Dissector for the Osmocom GSUP Protocol

The Osmocom GSUP protocol is a light-weight alternative to the
classic GSM MAP protocol. It operates between (MSC|SGSN) and HLR.

Change-Id: I954c7e332dce3a8855f7f4ace0b878f66da6f02e
Reviewed-on: https://code.wireshark.org/review/25477
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 448 insertions, 0 deletions

diff --git a/epan/dissectors/packet-gsm_gsup.c b/epan/dissectors/packet-gsm_gsup.c
new file mode 100644
index 0000000000..e67e412a43
--- /dev/null
+++ b/epan/dissectors/packet-gsm_gsup.c
@@ -0,0 +1,448 @@
+/* packet-gsm_gsup.c
+ * Dissector for Osmocom Generic Subscriber Update Protocol (GSUP)
+ *
+ * (C) 2017-2018 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * 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.
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+#include <epan/conversation.h>
+
+#include "packet-e164.h"
+#include "packet-e212.h"
+#include "packet-dns.h"
+
+/* GSUP is a non-standard, Osmocom-specific protocol used between cellular
+ * network core elements and the HLR.  It is a much simplified replacement
+ * for the GSM MAP (Mobile Application Part), which requires a full stack
+ * of SIGTRAN transport, SCCP as well as TCP.
+ *
+ * More information about GSUP can be found in the OsmoHLR user manual
+ * found at http://ftp.osmocom.org/docs/latest/osmohlr-usermanual.pdf
+ */
+
+/***********************************************************************
+ * GSUP Protocol Definitions, see libosmocore/include/gsm/gsup.h
+ ***********************************************************************/
+
+#define OSMO_GSUP_PORT 4222
+#define IPAC_PROTO_EXT_GSUP 0x05
+
+/*! Maximum nubmer of PDP inside \ref osmo_gsup_message */
+#define OSMO_GSUP_MAX_NUM_PDP_INFO		10 /* GSM 09.02 limits this to 50 */
+/*! Maximum number of auth info inside \ref osmo_gsup_message */
+#define OSMO_GSUP_MAX_NUM_AUTH_INFO		5
+/*! Maximum number of octets encoding MSISDN in BCD format */
+#define OSMO_GSUP_MAX_MSISDN_LEN		9
+
+#define OSMO_GSUP_PDP_TYPE_SIZE			2
+
+/*! Information Element Identifiers for GSUP IEs */
+enum osmo_gsup_iei {
+	OSMO_GSUP_IMSI_IE			= 0x01,
+	OSMO_GSUP_CAUSE_IE			= 0x02,
+	OSMO_GSUP_AUTH_TUPLE_IE			= 0x03,
+	OSMO_GSUP_PDP_INFO_COMPL_IE		= 0x04,
+	OSMO_GSUP_PDP_INFO_IE			= 0x05,
+	OSMO_GSUP_CANCEL_TYPE_IE		= 0x06,
+	OSMO_GSUP_FREEZE_PTMSI_IE		= 0x07,
+	OSMO_GSUP_MSISDN_IE			= 0x08,
+	OSMO_GSUP_HLR_NUMBER_IE			= 0x09,
+	OSMO_GSUP_PDP_CONTEXT_ID_IE		= 0x10,
+	OSMO_GSUP_PDP_TYPE_IE			= 0x11,
+	OSMO_GSUP_ACCESS_POINT_NAME_IE		= 0x12,
+	OSMO_GSUP_PDP_QOS_IE			= 0x13,
+	OSMO_GSUP_CHARG_CHAR_IE			= 0x14,
+	OSMO_GSUP_RAND_IE			= 0x20,
+	OSMO_GSUP_SRES_IE			= 0x21,
+	OSMO_GSUP_KC_IE				= 0x22,
