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/* packet-sbc.c
* Routines for Bluetooth SBC dissection
*
* Copyright 2012, Michal Labedzki for Tieto Corporation
*
* 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/expert.h>
#include <epan/prefs.h>
#include <epan/unit_strings.h>
#include <wsutil/array.h>
#include "packet-btavdtp.h"
#define CHANNELS_MONO 0x00
#define CHANNELS_DUAL_CHANNEL 0x01
#define CHANNELS_JOINT_STEREO 0x03
#define FREQUENCY_16000 0x00
#define FREQUENCY_32000 0x01
#define FREQUENCY_44100 0x02
#define FREQUENCY_48000 0x03
void proto_register_sbc(void);
static int proto_sbc;
static int hf_sbc_fragmented;
static int hf_sbc_starting_packet;
static int hf_sbc_last_packet;
static int hf_sbc_rfa;
static int hf_sbc_number_of_frames;
static int hf_sbc_syncword;
static int hf_sbc_sampling_frequency;
static int hf_sbc_blocks;
static int hf_sbc_channel_mode;
static int hf_sbc_allocation_method;
static int hf_sbc_subbands;
static int hf_sbc_bitpool;
static int hf_sbc_crc_check;
static int hf_sbc_expected_data_speed;
static int hf_sbc_frame_duration;
static int hf_sbc_cumulative_frame_duration;
static int hf_sbc_delta_time;
static int hf_sbc_delta_time_from_the_beginning;
static int hf_sbc_cumulative_duration;
static int hf_sbc_avrcp_song_position;
static int hf_sbc_diff;
static int hf_sbc_data;
static int ett_sbc;
static int ett_sbc_list;
static expert_field ei_sbc_syncword;
extern value_string_ext media_codec_audio_type_vals_ext;
static const value_string sampling_frequency_vals[] = {
{ 0x00, "16 kHz"},
{ 0x01, "32 kHz"},
{ 0x02, "44.1 kHz"},
{ 0x03, "48 kHz"},
{ 0, NULL }
};
static const value_string blocks_vals[] = {
{ 0x00, "4"},
{ 0x01, "8"},
{ 0x02, "12"},
{ 0x03, "16"},
{ 0, NULL }
};
static const value_string channel_mode_vals[] = {
{ 0x00, "Mono"},
{ 0x01, "Dual Channel"},
{ 0x02, "Stereo"},
{ 0x03, "Joint Stereo"},
{ 0, NULL }
};
static const value_string allocation_method_vals[] = {
{ 0x00, "Loudness"},
{ 0x01, "SNR"},
{ 0, NULL }
};
static const value_string subbands_vals[] = {
{ 0x00, "4"},
{ 0x01, "8"},
{ 0, NULL }
};
static int
dissect_sbc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
proto_item *ti;
proto_tree *sbc_tree;
proto_item *pitem;
proto_tree *rtree;
int offset = 0;
uint8_t number_of_frames;
uint8_t syncword;
uint8_t byte;
uint8_t blocks;
uint8_t channels;
uint8_t subbands;
uint8_t bitpool;
unsigned frequency;
uint8_t sbc_blocks;
int sbc_channels;
uint8_t sbc_subbands;
int val;
int counter = 1;
int frame_length;
int expected_speed_data;
double frame_duration;
double cumulative_frame_duration = 0;
bta2dp_codec_info_t *info;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "SBC");
info = (bta2dp_codec_info_t *) data;
ti = proto_tree_add_item(tree, proto_sbc, tvb, offset, -1, ENC_NA);
sbc_tree = proto_item_add_subtree(ti, ett_sbc);
proto_tree_add_item(sbc_tree, hf_sbc_fragmented, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(sbc_tree, hf_sbc_starting_packet, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(sbc_tree, hf_sbc_last_packet, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(sbc_tree, hf_sbc_rfa, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(sbc_tree, hf_sbc_number_of_frames, tvb, offset, 1, ENC_BIG_ENDIAN);
number_of_frames = tvb_get_uint8(tvb, offset) & 0x0F;
offset += 1;
while (tvb_reported_length_remaining(tvb, offset) > 0) {
byte = tvb_get_uint8(tvb, offset + 1);
frequency = (byte & 0xC0) >> 6;
blocks = (byte & 0x30) >> 4;
channels = (byte & 0x0C)>> 2;
subbands = byte & 0x01;
bitpool = tvb_get_uint8(tvb, offset + 2);
if (channels == CHANNELS_MONO)
sbc_channels = 1;
else
sbc_channels = 2;
switch (frequency) {
case FREQUENCY_16000:
frequency = 16000;
break;
case FREQUENCY_32000:
frequency = 32000;
break;
case FREQUENCY_44100:
frequency = 44100;
break;
case FREQUENCY_48000:
