Osmocom Libraries » libosmo-sccp + libosmo-sigtran

https://gerrit.osmocom.org/c/libosmo-sccp/+/24213

TTCN3 test case still missing

After writing a TTCN3 test, I found out during testing that the intended behavior is actually already supported: If there is no asp->lm (layer manager) assigned, the xua_asp_fsm directly proceeds to ASP-ACTIVATE after athe ASP-UP procedure!

So the in this case undesired behavior is present in the xua_default_lm_fsm, our default layer manager. That is only ever used when osmo_sccp_simple_client_on_ss7_id() is used, and I'm starting to regret I ever wrote the notion of this "simple client" back then, wanting to make it easier for other developers to set up SIGTRAN in the various applications.

The related commit reads :

commit ed15c74a01a044afc087a02f0e947ae49533762a
Author: Harald Welte <laforge@gnumonks.org>
Date:   Fri Apr 7 17:14:54 2017 +0200

    Add a default layer manager using RKM to register PC with SG

    This "default layer manager" can optionally be used by a xUA ASP. It
    will handle the xUA Layer Manager (xlm) primitives and use them to
    behave as follows:

    * bring the ASP into state "INACTIVE" 
    * see if the SG can match our connection (based on IP address + port
      information) to a statically configured ASP configuration with
      associated AS(s).  If yes, it will send us a NOTIFY message with
      AS-INACTIVE.
    * if the above doesn't work, try to dynamically register a routing key
      using RKM for the point code that was locally confiured on the
      ASP/client.   If that works, the SG will now have created ASP and AS
      objects as well as a routing key and be able to serve us, sending the
      NOTIFY with the AS-INACTIVE state.
    * After either of the two above, we will attempt to transition into
      ASP-ACTIVE.  The SG should send us an AS-ACTIVE notification in return
    * if anything fails, abort and disconnect the SCTP connection, restart
      related FSMs and start from scratch

So now we have the choice on whether to keep the quirk, or whether to make the default layer manager optional in the simple_client...

patch and test case merged