+	/* 3G support */
+	OSMO_GSUP_IK_IE				= 0x23,
+	OSMO_GSUP_CK_IE				= 0x24,
+	OSMO_GSUP_AUTN_IE			= 0x25,
+	OSMO_GSUP_AUTS_IE			= 0x26,
+	OSMO_GSUP_RES_IE			= 0x27,
+	OSMO_GSUP_CN_DOMAIN_IE			= 0x28,
+};
+
+/*! GSUP message type */
+enum osmo_gsup_message_type {
+	OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST	= 0x04,
+	OSMO_GSUP_MSGT_UPDATE_LOCATION_ERROR	= 0x05,
+	OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT	= 0x06,
+
+	OSMO_GSUP_MSGT_SEND_AUTH_INFO_REQUEST	= 0x08,
+	OSMO_GSUP_MSGT_SEND_AUTH_INFO_ERROR	= 0x09,
+	OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT	= 0x0a,
+
+	OSMO_GSUP_MSGT_AUTH_FAIL_REPORT		= 0x0b,
+
+	OSMO_GSUP_MSGT_PURGE_MS_REQUEST		= 0x0c,
+	OSMO_GSUP_MSGT_PURGE_MS_ERROR		= 0x0e,
+	OSMO_GSUP_MSGT_PURGE_MS_RESULT		= 0x0f,
+
+	OSMO_GSUP_MSGT_INSERT_DATA_REQUEST	= 0x10,
+	OSMO_GSUP_MSGT_INSERT_DATA_ERROR	= 0x11,
+	OSMO_GSUP_MSGT_INSERT_DATA_RESULT	= 0x12,
+
+	OSMO_GSUP_MSGT_DELETE_DATA_REQUEST	= 0x14,
+	OSMO_GSUP_MSGT_DELETE_DATA_ERROR	= 0x15,
+	OSMO_GSUP_MSGT_DELETE_DATA_RESULT	= 0x16,
+
+	OSMO_GSUP_MSGT_LOCATION_CANCEL_REQUEST	= 0x1c,
+	OSMO_GSUP_MSGT_LOCATION_CANCEL_ERROR	= 0x1d,
+	OSMO_GSUP_MSGT_LOCATION_CANCEL_RESULT	= 0x1f,
+};
+
+#define OSMO_GSUP_IS_MSGT_REQUEST(msgt) (((msgt) & 0b00000011) == 0b00)
+#define OSMO_GSUP_IS_MSGT_ERROR(msgt)   (((msgt) & 0b00000011) == 0b01)
+#define OSMO_GSUP_TO_MSGT_ERROR(msgt)   (((msgt) & 0b11111100) | 0b01)
+
+enum osmo_gsup_cancel_type {
+	OSMO_GSUP_CANCEL_TYPE_UPDATE		= 1, /* on wire: 0 */
+	OSMO_GSUP_CANCEL_TYPE_WITHDRAW		= 2, /* on wire: 1 */
+};
+
+enum osmo_gsup_cn_domain {
+	OSMO_GSUP_CN_DOMAIN_PS			= 1,
+	OSMO_GSUP_CN_DOMAIN_CS			= 2,
+};
+
+
+/***********************************************************************
+ * Wireshark Dissector Implementation
+ ***********************************************************************/
+
+void proto_register_gsup(void);
+void proto_reg_handoff_gsup(void);
+
+static int proto_gsup = -1;
+
+static int hf_gsup_msg_type = -1;
+static int hf_gsup_iei = -1;
+static int hf_gsup_ie_len = -1;
+static int hf_gsup_ie_payload = -1;
+static int hf_gsup_cause = -1;
+static int hf_gsup_pdp_info_compl = -1;
+static int hf_gsup_cancel_type = -1;
+static int hf_gsup_freeze_ptmsi = -1;
+static int hf_gsup_pdp_context_id = -1;
+static int hf_gsup_charg_char = -1;
+static int hf_gsup_apn = -1;
+static int hf_gsup_cn_domain = -1;
+static int hf_gsup_rand = -1;
+static int hf_gsup_sres = -1;
+static int hf_gsup_kc = -1;
+static int hf_gsup_ik = -1;
+static int hf_gsup_ck = -1;
+static int hf_gsup_autn = -1;
+static int hf_gsup_auts = -1;
+static int hf_gsup_res = -1;
+
+static gint ett_gsup = -1;
+static gint ett_gsup_ie = -1;
