Prepare entry/exit point for MSC -> BSC and MSC -> RNC communication.

Add msc_ifaces.[hc], a_iface.c, with a general msc_tx_dtap() to redirect to
different interfaces depending on the actual subscriber connection.

While iu_tx() is going to be functional fairly soon, the a_tx() is going to be
just a dummy for some time (see comment).

Add Iu specific fields in gsm_subscriber_connection: the UE connection pointer
and an indicator for the Integrity Protection status on Iu (to be fully
implemented in later commits).

Add lac member to gsm_subscriber_connection, to allow decoupling from
bts->location_area_code. The conn->lac will actually be set in iu.c in an
upcoming commit ("add iucs.[hc]").

Change-Id: Idf8020a30562426e8f939706bf5c2188d5a09798

1 files changed, 33 insertions, 0 deletions

diff --git a/openbsc/src/libmsc/a_iface.c b/openbsc/src/libmsc/a_iface.c
new file mode 100644
index 000000000..0eaeef188
--- /dev/null
+++ b/openbsc/src/libmsc/a_iface.c
@@ -0,0 +1,33 @@
+/* A-interface implementation, from MSC to BSC */
+
+/* (C) 2016 by sysmocom s.m.f.c GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/logging.h>
+
+#include <openbsc/msc_ifaces.h>
+#include <openbsc/debug.h>
+
+int a_tx(struct msgb *msg)
+{
+	LOGP(DMSC, LOGL_ERROR, "message to be sent to BSC, but A-interface"
+	     " not implemented.\n%s\n", osmo_hexdump(msg->data, msg->len));
+	return -1;
+}