summaryrefslogtreecommitdiffstats
path: root/epan/dissectors/packet-gmr1_dtap.c
blob: 914f7c358304af8b06fc2b03638209e72018af42 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/* packet-gmr1_dtap.c
 *
 * Routines for GMR-1 DTAP dissection in wireshark.
 * Copyright (c) 2011 Sylvain Munaut <tnt@246tNt.com>
 *
 * References:
 *  [1] ETSI TS 101 376-4-8 V1.3.1 - GMR-1 04.008
 *  [2] ETSI TS 101 376-4-8 V2.2.1 - GMPRS-1 04.008
 *  [3] ETSI TS 101 376-4-8 V3.1.1 - GMR-1 3G 44.008
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <epan/packet.h>

#include "packet-gmr1_common.h"

void proto_register_gmr1_dtap(void);
void proto_reg_handoff_gmr1_dtap(void);

/* GMR-1 DTAP proto */
static int proto_gmr1_dtap = -1;

static int hf_gmr1_dtap_protocol_discriminator = -1;
static int hf_gmr1_dtap_message_elements = -1;

/* GMR-1 DTAP sub tree */
static gint ett_gmr1_dtap = -1;
static gint ett_gmr1_pd = -1;

/* Handoffs */
static dissector_handle_t gsm_dtap_handle;
static dissector_handle_t dtap_handle;


static int
dissect_gmr1_dtap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
	guint32 len, offset;
	gmr1_msg_func_t msg_func;
	const gchar *msg_str;
	gint ett_tree;
	int hf_idx;
	proto_item *dtap_item = NULL/*, *pd_item = NULL*/;
	proto_tree *dtap_tree = NULL/*, *pd_tree = NULL*/;
	guint32 oct[2];
	guint8 pd;

	/* Scan init */
	len = tvb_captured_length(tvb);
	offset = 0;

	/* Protocol descriptor */
	oct[0] = tvb_get_guint8(tvb, offset++);

	if ((oct[0] & GMR1_PD_EXT_MSK) == GMR1_PD_EXT_VAL)
		pd = oct[0] & 0xff;
	else
		pd = oct[0] & 0x0f;

	/* HACK: Quick delegation hack to GSM */
	if (pd != GMR1_PD_RR) {
		call_dissector(gsm_dtap_handle, tvb, pinfo, tree);
		return tvb_captured_length(tvb);
	}

	/* Fill up some info */
	col_append_str(pinfo->cinfo, COL_INFO, " (DTAP) ");

	col_append_fstr(pinfo->cinfo, COL_INFO, "(%s) ",
		val_to_str(pd, gmr1_pd_short_vals, "Unknown (%u)"));

	/* Get message parameters */
	oct[1] = tvb_get_guint8(tvb, offset);

	gmr1_get_msg_params((gmr1_pd_e)pd, oct[1], &msg_str, &ett_tree, &hf_idx, &msg_func);

	/* Create protocol tree */
	if (msg_str == NULL)
	{
		dtap_item = proto_tree_add_protocol_format(
			tree, proto_gmr1_dtap, tvb, 0, len,
			"GMR-1 DTAP - Message Type (0x%02x)", oct[1]);
		dtap_tree = proto_item_add_subtree(dtap_item, ett_gmr1_dtap);

		col_append_fstr(pinfo->cinfo, COL_INFO, "Message Type (0x%02x) ", oct[1]);
	}
	else
	{
		dtap_item = proto_tree_add_protocol_format(
			tree, proto_gmr1_dtap, tvb, 0, -1,
			"GMR-1 DTAP - %s", msg_str);
		dtap_tree = proto_item_add_subtree(dtap_item, ett_gmr1_dtap);

		col_append_fstr(pinfo->cinfo, COL_INFO, "%s ", msg_str);
	}

	/* Start over */
	offset = 0;

	/* Protocol discriminator item */
	/*pd_item =*/ proto_tree_add_uint(
		dtap_tree, hf_gmr1_dtap_protocol_discriminator, tvb, 1, 1, pd);

	/*pd_tree = proto_item_add_subtree(pd_item, ett_gmr1_pd);*/

		/* Move on */
	offset++;

	/* Message type - [1] 11.4 */
	proto_tree_add_uint_format(
		dtap_tree, hf_idx, tvb, offset, 1, oct[1],
		"Message Type: %s", msg_str ? msg_str : "(Unknown)"
	);

	offset++;

	/* Decode elements */
	if (msg_func) {
		(*msg_func)(tvb, dtap_tree, pinfo, offset, len - offset);
	} else {
		proto_tree_add_item(dtap_tree, hf_gmr1_dtap_message_elements, tvb, offset, len - offset, ENC_NA);
	}

	/* Done ! */
	return tvb_captured_length(tvb);
}


void
proto_register_gmr1_dtap(void)
{
	static hf_register_info hf[] = {
		{ &hf_gmr1_dtap_protocol_discriminator,
		  { "Protocol Discriminator", "gmr1.dtap.protocol_discriminator",
			FT_UINT8, BASE_DEC, VALS(gmr1_pd_vals), 0x0,
			NULL, HFILL }
		},
		{ &hf_gmr1_dtap_message_elements,
		  { "Message elements", "gmr1.dtap.message_elements",
			FT_BYTES, BASE_NONE, NULL, 0x0,
			NULL, HFILL }
		},
	};

	static gint *ett[] = {
		&ett_gmr1_dtap,
		&ett_gmr1_pd,
	};

	/* Setup protocol subtree array */
	proto_register_subtree_array(ett, array_length(ett));

	/* Register the protocol name and field description */
	proto_gmr1_dtap = proto_register_protocol("GEO-Mobile Radio (1) DTAP", "GMR-1 DTAP", "gmr1.dtap");
	proto_register_field_array(proto_gmr1_dtap, hf, array_length(hf));

	/* Register dissector */
	dtap_handle = register_dissector("gmr1_dtap", dissect_gmr1_dtap, proto_gmr1_dtap);
}

void
proto_reg_handoff_gmr1_dtap(void)
{
	dissector_add_uint("lapsat.sapi", 0 , dtap_handle); /* LAPSat: CC/RR/MM */
	dissector_add_uint("lapsat.sapi", 3 , dtap_handle); /* LAPSat: SMS/SS */

	gsm_dtap_handle = find_dissector_add_dependency("gsm_a_dtap", proto_gmr1_dtap);
}

/*
 * Editor modelines  -  https://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:
 */