[sr-dev] [kamailio/kamailio] dialog/dmq access dialog table by reference (#2570)

[pwakano]

- Access to the d_table entries should be done by reference so there is
no risk of race conditions to get and release the lock

<!-- Kamailio Pull Request Template -->

<!--
IMPORTANT:
  - for detailed contributing guidelines, read:
    https://github.com/kamailio/kamailio/blob/master/.github/CONTRIBUTING.md
  - pull requests must be done to master branch, unless they are backports
    of fixes from master branch to a stable branch
  - backports to stable branches must be done with 'git cherry-pick -x ...'
  - code is contributed under BSD for core and main components (tm, sl, auth, tls)
  - code is contributed GPLv2 or a compatible license for the other components
  - GPL code is contributed with OpenSSL licensing exception
-->

#### Pre-Submission Checklist
<!-- Go over all points below, and after creating the PR, tick all the checkboxes that apply -->
<!-- All points should be verified, otherwise, read the CONTRIBUTING guidelines from above-->
<!-- If you're unsure about any of these, don't hesitate to ask on sr-dev mailing list -->
- [x] Commit message has the format required by CONTRIBUTING guide
- [x] Commits are split per component (core, individual modules, libs, utils, ...)
- [x] Each component has a single commit (if not, squash them into one commit)
- [x] No commits to README files for modules (changes must be done to docbook files
in `doc/` subfolder, the README file is autogenerated)

#### Type Of Change
- [ x ] Small bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds new functionality)
- [ ] Breaking change (fix or feature that would change existing functionality)

#### Checklist:
<!-- Go over all points below, and after creating the PR, tick the checkboxes that apply -->
- [x] PR should be backported to stable branches
- [x] Tested changes locally
- [x] Related to issue #2547

#### Description
<!-- Describe your changes in detail -->
It was seen the access to the d_table was not being made by reference on the function dmq_send_all_dlgs. It was then leading to race conditions where the same entry could have its lock changed elsewhere and then a dead lock would occur. By checking the code in other places where the d_table is used, everywhere it is accessed by reference, this function was the only one not following this logic.
Changes were done to have "entry" as a reference to d_table and not a copy.
You can view, comment on, or merge this pull request online at:

  https://github.com/kamailio/kamailio/pull/2570

-- Commit Summary --

  * dialog/dmq access dialog table by reference

-- File Changes --

    M src/modules/dialog/dlg_dmq.c (10)

-- Patch Links --

https://github.com/kamailio/kamailio/pull/2570.patch
https://github.com/kamailio/kamailio/pull/2570.diff

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/pull/2570
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.kamailio.org/pipermail/sr-dev/attachments/20201130/b3bcee6c/attachment.htm>