/*
 *
 * Copyright (c) 2011-2016 The University of Waikato, Hamilton, New Zealand.
 * All rights reserved.
 *
 * This file is part of libprotoident.
 *
 * This code has been developed by the University of Waikato WAND
 * research group. For further information please see http://www.wand.net.nz/
 *
 * libprotoident is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * libprotoident is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 */

#include <string.h>

#include "libprotoident.h"
#include "proto_manager.h"
#include "proto_common.h"

static inline bool match_netbios_name_req(uint32_t payload, uint32_t len) {

        if (MATCH(payload, ANY, ANY, 0x00, 0x00)) {
                if (len == 50)
                        return true;
                if (len == 20)
                        return true;
		if (len == 33)
			return true;
        }
        
        if (MATCH(payload, ANY, ANY, 0x01, 0x00)) {
                if (len == 50)
                        return true;

        }
        
	if (MATCH(payload, ANY, ANY, 0x40, 0x00)) {
                if (len == 68)
                        return true;

        }

	if (MATCH(payload, ANY, ANY, 0x29, 0x10)) {
		if (len == 68)
			return true;
	}

        /* Broadcast traffic */
        if (MATCH(payload, ANY, ANY, 0x01, 0x10)) {
                if (len == 50)
                        return true;

        }
        return false;

}

static inline bool match_netbios_name_resp(uint32_t resp, uint32_t req) {

	if (!MATCH(resp, ANY, ANY, 0x84, 0x00))
		return false;
	
	/* First two bytes must match */
	if ((resp & 0x0000ffff) != (req & 0x0000ffff))
		return false;

	return true;

}

static inline bool match_netbios_datagram(uint32_t payload, uint32_t len) {

	if (MATCH(payload, 0x11, 0x02, ANY, ANY))
		return true;
	if (MATCH(payload, 0x11, 0x06, ANY, ANY))
		return true;
	if (MATCH(payload, 0x11, 0x0e, ANY, ANY))
		return true;

	return false;
}

static inline bool match_name_resp_only(lpi_data_t *data) {

	/* Match the "special" case where only a name response is 
	 * observed, presumably misdirected traffic */

	if (data->payload_len[0] != 0 && data->payload_len[1] != 0)
		return false;
	
	if (data->server_port != 137 && data->client_port != 137)
		return false;

	if (!match_chars_either(data, ANY, ANY, 0x84, 0x00))
		return false;

	return true;


}

static inline bool match_netbios_udp(lpi_data_t *data, lpi_module_t *mod UNUSED) {

        if (match_netbios_name_req(data->payload[0], data->payload_len[0])) {
		if (data->server_port != 137 && data->client_port != 137)
			return false;

		if (match_netbios_name_resp(data->payload[1], data->payload[0]))
			return true;
                if (data->payload_len[1] == 0)
                        return true;
        }

        if (match_netbios_name_req(data->payload[1], data->payload_len[1])) {
		if (data->server_port != 137 && data->client_port != 137)
			return false;
		if (match_netbios_name_resp(data->payload[0], data->payload[1]))
			return true;
                if (data->payload_len[0] == 0)
                        return true;
        }

        if (match_netbios_datagram(data->payload[0], data->payload_len[0])) {
		if (data->server_port != 138 && data->client_port != 138)
			return false;

                if (data->payload_len[1] == 0)
                        return true;
        }

        if (match_netbios_datagram(data->payload[1], data->payload_len[1])) {
		if (data->server_port != 138 && data->client_port != 138)
			return false;
                if (data->payload_len[0] == 0)
                        return true;
        }

	if (match_name_resp_only(data))
		return true;
	
	return false;
}

static lpi_module_t lpi_netbios_udp = {
	LPI_PROTO_UDP_NETBIOS,
	LPI_CATEGORY_SERVICES,
	"NetBIOS_UDP",
	5,
	match_netbios_udp
};

void register_netbios_udp(LPIModuleMap *mod_map) {
	register_protocol(&lpi_netbios_udp, mod_map);
}