tree 786a1e55afccd29551fe1dd0f6f025a5441432dd
parent 622dd61764a454bc19a54de5ee1097bc3d3fa5d7
author Oliver Smith <osmith@sysmocom.de> 1548171096 +0100
committer Oliver Smith <osmith@sysmocom.de> 1549450866 +0100

Inactive connection cleanup (disabled by default)

Add a watchdog timer to connections, and close these connections when
the watchdog timer expires. Kick the watchdog whenever RTP messages or
the relevant MGCP messages arrive. Add the currently remaining timeout
to "show mgcp stats" in the VTY.

This feature is disabled by default, as it is incompatible with LCLS
(connections in LCLS state appear to be inactive). Enable it with the
new "conn-timeout" VTY setting. In general, this feature can be used to
work around interoperability problems causing connections to stay open
forever, and slowly exhausting all available ports. This happened for
various reasons already.

MDCX is the only relevant MGCP message:
- CRCX creates the conn and timer
- DLCX deletes the conn and timer
- MDCX is the only remaining supported MGCP message that indicates a CI
- Can't easily generically parse a CI for all MGCP messages, parsing is
  done in handle_modify_con().

Related: OS#3429
Change-Id: I18886052e090466f73829133c24f011806cc1fe0