wireshark/epan/dissectors/packet-etv.c

/* packet-etv.c
 *
 * Routines for ETV-AM from OC-SP-ETV-AM1.0-IO5
 * Copyright 2012, Weston Schmidt <weston_schmidt@alumni.purdue.edu>
 *
 * 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 "packet-mpeg-sect.h"

void proto_register_etv(void);
void proto_reg_handoff_etv(void);

static int proto_etv_dii = -1;
static int proto_etv_ddb = -1;

static dissector_handle_t dsmcc_handle;

static int hf_etv_dii_filter_info = -1;
static int hf_etv_dii_reserved = -1;

static expert_field ei_etv_dii_invalid_section_syntax_indicator = EI_INIT;
static expert_field ei_etv_dii_invalid_section_length = EI_INIT;
static expert_field ei_etv_dii_invalid_reserved_bits = EI_INIT;
static expert_field ei_etv_dii_filter_info = EI_INIT;

static int hf_etv_ddb_filter_info = -1;
static int hf_etv_ddb_reserved = -1;

static expert_field ei_etv_ddb_invalid_section_syntax_indicator = EI_INIT;
static expert_field ei_etv_ddb_invalid_section_length = EI_INIT;
static expert_field ei_etv_ddb_invalid_reserved_bits = EI_INIT;
static expert_field ei_etv_ddb_filter_info = EI_INIT;

static gint ett_etv = -1;
static gint ett_etv_payload = -1;

static void
dissect_etv_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int proto,
	int hf_filter_info, int hf_reserved,
	expert_field* ei_section_syntax_indicator, expert_field* ei_reserved,
	expert_field* ei_section_length, expert_field* ei_filter_info)
{
	tvbuff_t   *sub_tvb;
	guint       offset = 0;
	proto_item *ti;
	proto_item *pi;
	proto_tree *etv_tree;
	proto_item *items[PACKET_MPEG_SECT_PI__SIZE];
	gboolean    ssi;
	guint       reserved;
	guint8      reserved2;
	guint16     filter_info;
	guint       sect_len;

	ti = proto_tree_add_item(tree, proto, tvb, offset, -1, ENC_NA);
	etv_tree = proto_item_add_subtree(ti, ett_etv);

	offset += packet_mpeg_sect_header_extra(tvb, offset, etv_tree, &sect_len,
						&reserved, &ssi, items);

	if (FALSE != ssi) {
		proto_item *msg_error;
		msg_error = items[PACKET_MPEG_SECT_PI__SSI];

		proto_item_set_generated(msg_error);
		expert_add_info(pinfo, msg_error, ei_section_syntax_indicator);
	}

	if (4 != reserved) {
		proto_item *msg_error;
		msg_error = items[PACKET_MPEG_SECT_PI__RESERVED];

		proto_item_set_generated(msg_error);
		expert_add_info(pinfo, msg_error, ei_reserved);
	}

	col_append_fstr(pinfo->cinfo, COL_INFO, ", Length: %u", sect_len);
	proto_item_append_text(ti, " Length=%u", sect_len);
	if (1021 < sect_len) {
		proto_item *msg_error;
		msg_error = items[PACKET_MPEG_SECT_PI__LENGTH];

		proto_item_set_generated(msg_error);
		expert_add_info(pinfo, msg_error, ei_section_length);
	}

	filter_info = tvb_get_ntohs(tvb, offset);
	col_append_fstr(pinfo->cinfo, COL_INFO, ", Filter: 0x%x", filter_info);
	proto_item_append_text(ti, " Filter=0x%x", filter_info);
	pi = proto_tree_add_item(etv_tree, hf_filter_info, tvb, offset, 2, ENC_BIG_ENDIAN);
	if ((proto_etv_dii == proto) && (0xFBFB != filter_info)) {
		expert_add_info_format(pinfo, pi, ei_filter_info,
					"Invalid filter_info value (must be 0xFBFB)");
	} else if ((proto_etv_ddb == proto) &&
			((filter_info < 1) || (0xfbef < filter_info)))
	{
		expert_add_info_format(pinfo, pi, ei_filter_info,
					"Invalid filter_info value (must be [0x0001-0xFBEF] inclusive)");
	}
	offset += 2;

	reserved2 = tvb_get_guint8(tvb, offset);
	pi = proto_tree_add_item(etv_tree, hf_reserved, tvb, offset, 1, ENC_BIG_ENDIAN);
	if (0 != reserved2) {
		expert_add_info_format(pinfo, pi, ei_reserved,
					"Invalid reserved2 bits (should all be 0)");
	}
	offset += 1;

	sub_tvb = tvb_new_subset_length(tvb, offset, sect_len-7);
	call_dissector(dsmcc_handle, sub_tvb, pinfo, tree);

	sect_len += 3 - 4; /* add header, remove crc */

	packet_mpeg_sect_crc(tvb, pinfo, etv_tree, 0, sect_len);
}


static int
dissect_etv_ddb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
	col_set_str(pinfo->cinfo, COL_PROTOCOL, "ETV-DDB");
	col_set_str(pinfo->cinfo, COL_INFO, "ETV DDB");

