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/* packet-dvb-data-mpe.c
* Routines for DVB-DATA (ETSI EN 301 192) MultiProtocol Encapsulation
* Copyright 2012, Guy Martin <gmsoft@tuxicoman.be>
*
* 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/to_str.h>
#include "packet-mpeg-sect.h"
void proto_register_dvb_data_mpe(void);
void proto_reg_handoff_dvb_data_mpe(void);
static int proto_dvb_data_mpe = -1;
static int hf_dvb_data_mpe_reserved = -1;
static int hf_dvb_data_mpe_payload_scrambling_control = -1;
static int hf_dvb_data_mpe_address_scrambling_control = -1;
static int hf_dvb_data_mpe_llc_snap_flag = -1;
static int hf_dvb_data_mpe_current_next_indicator = -1;
static int hf_dvb_data_mpe_section_number = -1;
static int hf_dvb_data_mpe_last_section_number = -1;
static int hf_dvb_data_mpe_dst_mac = -1;
static int hf_dvb_data_mpe_dst_mac_scrambled = -1;
static gint ett_dvb_data_mpe = -1;
static expert_field ei_dvb_data_mpe_reserved_not_one = EI_INIT;
static expert_field ei_dvb_data_mpe_payload_scrambled = EI_INIT;
static expert_field ei_dvb_data_mpe_address_scrambled = EI_INIT;
static dissector_handle_t ip_handle;
static dissector_handle_t llc_handle;
#define DVB_DATA_MPE_RESERVED_MASK 0xC0
#define DVB_DATA_MPE_PAYLOAD_SCRAMBLING_MASK 0x30
#define DVB_DATA_MPE_ADDRESS_SCRAMBLING_MASK 0x0C
#define DVB_DATA_MPE_LLC_SNAP_FLAG_MASK 0x02
#define DVB_DATA_MPE_CURRENT_NEXT_INDICATOR_MASK 0x01
/* Field positions for the MAC Address */
/* It is split into two chunks, one of two octets and a second
* one of four octets. Also, the octets are in reverse order. */
#define DVB_DATA_MPE_DST_MAC_FIRST 3
#define DVB_DATA_MPE_DST_MAC_SECOND 8
static const value_string dvb_data_mpe_scrambling_vals[] = {
{ 0, "Unscrambled" },
{ 1, "Defined by service" },
{ 2, "Defined by service" },
{ 3, "Defined by service" },
{ 0, NULL }
};
static const value_string dvb_rcs_cur_next_vals[] = {
{ 0x0, "Not yet applicable" },
{ 0x1, "Currently applicable" },
{ 0, NULL },
};
static int
dissect_dvb_data_mpe(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
guint offset = 0, tot_len = 0;
guint32 reserved, address_scrambling, payload_scrambling, llc_snap_flag;
int i;
proto_item *ti;
proto_tree *dvb_data_mpe_tree;
guchar *dst = (guchar*)wmem_alloc(pinfo->pool, 6);
address dst_addr;
tvbuff_t *data_tvb;
/* The TVB should start right after the section_length in the Section packet */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "DVB-DATA");
col_set_str(pinfo->cinfo, COL_INFO, "MultiProtocol Encapsulation");
ti = proto_tree_add_item(tree, proto_dvb_data_mpe, tvb, offset, -1, ENC_NA);
dvb_data_mpe_tree = proto_item_add_subtree(ti, ett_dvb_data_mpe);
offset += packet_mpeg_sect_header(tvb, offset, dvb_data_mpe_tree, &tot_len, NULL);
/* Parse the DMC-CC private section header */
dst[5] = tvb_get_guint8(tvb, offset);
offset += 1;
dst[4] = tvb_get_guint8(tvb, offset);
offset += 1;
ti = proto_tree_add_item_ret_uint(dvb_data_mpe_tree, hf_dvb_data_mpe_reserved, tvb, offset, 1, ENC_BIG_ENDIAN, &reserved);
if (reserved != 3) {
expert_add_info(pinfo, ti, &ei_dvb_data_mpe_reserved_not_one);
}
ti = proto_tree_add_item_ret_uint(dvb_data_mpe_tree, hf_dvb_data_mpe_payload_scrambling_control, tvb, offset, 1, ENC_BIG_ENDIAN, &payload_scrambling);
if (payload_scrambling) {
expert_add_info(pinfo, ti, &ei_dvb_data_mpe_payload_scrambled);
}
proto_tree_add_item_ret_uint(dvb_data_mpe_tree, hf_dvb_data_mpe_address_scrambling_control, tvb, offset, 1, ENC_BIG_ENDIAN, &address_scrambling);
proto_tree_add_item_ret_uint(dvb_data_mpe_tree, hf_dvb_data_mpe_llc_snap_flag, tvb, offset, 1, ENC_BIG_ENDIAN, &llc_snap_flag);
proto_tree_add_item(dvb_data_mpe_tree, hf_dvb_data_mpe_current_next_indicator, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(dvb_data_mpe_tree, hf_dvb_data_mpe_section_number, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
proto_tree_add_item(dvb_data_mpe_tree, hf_dvb_data_mpe_last_section_number, tvb, offset, 1, ENC_BIG_ENDIAN);
offset += 1;
for (i = 3; i >= 0; i--) {
dst[i] = tvb_get_guint8(tvb, offset);
offset += 1;
}
if (address_scrambling) {
ti = proto_tree_add_bytes_with_length(dvb_data_mpe_tree, hf_dvb_data_mpe_dst_mac_scrambled, tvb, DVB_DATA_MPE_DST_MAC_FIRST, 2, dst, 6);
expert_add_info(pinfo, ti, &ei_dvb_data_mpe_address_scrambled);
} else {
ti = proto_tree_add_ether(dvb_data_mpe_tree, hf_dvb_data_mpe_dst_mac, tvb, DVB_DATA_MPE_DST_MAC_FIRST, 2, dst);
set_address(&dst_addr, AT_ETHER, 6, dst);
col_add_str(pinfo->cinfo, COL_RES_DL_DST, address_to_str(pinfo->pool, &dst_addr));
}
/* Extend the highlighting for the second chunk. */
proto_tree_set_appendix(ti, tvb, DVB_DATA_MPE_DST_MAC_SECOND, 4);
data_tvb = tvb_new_subset_remaining(tvb, offset);
if (payload_scrambling) {
call_data_dissector(data_tvb, pinfo, tree);
} else if (llc_snap_flag) {
call_dissector(llc_handle, data_tvb, pinfo, tree);
} else {
call_dissector(ip_handle, data_tvb, pinfo, tree);
}
packet_mpeg_sect_crc(tvb, pinfo, dvb_data_mpe_tree, 0, tot_len - 1);
return tvb_captured_length(tvb);
}
void
proto_register_dvb_data_mpe(void)
{
static hf_register_info hf[] = {
/* DSM-CC common fields */
{ &hf_dvb_data_mpe_reserved, {
"Reserved", "dvb_data_mpe.reserved",
FT_UINT8, BASE_HEX, NULL, DVB_DATA_MPE_RESERVED_MASK, NULL, HFILL
} },
{ &hf_dvb_data_mpe_payload_scrambling_control, {
"Payload Scrambling Control", "dvb_data_mpe.pload_scrambling",
FT_UINT8, BASE_HEX, VALS(dvb_data_mpe_scrambling_vals),
DVB_DATA_MPE_PAYLOAD_SCRAMBLING_MASK, NULL, HFILL
} },
{ &hf_dvb_data_mpe_address_scrambling_control, {
"Address Scrambling Control", "dvb_data_mpe.addr_scrambling",
FT_UINT8, BASE_HEX, VALS(dvb_data_mpe_scrambling_vals),
DVB_DATA_MPE_ADDRESS_SCRAMBLING_MASK, NULL, HFILL
} },
{ &hf_dvb_data_mpe_llc_snap_flag, {
"LLC SNAP Flag", "dvb_data_mpe.llc_snap_flag",
FT_UINT8, BASE_HEX, NULL, DVB_DATA_MPE_LLC_SNAP_FLAG_MASK, NULL, HFILL
} },
{ &hf_dvb_data_mpe_current_next_indicator, {
"Current/Next Indicator", "mpeg_sect.cur_next_ind",
FT_UINT8, BASE_HEX, VALS(dvb_rcs_cur_next_vals), DVB_DATA_MPE_CURRENT_NEXT_INDICATOR_MASK, NULL, HFILL
} },
{ &hf_dvb_data_mpe_section_number, {
"Section Number", "dvb_data_mpe.sect_num",
FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL
} },
{ &hf_dvb_data_mpe_last_section_number, {
"Last Section Number", "dvb_data_mpe.last_sect_num",
FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL
} },
{ &hf_dvb_data_mpe_dst_mac, {
"Destination MAC address", "dvb_data_mpe.dst_mac",
FT_ETHER, BASE_NONE, NULL, 0, NULL, HFILL
} },
{ &hf_dvb_data_mpe_dst_mac_scrambled, {
"Destination MAC address (scrambled)",
"dvb_data_mpe.dst_mac.scrambled",
FT_BYTES, SEP_COLON, NULL, 0, NULL, HFILL
} },
};
static gint *ett[] = {
&ett_dvb_data_mpe,
};
expert_module_t *expert_dvb_data_mpe;
static ei_register_info ei[] = {
{ &ei_dvb_data_mpe_reserved_not_one,
{ "dvb_data_mpe.reserved.not_one", PI_PROTOCOL, PI_WARN,
"Reserved bits not all ones", EXPFILL }},
{ &ei_dvb_data_mpe_address_scrambled,
{ "dvb_data_mpe.address_scrambled", PI_UNDECODED, PI_WARN,
"Cannot descramble destination MAC address (user private scrambling)", EXPFILL }},
{ &ei_dvb_data_mpe_payload_scrambled,
{ "dvb_data_mpe.payload.scrambled", PI_UNDECODED, PI_WARN,
"Cannot descramble payload (user private scrambling)", EXPFILL }},
};
proto_dvb_data_mpe = proto_register_protocol("DVB-DATA MultiProtocol Encapsulation", "DVB-DATA MPE", "dvb_data_mpe");
proto_register_field_array(proto_dvb_data_mpe, hf, array_length(hf));
expert_dvb_data_mpe = expert_register_protocol(proto_dvb_data_mpe);
expert_register_field_array(expert_dvb_data_mpe, ei, array_length(ei));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_dvb_data_mpe(void)
{
dissector_handle_t dvb_data_mpe_handle;
dvb_data_mpe_handle = create_dissector_handle(dissect_dvb_data_mpe, proto_dvb_data_mpe);
dissector_add_uint("mpeg_sect.tid", DVB_DATA_MPE_TID, dvb_data_mpe_handle);
ip_handle = find_dissector_add_dependency("ip", proto_dvb_data_mpe);
llc_handle = find_dissector_add_dependency("llc", proto_dvb_data_mpe);
}
/*
* 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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