204 lines
5.4 KiB
C
204 lines
5.4 KiB
C
/* MPEG audio packet decoder.
|
|
* Written by Shaun Jackman <sjackman@gmail.com>.
|
|
* Copyright 2007 Shaun Jackman
|
|
*
|
|
* $Id$
|
|
*
|
|
* Wireshark - Network traffic analyzer
|
|
* By Gerald Combs <gerald@wireshark.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#include <glib.h>
|
|
|
|
#include <epan/packet.h>
|
|
#include <epan/prefs.h>
|
|
#include <epan/asn1.h>
|
|
|
|
#include <wsutil/mpeg-audio.h>
|
|
|
|
#include "packet-per.h"
|
|
|
|
#include "packet-mpeg-audio-hf.c"
|
|
#include "packet-mpeg-audio-ett.c"
|
|
#include "packet-mpeg-audio-fn.c"
|
|
|
|
static int proto_mpeg_audio = -1;
|
|
|
|
static int hf_mpeg_audio = -1;
|
|
static int hf_mpeg_audio_data = -1;
|
|
static int hf_mpeg_audio_padbytes = -1;
|
|
static int hf_id3v1 = -1;
|
|
static int hf_id3v2 = -1;
|
|
|
|
static gboolean
|
|
dissect_mpeg_audio_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
guint32 h;
|
|
struct mpa mpa;
|
|
size_t data_size = 0;
|
|
asn1_ctx_t asn1_ctx;
|
|
int offset = 0;
|
|
|
|
if (!tvb_bytes_exist(tvb, 0, 4))
|
|
return FALSE; /* not enough data for an MPEG audio frame */
|
|
|
|
h = tvb_get_ntohl(tvb, 0);
|
|
MPA_UNMARSHAL(&mpa, h);
|
|
if (!MPA_SYNC_VALID(&mpa))
|
|
return FALSE;
|
|
if (!MPA_VERSION_VALID(&mpa))
|
|
return FALSE;
|
|
if (!MPA_LAYER_VALID(&mpa))
|
|
return FALSE;
|
|
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
|
|
static const char *version_names[] = { "1", "2", "2.5" };
|
|
col_add_fstr(pinfo->cinfo, COL_PROTOCOL,
|
|
"MPEG-%s", version_names[mpa_version(&mpa)]);
|
|
}
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_add_fstr(pinfo->cinfo, COL_INFO,
|
|
"Audio Layer %d", mpa_layer(&mpa) + 1);
|
|
if (MPA_BITRATE_VALID(&mpa) && MPA_FREQUENCY_VALID(&mpa)) {
|
|
data_size = MPA_DATA_BYTES(&mpa) - sizeof mpa;
|
|
if (check_col(pinfo->cinfo, COL_DEF_SRC)) {
|
|
SET_ADDRESS(&pinfo->src, AT_NONE, 0, NULL);
|
|
col_add_fstr(pinfo->cinfo, COL_DEF_SRC,
|
|
"%d kb/s", mpa_bitrate(&mpa) / 1000);
|
|
}
|
|
if (check_col(pinfo->cinfo, COL_DEF_DST)) {
|
|
SET_ADDRESS(&pinfo->dst, AT_NONE, 0, NULL);
|
|
col_add_fstr(pinfo->cinfo, COL_DEF_DST,
|
|
"%g kHz", mpa_frequency(&mpa) / (float)1000);
|
|
}
|
|
}
|
|
|
|
if (tree == NULL)
|
|
return TRUE;
|
|
|
|
asn1_ctx_init(&asn1_ctx, ASN1_ENC_PER, TRUE, pinfo);
|
|
offset = dissect_mpeg_audio_Audio(tvb, offset, &asn1_ctx,
|
|
tree, hf_mpeg_audio);
|
|
if (data_size > 0) {
|
|
unsigned int padding;
|
|
|
|
proto_tree_add_item(tree, hf_mpeg_audio_data, tvb,
|
|
offset / 8, data_size, FALSE);
|
|
offset += data_size * 8;
|
|
padding = mpa_padding(&mpa);
|
|
if (padding > 0) {
|
|
proto_tree_add_item(tree, hf_mpeg_audio_padbytes, tvb,
|
|
offset / 8, padding, FALSE);
|
|
offset += padding * 8;
|
|
}
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
static void
|
|
dissect_id3v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
asn1_ctx_t asn1_ctx;
|
|
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "ID3v1");
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
if (tree == NULL)
|
|
return;
|
|
asn1_ctx_init(&asn1_ctx, ASN1_ENC_PER, TRUE, pinfo);
|
|
dissect_mpeg_audio_ID3v1(tvb, 0, &asn1_ctx,
|
|
tree, hf_id3v1);
|
|
}
|
|
|
|
static void
|
|
dissect_id3v2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
if (check_col(pinfo->cinfo, COL_PROTOCOL))
|
|
col_set_str(pinfo->cinfo, COL_PROTOCOL, "ID3v2");
|
|
if (check_col(pinfo->cinfo, COL_INFO))
|
|
col_clear(pinfo->cinfo, COL_INFO);
|
|
proto_tree_add_item(tree, hf_id3v2, tvb,
|
|
0, -1, FALSE);
|
|
}
|
|
|
|
static gboolean
|
|
dissect_mpeg_audio(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
|
|
{
|
|
int magic;
|
|
|
|
if (!tvb_bytes_exist(tvb, 0, 3))
|
|
return FALSE; /* not enough data for an ID tag or audio frame */
|
|
magic = tvb_get_ntoh24(tvb, 0);
|
|
switch (magic) {
|
|
case 0x544147: /* TAG */
|
|
dissect_id3v1(tvb, pinfo, tree);
|
|
return TRUE;
|
|
case 0x494433: /* ID3 */
|
|
dissect_id3v2(tvb, pinfo, tree);
|
|
return TRUE;
|
|
default:
|
|
return dissect_mpeg_audio_frame(tvb, pinfo, tree);
|
|
}
|
|
}
|
|
|
|
void
|
|
proto_register_mpeg_audio(void)
|
|
{
|
|
static hf_register_info hf[] = {
|
|
#include "packet-mpeg-audio-hfarr.c"
|
|
{ &hf_mpeg_audio,
|
|
{ "MPEG Audio", "mpeg.audio",
|
|
FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }},
|
|
{ &hf_mpeg_audio_data,
|
|
{ "Data", "mpeg.audio.data",
|
|
FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},
|
|
{ &hf_mpeg_audio_padbytes,
|
|
{ "Padding", "mpeg.audio.padbytes",
|
|
FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},
|
|
|
|
{ &hf_id3v1,
|
|
{ "ID3v1", "id3v1",
|
|
FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }},
|
|
{ &hf_id3v2,
|
|
{ "ID3v2", "id3v2",
|
|
FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }},
|
|
};
|
|
|
|
static gint *ett[] = {
|
|
#include "packet-mpeg-audio-ettarr.c"
|
|
};
|
|
|
|
proto_mpeg_audio = proto_register_protocol(
|
|
"Moving Picture Experts Group Audio", "MPEG Audio", "mpeg.audio");
|
|
proto_register_field_array(proto_mpeg_audio, hf, array_length(hf));
|
|
proto_register_subtree_array(ett, array_length(ett));
|
|
}
|
|
|
|
void
|
|
proto_reg_handoff_mpeg_audio(void)
|
|
{
|
|
heur_dissector_add("mpeg", dissect_mpeg_audio, proto_mpeg_audio);
|
|
}
|