[OpenSIPS-Devel] [OpenSIPS/opensips] a0fcf8: fraud_detection: Improve accuracy for 'concurrent ...

[Liviu Chircu]

  Branch: refs/heads/2.4
  Home:   https://github.com/OpenSIPS/opensips
  Commit: a0fcf857ddb6d01ced57e0681d488bbd703753a4
      https://github.com/OpenSIPS/opensips/commit/a0fcf857ddb6d01ced57e0681d488bbd703753a4
  Author: Liviu Chircu <liviu at opensips.org>
  Date:   2020-08-03 (Mon, 03 Aug 2020)

  Changed paths:
    M modules/dialog/dlg_cb.h
    M modules/fraud_detection/fraud_detection.c

  Log Message:
  -----------
  fraud_detection: Improve accuracy for 'concurrent calls'

Avoid using the DLGCB_FAILED callback, since it has no protection
against the "408 Request Timeout / 200 OK" race condition, and simply
use DLGCB_DESTROY in order to decrement the concurrent calls counter.

This fixes a bug where a "408 Timeout / 200 OK" call would cause a
concurrent calls value of 4294967295, due to an extra decrement.

Fixes #2079

(cherry picked from commit 2404b96c87982387071cea63f5fc42d9169d8798)