1 /* packet-m2pa.c
2 * Routines for MTP2 Peer Adaptation Layer dissection
3 * It is hopefully (needs testing) compliant to
4 * https://tools.ietf.org/html/draft-ietf-sigtran-m2pa-02
5 * https://tools.ietf.org/html/draft-ietf-sigtran-m2pa-08
6 * https://tools.ietf.org/html/rfc4165
7 *
8 * Copyright 2001, 2002, Jeff Morriss <jeff.morriss.ws [AT] gmail.com>,
9 * updated by Michael Tuexen <tuexen [AT] fh-muenster.de>
10 *
11 * Wireshark - Network traffic analyzer
12 * By Gerald Combs <gerald@wireshark.org>
13 * Copyright 1998 Gerald Combs
14 *
15 * Copied from packet-m3ua.c
16 *
17 * SPDX-License-Identifier: GPL-2.0-or-later
18 */
19
20
21 #include "config.h"
22
23 #include <epan/packet.h>
24 #include <epan/exceptions.h>
25 #include <epan/prefs.h>
26 #include <epan/sctpppids.h>
27 #include <epan/expert.h>
28
29 void proto_register_m2pa(void);
30 void proto_reg_handoff_m2pa(void);
31
32 #define SCTP_PORT_M2PA 3565
33
34 static guint global_sctp_port = SCTP_PORT_M2PA;
35
36 static int proto_m2pa = -1;
37 static module_t *m2pa_module;
38
39 static int hf_version = -1;
40 static int hf_spare = -1;
41 static int hf_v2_type = -1;
42 static int hf_v8_type = -1;
43 static int hf_type = -1;
44 static int hf_class = -1;
45 static int hf_length = -1;
46 static int hf_unused = -1;
47 static int hf_bsn = -1;
48 static int hf_fsn = -1;
49 static int hf_v2_status = -1;
50 static int hf_v8_status = -1;
51 static int hf_status = -1;
52 static int hf_v2_li_spare = -1;
53 static int hf_v8_li_spare = -1;
54 static int hf_v2_li_prio = -1;
55 static int hf_v8_li_prio = -1;
56 static int hf_filler = -1;
57 static int hf_unknown_data = -1;
58 static int hf_pri_prio = -1;
59 static int hf_pri_spare = -1;
60 static int hf_undecode_data = -1;
61
62 static gint ett_m2pa = -1;
63 static gint ett_m2pa_li = -1;
64
65 static expert_field ei_undecode_data = EI_INIT;
66 static expert_field ei_length = EI_INIT;
67
68 static dissector_handle_t m2pa_handle;
69 static dissector_handle_t mtp3_handle;
70
71 typedef enum {
72 M2PA_V02 = 1,
73 M2PA_V08 = 2,
74 M2PA_RFC4165 = 3
75 } Version_Type;
76
77 static gint m2pa_version = M2PA_RFC4165;
78
79 #define VERSION_LENGTH 1
80 #define SPARE_LENGTH 1
81 #define CLASS_LENGTH 1
82 #define V2_TYPE_LENGTH 2
83 #define V8_TYPE_LENGTH 1
84 #define TYPE_LENGTH V8_TYPE_LENGTH
85 #define LENGTH_LENGTH 4
86 #define UNUSED_LENGTH 1
87 #define BSN_LENGTH 3
88 #define FSN_LENGTH 3
89
90 #define V2_HEADER_LENGTH (VERSION_LENGTH + SPARE_LENGTH + \
91 V2_TYPE_LENGTH + LENGTH_LENGTH)
92
93 #define V8_HEADER_LENGTH (VERSION_LENGTH + SPARE_LENGTH + \
94 CLASS_LENGTH + V8_TYPE_LENGTH + LENGTH_LENGTH + \
95 UNUSED_LENGTH + BSN_LENGTH + UNUSED_LENGTH + \
96 FSN_LENGTH)
97 #define HEADER_LENGTH V8_HEADER_LENGTH
98
99 #define HEADER_OFFSET 0
100 #define VERSION_OFFSET HEADER_OFFSET
101 #define SPARE_OFFSET (VERSION_OFFSET + VERSION_LENGTH)
102 #define CLASS_OFFSET (SPARE_OFFSET + SPARE_LENGTH)
103 #define V2_TYPE_OFFSET (SPARE_OFFSET + SPARE_LENGTH)
104 #define V8_TYPE_OFFSET (CLASS_OFFSET + CLASS_LENGTH)
105 #define TYPE_OFFSET V8_TYPE_OFFSET
106 #define V8_LENGTH_OFFSET (V8_TYPE_OFFSET + V8_TYPE_LENGTH)
107 #define LENGTH_OFFSET V8_LENGTH_OFFSET
108 #define V2_LENGTH_OFFSET (V2_TYPE_OFFSET + V2_TYPE_LENGTH)