+
+static const value_string gsup_iei_types[] = {
+	{ OSMO_GSUP_IMSI_IE,		"IMSI" },
+	{ OSMO_GSUP_CAUSE_IE,		"Cause" },
+	{ OSMO_GSUP_AUTH_TUPLE_IE,	"Authentication Tuple" },
+	{ OSMO_GSUP_PDP_INFO_COMPL_IE,	"PDP Information Complete" },
+	{ OSMO_GSUP_PDP_INFO_IE,	"PDP Information" },
+	{ OSMO_GSUP_CANCEL_TYPE_IE,	"Cancel Type" },
+	{ OSMO_GSUP_FREEZE_PTMSI_IE,	"Freeze P-TMSI" },
+	{ OSMO_GSUP_MSISDN_IE,		"MSISDN" },
+	{ OSMO_GSUP_HLR_NUMBER_IE,	"HLR Number" },
+	{ OSMO_GSUP_PDP_CONTEXT_ID_IE,	"PDP Context ID" },
+	{ OSMO_GSUP_PDP_TYPE_IE,	"PDP Type" },
+	{ OSMO_GSUP_ACCESS_POINT_NAME_IE, "Access Point Name (APN)" },
+	{ OSMO_GSUP_PDP_QOS_IE,		"PDP Quality of Service (QoS)" },
+	{ OSMO_GSUP_CHARG_CHAR_IE,	"Charging Character" },
+	{ OSMO_GSUP_RAND_IE,		"RAND" },
+	{ OSMO_GSUP_SRES_IE,		"SRES" },
+	{ OSMO_GSUP_KC_IE,		"Kc" },
+	{ OSMO_GSUP_IK_IE,		"IK" },
+	{ OSMO_GSUP_CK_IE,		"CK" },
+	{ OSMO_GSUP_AUTN_IE,		"AUTN" },
+	{ OSMO_GSUP_AUTS_IE,		"AUTS" },
+	{ OSMO_GSUP_RES_IE,		"RES" },
+	{ OSMO_GSUP_CN_DOMAIN_IE,	"CN Domain" },
+	{ 0, NULL }
+};
+
+static const value_string gsup_msg_types[] = {
+	{ OSMO_GSUP_MSGT_UPDATE_LOCATION_REQUEST, 	"UpdateLocation Request" },
+	{ OSMO_GSUP_MSGT_UPDATE_LOCATION_ERROR, 	"UpdateLocation Error" },
+	{ OSMO_GSUP_MSGT_UPDATE_LOCATION_RESULT,	"UpdateLocation Result" },
+	{ OSMO_GSUP_MSGT_SEND_AUTH_INFO_REQUEST,	"SendAuthInfo Request" },
+	{ OSMO_GSUP_MSGT_SEND_AUTH_INFO_ERROR,		"SendAuthInfo Error" },
+	{ OSMO_GSUP_MSGT_SEND_AUTH_INFO_RESULT,		"SendAuthInfo Result" },
+	{ OSMO_GSUP_MSGT_AUTH_FAIL_REPORT,		"AuthFail Report" },
+	{ OSMO_GSUP_MSGT_PURGE_MS_REQUEST,		"PurgeMS Request" },
+	{ OSMO_GSUP_MSGT_PURGE_MS_ERROR,		"PurgeMS Error" },
+	{ OSMO_GSUP_MSGT_PURGE_MS_RESULT,		"PurgeMS Result" },
+	{ OSMO_GSUP_MSGT_INSERT_DATA_REQUEST,		"InsertSubscriberData Request" },
+	{ OSMO_GSUP_MSGT_INSERT_DATA_ERROR,		"InsertSubscriberData Error" },
+	{ OSMO_GSUP_MSGT_INSERT_DATA_RESULT,		"InsertSubscriberData Result" },
+	{ OSMO_GSUP_MSGT_DELETE_DATA_REQUEST,		"DeleteSubscriberData Request" },
+	{ OSMO_GSUP_MSGT_DELETE_DATA_ERROR,		"DeleteSubscriberData Error" },
+	{ OSMO_GSUP_MSGT_DELETE_DATA_RESULT,		"DeleteSubscriberData Result" },
+	{ OSMO_GSUP_MSGT_LOCATION_CANCEL_REQUEST,	"LocationCancel Request" },
+	{ OSMO_GSUP_MSGT_LOCATION_CANCEL_ERROR,		"LocationCancel Error" },
+	{ OSMO_GSUP_MSGT_LOCATION_CANCEL_RESULT,	"LocationCancel Result" },
+	{ 0, NULL }
+};
+
+static const value_string gsup_cancel_types[] = {
+	{ OSMO_GSUP_CANCEL_TYPE_UPDATE,		"Update" },
+	{ OSMO_GSUP_CANCEL_TYPE_WITHDRAW,	"Withdraw" },
+	{ 0, NULL }
+};
+
+static const value_string gsup_cndomain_types[] = {
+	{ OSMO_GSUP_CN_DOMAIN_PS,		"PS" },
