forked from osmocom/wireshark
![Bill Meier](/assets/img/avatar_default.png)
Change-Id: I36b2731d67f9345d2fd0c23800bba7d2be94c387 Reviewed-on: https://code.wireshark.org/review/6008 Reviewed-by: Bill Meier <wmeier@newsguy.com>
181 lines
4.9 KiB
C
181 lines
4.9 KiB
C
/* MPEG audio packet decoder.
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* Written by Shaun Jackman <sjackman@gmail.com>.
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* Copyright 2007 Shaun Jackman
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <epan/packet.h>
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#include <epan/asn1.h>
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#include <wsutil/mpeg-audio.h>
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#include "packet-per.h"
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#include "packet-mpeg-audio-hf.c"
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#include "packet-mpeg-audio-ett.c"
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#include "packet-mpeg-audio-fn.c"
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void proto_register_mpeg_audio(void);
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void proto_reg_handoff_mpeg_audio(void);
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static int proto_mpeg_audio = -1;
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static int hf_mpeg_audio_data = -1;
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static int hf_mpeg_audio_padbytes = -1;
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static int hf_id3v1 = -1;
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static int hf_id3v2 = -1;
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static gboolean
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dissect_mpeg_audio_frame(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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guint32 h;
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struct mpa mpa;
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int data_size = 0;
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asn1_ctx_t asn1_ctx;
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int offset = 0;
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static const char *version_names[] = { "1", "2", "2.5" };
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if (!tvb_bytes_exist(tvb, 0, 4))
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return FALSE; /* not enough data for an MPEG audio frame */
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h = tvb_get_ntohl(tvb, 0);
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MPA_UNMARSHAL(&mpa, h);
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if (!MPA_SYNC_VALID(&mpa))
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return FALSE;
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if (!MPA_VERSION_VALID(&mpa))
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return FALSE;
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if (!MPA_LAYER_VALID(&mpa))
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return FALSE;
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col_add_fstr(pinfo->cinfo, COL_PROTOCOL,
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"MPEG-%s", version_names[mpa_version(&mpa)]);
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col_add_fstr(pinfo->cinfo, COL_INFO,
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"Audio Layer %d", mpa_layer(&mpa) + 1);
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if (MPA_BITRATE_VALID(&mpa) && MPA_FREQUENCY_VALID(&mpa)) {
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data_size = (int)(MPA_DATA_BYTES(&mpa) - sizeof mpa);
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SET_ADDRESS(&pinfo->src, AT_NONE, 0, NULL);
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col_add_fstr(pinfo->cinfo, COL_DEF_SRC,
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"%d kb/s", mpa_bitrate(&mpa) / 1000);
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SET_ADDRESS(&pinfo->dst, AT_NONE, 0, NULL);
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col_add_fstr(pinfo->cinfo, COL_DEF_DST,
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"%g kHz", mpa_frequency(&mpa) / (float)1000);
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}
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if (tree == NULL)
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return TRUE;
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asn1_ctx_init(&asn1_ctx, ASN1_ENC_PER, TRUE, pinfo);
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offset = dissect_mpeg_audio_Audio(tvb, offset, &asn1_ctx,
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tree, proto_mpeg_audio);
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if (data_size > 0) {
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unsigned int padding;
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proto_tree_add_item(tree, hf_mpeg_audio_data, tvb,
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offset / 8, data_size, ENC_NA);
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offset += data_size * 8;
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padding = mpa_padding(&mpa);
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if (padding > 0) {
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proto_tree_add_item(tree, hf_mpeg_audio_padbytes, tvb,
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offset / 8, padding, ENC_NA);
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}
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}
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return TRUE;
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}
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static void
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dissect_id3v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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asn1_ctx_t asn1_ctx;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "ID3v1");
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col_clear(pinfo->cinfo, COL_INFO);
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if (tree == NULL)
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return;
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asn1_ctx_init(&asn1_ctx, ASN1_ENC_PER, TRUE, pinfo);
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dissect_mpeg_audio_ID3v1(tvb, 0, &asn1_ctx,
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tree, hf_id3v1);
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}
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static void
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dissect_id3v2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "ID3v2");
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col_clear(pinfo->cinfo, COL_INFO);
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proto_tree_add_item(tree, hf_id3v2, tvb,
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0, -1, ENC_NA);
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}
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static gboolean
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dissect_mpeg_audio(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
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{
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int magic;
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if (!tvb_bytes_exist(tvb, 0, 3))
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return FALSE; /* not enough data for an ID tag or audio frame */
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magic = tvb_get_ntoh24(tvb, 0);
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switch (magic) {
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case 0x544147: /* TAG */
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dissect_id3v1(tvb, pinfo, tree);
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return TRUE;
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case 0x494433: /* ID3 */
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dissect_id3v2(tvb, pinfo, tree);
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return TRUE;
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default:
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return dissect_mpeg_audio_frame(tvb, pinfo, tree);
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}
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}
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void
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proto_register_mpeg_audio(void)
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{
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static hf_register_info hf[] = {
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#include "packet-mpeg-audio-hfarr.c"
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{ &hf_mpeg_audio_data,
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{ "Data", "mpeg-audio.data",
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FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},
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{ &hf_mpeg_audio_padbytes,
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{ "Padding", "mpeg-audio.padbytes",
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FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},
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{ &hf_id3v1,
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{ "ID3v1", "mpeg-audio.id3v1",
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FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }},
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{ &hf_id3v2,
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{ "ID3v2", "mpeg-audio.id3v2",
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FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }},
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};
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static gint *ett[] = {
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#include "packet-mpeg-audio-ettarr.c"
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};
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proto_mpeg_audio = proto_register_protocol(
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"Moving Picture Experts Group Audio", "MPEG Audio", "mpeg-audio");
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proto_register_field_array(proto_mpeg_audio, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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void
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proto_reg_handoff_mpeg_audio(void)
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{
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heur_dissector_add("mpeg", dissect_mpeg_audio, proto_mpeg_audio);
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}
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