109 #define FIRST_UNUSED_OFFSET (V8_LENGTH_OFFSET + LENGTH_LENGTH)
110 #define BSN_OFFSET (FIRST_UNUSED_OFFSET + UNUSED_LENGTH)
111 #define SECOND_UNUSED_OFFSET (BSN_OFFSET + BSN_LENGTH)
112 #define FSN_OFFSET (SECOND_UNUSED_OFFSET + UNUSED_LENGTH)
113
114 static const value_string protocol_version_values[] = {
115 { 1, "Release 1" },
116 { 0, NULL } };
117
118 static const value_string message_class_values[] = {
119 { 0xb, "M2PA" },
120 { 0, NULL } };
121
122 #define V2_USER_DATA_TYPE 0x0601
123 #define V2_LINK_STATUS_TYPE 0x0602
124
125 static const value_string v2_message_type_values[] = {
126 { V2_USER_DATA_TYPE, "User Data" },
127 { V2_LINK_STATUS_TYPE, "Link Status" },
128 { 0, NULL } };
129
130 #define V8_USER_DATA_TYPE 0x0001
131 #define V8_LINK_STATUS_TYPE 0x0002
132
133 static const value_string v8_message_type_values[] = {
134 { V8_USER_DATA_TYPE, "User Data" },
135 { V8_LINK_STATUS_TYPE, "Link Status" },
136 { 0, NULL } };
137
138 #define USER_DATA_TYPE V8_USER_DATA_TYPE
139 #define LINK_STATUS_TYPE V8_LINK_STATUS_TYPE
140
141 static const value_string message_type_values[] = {
142 { USER_DATA_TYPE, "User Data" },
143 { LINK_STATUS_TYPE, "Link Status" },
144 { 0, NULL } };
145
146 static void
dissect_v2_header(tvbuff_t * header_tvb,packet_info * pinfo,proto_tree * m2pa_tree)147 dissect_v2_header(tvbuff_t *header_tvb, packet_info *pinfo, proto_tree *m2pa_tree)
148 {
149 guint16 message_type;
150
151 message_type = tvb_get_ntohs(header_tvb, V2_TYPE_OFFSET);
152
153 col_add_fstr(pinfo->cinfo, COL_INFO, "%s ", val_to_str_const(message_type, v2_message_type_values, "reserved"));
154
155 proto_tree_add_item(m2pa_tree, hf_version, header_tvb, VERSION_OFFSET, VERSION_LENGTH, ENC_BIG_ENDIAN);
156 proto_tree_add_item(m2pa_tree, hf_spare, header_tvb, SPARE_OFFSET, SPARE_LENGTH, ENC_BIG_ENDIAN);
157 proto_tree_add_item(m2pa_tree, hf_v2_type, header_tvb, V2_TYPE_OFFSET, V2_TYPE_LENGTH, ENC_BIG_ENDIAN);
158 proto_tree_add_item(m2pa_tree, hf_length, header_tvb, V2_LENGTH_OFFSET, LENGTH_LENGTH, ENC_BIG_ENDIAN);
159 }
160
161 static void
dissect_v8_header(tvbuff_t * header_tvb,packet_info * pinfo,proto_tree * m2pa_tree)162 dissect_v8_header(tvbuff_t *header_tvb, packet_info *pinfo, proto_tree *m2pa_tree)
163 {
164 guint8 message_type;
165
166 message_type = tvb_get_guint8(header_tvb, V8_TYPE_OFFSET);
167
168 col_add_fstr(pinfo->cinfo, COL_INFO, "%s ", val_to_str_const(message_type, v8_message_type_values, "Unknown"));
169
170 proto_tree_add_item(m2pa_tree, hf_version, header_tvb, VERSION_OFFSET, VERSION_LENGTH, ENC_BIG_ENDIAN);
171 proto_tree_add_item(m2pa_tree, hf_spare, header_tvb, SPARE_OFFSET, SPARE_LENGTH, ENC_BIG_ENDIAN);
172 proto_tree_add_item(m2pa_tree, hf_class, header_tvb, CLASS_OFFSET, CLASS_LENGTH, ENC_BIG_ENDIAN);
173 proto_tree_add_item(m2pa_tree, hf_v8_type, header_tvb, V8_TYPE_OFFSET, V8_TYPE_LENGTH, ENC_BIG_ENDIAN);
174 proto_tree_add_item(m2pa_tree, hf_length, header_tvb, V8_LENGTH_OFFSET, LENGTH_LENGTH, ENC_BIG_ENDIAN);
175 proto_tree_add_item(m2pa_tree, hf_unused, header_tvb, FIRST_UNUSED_OFFSET, UNUSED_LENGTH, ENC_BIG_ENDIAN);
176 proto_tree_add_item(m2pa_tree, hf_bsn, header_tvb, BSN_OFFSET, BSN_LENGTH, ENC_BIG_ENDIAN);
