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
|
/* packet-cwids.c
* Routines for dissecting wireless ids packets sent from a Cisco
* access point to the WLSE (or whatever)
*
* Copyright 2006 Joerg Mayer (see AUTHORS file)
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
/* With current IOS, you can use Cisco wireless Bridges/APs as
* wireless sniffers and configure them to send the data to some
* central IDS:
* interface dot11Radio 0
* station-role scanner
* monitor frames endpoint ip address 172.22.1.1 port 8999 truncate 2312
* These frames are raw, i.e. they don't have a pcap header.
* Running wireshark at the receiving end will provide those.
*/
/* 2do:
* - Find out more about the contents of the capture header
* - Protect the address fields etc (all columns?)
* - Create subelements and put each header and packet into it
* - fuzz-test the dissector
* - Find some heuristic to detect the packet automagically and
* convert dissector into a heuristic dissector
* - Is the TRY/CATCH stuff OK?
*/
#include "config.h"
#include <wiretap/wtap.h>
#include <epan/packet.h>
#include <epan/exceptions.h>
#include <epan/expert.h>
#include <epan/show_exception.h>
static int proto_cwids;
static int hf_cwids_version;
static int hf_cwids_timestamp;
static int hf_cwids_unknown1;
static int hf_cwids_channel;
static int hf_cwids_unknown2;
static int hf_cwids_reallength;
static int hf_cwids_capturelen;
static int hf_cwids_unknown3;
static int ett_cwids;
static expert_field ei_ieee80211_subpacket;
static dissector_handle_t cwids_handle;
static dissector_handle_t ieee80211_radio_handle;
static int
dissect_cwids(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
tvbuff_t *wlan_tvb;
proto_tree *ti, *cwids_tree;
volatile int offset = 0;
uint16_t capturelen;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "CWIDS");
col_set_str(pinfo->cinfo, COL_INFO, "Cwids: ");
/* FIXME: col_set_fence(pinfo->cinfo, all-cols, only addr-cols?); */
cwids_tree = NULL;
while(tvb_reported_length_remaining(tvb, offset) > 0) {
struct ieee_802_11_phdr phdr;
ti = proto_tree_add_item(tree, proto_cwids, tvb, offset, 28, ENC_NA);
cwids_tree = proto_item_add_subtree(ti, ett_cwids);
memset(&phdr, 0, sizeof(phdr));
phdr.fcs_len = 0; /* no FCS */
phdr.decrypted = false;
phdr.datapad = false;
phdr.phy = PHDR_802_11_PHY_UNKNOWN;
proto_tree_add_item(cwids_tree, hf_cwids_version, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(cwids_tree, hf_cwids_timestamp, tvb, offset, 6, ENC_NA);
offset += 6;
proto_tree_add_item(cwids_tree, hf_cwids_unknown1, tvb, offset, 1, ENC_NA);
offset += 1;
phdr.has_channel = true;
phdr.channel = tvb_get_uint8(tvb, offset);
proto_tree_add_item(cwids_tree, hf_cwids_channel, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(cwids_tree, hf_cwids_unknown2, tvb, offset, 6, ENC_NA);
offset += 6;
proto_tree_add_item(cwids_tree, hf_cwids_reallength, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
capturelen = tvb_get_ntohs(tvb, offset);
proto_tree_add_item(cwids_tree, hf_cwids_capturelen, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(cwids_tree, hf_cwids_unknown3, tvb, offset, 8, ENC_NA);
offset += 8;
wlan_tvb = tvb_new_subset_length(tvb, offset, capturelen);
/* Continue after ieee80211 dissection errors */
TRY {
call_dissector_with_data(ieee80211_radio_handle, wlan_tvb, pinfo, tree, &phdr);
} CATCH_BOUNDS_ERRORS {
show_exception(wlan_tvb, pinfo, tree, EXCEPT_CODE, GET_MESSAGE);
expert_add_info(pinfo, ti, &ei_ieee80211_subpacket);
} ENDTRY;
offset += capturelen;
}
return tvb_captured_length(tvb);
}
void proto_register_cwids(void);
void proto_reg_handoff_cwids(void);
void
proto_register_cwids(void)
{
static hf_register_info hf[] = {
{ &hf_cwids_version,
{ "Capture Version", "cwids.version", FT_UINT16, BASE_DEC, NULL,
0x0, "Version or format of record", HFILL }},
{ &hf_cwids_timestamp,
{ "Timestamp [us]", "cwids.timestamp", FT_BYTES, BASE_NONE, NULL,
0x0, NULL, HFILL }},
{ &hf_cwids_unknown1,
{ "Unknown1", "cwids.unknown1", FT_BYTES, BASE_NONE, NULL,
0x0, "1st Unknown block", HFILL }},
{ &hf_cwids_channel,
{ "Channel", "cwids.channel", FT_UINT8, BASE_DEC, NULL,
0x0, "Channel for this capture", HFILL }},
{ &hf_cwids_unknown2,
{ "Unknown2", "cwids.unknown2", FT_BYTES, BASE_NONE, NULL,
0x0, "2nd Unknown block", HFILL }},
{ &hf_cwids_reallength,
{ "Original length", "cwids.reallen", FT_UINT16, BASE_DEC, NULL,
0x0, "Original num bytes in frame", HFILL }},
{ &hf_cwids_capturelen,
{ "Capture length", "cwids.caplen", FT_UINT16, BASE_DEC, NULL,
0x0, "Captured bytes in record", HFILL }},
{ &hf_cwids_unknown3,
{ "Unknown3", "cwids.unknown3", FT_BYTES, BASE_NONE, NULL,
0x0, "3rd Unknown block", HFILL }},
};
static int *ett[] = {
&ett_cwids,
};
static ei_register_info ei[] = {
{ &ei_ieee80211_subpacket, { "cwids.ieee80211_malformed", PI_MALFORMED, PI_ERROR, "Malformed or short IEEE80211 subpacket", EXPFILL }},
};
expert_module_t* expert_cwids;
proto_cwids = proto_register_protocol("Cisco Wireless IDS Captures", "CWIDS", "cwids");
proto_register_field_array(proto_cwids, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_cwids = expert_register_protocol(proto_cwids);
expert_register_field_array(expert_cwids, ei, array_length(ei));
cwids_handle = register_dissector("cwids", dissect_cwids, proto_cwids);
}
void
proto_reg_handoff_cwids(void)
{
dissector_add_for_decode_as_with_preference("udp.port", cwids_handle);
ieee80211_radio_handle = find_dissector_add_dependency("wlan_noqos_radio", proto_cwids);
}
/*
* 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:
*/
|
