commit aae68b2791c636b6a58068bb43cf4c01cfd86c5d
author Neels Hofmeyr <nhofmeyr@sysmocom.de> Wed Jul 05 14:38:52 2017 +0200
committer Neels Hofmeyr <nhofmeyr@sysmocom.de> Mon Jul 31 13:20:00 2017 +0200
tree 4ce5e04c400afe84f752d49b4d612e5ab4bbc56d
parent 13850b1e5dc10975bf0452d2b8290bdbe2a8356f

move openbsc.git's iu.h, iu.c, iu_vty.c here as iu_client

To help split openbsc.git to separate MSC and SGSN repositories, place the
common Iu interface related code here in libosmo-ranap. Also apply various
improvements while moving (from intermittent code review).

The code depends on libosmo-ranap tightly. One reason to want this separate
from libosmo-ranap could be that it uses libosmo-sigtran, accepting an sccp
instance. However, including in libosmo-ranap is the simplest way to go. The
osmo-iuh build depends on libosmo-sigtran anyway because of OsmoHNBGW, and all
current users of libosmo-ranap also naturally link libosmo-sigtran already.

Apply prefix ranap_iu_ and RANAP_IU_ to allow smooth transition from the
openbsc.git iu_ to the libranap ranap_iu_ implementations.

Prune unneeded #include statements.

Instead of sccp_addr, store an rnc pointer in the ue_conn_ctx. To facilitate,
also:
- Move iu_rnc struct to iu_client.h (as ranap_iu_rnc).
- Instead of sccp_addr, pass rnc to ue_conn_ctx_alloc().
- Pass a local struct new_ue_conn_ctx containing the sccp_addr and conn_id up
  the RANAP handling stack in case of an InitialUE message.
- Separate the InitialUE message handling from cn_ranap_handle_co(), by moving
  to new and separate cn_ranap_handle_co_initial(), so we can still pass a
  looked-up ue_conn_ctx to all other cn_ranap_handle_co() code paths.
- Allocate the ue_conn_ctx only in ranap_handle_co_initial_ue(), not as early
  as before.
Note that we are not actually ever using the rnc pointer now present in
ue_conn_ctx. It could be used for more concise paging, to first page only the
RNC where we last saw the subscriber. So far we page all matching LAC/RACs.

Tweak error logging: use __func__ instead of writing the function names as
string constants.

In iu_client_vty.c:
- Move the asn.1 debug commands from logging over to the iu node. They are not
  specific to the logging target. They could qualify for an entirely separate
  'asn1' root node, but for simplicity place under 'iu'.
- Add the 'asn1' commands to ranap_iu_vty_config_write(), so far missing.
- remove the legacy "net." from a VTY error message, it is not known which name
  the parent node of 'iu' has.

Depends: libosmo-sccp I85b46269dbe7909e52873ace3f720f6292a4516c,
	 libosmo-sccp Ie1aedd7894acd69ddc887cd65a8a0df4b888838c
Change-Id: I6a3f7ad15be03fb94689b4af6ccfa828c25f45c0