/*
 * zattoo.c
 *
 * Copyright (C) 2016-18 - ntop.org
 *
 * This file is part of nDPI, an open source deep packet inspection
 * library based on the OpenDPI and PACE technology by ipoque GmbH
 *
 * nDPI 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.
 *
 * nDPI 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 nDPI.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "ndpi_protocol_ids.h"

#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_ZATTOO

#include "ndpi_api.h"

#define ZATTOO_DETECTED \
    if (src != NULL) \
        src->zattoo_ts = packet->tick_timestamp; \
    if (dst != NULL) \
        dst->zattoo_ts = packet->tick_timestamp; \
    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_ZATTOO)

#if !defined(WIN32)
static inline
#elif defined(MINGW_GCC)
__mingw_forceinline static
#else
__forceinline static
#endif
u_int8_t ndpi_int_zattoo_user_agent_set(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
    if(flow->packet.user_agent_line.ptr != NULL && flow->packet.user_agent_line.len == 111) {
        if(memcmp(flow->packet.user_agent_line.ptr + flow->packet.user_agent_line.len - 25, "Zattoo/4", sizeof("Zattoo/4") - 1) == 0) {
            NDPI_LOG_DBG(ndpi_struct, "found zattoo useragent\n");
            return 1;
        }
    }
    return 0;
}

void ndpi_search_zattoo(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
    struct ndpi_packet_struct *packet = &flow->packet;
    struct ndpi_id_struct *src = flow->src;
    struct ndpi_id_struct *dst = flow->dst;

    u_int16_t i;

    NDPI_LOG_DBG(ndpi_struct, "search ZATTOO\n");

    if(packet->detected_protocol == NDPI_PROTOCOL_ZATTOO) {
        if(src != NULL && ((u_int32_t) (packet->tick_timestamp - src->zattoo_ts) < ndpi_struct->zattoo_connection_timeout))
            src->zattoo_ts = packet->tick_timestamp;
        if (dst != NULL && ((u_int32_t) (packet->tick_timestamp - dst->zattoo_ts) < ndpi_struct->zattoo_connection_timeout))
            dst->zattoo_ts = packet->tick_timestamp;
        return;
    }
    /* search over TCP */
    if(packet->tcp != NULL) {
        if(packet->payload_packet_len > 50 && memcmp(packet->payload, "GET /frontdoor/fd?brand=Zattoo&v=", 33) == 0) {

            NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over tcp with pattern GET /frontdoor/fd?brand=Zattoo&v=\n");
            ZATTOO_DETECTED;
            return;
        }
        if(packet->payload_packet_len > 50	&& memcmp(packet->payload, "GET /ZattooAdRedirect/redirect.jsp?user=", 40) == 0) {

            NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over tcp with pattern GET /ZattooAdRedirect/redirect.jsp?user=\n");
            ZATTOO_DETECTED;
            return;
        }
        if(packet->payload_packet_len > 50 && (memcmp(packet->payload, "POST /channelserver/player/channel/update HTTP/1.1", 50) == 0
                    || memcmp(packet->payload, "GET /epg/query", 14) == 0)) {

            ndpi_parse_packet_line_info(ndpi_struct, flow);

            for(i = 0; i < packet->parsed_lines; i++) {
                if(packet->line[i].len >= 18 && (memcmp(packet->line[i].ptr, "User-Agent: Zattoo", 18) == 0)) {

                    NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over tcp with pattern POST /channelserver/player/channel/update HTTP/1.1\n");
                    ZATTOO_DETECTED;
                    return;
                }
            }
        } else if(packet->payload_packet_len > 50 && (memcmp(packet->payload, "GET /", 5) == 0 || memcmp(packet->payload, "POST /", NDPI_STATICSTRING_LEN("POST /")) == 0)) {
            /* TODO to avoid searching currently only a specific length and offset is used
             * that might be changed later */
            ndpi_parse_packet_line_info(ndpi_struct, flow);

            if(ndpi_int_zattoo_user_agent_set(ndpi_struct, flow)) {

                NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over tcp with pattern GET / or POST /\n");
                ZATTOO_DETECTED;
                return;
            }
        } else if(packet->payload_packet_len > 50 && memcmp(packet->payload, "POST http://", 12) == 0) {

            ndpi_parse_packet_line_info(ndpi_struct, flow);

            // test for unique character of the zattoo header
            if(packet->parsed_lines == 4 && packet->host_line.ptr != NULL) {
                u_int32_t ip;
                u_int16_t bytes_read = 0;

                ip = ndpi_bytestream_to_ipv4(&packet->payload[12], packet->payload_packet_len, &bytes_read);

