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
|
/* packet-pmproxy.c
*
* Routines for dissecting Performance Co-Pilot Proxy
*
* 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/conversation.h>
#include <epan/strutil.h>
#define PMPROXY_PORT 44322
/* length of "pmproxy-server 1\n" and also "pmproxy-client 1\n" */
#define PMPROXY_CLIENT_SERVER_VERSION_LENGTH 17
#define PMPROXY_START_OF_PACKET 0
#define PMPROXY_HOST_AND_PORT_DELIMETER_LENGTH 1
static dissector_handle_t pmproxy_handle;
static dissector_handle_t pcp_handle;
static int proto_pmproxy = -1;
static int hf_pmproxy_host = -1;
static int hf_pmproxy_port = -1;
static int hf_pmproxy_client_version = -1;
static int hf_pmproxy_server_version = -1;
static gint ett_pmproxy = -1;
typedef struct pmproxy_conversation_info_t {
guint32 last_proxy_frame;
} pmproxy_conversation_info_t;
void proto_register_pmproxy(void);
void proto_reg_handoff_pmproxy(void);
static int is_ascii(const guchar *data, gint size)
{
const unsigned char *str = data;
const unsigned char *end = str + size;
for (; str != end; str++) {
if (*str & 0x80)
return FALSE;
}
return TRUE;
}
static int looks_like_proxy_exchange(tvbuff_t *tvb) {
gint packet_length;
const guchar *packet_data;
packet_length = tvb_ensure_captured_length_remaining(tvb, PMPROXY_START_OF_PACKET);
packet_data = tvb_get_ptr(tvb, PMPROXY_START_OF_PACKET, packet_length);
/* A proxy exchange packet only contains ascii characters (eg "localhost 44321") and terminated with \n */
return is_ascii(packet_data, packet_length) && packet_data[packet_length-1] == '\n';
}
static int dissect_proxy_to_host(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
int offset = 0;
gint next_offset;
gint proxy_to_length;
gchar *pmproxy_host_and_port_string;
gchar **host_and_port;
gchar *host;
gchar *port;
col_set_str(pinfo->cinfo, COL_INFO, "Proxy");
proxy_to_length = tvb_find_line_end(tvb, offset, tvb_ensure_captured_length_remaining(tvb, offset), &next_offset, FALSE);
if(proxy_to_length != -1) {
pmproxy_host_and_port_string = (gchar *) tvb_get_string_enc(wmem_packet_scope(), tvb, offset, proxy_to_length, ENC_ASCII);
host_and_port = wmem_strsplit(wmem_packet_scope(), pmproxy_host_and_port_string, " ", -1);
if(host_and_port != NULL) {
host = host_and_port[0];
if (host) {
proto_tree_add_string(tree, hf_pmproxy_host, tvb, offset, (guint32)strlen(host), host);
offset += (int)strlen(host) + PMPROXY_HOST_AND_PORT_DELIMETER_LENGTH;
port = host_and_port[1];
if (port) {
proto_tree_add_string(tree, hf_pmproxy_port, tvb, offset, (guint32)strlen(port), port);
}
} else {
port = NULL;
}
col_append_fstr(pinfo->cinfo, COL_INFO, " Host=%s, Port=%s", host ? host : "", port ? port : "");
}
}
return proxy_to_length;
}
static int is_banner_exchange_for(const gchar *type, tvbuff_t *tvb) {
gchar *pmproxy_exchange_string;
/* Exchange packets have to be this length */
if(tvb_ensure_captured_length_remaining(tvb, PMPROXY_START_OF_PACKET) != PMPROXY_CLIENT_SERVER_VERSION_LENGTH) {
return 0;
}
pmproxy_exchange_string = (gchar *) tvb_get_string_enc(wmem_packet_scope(), tvb, PMPROXY_START_OF_PACKET,
PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII);
return g_strcmp0(pmproxy_exchange_string, wmem_strdup_printf(wmem_packet_scope(), "pmproxy-%s 1\n", type)) == 0;
}
static int is_server_exchange(tvbuff_t *tvb) {
return is_banner_exchange_for("server", tvb);
}
static int is_client_exchange(tvbuff_t *tvb) {
return is_banner_exchange_for("client", tvb);
}
static int dissect_server_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *pmproxy_tree) {
int offset = PMPROXY_START_OF_PACKET;
col_set_str(pinfo->cinfo, COL_INFO, "Server exchange");
proto_tree_add_item(pmproxy_tree, hf_pmproxy_server_version, tvb, offset, PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII);
