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
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
|
/* packet-smp.c
* Routines for Session Multiplex Protocol (SMP) dissection
* January 2017 Uli Heilmeier with the help of Michael Mann
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/*
* References:
*
* MC-SMP - https://docs.microsoft.com/en-us/openspecs/windows_protocols/mc-smp
* MS-TDS - https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-tds
* https://docs.microsoft.com/en-us/sql/relational-databases/native-client/features/using-multiple-active-result-sets-mars
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SMID | FLAGS | SID |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | LENGTH |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SEQNUM |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | WNDW |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* / DATA (variable) /
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
#include <config.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/decode_as.h>
#include "packet-tcp.h"
void proto_reg_handoff_smp(void);
void proto_register_smp(void);
static int proto_smp;
static int hf_smp_smid;
static int hf_smp_flags;
static int hf_smp_flags_syn;
static int hf_smp_flags_ack;
static int hf_smp_flags_fin;
static int hf_smp_flags_data;
static int hf_smp_sid;
static int hf_smp_length;
static int hf_smp_seqnum;
static int hf_smp_wndw;
static int hf_smp_data;
static int ett_smp;
static int ett_smp_flags;
#define SMP_FLAGS_SYN 0x01
#define SMP_FLAGS_ACK 0x02
#define SMP_FLAGS_FIN 0x04
#define SMP_FLAGS_DATA 0x08
#define SMP_MIN_LENGTH 16
static dissector_handle_t tds_handle;
static dissector_handle_t smp_handle;
static dissector_table_t smp_payload_table;
static bool reassemble_smp = true;
static void smp_prompt(packet_info *pinfo _U_, char* result)
{
snprintf(result, MAX_DECODE_AS_PROMPT_LEN, "Payload as");
}
/* Code to actually dissect the packets */
static int
dissect_smp_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, bool tds_payload)
{
unsigned offset = 0;
unsigned remaining_bytes;
proto_item *ti;
proto_tree *smp_tree;
uint32_t flags, sid, smp_length;
tvbuff_t* next_tvb;
int parsed_bytes;
static int * const flag_fields[] = {
&hf_smp_flags_syn,
&hf_smp_flags_ack,
&hf_smp_flags_fin,
&hf_smp_flags_data,
NULL
};
if (tvb_reported_length(tvb) < SMP_MIN_LENGTH)
return 0;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "SMP");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_smp, tvb, 0, -1, ENC_NA);
smp_tree = proto_item_add_subtree(ti, ett_smp);
proto_tree_add_item(smp_tree, hf_smp_smid, tvb, offset, 1, ENC_NA);
offset+=1;
proto_tree_add_bitmask(smp_tree, tvb, offset, hf_smp_flags, ett_smp_flags, flag_fields, ENC_NA);
flags = tvb_get_uint8(tvb, offset);
offset += 1;
proto_tree_add_item_ret_uint(smp_tree, hf_smp_sid, tvb, offset, 2, ENC_LITTLE_ENDIAN, &sid);
col_append_fstr(pinfo->cinfo, COL_INFO, "SID: %u", sid);
offset += 2;
if (flags & SMP_FLAGS_SYN)
col_append_str(pinfo->cinfo, COL_INFO, ", Syn");
if (flags & SMP_FLAGS_ACK)
col_append_str(pinfo->cinfo, COL_INFO, ", Ack");
if (flags & SMP_FLAGS_FIN)
col_append_str(pinfo->cinfo, COL_INFO, ", Fin");
if (flags & SMP_FLAGS_DATA)
col_append_str(pinfo->cinfo, COL_INFO, ", Data");
proto_tree_add_item_ret_uint(smp_tree, hf_smp_length, tvb, offset, 4, ENC_LITTLE_ENDIAN, &smp_length);
offset += 4;
proto_tree_add_item(smp_tree, hf_smp_seqnum, tvb, offset, 4, ENC_LITTLE_ENDIAN);
offset += 4;
proto_tree_add_item(smp_tree, hf_smp_wndw, tvb, offset, 4, ENC_LITTLE_ENDIAN);
offset += 4;
if ((flags & SMP_FLAGS_DATA) && (tvb_reported_length(tvb) > SMP_MIN_LENGTH)) {