+	{ OSMO_GSUP_CN_DOMAIN_CS,		"CS" },
+	{ 0, NULL }
+};
+
+static gint
+dissect_gsup_tlvs(tvbuff_t *tvb, int base_offs, int length, packet_info *pinfo, proto_tree *tree,
+		  proto_item *gsup_ti)
+{
+	int offset = base_offs;
+
+	while (offset - base_offs < length) {
+		guint8 tag;
+		unsigned int len;
+		proto_item *ti;
+		proto_tree *att_tree;
+		const guchar *apn;
+		const gchar *str;
+		guint apn_len;
+
+		tag = tvb_get_guint8(tvb, offset);
+		offset++;
+
+		len = tvb_get_guint8(tvb, offset);
+		offset++;
+
+		att_tree = proto_tree_add_subtree_format(tree, tvb, offset-2, len+2, ett_gsup_ie, &ti,
+						"IE: %s",
+						val_to_str(tag, gsup_iei_types, "Unknown 0x%02x"));
+		proto_tree_add_item(att_tree, hf_gsup_iei, tvb, offset-2, 1, ENC_BIG_ENDIAN);
+		proto_tree_add_uint(att_tree, hf_gsup_ie_len, tvb, offset-1, 1, len);
+
+		switch (tag) {
+		/* Nested TLVs */
+		case OSMO_GSUP_AUTH_TUPLE_IE:
+		case OSMO_GSUP_PDP_INFO_IE:
+			dissect_gsup_tlvs(tvb, offset, len, pinfo, att_tree, gsup_ti);
+			break;
+		/* Normal IEs */
+		case OSMO_GSUP_RAND_IE:
+			proto_tree_add_item(att_tree, hf_gsup_rand, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_SRES_IE:
+			proto_tree_add_item(att_tree, hf_gsup_sres, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_KC_IE:
+			proto_tree_add_item(att_tree, hf_gsup_kc, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_IK_IE:
+			proto_tree_add_item(att_tree, hf_gsup_ik, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_CK_IE:
+			proto_tree_add_item(att_tree, hf_gsup_ck, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_AUTN_IE:
+			proto_tree_add_item(att_tree, hf_gsup_autn, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_AUTS_IE:
+			proto_tree_add_item(att_tree, hf_gsup_auts, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_RES_IE:
+			proto_tree_add_item(att_tree, hf_gsup_res, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_CN_DOMAIN_IE:
+			proto_tree_add_item(att_tree, hf_gsup_cn_domain, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_CANCEL_TYPE_IE:
+			proto_tree_add_item(att_tree, hf_gsup_cancel_type, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_IMSI_IE:
+			str = dissect_e212_imsi(tvb, pinfo, att_tree, offset, len, FALSE);
+			proto_item_append_text(ti, ", %s", str);
+			proto_item_append_text(gsup_ti, ", IMSI: %s", str);
+			break;
+		case OSMO_GSUP_MSISDN_IE:
+			str = dissect_e164_msisdn(tvb, att_tree, offset+1, len-1, E164_ENC_BCD);
+			proto_item_append_text(ti, ", %s", str);
+			proto_item_append_text(gsup_ti, ", MSISDN: %s", str);
+			break;
+		case OSMO_GSUP_ACCESS_POINT_NAME_IE:
+			get_dns_name(tvb, offset, len, 0, &apn, &apn_len);
