Changes

vty: Allow configuring xua timers in ASP mode

non-STP users of the API may also want to configure per-ASP timers, like
the Heartbeat timer.

Change-Id: I3801d10175f42c13e6f7994e1e4da8e7c99e8e16

vty: Allow configuring xua server in ASP mode

The xua server has nothing to do with a node being an ASP or an SG,
it used to allow transport server features (SCTP/TCP server).
One may want to configure an ASP role with a SCTCP server.

Change-Id: I9b07d2c96404b7b86c51fd9c7bab5e52a2343ade

Move osmo_xua_layer_manager definition to ss7_asp.h

The struct osmo_xua_layer_manager has no relation to a xua_server, hence
move it to ss7_asp.h, where it is used.

Change-Id: If7efb8996de0c407f5a466ff959095c8872ddc76

Document osmo_xua_layer_manager prim_cb

Change-Id: I1347c3538435985836ee5fe1d9dd42996e32ff94

ss7_asp: remove lm during ASP destroy

Otherwise the xua_default_lm_fsm instance is freed with talloc_free()
instead of osmo_fsm_inst_free().

Change-Id: Iee339b49d4b73a9afde60c4b8f6f5a03ad8a822d

Move osmo_xlm_sap_down to ss7_asp.c

That's a generic function to interact with the ASP from the LM.
Only some of the primitives are related to RKM.

Change-Id: I9a8d0e0fc1fd193db8dd3901911848ed8564616f

Refactor xua_layer_manager object

Several changes to improve separation of the LM object and its
lifecycle:
* Store in ss7_asp a pointer to a xua_layer_manager, which contains all
  implementation dependent information inside its priv pointer.
* Add a new free_func field to the xua_layer_manager struct in order to
  be able to free it without knowing how it was allocated.
* Get rid og the loglevel param, LOGL_DEBUG was always passed and that
  was actually an implementation specific detail of the default xua
  layer manager.
* Pass pointer to function to be called by LM to submit primitives to
  M3UA.

Change-Id: Ia96ebf40444f46ad718d61befbecb523f267fd6c

xua_default_lm_fsm: Move timer_cb further below

As usually done in osmo_fsm implemnetations.

Change-Id: Ibdc04d9ece0b3955da44849755a87ec28c17f140

lm: Use layer manager also on transport-role=server

The upper layers (M3UA) should behave similarly eg. on role ASP
independently of transport role being client or server.

Change-Id: I5f0109463323f214e15610b2c4fe253b828fce3b

lm: Initialize layer manager also on role=SG

Right now the LM will stay in IDLE for role=SG, but it already provides
with an easier logic where all xUA ASPs (no matter their role) have an
associated FSM object, which can be extnded later on.
This way we already valdiate the FSM instance lifecycle wroks as
expected.
It also allows in the future more easily integrating the LM in role
IPSP, where it will need to be extended.

Change-Id: I1f25cf8371ba72d710796e01a9a967d3fafffb99

IPSP: don't route any incoming M3UA messages in IPSP case

An IPSP is a point-to-point association, and we must not route any
such messages.

Change-Id: Iad7280619ec5814cda7a179418079048a5955976

IPSP: Add a comment that it's intentional to drop all M3UA SNM for IPSP

An IPSP doesn't have MTP3 network management.

Change-Id: I7b87bf03964e7e9aac683ad860e511f83a685821

IPSP: Allow vty-configuration of IPSP role "ASPs"

We should now have everything in place to support IPSP-SE, let's
accept enabling IPSP role via the VTY.

Change-Id: I0f0fa881471b87a4bb82a0211c6fb6e4c50b48ec

vty: Prohibit configuring an ASP as IPSP in an SG node

The spec explicitly prohibits it.

Change-Id: I38bbd9226bad478f8068d02f7a4d7b3711596208