177 proto_tree_add_item(m2pa_tree, hf_unused, header_tvb, SECOND_UNUSED_OFFSET, UNUSED_LENGTH, ENC_BIG_ENDIAN);
178 proto_tree_add_item(m2pa_tree, hf_fsn, header_tvb, FSN_OFFSET, FSN_LENGTH, ENC_BIG_ENDIAN);
179 }
180
181 static void
dissect_header(tvbuff_t * header_tvb,packet_info * pinfo,proto_tree * m2pa_tree)182 dissect_header(tvbuff_t *header_tvb, packet_info *pinfo, proto_tree *m2pa_tree)
183 {
184 guint8 message_type;
185
186 message_type = tvb_get_guint8(header_tvb, V8_TYPE_OFFSET);
187
188 col_add_fstr(pinfo->cinfo, COL_INFO, "%s ", val_to_str_const(message_type, v8_message_type_values, "Unknown"));
189
190 proto_tree_add_item(m2pa_tree, hf_version, header_tvb, VERSION_OFFSET, VERSION_LENGTH, ENC_BIG_ENDIAN);
191 proto_tree_add_item(m2pa_tree, hf_spare, header_tvb, SPARE_OFFSET, SPARE_LENGTH, ENC_BIG_ENDIAN);
192 proto_tree_add_item(m2pa_tree, hf_class, header_tvb, CLASS_OFFSET, CLASS_LENGTH, ENC_BIG_ENDIAN);
193 proto_tree_add_item(m2pa_tree, hf_type, header_tvb, TYPE_OFFSET, TYPE_LENGTH, ENC_BIG_ENDIAN);
194 proto_tree_add_item(m2pa_tree, hf_length, header_tvb, LENGTH_OFFSET, LENGTH_LENGTH, ENC_BIG_ENDIAN);
195 proto_tree_add_item(m2pa_tree, hf_unused, header_tvb, FIRST_UNUSED_OFFSET, UNUSED_LENGTH, ENC_BIG_ENDIAN);
196 proto_tree_add_item(m2pa_tree, hf_bsn, header_tvb, BSN_OFFSET, BSN_LENGTH, ENC_BIG_ENDIAN);
197 proto_tree_add_item(m2pa_tree, hf_unused, header_tvb, SECOND_UNUSED_OFFSET, UNUSED_LENGTH, ENC_BIG_ENDIAN);
198 proto_tree_add_item(m2pa_tree, hf_fsn, header_tvb, FSN_OFFSET, FSN_LENGTH, ENC_BIG_ENDIAN);
199 }
200
201 #define LI_OFFSET 0
202 #define LI_LENGTH 1
203 #define MTP3_OFFSET (LI_OFFSET + LI_LENGTH)
204
205 #define V2_LI_SPARE_MASK 0xfc
206 #define V2_LI_PRIORITY_MASK 0x3
207
208 static void
dissect_v2_user_data_message(tvbuff_t * message_data_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)209 dissect_v2_user_data_message(tvbuff_t *message_data_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
210 {
211 proto_tree *m2pa_li_tree;
212 tvbuff_t *payload_tvb;
213
214 if (tvb_reported_length(message_data_tvb) > 0) {
215 m2pa_li_tree = proto_tree_add_subtree(m2pa_tree, message_data_tvb, LI_OFFSET, LI_LENGTH, ett_m2pa_li, NULL, "Length Indicator");
216
217 proto_tree_add_item(m2pa_li_tree, hf_v2_li_spare, message_data_tvb, LI_OFFSET, LI_LENGTH, ENC_BIG_ENDIAN);
218 proto_tree_add_item(m2pa_li_tree, hf_v2_li_prio, message_data_tvb, LI_OFFSET, LI_LENGTH, ENC_BIG_ENDIAN);
219
220 /* Re-adjust length of M2PA item since it will be dissected as MTP3 */
221 proto_item_set_len(m2pa_item, V2_HEADER_LENGTH + LI_LENGTH);
222 }
223
224 payload_tvb = tvb_new_subset_remaining(message_data_tvb, MTP3_OFFSET);
225 call_dissector(mtp3_handle, payload_tvb, pinfo, tree);
226 }
227
228 #define V8_LI_SPARE_MASK 0x3f
229 #define V8_LI_PRIORITY_MASK 0xc0
230
231 static void
dissect_v8_user_data_message(tvbuff_t * message_data_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)232 dissect_v8_user_data_message(tvbuff_t *message_data_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
233 {
234 proto_tree *m2pa_li_tree;
235 tvbuff_t *payload_tvb;
236
237 if (tvb_reported_length(message_data_tvb) > 0) {