+			proto_tree_add_string(att_tree, hf_gsup_apn, tvb, offset, len, apn);
+			proto_item_append_text(ti, ", %s", apn);
+			break;
+		case OSMO_GSUP_PDP_CONTEXT_ID_IE:
+			proto_tree_add_item(att_tree, hf_gsup_pdp_context_id, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_CHARG_CHAR_IE:
+			proto_tree_add_item(att_tree, hf_gsup_charg_char, tvb, offset, len, ENC_ASCII|ENC_NA);
+			break;
+		case OSMO_GSUP_CAUSE_IE:
+			proto_tree_add_item(att_tree, hf_gsup_cause, tvb, offset, len, ENC_NA);
+			break;
+		/* boolean flags: either they're present or not */
+		case OSMO_GSUP_PDP_INFO_COMPL_IE:
+			proto_tree_add_item(att_tree, hf_gsup_pdp_info_compl, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_FREEZE_PTMSI_IE:
+			proto_tree_add_item(att_tree, hf_gsup_freeze_ptmsi, tvb, offset, len, ENC_NA);
+			break;
+		case OSMO_GSUP_HLR_NUMBER_IE:
+		case OSMO_GSUP_PDP_TYPE_IE:
+		case OSMO_GSUP_PDP_QOS_IE:
+		default:
+			/* Unknown/unsupported IE: Print IEI, Length and Payload */
+			proto_tree_add_item(att_tree, hf_gsup_iei, tvb, offset-2, 1, ENC_BIG_ENDIAN);
+			proto_tree_add_uint(att_tree, hf_gsup_ie_len, tvb, offset-1, 1, len);
+			proto_tree_add_item(att_tree, hf_gsup_ie_payload, tvb, offset, len, ENC_NA);
+			break;
+		}
+
+		offset += len;
+	}
+
+	return offset;
+}
+
+static int
+dissect_gsup(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
+{
+	int len, offset = 0;
+	proto_item *ti;
+	proto_tree *gsup_tree = NULL;
+	guint8 msg_type;
+	const char *str;
+
+
+	len = tvb_reported_length(tvb);
+	msg_type = tvb_get_guint8(tvb, offset + 0);
+
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "GSUP");
+
+	col_clear(pinfo->cinfo, COL_INFO);
+	str = val_to_str(msg_type, gsup_msg_types, "Unknown GSUP Message Type 0x%02x");
+	col_append_fstr(pinfo->cinfo, COL_INFO, "%s ", str);
+
+	if (tree) {
+		ti = proto_tree_add_protocol_format(tree, proto_gsup, tvb, 0, len, "GSUP %s", str);
+		gsup_tree = proto_item_add_subtree(ti, ett_gsup);
+
+		proto_tree_add_item(gsup_tree, hf_gsup_msg_type,
+				    tvb, offset, 1, ENC_BIG_ENDIAN);
+		offset++;
+
+		dissect_gsup_tlvs(tvb, offset, tvb_reported_length_remaining(tvb, offset), pinfo,
+				  gsup_tree, ti);
+	}
+
+	return tvb_captured_length(tvb);
+}
+
+void
+proto_register_gsup(void)
+{
+	static hf_register_info hf[] = {
+		{ &hf_gsup_msg_type, { "Message Type", "gsup.msg_type",
+		  FT_UINT8, BASE_DEC, VALS(gsup_msg_types), 0, NULL, HFILL } },
+		{ &hf_gsup_iei, { "Information Element Identifier", "gsup.ie.iei",
+		  FT_UINT8, BASE_DEC, VALS(gsup_iei_types), 0, NULL, HFILL } },
+		{ &hf_gsup_ie_len, { "Information Element Length", "gsup.ie.len",
+		  FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } },
+		{ &hf_gsup_ie_payload, { "Information Element Payload", "gsup.ie.payload",
+		  FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL } },
+
+		{ &hf_gsup_rand, { "RAND", "gsup.rand",
+		  FT_BYTES, BASE_NONE, NULL, 0, "Random Challenge", HFILL } },
+		{ &hf_gsup_sres, { "SRES", "gsup.sres",
+		  FT_BYTES, BASE_NONE, NULL, 0, "GSM/GPRS Authentication Result SRES Value", HFILL } },
+		{ &hf_gsup_kc, { "Kc", "gsup.kc",
+		  FT_BYTES, BASE_NONE, NULL, 0, "GSM/GPRS Ciphering Key", HFILL } },
+		{ &hf_gsup_ik, { "IK", "gsup.ik",
+		  FT_BYTES, BASE_NONE, NULL, 0, "UMTS Integrity Protection Key", HFILL } },
+		{ &hf_gsup_ck, { "CK", "gsup.ck",
+		  FT_BYTES, BASE_NONE, NULL, 0, "UMTS Ciphering Key", HFILL } },
+		{ &hf_gsup_autn, { "AUTN", "gsup.autn",
+		  FT_BYTES, BASE_NONE, NULL, 0, "UMTS Authentication Nonce", HFILL } },
+		{ &hf_gsup_auts, { "AUTN", "gsup.auts",
+		  FT_BYTES, BASE_NONE, NULL, 0, "UMTS Authentication Sync", HFILL } },
+		{ &hf_gsup_res, { "RES", "gsup.res",
+		  FT_BYTES, BASE_NONE, NULL, 0, "UMTS Authentication Result", HFILL } },
+
+		{ &hf_gsup_cn_domain, { "CN Domain Indicator", "gsup.cn_domain",
+		  FT_UINT8, BASE_DEC, VALS(gsup_cndomain_types), 0, NULL, HFILL } },
+		{ &hf_gsup_cancel_type, { "Cancel Type", "gsup.cancel_type",
+		  FT_UINT8, BASE_DEC, VALS(gsup_cancel_types), 0, NULL, HFILL } },
+		{ &hf_gsup_pdp_info_compl, { "PDP Information Complete", "gsup.pdp_info_compl",
+		  FT_BOOLEAN, BASE_NONE, NULL, 0, NULL, HFILL } },
+		{ &hf_gsup_freeze_ptmsi, { "Freeze P-TMSI", "gsup.freeze_ptmsi",
+		  FT_BOOLEAN, BASE_NONE, NULL, 0, NULL, HFILL } },
+		{ &hf_gsup_apn, { "APN", "gsup.apn",
+		  FT_STRING, BASE_NONE, NULL, 0, "Access Point Name", HFILL } },
+		{ &hf_gsup_pdp_context_id, { "PDP Context ID", "gsup.pdp_context_id",
+		  FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL } },
+		{ &hf_gsup_charg_char, { "Charging Character", "gsup.charg_char",
+		  FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL } },
+		{ &hf_gsup_cause, { "Cause", "gsup.cause",
+		  FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL } },
+	};
+	static gint *ett[] = {
+		&ett_gsup,
+		&ett_gsup_ie,
+	};
+
+	proto_gsup = proto_register_protocol("Osmocom General Subscriber Update Protocol", "gsup", "gsup");
+	proto_register_field_array(proto_gsup, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_gsup(void)
+{
+	dissector_handle_t gsup_handle;
+	gsup_handle = create_dissector_handle(dissect_gsup, proto_gsup);
+	dissector_add_uint_with_preference("ipa.osmo.protocol", IPAC_PROTO_EXT_GSUP, gsup_handle);
+}
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vi: set shiftwidth=8 tabstop=8 noexpandtab:
+ * :indentSize=8:tabSize=8:noTabs=false:
+ */