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/* packet-bmc.c
* Routines for Broadcast/Multicast Control dissection
* Copyright 2011, Neil Piercy <Neil.Piercy@ipaccess.com>
*
* 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 <wsutil/bitswap.h>
#include <epan/asn1.h> /* needed for packet-gsm_map.h */
#include "packet-cell_broadcast.h"
#include "packet-gsm_map.h"
void proto_register_bmc(void);
static int dissect_bmc_cbs_message (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
static int dissect_bmc_schedule_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
static int dissect_bmc_cbs41_message (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
static int proto_bmc;
static int hf_bmc_message_type;
static int hf_bmc_message_id;
static int hf_bmc_serial_number;
/* static int hf_bmc_data_coding_scheme; */
/* static int hf_bmc_cb_data; */
static int hf_bmc_offset_to_begin_ctch_bs_index;
static int hf_bmc_length_of_cbs_schedule_period;
static int hf_bmc_new_message_bitmap;
static int hf_bmc_message_description_type;
static int hf_bmc_offset_to_ctch_bs_index_of_first_transmission;
static int hf_bmc_broadcast_address;
static int hf_bmc_cb_data41;
static int hf_bmc_future_extension_bitmap;
static int hf_bmc_length_of_serial_number_list;
static int hf_bmc_ctch_bs_index;
#define MESSAGE_TYPE_CBS_MESSAGE 1
#define MESSAGE_TYPE_SCHEDULE_MESSAGE 2
#define MESSAGE_TYPE_CBS41_MESSAGE 3
static const value_string message_type_vals[] = {
{MESSAGE_TYPE_CBS_MESSAGE, "CBS Message"},
{MESSAGE_TYPE_SCHEDULE_MESSAGE, "Schedule Message"},
{MESSAGE_TYPE_CBS41_MESSAGE, "CBS41 Message"},
{0, NULL}
};
static const value_string message_description_type_vals[] = {
{0, "Repetition of new BMC CBS message within schedule period"},
{1, "New BMC CBS message (a BMC CBS message never previously sent)"},
{2, "Reading advised"},
{3, "Reading optional"},
{4, "Repetition of old BMC CBS message within schedule period"},
{5, "Old BMC CBS message (repetition of a BMC CBS message sent in a previous schedule period)"},
{6, "Schedule message"},
{7, "CBS41 message"},
{8, "no message"},
{0, NULL}
};
static int ett_bmc;
static int ett_bmc_message_description;
static int
dissect_bmc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
uint8_t message_type;
uint8_t *reversing_buffer;
int offset = 0;
int len;
proto_item *ti;
proto_tree *bmc_tree;
tvbuff_t *bit_reversed_tvb;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BMC");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_bmc, tvb, 0, -1, ENC_NA);
bmc_tree = proto_item_add_subtree(ti, ett_bmc);
/* Needs bit-reversing. Create a new buffer, copy the message to it and bit-reverse */
len = tvb_reported_length(tvb);
reversing_buffer = (uint8_t *)tvb_memdup(pinfo->pool, tvb, offset, len);
bitswap_buf_inplace(reversing_buffer, len);
/* Make this new buffer part of the display and provide a way to dispose of it */
bit_reversed_tvb = tvb_new_child_real_data(tvb, reversing_buffer, len, len);
add_new_data_source(pinfo, bit_reversed_tvb, "Bit-reversed Data");
message_type = tvb_get_uint8(bit_reversed_tvb, offset);
proto_tree_add_item(bmc_tree, hf_bmc_message_type, bit_reversed_tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
col_add_str(pinfo->cinfo, COL_INFO, val_to_str(message_type, message_type_vals,"Reserved 0x%02x"));
switch (message_type) {
case MESSAGE_TYPE_CBS_MESSAGE:
offset = dissect_bmc_cbs_message(bit_reversed_tvb, pinfo, bmc_tree);
break;
case MESSAGE_TYPE_SCHEDULE_MESSAGE:
offset = dissect_bmc_schedule_message(bit_reversed_tvb, pinfo, bmc_tree);
break;
case MESSAGE_TYPE_CBS41_MESSAGE:
offset = dissect_bmc_cbs41_message(bit_reversed_tvb, pinfo, bmc_tree);
break;
default:
break;
}
return offset;
}
static int
dissect_bmc_cbs_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
tvbuff_t *cell_broadcast_tvb;
int offset = 1;
dissect_cbs_message_identifier(tvb, tree, offset);
offset += 2;
dissect_cbs_serial_number(tvb, tree, offset);
offset += 2;
dissect_cbs_data_coding_scheme(tvb, pinfo, tree, offset);
offset += 1;
cell_broadcast_tvb = tvb_new_subset_remaining(tvb, offset);
dissect_umts_cell_broadcast_message(cell_broadcast_tvb, pinfo, tree, NULL);
offset = tvb_reported_length(cell_broadcast_tvb);
return offset;
}
static int
dissect_bmc_schedule_message(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
int offset = 1, i, saved_offset;
uint8_t new_message_bitmap_len;
uint8_t length_of_cbs_schedule_period;
uint8_t message_description_type;
uint8_t future_extension_bitmap;
uint8_t length_of_serial_number_list;
uint8_t entry;
uint8_t bit;
proto_tree *message_description_tree;
proto_item *ti;
proto_tree_add_item(tree, hf_bmc_offset_to_begin_ctch_bs_index, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
length_of_cbs_schedule_period = tvb_get_uint8(tvb,offset);
proto_tree_add_item(tree, hf_bmc_length_of_cbs_schedule_period, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
new_message_bitmap_len = length_of_cbs_schedule_period>>3;
if (length_of_cbs_schedule_period & 0x7)
new_message_bitmap_len += 1;
proto_tree_add_item(tree, hf_bmc_new_message_bitmap, tvb, offset, new_message_bitmap_len, ENC_NA);
offset += new_message_bitmap_len;
message_description_tree = proto_tree_add_subtree(tree, tvb, offset, 0,
ett_bmc_message_description, &ti, "Message Description" );
saved_offset = offset;
bit=1;
for (i=0; i<new_message_bitmap_len; i++) {
for(; bit<=length_of_cbs_schedule_period; bit++) {
message_description_type = tvb_get_uint8(tvb,offset);
proto_tree_add_uint_format(message_description_tree, hf_bmc_message_description_type,
tvb, offset, 1, message_description_type,
"Message %d Message Description Type: %s (%d)",
bit,
val_to_str_const(message_description_type, message_description_type_vals,"Unknown"),
message_description_type);
offset += 1;
if ((message_description_type==1) || (message_description_type==5)) {
proto_tree_add_item(message_description_tree, hf_bmc_message_id, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
}
else if ((message_description_type==0) || (message_description_type==4)) {
proto_tree_add_item(message_description_tree, hf_bmc_offset_to_ctch_bs_index_of_first_transmission,
tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
}
}
}
proto_item_set_len(ti, offset-saved_offset);
if (tvb_reported_length_remaining(tvb,offset)) {
future_extension_bitmap = tvb_get_uint8(tvb,offset);
proto_tree_add_item(tree, hf_bmc_future_extension_bitmap, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
if (future_extension_bitmap & 0x01) {
length_of_serial_number_list = tvb_get_uint8(tvb,offset);
proto_tree_add_item(tree, hf_bmc_length_of_serial_number_list, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
for (entry=0; entry<length_of_serial_number_list; entry++) {
proto_tree_add_item(tree, hf_bmc_serial_number, tvb, offset, 2, ENC_BIG_ENDIAN);
offset += 2;
proto_tree_add_item(tree, hf_bmc_ctch_bs_index, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
}
}
}
return offset;
}
static int
dissect_bmc_cbs41_message(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree)
{
int offset=1;
proto_tree_add_item(tree, hf_bmc_broadcast_address, tvb, offset, 5, ENC_NA);
offset += 5;
proto_tree_add_item(tree, hf_bmc_cb_data41, tvb, offset, tvb_reported_length_remaining(tvb,offset), ENC_NA);
offset = tvb_reported_length(tvb);
return offset;
}
void
proto_register_bmc(void)
{
static hf_register_info hf[] = {
{ &hf_bmc_message_type,
{ "Message Type", "bmc.message_type",
FT_UINT8, BASE_DEC, VALS(message_type_vals), 0,
NULL, HFILL }
},
{ &hf_bmc_message_id,
{ "Message ID", "bmc.message_id",
FT_UINT16, BASE_HEX, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_serial_number,
{ "Serial Number", "bmc.serial_number",
FT_UINT16, BASE_HEX, NULL, 0,
NULL, HFILL }
},
#if 0
{ &hf_bmc_data_coding_scheme,
{ "Data Coding Scheme", "bmc.data_coding_scheme",
FT_UINT8, BASE_HEX, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_cb_data,
{ "CB Data", "bmc.cb_data",
FT_BYTES, BASE_NONE, NULL, 0,
NULL, HFILL }
},
#endif
{ &hf_bmc_offset_to_begin_ctch_bs_index,
{ "Offset to Begin CTCH Block Set Index", "bmc.offset_to_begin_ctch_bs_index",
FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_length_of_cbs_schedule_period,
{ "Length of CBS Schedule Period", "bmc.length_of_cbs_schedule_period",
FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_new_message_bitmap,
{ "New Message Bitmap", "bmc.new_message_bitmap",
FT_BYTES, BASE_NONE, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_message_description_type,
{ "Message Description Type", "bmc.message_description_type",
FT_UINT8, BASE_DEC, VALS(message_description_type_vals), 0,
NULL, HFILL }
},
{ &hf_bmc_offset_to_ctch_bs_index_of_first_transmission,
{ "Offset to CTCH BS index of first transmission", "bmc.offset_to_ctch_bs_index_of_first_transmission",
FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_broadcast_address,
{ "Broadcast Address", "bmc.broadcast_address",
FT_BYTES, BASE_NONE, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_cb_data41,
{ "CB Data41", "bmc.cb_data41",
FT_BYTES, BASE_NONE, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_future_extension_bitmap,
{ "Future Extension Bitmap", "bmc.future_extension_bitmap",
FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_length_of_serial_number_list,
{ "Length of Serial Number List", "bmc.length_of_serial_number_list",
FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }
},
{ &hf_bmc_ctch_bs_index,
{ "CTCH BS Index", "bmc.ctch_bs_index",
FT_UINT8, BASE_DEC, NULL, 0,
NULL, HFILL }
}
};
static int *ett[] = {
&ett_bmc,
&ett_bmc_message_description
};
proto_bmc = proto_register_protocol("Broadcast/Multicast Control", "BMC", "bmc");
register_dissector("bmc", dissect_bmc, proto_bmc);
proto_register_field_array(proto_bmc, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
/*
* 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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