238 m2pa_li_tree = proto_tree_add_subtree(m2pa_tree, message_data_tvb, LI_OFFSET, LI_LENGTH, ett_m2pa_li, NULL, "Length Indicator");
239 proto_tree_add_item(m2pa_li_tree, hf_v8_li_prio, message_data_tvb, LI_OFFSET, LI_LENGTH, ENC_BIG_ENDIAN);
240 proto_tree_add_item(m2pa_li_tree, hf_v8_li_spare, message_data_tvb, LI_OFFSET, LI_LENGTH, ENC_BIG_ENDIAN);
241
242 /* Re-adjust length of M2PA item since it will be dissected as MTP3 */
243 proto_item_set_len(m2pa_item, V8_HEADER_LENGTH + LI_LENGTH);
244
245 payload_tvb = tvb_new_subset_remaining(message_data_tvb, MTP3_OFFSET);
246 call_dissector(mtp3_handle, payload_tvb, pinfo, tree);
247 }
248 }
249
250 #define PRIORITY_MASK 0xc0
251 #define SPARE_MASK 0x3f
252
253 #define PRI_OFFSET 0
254 #define PRI_LENGTH 1
255
256 static void
dissect_user_data_message(tvbuff_t * message_data_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)257 dissect_user_data_message(tvbuff_t *message_data_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
258 {
259 proto_tree *m2pa_li_tree;
260 tvbuff_t *payload_tvb;
261
262 if (tvb_reported_length(message_data_tvb) > 0) {
263 m2pa_li_tree = proto_tree_add_subtree(m2pa_tree, message_data_tvb, PRI_OFFSET, PRI_LENGTH, ett_m2pa_li, NULL, "Priority");
264 proto_tree_add_item(m2pa_li_tree, hf_pri_prio, message_data_tvb, PRI_OFFSET, PRI_LENGTH, ENC_BIG_ENDIAN);
265 proto_tree_add_item(m2pa_li_tree, hf_pri_spare, message_data_tvb, PRI_OFFSET, PRI_LENGTH, ENC_BIG_ENDIAN);
266
267 /* Re-adjust length of M2PA item since it will be dissected as MTP3 */
268 proto_item_set_len(m2pa_item, HEADER_LENGTH + PRI_LENGTH);
269
270 payload_tvb = tvb_new_subset_remaining(message_data_tvb, MTP3_OFFSET);
271 call_dissector(mtp3_handle, payload_tvb, pinfo, tree);
272 }
273 }
274
275 static const value_string v2_link_status_values[] = {
276 { 1, "In Service" },
277 { 2, "Processor Outage" },
278 { 3, "Processor Outage Ended" },
279 { 4, "Busy" },
280 { 5, "Busy Ended" },
281 { 0, NULL } };
282
283 #define STATUS_LENGTH 4
284 #define STATUS_OFFSET 0
285 #define FILLER_OFFSET (STATUS_OFFSET + STATUS_LENGTH)
286
287 static void
dissect_v2_link_status_message(tvbuff_t * message_data_tvb,packet_info * pinfo,proto_tree * m2pa_tree)288 dissect_v2_link_status_message(tvbuff_t *message_data_tvb, packet_info *pinfo, proto_tree *m2pa_tree)
289 {
290 col_append_fstr(pinfo->cinfo, COL_INFO, "(%s) ", val_to_str_const(tvb_get_ntohl(message_data_tvb, STATUS_OFFSET), v2_link_status_values, "Unknown"));
291 proto_tree_add_item(m2pa_tree, hf_v2_status, message_data_tvb, STATUS_OFFSET, STATUS_LENGTH, ENC_BIG_ENDIAN);
292 }
293
294 static const value_string v8_link_status_values[] = {
295 { 1, "Alignment" },
296 { 2, "Proving Normal" },
297 { 3, "Proving Emergency" },
298 { 4, "Ready" },
299 { 5, "Processor Outage" },
300 { 6, "Processor Outage Ended" },
301 { 7, "Busy" },
302 { 8, "Busy Ended" },
303 { 9, "Out of Service" },
304 { 0, NULL } };
305
306 static void
dissect_v8_link_status_message(tvbuff_t * message_data_tvb,packet_info * pinfo,proto_tree * m2pa_tree)307 dissect_v8_link_status_message(tvbuff_t *message_data_tvb, packet_info *pinfo, proto_tree *m2pa_tree)
308 {
309 guint16 filler_length;
310
311 col_append_fstr(pinfo->cinfo, COL_INFO, "(%s) ", val_to_str_const(tvb_get_ntohl(message_data_tvb, STATUS_OFFSET), v8_link_status_values, "Unknown"));
