LCLS, TS 29.205: add GCR routines
Add functions to encode and decode Global Call Reference as per
3GPP TS 29.205 Table B 2.1.9.1 add corresponding tests.
Change-Id: Iee95aa4e5c056645b6cb5667e4a067097d52dfbf
Related: OS#2487
diff --git a/include/osmocom/gsm/gsm29205.h b/include/osmocom/gsm/gsm29205.h
new file mode 100644
index 0000000..0c3c153
--- /dev/null
+++ b/include/osmocom/gsm/gsm29205.h
@@ -0,0 +1,41 @@
+/*! \defgroup gsm29205 3GPP TS 29.205
+ * @{
+ * \file gsm29205.h */
+/*
+ * (C) 2018 by sysmocom - s.f.m.c. GmbH
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#pragma once
+
+#include <osmocom/core/msgb.h>
+
+#include <stdint.h>
+
+#define OSMO_GCR_MIN_LEN 13
+
+/*! Parsed representation of Global Call Reference, 3GPP TS 29.205 Table B 2.1.9.1. */
+struct osmo_gcr_parsed {
+ uint8_t net[5]; /** Network ID, ITU-T Q.1902.3 */
+ uint8_t net_len; /** length (3-5 octets) of gsm29205_gcr#net */
+ uint16_t node; /** Node ID */
+ uint8_t cr[5]; /** Call Reference ID */
+};
+
+uint8_t osmo_enc_gcr(struct msgb *msg, const struct osmo_gcr_parsed *g);
+int osmo_dec_gcr(struct osmo_gcr_parsed *gcr, const uint8_t *elem, uint8_t len);