is
incorrect for TLS.

----------------------------------------------------------------
*CLI> sip show registry
Host                           dnsmgr Username       Refresh State        
       Reg.Time                 
mydomain:5060               N      user             120 Request Sent
----------------------------------------------------------------

Now here's the odd part.  I decided to go into my sip.conf and explicitly
set the register line to have a port, and when I issued a sip reload
everything locked up, even the CLI.  I was able to reproduce the steps and
got the same results everytime.

It seems that this is somehow caused by the receiving end binding to port
5061 and me sending the registration using port 5060.  If I bind the
receiving end to 5060 this works even though that is not the correct port
for tls.  I tried another test where I pointed the register at a fake
domain, but nothing locked up.




======================================================================
Relationships       ID      Summary
----------------------------------------------------------------------
has duplicate       0015343 [patch] lock in sip_tcp_helper_thread
related to          0013136 [patch] sip peer qualified failed, aste...
====================================================================== 

---------------------------------------------------------------------- 
 (0112629) svnbot (reporter) - 2009-10-22 15:00
 https://issues.asterisk.org/view.php?id=15894#c112629 
---------------------------------------------------------------------- 
Repository: asterisk
Revision: 225445

U   trunk/apps/app_externalivr.c
U   trunk/channels/chan_sip.c
U   trunk/include/asterisk/tcptls.h
U   trunk/main/tcptls.c

------------------------------------------------------------------------
r225445 | dvossel | 2009-10-22 15:00:19 -0500 (Thu, 22 Oct 2009) | 50
lines

SIP TCP/TLS: move client connection setup/write into tcp helper thread,
various related locking/memory fixes.

        What this patch fixes
1.Moves sip TCP/TLS connection setup into the TCP helper thread:
  Connection setup takes awhile and before this it was being
  done while holding the monitor lock.
2.Moves TCP/TLS writing to the TCP helper thread:  Through the
  use of a packet queue and an alert pipe, the TCP helper thread
  can now be woken up to write data as well as read data.
3.Locking error: sip_xmit returned an XMIT_ERROR without giving
  up the tcptls_session lock.  This lock has been completely removed
  from sip_xmit and placed in the new sip_tcptls_write() function.
4.Memory leak:  When creating a tcptls_client the tls_cfg was alloced
  but never freed unless the tcptls_session failed to start.  Now the
  session_args for a sip client are an ao2 object which frees the
  tls_cfg on destruction.
5.Pointer to stack variable: During sip_prepare_socket the creation
  of a client's ast_tcptls_session_args was done on the stack and
  stored as a pointer in the newly created tcptls_session.  Depending
  on the events that followed, there was a slight possibility that
  pointer could have been accessed after the stack returned.  Given
  the new changes, it is always accessed after the stack returns
  which is why I found it.

Notable code changes
1.I broke tcptls.c's ast_tcptls_client_start() function into two
  functions.  One for creating and allocating the new tcptls_session,
  and a separate one for starting and handling the new connection.
  This allowed me to create the tcptls_session, launch the helper
  thread, and then establish the connection within the helper thread.
2.Writes to a tcptls_session are now done within the helper thread.
  This is done by using an alert pipe to wake up the thread if new
  data needs to be sent.  The thread's sip_threadinfo object contains
  the alert pipe as well as the packet queue.
3.Since the threadinfo object contains the alert pipe, it must now be
  accessed outside of the helper thread for every write (queuing of a
  packet).  For easy lookup, I moved the threadinfo objects from a
  linked list to an ao2_container.

(closes issue https://issues.asterisk.org/view.php?id=13136)
Reported by: pabelanger
Tested by: dvossel, whys

(closes issue https://issues.asterisk.org/view.php?id=15894)
Reported by: dvossel
Tested by: dvossel

Review: https://reviewboard.asterisk.org/r/380/


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

http://svn.digium.com/view/asterisk?view=rev&revision=225445 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2009-10-22 15:00 svnbot         Checkin                                      
2009-10-22 15:00 svnbot         Note Added: 0112629                          
2009-10-22 15:00 svnbot         Status                   ready for review =>
assigned
======================================================================




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