312
313 filler_length = tvb_reported_length(message_data_tvb) - STATUS_LENGTH;
314
315 proto_tree_add_item(m2pa_tree, hf_v8_status, message_data_tvb, STATUS_OFFSET, STATUS_LENGTH, ENC_BIG_ENDIAN);
316 if (filler_length > 0)
317 proto_tree_add_item(m2pa_tree, hf_filler, message_data_tvb, FILLER_OFFSET, filler_length, ENC_NA);
318 }
319
320 static const value_string link_status_values[] = {
321 { 1, "Alignment" },
322 { 2, "Proving Normal" },
323 { 3, "Proving Emergency" },
324 { 4, "Ready" },
325 { 5, "Processor Outage" },
326 { 6, "Processor Outage Ended" },
327 { 7, "Busy" },
328 { 8, "Busy Ended" },
329 { 9, "Out of Service" },
330 { 0, NULL } };
331
332 static void
dissect_link_status_message(tvbuff_t * message_data_tvb,packet_info * pinfo,proto_tree * m2pa_tree)333 dissect_link_status_message(tvbuff_t *message_data_tvb, packet_info *pinfo, proto_tree *m2pa_tree)
334 {
335 guint16 filler_length;
336
337 col_append_fstr(pinfo->cinfo, COL_INFO, "(%s) ", val_to_str_const(tvb_get_ntohl(message_data_tvb, STATUS_OFFSET), link_status_values, "Unknown"));
338
339 filler_length = tvb_reported_length(message_data_tvb) - STATUS_LENGTH;
340
341 proto_tree_add_item(m2pa_tree, hf_status, message_data_tvb, STATUS_OFFSET, STATUS_LENGTH, ENC_BIG_ENDIAN);
342 if (filler_length > 0)
343 proto_tree_add_item(m2pa_tree, hf_filler, message_data_tvb, FILLER_OFFSET, filler_length, ENC_NA);
344 }
345
346 static void
dissect_unknown_message(tvbuff_t * message_data_tvb,proto_tree * m2pa_tree)347 dissect_unknown_message(tvbuff_t *message_data_tvb, proto_tree *m2pa_tree)
348 {
349 guint length;
350
351 length = tvb_reported_length(message_data_tvb);
352 if (length > 0)
353 proto_tree_add_item(m2pa_tree, hf_unknown_data, message_data_tvb, 0, length, ENC_NA);
354 }
355
356 #define V2_MESSAGE_DATA_OFFSET (HEADER_OFFSET + V2_HEADER_LENGTH)
357
358 static void
dissect_v2_message_data(tvbuff_t * message_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)359 dissect_v2_message_data(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
360 {
361 guint32 message_data_length;
362 guint16 type;
363 tvbuff_t *message_data_tvb;
364
365 message_data_length = tvb_get_ntohl(message_tvb, V2_LENGTH_OFFSET);
366 if (message_data_length < 1 || message_data_length > G_MAXINT) {
367 proto_tree_add_expert_format(m2pa_tree, pinfo, &ei_length, message_tvb, V2_LENGTH_OFFSET, 4,
368 "Invalid message data length: %u", message_data_length);
369 return;
370 }
371
372 message_data_tvb = tvb_new_subset_length(message_tvb, V2_MESSAGE_DATA_OFFSET, message_data_length);
373 type = tvb_get_ntohs(message_tvb, V2_TYPE_OFFSET);
374
375 switch(type) {
376 case V2_USER_DATA_TYPE:
377 dissect_v2_user_data_message(message_data_tvb, pinfo, m2pa_item, m2pa_tree, tree);
378 break;
379 case V2_LINK_STATUS_TYPE:
380 dissect_v2_link_status_message(message_data_tvb, pinfo, m2pa_tree);
381 break;
382 default:
383 dissect_unknown_message(message_data_tvb, m2pa_tree);
384 }
385 }
386
387 #define V8_MESSAGE_DATA_OFFSET (HEADER_OFFSET + V8_HEADER_LENGTH)
388
389 static void
dissect_v8_message_data(tvbuff_t * message_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)390 dissect_v8_message_data(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
