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
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
/* packet-t124.c
* Routines for t124 packet dissection
* Copyright 2010, Graeme Lunt
*
* 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 <epan/exceptions.h>
#include <epan/conversation.h>
#include <epan/asn1.h>
#include "packet-per.h"
#include "packet-ber.h"
#include "packet-t124.h"
#ifdef _MSC_VER
/* disable: "warning C4146: unary minus operator applied to unsigned type, result still unsigned" */
#pragma warning(disable:4146)
#endif
#define PNAME "GENERIC-CONFERENCE-CONTROL T.124"
#define PSNAME "T.124"
#define PFNAME "t124"
void proto_register_t124(void);
void proto_reg_handoff_t124(void);
/* Initialize the protocol and registered fields */
static int proto_t124 = -1;
static proto_tree *top_tree = NULL;
#include "packet-t124-hf.c"
/* Initialize the subtree pointers */
static int ett_t124 = -1;
static int ett_t124_connectGCCPDU = -1;
static int hf_t124_ConnectData = -1;
static int hf_t124_connectGCCPDU = -1;
static int hf_t124_DomainMCSPDU_PDU = -1;
static guint32 channelId = -1;
static dissector_table_t t124_ns_dissector_table=NULL;
static dissector_table_t t124_sd_dissector_table=NULL;
#include "packet-t124-ett.c"
#include "packet-t124-fn.c"
static const per_sequence_t t124Heur_sequence[] = {
{ &hf_t124_t124Identifier , ASN1_NO_EXTENSIONS , ASN1_NOT_OPTIONAL, dissect_t124_Key },
{ NULL, 0, 0, NULL }
};
void
register_t124_ns_dissector(const char *nsKey, dissector_t dissector, int proto)
{
dissector_handle_t dissector_handle;
dissector_handle=create_dissector_handle(dissector, proto);
dissector_add_string("t124.ns", nsKey, dissector_handle);
}
void register_t124_sd_dissector(packet_info *pinfo _U_, guint32 channelId_param, dissector_t dissector, int proto)
{
/* XXX: we should keep the sub-dissectors list per conversation
as the same channels may be used.
While we are just using RDP over T.124, then we can get away with it.
*/
dissector_handle_t dissector_handle;
dissector_handle=create_dissector_handle(dissector, proto);
dissector_add_uint("t124.sd", channelId_param, dissector_handle);
}
guint32 t124_get_last_channelId(void)
{
return channelId;
}
void t124_set_top_tree(proto_tree *tree)
{
top_tree = tree;
}
int dissect_DomainMCSPDU_PDU(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
int offset = 0;
asn1_ctx_t asn1_ctx;
asn1_ctx_init(&asn1_ctx, ASN1_ENC_PER, TRUE, pinfo);
offset = dissect_t124_DomainMCSPDU(tvb, offset, &asn1_ctx, tree, hf_t124_DomainMCSPDU_PDU);
offset += 7; offset >>= 3;
return offset;
}
static int
dissect_t124(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data _U_)
{
proto_item *item = NULL;
proto_tree *tree = NULL;
asn1_ctx_t asn1_ctx;
top_tree = parent_tree;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "T.124");
col_clear(pinfo->cinfo, COL_INFO);
item = proto_tree_add_item(parent_tree, proto_t124, tvb, 0, tvb_captured_length(tvb), ENC_NA);
tree = proto_item_add_subtree(item, ett_t124);
asn1_ctx_init(&asn1_ctx, ASN1_ENC_PER, TRUE, pinfo);
dissect_t124_ConnectData(tvb, 0, &asn1_ctx, tree, hf_t124_ConnectData);
return tvb_captured_length(tvb);
}
static gboolean
dissect_t124_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, void *data _U_)
{
asn1_ctx_t asn1_ctx;
volatile gboolean failed = FALSE;
asn1_ctx_init(&asn1_ctx, ASN1_ENC_PER, TRUE, pinfo);
/*
* We must catch all the "ran past the end of the packet" exceptions
* here and, if we catch one, just return FALSE. It's too painful
* to have a version of dissect_per_sequence() that checks all
* references to the tvbuff before making them and returning "no"
* if they would fail.
*
* We (ab)use hf_t124_connectGCCPDU here just to give a valid entry...
*/
TRY {
(void) dissect_per_sequence(tvb, 0, &asn1_ctx, NULL, hf_t124_connectGCCPDU, -1, t124Heur_sequence);
} CATCH_BOUNDS_ERRORS {
failed = TRUE;
} ENDTRY;
if (!failed && ((asn1_ctx.external.direct_reference != NULL) &&
(strcmp(asn1_ctx.external.direct_reference, "0.0.20.124.0.1") == 0))) {
dissect_t124(tvb, pinfo, parent_tree, data);
return TRUE;
}
return FALSE;
}
/*--- proto_register_t124 -------------------------------------------*/
void proto_register_t124(void) {
/* List of fields */
static hf_register_info hf[] = {
{ &hf_t124_ConnectData,
{ "ConnectData", "t124.ConnectData",
FT_NONE, BASE_NONE, NULL, 0,
NULL, HFILL }},
{ &hf_t124_connectGCCPDU,
{ "connectGCCPDU", "t124.connectGCCPDU",
FT_UINT32, BASE_DEC, VALS(t124_ConnectGCCPDU_vals), 0,
NULL, HFILL }},
{ &hf_t124_DomainMCSPDU_PDU,
{ "DomainMCSPDU", "t124.DomainMCSPDU",
FT_UINT32, BASE_DEC, VALS(t124_DomainMCSPDU_vals), 0,
NULL, HFILL }},
#include "packet-t124-hfarr.c"
};
/* List of subtrees */
static gint *ett[] = {
&ett_t124,
&ett_t124_connectGCCPDU,
#include "packet-t124-ettarr.c"
};
/* Register protocol */
proto_t124 = proto_register_protocol(PNAME, PSNAME, PFNAME);
/* Register fields and subtrees */
proto_register_field_array(proto_t124, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
t124_ns_dissector_table = register_dissector_table("t124.ns", "T.124 H.221 Non Standard Dissectors", proto_t124, FT_STRING, STRING_CASE_SENSITIVE);
t124_sd_dissector_table = register_dissector_table("t124.sd", "T.124 H.221 Send Data Dissectors", proto_t124, FT_UINT32, BASE_HEX);
register_dissector("t124", dissect_t124, proto_t124);
}
void
proto_reg_handoff_t124(void) {
register_ber_oid_dissector("0.0.20.124.0.1", dissect_t124, proto_t124, "Generic Conference Control");
heur_dissector_add("t125", dissect_t124_heur, "T.124 over T.125", "t124_t125", proto_t124, HEURISTIC_ENABLE);
}
|