frequency = 48000;
break;
default:
frequency = 0;
}
sbc_subbands = 4 * (subbands + 1);
sbc_blocks = 4 * (blocks + 1);
frame_length = (4 * sbc_subbands * sbc_channels) / 8;
if (sbc_channels == 1 || channels == CHANNELS_DUAL_CHANNEL)
val = sbc_blocks * sbc_channels * bitpool;
else
val = (((channels == CHANNELS_JOINT_STEREO) ? 1 : 0) * sbc_subbands + sbc_blocks * bitpool);
frame_length += val / 8;
if (val % 8)
frame_length += 1;
expected_speed_data = (frame_length * frequency) / (sbc_subbands * sbc_blocks);
rtree = proto_tree_add_subtree_format(sbc_tree, tvb, offset, 4 + frame_length,
ett_sbc_list, NULL, "Frame: %3u/%3u", counter, number_of_frames);
pitem = proto_tree_add_item(rtree, hf_sbc_syncword, tvb, offset, 1, ENC_BIG_ENDIAN);
syncword = tvb_get_uint8(tvb, offset);
if (syncword != 0x9C) {
expert_add_info(pinfo, pitem, &ei_sbc_syncword);
}
offset += 1;
proto_tree_add_item(rtree, hf_sbc_sampling_frequency, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(rtree, hf_sbc_blocks, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(rtree, hf_sbc_channel_mode, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(rtree, hf_sbc_allocation_method, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(rtree, hf_sbc_subbands, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(rtree, hf_sbc_bitpool, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(rtree, hf_sbc_crc_check, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(rtree, hf_sbc_data, tvb, offset, frame_length, ENC_NA);
offset += frame_length;
/* TODO: expert_info for invalid CRC */
pitem = proto_tree_add_uint(rtree, hf_sbc_expected_data_speed, tvb, offset, 0, expected_speed_data / 1024);
proto_item_set_generated(pitem);
frame_duration = (((double) frame_length / (double) expected_speed_data) * 1000.0);
cumulative_frame_duration += frame_duration;
pitem = proto_tree_add_double(rtree, hf_sbc_frame_duration, tvb, offset, 0, frame_duration);
proto_item_set_generated(pitem);
counter += 1;
}
pitem = proto_tree_add_double(sbc_tree, hf_sbc_cumulative_frame_duration, tvb, offset, 0, cumulative_frame_duration);
proto_item_set_generated(pitem);
if (info && info->configuration && info->configuration_length > 0) {
/* TODO: display current codec configuration */
}
if (info && info->previous_media_packet_info && info->current_media_packet_info) {
nstime_t delta;
nstime_delta(&delta, &pinfo->abs_ts, &info->previous_media_packet_info->abs_ts);
pitem = proto_tree_add_double(sbc_tree, hf_sbc_delta_time, tvb, offset, 0, nstime_to_msec(&delta));
proto_item_set_generated(pitem);
pitem = proto_tree_add_double(sbc_tree, hf_sbc_avrcp_song_position, tvb, offset, 0, info->previous_media_packet_info->avrcp_song_position);
proto_item_set_generated(pitem);
nstime_delta(&delta, &pinfo->abs_ts, &info->previous_media_packet_info->first_abs_ts);
pitem = proto_tree_add_double(sbc_tree, hf_sbc_delta_time_from_the_beginning, tvb, offset, 0, nstime_to_msec(&delta));
proto_item_set_generated(pitem);
if (!pinfo->fd->visited) {
info->current_media_packet_info->cumulative_frame_duration += cumulative_frame_duration;
info->current_media_packet_info->avrcp_song_position += cumulative_frame_duration;
}
pitem = proto_tree_add_double(sbc_tree, hf_sbc_cumulative_duration, tvb, offset, 0, info->previous_media_packet_info->cumulative_frame_duration);
proto_item_set_generated(pitem);
pitem = proto_tree_add_double(sbc_tree, hf_sbc_diff, tvb, offset, 0, info->previous_media_packet_info->cumulative_frame_duration - nstime_to_msec(&delta));
proto_item_set_generated(pitem);
}
/* TODO: more precise dissection: blocks, channels, subbands, padding */
col_append_fstr(pinfo->cinfo, COL_INFO, " Frames=%u", number_of_frames);
return offset;
}
void
proto_register_sbc(void)
{
module_t *module;
expert_module_t* expert_sbc;
static hf_register_info hf[] = {
{ &hf_sbc_fragmented,
{ "Fragmented", "sbc.fragmented",
FT_BOOLEAN, 8, NULL, 0x80,
NULL, HFILL }
},
{ &hf_sbc_starting_packet,
{ "Starting Packet", "sbc.starting_packet",
FT_BOOLEAN, 8, NULL, 0x40,
NULL, HFILL }
},
{ &hf_sbc_last_packet,
{ "Last Packet", "sbc.last_packet",
FT_BOOLEAN, 8, NULL, 0x20,
NULL, HFILL }
},
{ &hf_sbc_rfa,
{ "RFA", "sbc.rfa",
FT_BOOLEAN, 8, NULL, 0x10,
NULL, HFILL }
},
{ &hf_sbc_number_of_frames,
{ "Number of Frames", "sbc.number_of_frames",
FT_UINT8, BASE_DEC, NULL, 0x0F,
NULL, HFILL }
},
{ &hf_sbc_syncword,
{ "Sync Word", "sbc.syncword",
FT_UINT8, BASE_HEX, NULL, 0x00,
NULL, HFILL }
},
{ &hf_sbc_sampling_frequency,
{ "Sampling Frequency", "sbc.sampling_frequency",
FT_UINT8, BASE_HEX, VALS(sampling_frequency_vals), 0xC0,
NULL, HFILL }
},
{ &hf_sbc_blocks,
{ "Blocks", "sbc.blocks",
FT_UINT8, BASE_HEX, VALS(blocks_vals), 0x30,
NULL, HFILL }
},
{ &hf_sbc_channel_mode,
{ "Channel Mode", "sbc.channel_mode",
FT_UINT8, BASE_HEX, VALS(channel_mode_vals), 0x0C,
NULL, HFILL }
},
{ &hf_sbc_allocation_method,
{ "Allocation Method", "sbc.allocation_method",
FT_UINT8, BASE_HEX, VALS(allocation_method_vals), 0x02,
NULL, HFILL }
},
{ &hf_sbc_subbands,
{ "Subbands", "sbc.subbands",
FT_UINT8, BASE_HEX, VALS(subbands_vals), 0x01,
NULL, HFILL }
},
{ &hf_sbc_bitpool,
{ "Bitpool", "sbc.bitpool",
FT_UINT8, BASE_DEC, NULL, 0x00,
NULL, HFILL }
},
{ &hf_sbc_crc_check,
{ "CRC Check", "sbc.crc_check",
FT_UINT8, BASE_HEX, NULL, 0x00,
NULL, HFILL }
},
{ &hf_sbc_expected_data_speed,
{ "Expected data speed", "sbc.expected_data_speed",
FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_kibps), 0x00,
NULL, HFILL }
},
{ &hf_sbc_frame_duration,
{ "Frame Duration", "sbc.frame_duration",
FT_DOUBLE, BASE_NONE|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
NULL, HFILL }
},
{ &hf_sbc_cumulative_frame_duration,
{ "Cumulative Frame Duration", "sbc.cumulative_frame_duration",
FT_DOUBLE, BASE_NONE|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
NULL, HFILL }
},
{ &hf_sbc_delta_time,
{ "Delta time", "sbc.delta_time",
FT_DOUBLE, BASE_NONE|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
NULL, HFILL }
},
{ &hf_sbc_delta_time_from_the_beginning,
{ "Delta time from the beginning", "sbc.delta_time_from_the_beginning",
FT_DOUBLE, BASE_NONE|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
NULL, HFILL }
},
{ &hf_sbc_cumulative_duration,
{ "Cumulative Music Duration", "sbc.cumulative_music_duration",
FT_DOUBLE, BASE_NONE|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
NULL, HFILL }
},
{ &hf_sbc_avrcp_song_position,
{ "AVRCP Song Position", "sbc.avrcp_song_position",
FT_DOUBLE, BASE_NONE|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
NULL, HFILL }
},
{ &hf_sbc_diff,
{ "Diff", "sbc.diff",
FT_DOUBLE, BASE_NONE|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
NULL, HFILL }
},
{ &hf_sbc_data,
{ "Frame Data", "sbc.data",
FT_NONE, BASE_NONE, NULL, 0x00,
NULL, HFILL }
},
};
static int *ett[] = {
&ett_sbc,
&ett_sbc_list,
};
static ei_register_info ei[] = {
{ &ei_sbc_syncword, { "sbc.syncword.unexpected", PI_PROTOCOL, PI_WARN, "Unexpected syncword", EXPFILL }},
};
proto_sbc = proto_register_protocol("Bluetooth SBC Codec", "SBC", "sbc");
proto_register_field_array(proto_sbc, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_sbc = expert_register_protocol(proto_sbc);
expert_register_field_array(expert_sbc, ei, array_length(ei));
register_dissector("sbc", dissect_sbc, proto_sbc);
module = prefs_register_protocol_subtree("Bluetooth", proto_sbc, NULL);
prefs_register_static_text_preference(module, "a2dp.version",
"Bluetooth Audio Codec SBC version based on A2DP 1.3",
"Version of codec supported by this dissector.");
}
/*
* 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:
*/
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