391 {
392 guint32 message_data_length;
393 guint8 type;
394 tvbuff_t *message_data_tvb;
395
396 message_data_length = tvb_get_ntohl(message_tvb, V8_LENGTH_OFFSET) - V8_HEADER_LENGTH;
397 if (message_data_length < 1 || message_data_length > G_MAXINT) {
398 proto_tree_add_expert_format(m2pa_tree, pinfo, &ei_length, message_tvb, V8_LENGTH_OFFSET, 4,
399 "Invalid message data length: %u", message_data_length);
400 return;
401 }
402 message_data_tvb = tvb_new_subset_length(message_tvb, V8_MESSAGE_DATA_OFFSET, message_data_length);
403 type = tvb_get_guint8(message_tvb, V8_TYPE_OFFSET);
404
405
406 switch(type) {
407 case V8_USER_DATA_TYPE:
408 dissect_v8_user_data_message(message_data_tvb, pinfo, m2pa_item, m2pa_tree, tree);
409 break;
410 case V8_LINK_STATUS_TYPE:
411 dissect_v8_link_status_message(message_data_tvb, pinfo, m2pa_tree);
412 break;
413 default:
414 dissect_unknown_message(message_data_tvb, m2pa_tree);
415 }
416 }
417
418 #define MESSAGE_DATA_OFFSET (HEADER_OFFSET + HEADER_LENGTH)
419
420 static void
dissect_message_data(tvbuff_t * message_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)421 dissect_message_data(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
422 {
423 guint32 length, message_data_length, actual_length;
424 guint8 type;
425 tvbuff_t *message_data_tvb;
426
427 length = tvb_get_ntohl(message_tvb, LENGTH_OFFSET);
428 message_data_length = length - HEADER_LENGTH;
429 message_data_tvb = tvb_new_subset_length(message_tvb, MESSAGE_DATA_OFFSET, message_data_length);
430 type = tvb_get_guint8(message_tvb, TYPE_OFFSET);
431
432
433 switch(type) {
434 case USER_DATA_TYPE:
435 dissect_user_data_message(message_data_tvb, pinfo, m2pa_item, m2pa_tree, tree);
436 break;
437 case LINK_STATUS_TYPE:
438 dissect_link_status_message(message_data_tvb, pinfo, m2pa_tree);
439 break;
440 default:
441 dissect_unknown_message(message_data_tvb, m2pa_tree);
442 }
443
444 actual_length = tvb_reported_length(message_tvb);
445
446 if (actual_length > length)
447 {
448 proto_item *pi;
449
450 pi = proto_tree_add_item(m2pa_tree, hf_undecode_data, message_tvb, length, (actual_length - length), ENC_NA);
451 expert_add_info_format(pinfo, pi, &ei_undecode_data,
452 "There are %d bytes of data which is greater than M2PA's length parameter (%d)",
453 actual_length, length);
454 }
455 }
456
457 static void
dissect_v2_message(tvbuff_t * message_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)458 dissect_v2_message(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
459 {
460 dissect_v2_header(message_tvb, pinfo, m2pa_tree);
461 dissect_v2_message_data(message_tvb, pinfo, m2pa_item, m2pa_tree, tree);
462 }
463
464 static void
dissect_v8_message(tvbuff_t * message_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)465 dissect_v8_message(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
466 {
467 dissect_v8_header(message_tvb, pinfo, m2pa_tree);
468 dissect_v8_message_data(message_tvb, pinfo, m2pa_item, m2pa_tree, tree);
469 }
470
471 static void
dissect_message(tvbuff_t * message_tvb,packet_info * pinfo,proto_item * m2pa_item,proto_tree * m2pa_tree,proto_tree * tree)472 dissect_message(tvbuff_t *message_tvb, packet_info *pinfo, proto_item *m2pa_item, proto_tree *m2pa_tree, proto_tree *tree)
473 {
474 dissect_header(message_tvb, pinfo, m2pa_tree);
475 dissect_message_data(message_tvb, pinfo, m2pa_item, m2pa_tree, tree);
476 }
477
478 static int
dissect_m2pa(tvbuff_t * tvb,packet_info * pinfo,proto_tree * tree,void * data _U_)479 dissect_m2pa(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
480 {
481 proto_item *m2pa_item;
482 proto_tree *m2pa_tree;
483
484 switch(m2pa_version) {
485 case M2PA_V02:
486 col_set_str(pinfo->cinfo, COL_PROTOCOL, "M2PA (ID 02)");
487 break;
488 case M2PA_V08:
489 col_set_str(pinfo->cinfo, COL_PROTOCOL, "M2PA (ID 08)");
490 break;
491 case M2PA_RFC4165:
492 col_set_str(pinfo->cinfo, COL_PROTOCOL, "M2PA");
493 break;
494 };
495
496 m2pa_item = proto_tree_add_item(tree, proto_m2pa, tvb, 0, -1, ENC_NA);
497 m2pa_tree = proto_item_add_subtree(m2pa_item, ett_m2pa);
498
499 switch(m2pa_version) {
500 case M2PA_V02:
501 dissect_v2_message(tvb, pinfo, m2pa_item, m2pa_tree, tree);
502 break;
503 case M2PA_V08:
504 dissect_v8_message(tvb, pinfo, m2pa_item, m2pa_tree, tree);
505 break;
506 case M2PA_RFC4165:
507 dissect_message(tvb, pinfo, m2pa_item, m2pa_tree, tree);
508 break;
509 };
510 return tvb_captured_length(tvb);
511 }
512
513 void
proto_register_m2pa(void)514 proto_register_m2pa(void)
515 {
516 static hf_register_info hf[] =
517 { { &hf_version, { "Version", "m2pa.version", FT_UINT8, BASE_DEC, VALS(protocol_version_values), 0x0, NULL, HFILL} },
518 { &hf_spare, { "Spare", "m2pa.spare", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL} },
519 { &hf_v2_type, { "Message Type", "m2pa.type_v2", FT_UINT16, BASE_HEX, VALS(v2_message_type_values), 0x0, NULL, HFILL} },
520 { &hf_v8_type, { "Message Type", "m2pa.type_v8", FT_UINT8, BASE_DEC, VALS(v8_message_type_values), 0x0, NULL, HFILL} },
521 { &hf_type, { "Message Type", "m2pa.type", FT_UINT8, BASE_DEC, VALS(message_type_values), 0x0, NULL, HFILL} },
522 { &hf_class, { "Message Class", "m2pa.class", FT_UINT8, BASE_DEC, VALS(message_class_values), 0x0, NULL, HFILL} },
523 { &hf_length, { "Message length", "m2pa.length", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL} },
524 { &hf_unused, { "Unused", "m2pa.unused", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL} },
525 { &hf_bsn, { "BSN", "m2pa.bsn", FT_UINT24, BASE_DEC, NULL, 0x0, NULL, HFILL} },
526 { &hf_fsn, { "FSN", "m2pa.fsn", FT_UINT24, BASE_DEC, NULL, 0x0, NULL, HFILL} },
527 { &hf_v2_li_spare, { "Spare", "m2pa.li_spare_v2", FT_UINT8, BASE_DEC, NULL, V2_LI_SPARE_MASK, NULL, HFILL} },
528 { &hf_v8_li_spare, { "Spare", "m2pa.li_spare_v8", FT_UINT8, BASE_HEX, NULL, V8_LI_SPARE_MASK, NULL, HFILL} },
529 { &hf_pri_spare, { "Spare", "m2pa.priority_spare", FT_UINT8, BASE_HEX, NULL, SPARE_MASK, NULL, HFILL} },
530 { &hf_v2_li_prio, { "Priority", "m2pa.li_priority_v2", FT_UINT8, BASE_DEC, NULL, V2_LI_PRIORITY_MASK, NULL, HFILL} },
531 { &hf_v8_li_prio, { "Priority", "m2pa.li_priority_v8", FT_UINT8, BASE_HEX, NULL, V8_LI_PRIORITY_MASK, NULL, HFILL} },
532 { &hf_pri_prio, { "Priority", "m2pa.priority", FT_UINT8, BASE_HEX, NULL, PRIORITY_MASK, NULL, HFILL} },
533 { &hf_v2_status, { "Link Status", "m2pa.status_v2", FT_UINT32, BASE_DEC, VALS(v2_link_status_values), 0x0, NULL, HFILL} },
534 { &hf_v8_status, { "Link Status", "m2pa.status_v8", FT_UINT32, BASE_DEC, VALS(v8_link_status_values), 0x0, NULL, HFILL} },
535 { &hf_status, { "Link Status", "m2pa.status", FT_UINT32, BASE_DEC, VALS(link_status_values), 0x0, NULL, HFILL} },
536 { &hf_filler, { "Filler", "m2pa.filler", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL} },
537 { &hf_unknown_data, { "Unknown Data", "m2pa.unknown_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL} },
538 { &hf_undecode_data,{ "Undecoded data", "m2pa.undecoded_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL} }
539 };
540
541 static gint *ett[] = {
542 &ett_m2pa,
543 &ett_m2pa_li
544 };
545
546 static const enum_val_t m2pa_version_options[] = {
547 { "draft-2", "Internet Draft version 2", M2PA_V02 },
548 { "draft-8", "Internet Draft version 8", M2PA_V08 },
549 { "RFC4165", "RFC 4165", M2PA_RFC4165 },
550 { NULL, NULL, 0 }
551 };
552
553 static ei_register_info ei[] = {
554 { &ei_undecode_data, { "m2pa.undecoded_data.expert", PI_MALFORMED, PI_WARN, "There are bytes of data which is greater than M2PA's length parameter", EXPFILL }},
555 { &ei_length, { "m2pa.length.invalid", PI_MALFORMED, PI_ERROR, "Invalid message data length", EXPFILL }},
556 };
557
558 expert_module_t* expert_m2pa;
559
560 proto_m2pa = proto_register_protocol("MTP2 Peer Adaptation Layer", "M2PA", "m2pa");
561
562 proto_register_field_array(proto_m2pa, hf, array_length(hf));
563 proto_register_subtree_array(ett, array_length(ett));
564 expert_m2pa = expert_register_protocol(proto_m2pa);
565 expert_register_field_array(expert_m2pa, ei, array_length(ei));
566
567 /* Allow other dissectors to find this one by name. */
568 m2pa_handle = register_dissector("m2pa", dissect_m2pa, proto_m2pa);
569
570 m2pa_module = prefs_register_protocol(proto_m2pa, proto_reg_handoff_m2pa);
571
572 prefs_register_enum_preference(m2pa_module, "version", "M2PA version", "Version used by Wireshark", &m2pa_version, m2pa_version_options, FALSE);
573 prefs_register_uint_preference(m2pa_module, "port", "M2PA SCTP Port", "Set the port for M2PA messages (default: " G_STRINGIFY(SCTP_PORT_M2PA) ")", 10, &global_sctp_port);
574 }
575
576 void
proto_reg_handoff_m2pa(void)577 proto_reg_handoff_m2pa(void)
578 {
579 static gboolean prefs_initialized = FALSE;
580 static guint sctp_port;
581
582 /* Port preferences code shamelessly copied from packet-beep.c */
583 if (!prefs_initialized) {
584 mtp3_handle = find_dissector_add_dependency("mtp3", proto_m2pa);
585
586 dissector_add_uint("sctp.ppi", M2PA_PAYLOAD_PROTOCOL_ID, m2pa_handle);
587
588 prefs_initialized = TRUE;
589
590 } else {
591
592 dissector_delete_uint("sctp.port", sctp_port, m2pa_handle);
593
594 }
595
596 /* Set our port number for future use */
597 sctp_port = global_sctp_port;
598
599 dissector_add_uint("sctp.port", sctp_port, m2pa_handle);
600 }
601
602 /*
603 * Editor modelines - https://www.wireshark.org/tools/modelines.html
604 *
605 * Local Variables:
606 * c-basic-offset: 2
607 * tab-width: 8
608 * indent-tabs-mode: nil
609 * End:
610 *
611 * ex: set shiftwidth=2 tabstop=8 expandtab:
612 * :indentSize=2:tabSize=8:noTabs=true:
613 */
614