offset += PMPROXY_CLIENT_SERVER_VERSION_LENGTH;
return offset;
}
static int dissect_client_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *pmproxy_tree) {
int offset = PMPROXY_START_OF_PACKET;
col_set_str(pinfo->cinfo, COL_INFO, "Client exchange");
proto_tree_add_item(pmproxy_tree, hf_pmproxy_client_version, tvb, offset, PMPROXY_CLIENT_SERVER_VERSION_LENGTH, ENC_ASCII);
offset += PMPROXY_CLIENT_SERVER_VERSION_LENGTH;
return offset;
}
static void mark_pmproxy_exchange_complete(packet_info *pinfo) {
conversation_t *conversation;
pmproxy_conversation_info_t *pmproxy_conversation;
conversation = find_or_create_conversation(pinfo);
pmproxy_conversation = (pmproxy_conversation_info_t *)conversation_get_proto_data(conversation, proto_pmproxy);
if(pmproxy_conversation == NULL) {
pmproxy_conversation = wmem_new(wmem_file_scope(), pmproxy_conversation_info_t);
}
pmproxy_conversation->last_proxy_frame = pinfo->num;
conversation_add_proto_data(conversation, proto_pmproxy, pmproxy_conversation);
}
static int is_pmproxy_exchange_complete(packet_info *pinfo) {
conversation_t *conversation;
pmproxy_conversation_info_t *pmproxy_conversation;
conversation = find_or_create_conversation(pinfo);
pmproxy_conversation = (pmproxy_conversation_info_t *)conversation_get_proto_data(conversation, proto_pmproxy);
if(pmproxy_conversation == NULL) {
return FALSE;
}
return pinfo->num >= pmproxy_conversation->last_proxy_frame;
}
static int dissect_through_pcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
pinfo->can_desegment = pinfo->saved_can_desegment;
return call_dissector(pcp_handle, tvb, pinfo, tree);
}
static int dissect_pmproxy_exchange(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
proto_item *root_pmproxy_item;
proto_tree *pmproxy_tree;
root_pmproxy_item = proto_tree_add_item(tree, proto_pmproxy, tvb, 0, -1, ENC_NA);
pmproxy_tree = proto_item_add_subtree(root_pmproxy_item, ett_pmproxy);
if (is_server_exchange(tvb)) {
return dissect_server_exchange(tvb, pinfo, pmproxy_tree);
} else if (is_client_exchange(tvb)) {
return dissect_client_exchange(tvb, pinfo, pmproxy_tree);
} else if (looks_like_proxy_exchange(tvb)) {
return dissect_proxy_to_host(tvb, pinfo, pmproxy_tree);
} else {
/* If its none of these, it is going to be vanilla PCP traffic */
mark_pmproxy_exchange_complete(pinfo);
}
return tvb_reported_length_remaining(tvb, 0);
}
static int dissect_pmproxy(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) {
col_set_str(pinfo->cinfo, COL_PROTOCOL, "PMPROXY");
col_clear(pinfo->cinfo, COL_INFO);
if(is_pmproxy_exchange_complete(pinfo)) {
return dissect_through_pcp(tvb, pinfo, tree);
}
else {
return dissect_pmproxy_exchange(tvb, pinfo, tree);
}
}
void proto_register_pmproxy(void) {
static hf_register_info hf[] = {
{ &hf_pmproxy_host,
{ "Host", "pmproxy.host",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{ &hf_pmproxy_port,
{ "Port", "pmproxy.port",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{ &hf_pmproxy_client_version,
{ "Client Version", "pmproxy.client_version",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
{ &hf_pmproxy_server_version,
{ "Server Version", "pmproxy.server_version",
FT_STRING, BASE_NONE,
NULL, 0x0,
NULL, HFILL
}
},
};
static gint *ett[] = {
&ett_pmproxy,
};
proto_pmproxy = proto_register_protocol("Performance Co-Pilot Proxy", "PMPROXY", "pmproxy");
proto_register_field_array(proto_pmproxy, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
pmproxy_handle = register_dissector("pmproxy", dissect_pmproxy, proto_pmproxy);
}
void proto_reg_handoff_pmproxy(void) {
pcp_handle = find_dissector_add_dependency("pcp", proto_pmproxy);
dissector_add_uint_with_preference("tcp.port", PMPROXY_PORT, pmproxy_handle);
}
/*
* 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:
*/
|