next_tvb = tvb_new_subset_remaining(tvb, offset);
if (tds_payload) {
parsed_bytes = call_dissector(tds_handle, next_tvb, pinfo, tree);
} else {
parsed_bytes = dissector_try_payload(smp_payload_table, next_tvb, pinfo, tree);
}
if (parsed_bytes <= 0)
{
remaining_bytes = tvb_reported_length_remaining(tvb, offset);
if ( remaining_bytes < (smp_length - SMP_MIN_LENGTH)) {
// Fragmented
proto_tree_add_item(smp_tree, hf_smp_data, tvb, offset, remaining_bytes, ENC_NA);
offset += remaining_bytes;
}
else {
proto_tree_add_item(smp_tree, hf_smp_data, tvb, offset, smp_length - SMP_MIN_LENGTH, ENC_NA);
offset += (smp_length - SMP_MIN_LENGTH);
}
}
else {
offset += parsed_bytes;
}
}
return offset;
}
static unsigned get_smp_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
{
return tvb_get_letohl(tvb, offset + 4);
}
static int
dissect_smp_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
return dissect_smp_common(tvb, pinfo, tree, false);
}
static int dissect_smp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
{
if ((tvb_reported_length(tvb) > 0) && (tvb_get_uint8(tvb, 0) == 0x53)) {
tcp_dissect_pdus(tvb, pinfo, tree, reassemble_smp, SMP_MIN_LENGTH,
get_smp_pdu_len, dissect_smp_pdu, data);
return tvb_captured_length(tvb);
}
return 0;
}
static int
dissect_smp_tds(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
return dissect_smp_common(tvb, pinfo, tree, true);
}
void
proto_register_smp(void)
{
static hf_register_info hf[] = {
{ &hf_smp_smid,
{ "Smid", "smp.smid", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }},
{ &hf_smp_flags,
{ "Flags", "smp.flags", FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL } },
{ &hf_smp_flags_syn,
{ "Syn", "smp.flags.syn", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_SYN, NULL, HFILL }},
{ &hf_smp_flags_ack,
{ "Ack", "smp.flags.ack", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_ACK, NULL, HFILL }},
{ &hf_smp_flags_fin,
{ "Fin", "smp.flags.fin", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_FIN, NULL, HFILL }},
{ &hf_smp_flags_data,
{ "Data", "smp.flags.data", FT_BOOLEAN, 8, TFS(&tfs_set_notset), SMP_FLAGS_DATA, NULL, HFILL }},
{ &hf_smp_sid,
{ "SID", "smp.sid", FT_UINT16, BASE_DEC, NULL, 0, "Session ID", HFILL }},
{ &hf_smp_length,
{ "Length", "smp.length", FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }},
{ &hf_smp_seqnum,
{ "SeqNum", "smp.seqnum", FT_UINT32, BASE_HEX, NULL, 0, "Sequence Number", HFILL }},
{ &hf_smp_wndw,
{ "Wndw", "smp.wndw", FT_UINT32, BASE_HEX, NULL, 0, "Window Size", HFILL }},
{ &hf_smp_data,
{ "Data", "smp.data", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},
};
static int *ett[] = {
&ett_smp,
&ett_smp_flags,
};
module_t *smp_module;
proto_smp = proto_register_protocol("Session Multiplex Protocol", "SMP", "smp");
proto_register_field_array(proto_smp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
register_dissector("smp_tds", dissect_smp_tds, proto_smp);
smp_handle = register_dissector("smp", dissect_smp, proto_smp);
smp_payload_table = register_decode_as_next_proto(proto_smp, "smp.payload", "SMP Payload", smp_prompt);
smp_module = prefs_register_protocol(proto_smp, NULL);
prefs_register_bool_preference(smp_module, "desegment",
"Reassemble SMP messages spanning multiple TCP segments",
"Whether the SMP dissector should reassemble messages spanning multiple TCP segments."
" To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
&reassemble_smp);
}
void
proto_reg_handoff_smp(void)
{
dissector_add_for_decode_as_with_preference("tcp.port", smp_handle);
tds_handle = find_dissector_add_dependency("tds", proto_smp);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
|
