gprs: Add encoder/decoder for the Subscriber Update Protocol

This patch adds functions to encode and decode GSUP messages. This
does not include the layer 1 framing (IPA). The messages so far
supported are: send_auth_info_*, update_location_*,
location_cancellation_*.

Sponsored-by: On-Waves ehf

2 files changed, 104 insertions, 1 deletions

diff --git a/openbsc/include/openbsc/Makefile.am b/openbsc/include/openbsc/Makefile.am
index 70365f2b3..92978e7ce 100644
--- a/openbsc/include/openbsc/Makefile.am
+++ b/openbsc/include/openbsc/Makefile.am
@@ -15,7 +15,7 @@ noinst_HEADERS = abis_nm.h abis_rsl.h db.h gsm_04_08.h gsm_data.h \
 		bss.h gsm_data_shared.h ipaccess.h mncc_int.h \
 		arfcn_range_encode.h nat_rewrite_trie.h bsc_nat_callstats.h \
 		osmux.h mgcp_transcode.h rtp.h gprs_utils.h \
-		 gprs_gb_parse.h smpp.h meas_feed.h
+		 gprs_gb_parse.h smpp.h meas_feed.h gprs_gsup_messages.h
 
 openbsc_HEADERS = gsm_04_08.h meas_rep.h bsc_api.h
 openbscdir = $(includedir)/openbsc
diff --git a/openbsc/include/openbsc/gprs_gsup_messages.h b/openbsc/include/openbsc/gprs_gsup_messages.h
new file mode 100644
index 000000000..f1a9978a3
--- /dev/null
+++ b/openbsc/include/openbsc/gprs_gsup_messages.h
@@ -0,0 +1,103 @@
+/* GPRS Subscriber Update Protocol message encoder/decoder */
+
+/* (C) 2014 by Sysmocom s.f.m.c. GmbH
+ * All Rights Reserved
+ *
+ * Author: Jacob Erlbeck
+ *
+ * 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/>.
+ *
+ */
+#pragma once
+
+#include <stdint.h>
+#include <openbsc/gsm_04_08_gprs.h>
+#include <openbsc/gsm_data.h>
+/* Needed for GSM_IMSI_LENGTH: */
+#include <openbsc/gsm_subscriber.h>
+
+#define GPRS_GSUP_MAX_NUM_PDP_INFO		10 /* GSM 09.02 limits this to 50 */
+#define GPRS_GSUP_MAX_NUM_AUTH_INFO		5
+
+#define GPRS_GSUP_PDP_TYPE_SIZE			2
+
+enum gprs_gsup_iei {
+	GPRS_GSUP_IMSI_IE			= 0x01,
+	GPRS_GSUP_CAUSE_IE			= 0x02,
+	GPRS_GSUP_AUTH_TUPLE_IE			= 0x03,
+	GPRS_GSUP_PDP_INFO_COMPL_IE		= 0x04,
+	GPRS_GSUP_PDP_INFO_IE			= 0x05,
+	GPRS_GSUP_CANCEL_TYPE_IE		= 0x06,
+	GPRS_GSUP_PDP_CONTEXT_ID_IE		= 0x10,
+	GPRS_GSUP_PDP_TYPE_IE			= 0x11,
+	GPRS_GSUP_ACCESS_POINT_NAME_IE		= 0x12,
+	GPRS_GSUP_RAND_IE			= 0x20,
+	GPRS_GSUP_SRES_IE			= 0x21,
+	GPRS_GSUP_KC_IE				= 0x22
+};
+
+enum gprs_gsup_message_type {
+	GPRS_GSUP_MSGT_UPDATE_LOCATION_REQUEST	= 0b00000100,
+	GPRS_GSUP_MSGT_UPDATE_LOCATION_ERROR	= 0b00000101,
+	GPRS_GSUP_MSGT_UPDATE_LOCATION_RESULT	= 0b00000110,
+
+	GPRS_GSUP_MSGT_SEND_AUTH_INFO_REQUEST	= 0b00001000,
+	GPRS_GSUP_MSGT_SEND_AUTH_INFO_ERROR	= 0b00001001,
+	GPRS_GSUP_MSGT_SEND_AUTH_INFO_RESULT	= 0b00001010,
+
+	GPRS_GSUP_MSGT_PURGE_MS_REQUEST		= 0b00001100,
+	GPRS_GSUP_MSGT_PURGE_MS_ERROR		= 0b00001101,
+	GPRS_GSUP_MSGT_PURGE_MS_RESULT		= 0b00001110,
+
+	GPRS_GSUP_MSGT_INSERT_DATA_REQUEST	= 0b00010000,
+	GPRS_GSUP_MSGT_INSERT_DATA_ERROR	= 0b00010001,
+	GPRS_GSUP_MSGT_INSERT_DATA_RESULT	= 0b00010010,
+
+	GPRS_GSUP_MSGT_DELETE_DATA_REQUEST	= 0b00010100,
+	GPRS_GSUP_MSGT_DELETE_DATA_ERROR	= 0b00010101,
+	GPRS_GSUP_MSGT_DELETE_DATA_RESULT	= 0b00010110,
+
+	GPRS_GSUP_MSGT_LOCATION_CANCEL_REQUEST	= 0b00011100,
+	GPRS_GSUP_MSGT_LOCATION_CANCEL_ERROR	= 0b00011101,
+	GPRS_GSUP_MSGT_LOCATION_CANCEL_RESULT	= 0b00011110,
+};
+
+enum gprs_gsup_cancel_type {
+	GPRS_GSUP_CANCEL_TYPE_UPDATE		= 1, /* on wire: 0 */
+	GPRS_GSUP_CANCEL_TYPE_WITHDRAW		= 2, /* on wire: 1 */
+};
+
+struct gprs_gsup_pdp_info {
+	unsigned int			context_id;
+	int				have_info;
+	uint16_t			pdp_type;
+	const uint8_t			*apn_enc;
+	size_t				apn_enc_len;
+};
+
+struct gprs_gsup_message {
+	enum gprs_gsup_message_type	message_type;
+	char				imsi[GSM_IMSI_LENGTH];
+	enum gsm48_gmm_cause		cause;
+	enum gprs_gsup_cancel_type	cancel_type;
+	int				pdp_info_compl;
+	struct gsm_auth_tuple		auth_tuples[GPRS_GSUP_MAX_NUM_AUTH_INFO];
+	size_t				num_auth_tuples;
+	struct gprs_gsup_pdp_info	pdp_infos[GPRS_GSUP_MAX_NUM_PDP_INFO];
+	size_t				num_pdp_infos;
+};
+
+int gprs_gsup_decode(const uint8_t *data, size_t data_len,
+		     struct gprs_gsup_message *gsup_msg);
+void gprs_gsup_encode(struct msgb *msg, const struct gprs_gsup_message *gsup_msg);