/*
 *
 * 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_socks5_req(uint32_t payload, uint32_t len) {

        if(MATCH(payload, 0x05, ANY, ANY, ANY) && len < 6)
        {

                if (MATCH(payload, 0x05, 0x01, ANY, ANY) && len == 3)
                        return true;

                if (MATCH(payload, 0x05, 0x02, ANY, ANY) && len == 4)
                        return true;

                if (MATCH(payload, 0x05, 0x03, ANY, ANY) && len == 5)
                        return true;
        }

#if 0
        /* Just assume "no auth" method supported, for now */
        if (!(MATCH(payload, 0x05, 0x01, 0x00, 0x00)) && !(MATCH(payload, 0x05, 0x02, 0x00, 0x01)) && !(MATCH(payload, 0x05, 0x01, 0x02, ANY)))
                return false;

        if (len != 4 && len != 3)
                return false;
#endif
        return false;

}

static inline bool match_socks5_resp(uint32_t payload, uint32_t len) {

        //if (len == 0)
        //        return true;

        /* Just assume "no auth" method supported, for now */
        if (!(MATCH(payload, 0x05, 0x00, ANY, ANY)) && !(MATCH(payload, 0x05, 0x02, ANY, ANY)) && !(MATCH(payload, 0x05, 0xff, ANY, ANY)))
                return false;

        if (len != 2)
                return false;

        return true;

}


static inline bool match_socks5(lpi_data_t *data, lpi_module_t *mod UNUSED) {

        if (data->payload_len[0] != 0 && data->observed[0] == data->payload_len[0] && data->payload_len[1] != 0 && data->observed[1] == data->payload_len[1])
        {
                if (match_socks5_req(data->payload[0], data->payload_len[0]))
                {
                        if (match_socks5_resp(data->payload[1], data->payload_len[1]))
                                return true;
                }

                if (match_socks5_req(data->payload[1], data->payload_len[1]))
                {
                        if (match_socks5_resp(data->payload[0], data->payload_len[0]))
                                return true;
                }
        }
        return false;
}

static lpi_module_t lpi_socks5 = {
	LPI_PROTO_SOCKS5,
	LPI_CATEGORY_TUNNELLING,
	"SOCKS5",
	3,
	match_socks5
};

void register_socks5(LPIModuleMap *mod_map) {
	register_protocol(&lpi_socks5, mod_map);
}