	dissect_etv_common(tvb, pinfo, tree, proto_etv_ddb, hf_etv_ddb_filter_info,
		hf_etv_ddb_reserved, &ei_etv_ddb_invalid_section_syntax_indicator,
		&ei_etv_ddb_invalid_reserved_bits, &ei_etv_ddb_invalid_section_length,
		&ei_etv_ddb_filter_info);
	return tvb_captured_length(tvb);
}


static int
dissect_etv_dii(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
	col_set_str(pinfo->cinfo, COL_PROTOCOL, "ETV-DII");
	col_set_str(pinfo->cinfo, COL_INFO, "ETV DII");
	dissect_etv_common(tvb, pinfo, tree, proto_etv_dii, hf_etv_dii_filter_info,
		hf_etv_dii_reserved, &ei_etv_dii_invalid_section_syntax_indicator,
		&ei_etv_dii_invalid_reserved_bits, &ei_etv_dii_invalid_section_length,
		&ei_etv_dii_filter_info);
	return tvb_captured_length(tvb);
}


void
proto_register_etv(void)
{
	static hf_register_info hf_ddb[] = {
		{ &hf_etv_ddb_filter_info, {
			"Filter Info", "etv-ddb.filter_info",
			FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL
		} },

		{ &hf_etv_ddb_reserved, {
			"Reserved", "etv-ddb.reserved",
			FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL
		} }
	};

	static hf_register_info hf_dii[] = {
		{ &hf_etv_dii_filter_info, {
			"Filter Info", "etv-dii.filter_info",
			FT_UINT16, BASE_HEX, NULL, 0, NULL, HFILL
		} },

		{ &hf_etv_dii_reserved, {
			"Reserved", "etv-dii.reserved",
			FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL
		} }
	};

	static gint *ett[] = {
		&ett_etv,
		&ett_etv_payload
	};

	static ei_register_info ei_ddb[] = {
		{ &ei_etv_ddb_invalid_section_syntax_indicator, { "etv-ddb.invalid_section_syntax_indicator", PI_MALFORMED, PI_ERROR, "Invalid section_syntax_indicator (should be 0)", EXPFILL }},
		{ &ei_etv_ddb_invalid_reserved_bits, { "etv-ddb.invalid_reserved_bits", PI_MALFORMED, PI_ERROR, "Invalid reserved bits", EXPFILL }},
		{ &ei_etv_ddb_invalid_section_length, { "etv-ddb.invalid_section_length", PI_MALFORMED, PI_ERROR, "Invalid section_length (must not exceed 1021)", EXPFILL }},
		{ &ei_etv_ddb_filter_info, { "etv-ddb.filter_info.invalid", PI_MALFORMED, PI_ERROR, "Invalid filter info", EXPFILL }},
	};

	static ei_register_info ei_dii[] = {
		{ &ei_etv_dii_invalid_section_syntax_indicator, { "etv-dii.invalid_section_syntax_indicator", PI_MALFORMED, PI_ERROR, "Invalid section_syntax_indicator (should be 0)", EXPFILL }},
		{ &ei_etv_dii_invalid_reserved_bits, { "etv-dii.invalid_reserved_bits", PI_MALFORMED, PI_ERROR, "Invalid reserved bits", EXPFILL }},
		{ &ei_etv_dii_invalid_section_length, { "etv-dii.invalid_section_length", PI_MALFORMED, PI_ERROR, "Invalid section_length (must not exceed 1021)", EXPFILL }},
		{ &ei_etv_dii_filter_info, { "etv-dii.filter_info.invalid", PI_MALFORMED, PI_ERROR, "Invalid filter info", EXPFILL }},
	};

	expert_module_t* expert_etv_dii;
	expert_module_t* expert_etv_ddb;

	proto_etv_dii = proto_register_protocol("ETV-AM DII Section", "ETV-AM DII", "etv-dii");
	proto_etv_ddb = proto_register_protocol("ETV-AM DDB Section", "ETV-AM DDB", "etv-ddb");

	proto_register_field_array(proto_etv_dii, hf_dii, array_length(hf_dii));
	proto_register_field_array(proto_etv_ddb, hf_ddb, array_length(hf_ddb));
	proto_register_subtree_array(ett, array_length(ett));
	expert_etv_dii = expert_register_protocol(proto_etv_dii);
	expert_register_field_array(expert_etv_dii, ei_dii, array_length(ei_dii));
	expert_etv_ddb = expert_register_protocol(proto_etv_ddb);
	expert_register_field_array(expert_etv_ddb, ei_ddb, array_length(ei_ddb));
}


void
proto_reg_handoff_etv(void)
{
	dissector_handle_t etv_dii_handle;
	dissector_handle_t etv_ddb_handle;

	etv_dii_handle = create_dissector_handle(dissect_etv_dii, proto_etv_dii);
	etv_ddb_handle = create_dissector_handle(dissect_etv_ddb, proto_etv_ddb);
	dissector_add_uint("mpeg_sect.tid", ETV_TID_DII_SECTION, etv_dii_handle);
	dissector_add_uint("mpeg_sect.tid", ETV_TID_DDB_SECTION, etv_ddb_handle);
	dsmcc_handle = find_dissector_add_dependency("mp2t-dsmcc", proto_etv_dii);
	find_dissector_add_dependency("mp2t-dsmcc", proto_etv_ddb);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */