[Asterisk-code-review] res pjsip registrar: Fix bad memory-ness with user agent. (asterisk[master])

[Mark Michelson]

Hello Anonymous Coward #1000019, Joshua Colp,

I'd like you to reexamine a change.  Please visit

    https://gerrit.asterisk.org/2641

to look at the new patch set (#2).

Change subject: res_pjsip_registrar: Fix bad memory-ness with user_agent.
......................................................................

res_pjsip_registrar: Fix bad memory-ness with user_agent.

Recent changes to the PJSIP registrar resulted in tests failing due to
missing AOR_CONTACT_ADDED test events. The reason for this was that the
user_agent string had junk values in it, resulting in being unable to
generate the event.

I'm going to be honest here, I have no idea why this was happening. Here
are the steps needed for the user_agent variable to get messed up:
* REGISTER is received
* First contact in the REGISTER results in a contact being removed
* Second contact in the REGISTER results in a contact being added
* The contact, AOR, expiration, and user agent all have to be passed as
  format parameters to the creation of a string. Any subset of those
  parameters would not be enough to cause the problem.

Looking into what was happening, the thing that struck me as odd was
that the user_agent variable was meant to be set to the value of the
User-Agent SIP header in the incoming REGISTER. However, when removing a
contact, the user_agent variable would be set (via ast_strdupa inside a
loop) to the stored contact's user_agent. This means that the
user_agent's value would be incorrect when attempting to process further
contacts in the incoming REGISTER.

The fix here is to use a different variable for the stored user agent
when removing a contact. Correcting the behavior to be correct also
means the memory usage is less weird, and the issue no longer occurs.

ASTERISK-25929 #close
Reported by Joshua Colp

Change-Id: I7cd24c86a38dec69ebcc94150614bc25f46b8c08
---
M res/res_pjsip_registrar.c
1 file changed, 1 insertion(+), 2 deletions(-)


  git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/41/2641/2
-- 
To view, visit https://gerrit.asterisk.org/2641
To unsubscribe, visit https://gerrit.asterisk.org/settings

Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I7cd24c86a38dec69ebcc94150614bc25f46b8c08
Gerrit-PatchSet: 2
Gerrit-Project: asterisk
Gerrit-Branch: master
Gerrit-Owner: Mark Michelson <mmichelson at digium.com>
Gerrit-Reviewer: Anonymous Coward #1000019
Gerrit-Reviewer: Joshua Colp <jcolp at digium.com>
Gerrit-Reviewer: Mark Michelson <mmichelson at digium.com>