                // and now test the firt 5 bytes of the payload for zattoo pattern
                if(ip == packet->iph->daddr
                        && packet->empty_line_position_set != 0
                        && ((packet->payload_packet_len - packet->empty_line_position) > 10)
                        && packet->payload[packet->empty_line_position + 2] ==
                        0x03
                        && packet->payload[packet->empty_line_position + 3] ==
                        0x04
                        && packet->payload[packet->empty_line_position + 4] ==
                        0x00
                        && packet->payload[packet->empty_line_position + 5] ==
                        0x04
                        && packet->payload[packet->empty_line_position + 6] ==
                        0x0a && packet->payload[packet->empty_line_position + 7] == 0x00) {

                    NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over tcp with pattern POST http://\n");
                    ZATTOO_DETECTED;
                    return;
                }
            }
        } else if(flow->zattoo_stage == 0) {

            if(packet->payload_packet_len > 50
                    && packet->payload[0] == 0x03
                    && packet->payload[1] == 0x04
                    && packet->payload[2] == 0x00
                    && packet->payload[3] == 0x04 && packet->payload[4] == 0x0a && packet->payload[5] == 0x00) {
                flow->zattoo_stage = 1 + packet->packet_direction;
                NDPI_LOG_DBG2(ndpi_struct, "need next packet, seen pattern 0x030400040a00\n");
                return;
            }
            /* the following is searching for flash, not for zattoo. */
        } else if(flow->zattoo_stage == 2 - packet->packet_direction && packet->payload_packet_len > 50 && packet->payload[0] == 0x03 && packet->payload[1] == 0x04) {

            NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over tcp with 0x0304\n");
            ZATTOO_DETECTED;
            return;

        } else if(flow->zattoo_stage == 1 + packet->packet_direction) {
            if(packet->payload_packet_len > 500 && packet->payload[0] == 0x00 && packet->payload[1] == 0x00) {

                flow->zattoo_stage = 3 + packet->packet_direction;

                NDPI_LOG_DBG2(ndpi_struct, "need next packet, seen pattern 0x0000\n");
                return;
            }
            if(packet->payload_packet_len > 50
                    && packet->payload[0] == 0x03
                    && packet->payload[1] == 0x04
                    && packet->payload[2] == 0x00
                    && packet->payload[3] == 0x04 && packet->payload[4] == 0x0a && packet->payload[5] == 0x00) {
            }
            NDPI_LOG_DBG2(ndpi_struct, "need next packet, seen pattern 0x030400040a00\n");
            return;

        } else if(flow->zattoo_stage == 4 - packet->packet_direction && packet->payload_packet_len > 50 && packet->payload[0] == 0x03 && packet->payload[1] == 0x04) {

            NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over tcp with 0x0304\n");
            ZATTOO_DETECTED;
            return;

        } else if(flow->zattoo_stage == 5 + packet->packet_direction && (packet->payload_packet_len == 125)) {

            NDPI_LOG_INFO(ndpi_struct, "found zattoo\n");
            ZATTOO_DETECTED;
            return;

        } else if(flow->zattoo_stage == 6 - packet->packet_direction && packet->payload_packet_len == 1412) {

            NDPI_LOG_INFO(ndpi_struct, "found zattoo\n");
            ZATTOO_DETECTED;
            return;
        }

        NDPI_LOG_DBG2(ndpi_struct,
                "ZATTOO: discarded the flow (TCP): packet_size: %u; Flowstage: %u\n",
                packet->payload_packet_len, flow->zattoo_stage);

    }
    /* search over UDP */
    else if(packet->udp != NULL) {

        if(packet->payload_packet_len > 20 && (packet->udp->dest == htons(5003) || packet->udp->source == htons(5003))
                && (get_u_int16_t(packet->payload, 0) == htons(0x037a)
                    || get_u_int16_t(packet->payload, 0) == htons(0x0378)
                    || get_u_int16_t(packet->payload, 0) == htons(0x0305)
                    || get_u_int32_t(packet->payload, 0) == htonl(0x03040004)
                    || get_u_int32_t(packet->payload, 0) == htonl(0x03010005))) {

            if(++flow->zattoo_stage == 2) {

                NDPI_LOG_INFO(ndpi_struct, "found zattoo. add connection over udp\n");
                ZATTOO_DETECTED;
                return;
            }
            NDPI_LOG_DBG2(ndpi_struct, "need next packet udp\n");
            return;
        }

        NDPI_LOG_DBG2(ndpi_struct,
                "ZATTOO: discarded the flow (UDP): packet_size: %u; Flowstage: %u\n",
                packet->payload_packet_len, flow->zattoo_stage);

    }

    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
}


void init_zattoo_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
    ndpi_set_bitmask_protocol_detection("Zattoo", ndpi_struct, detection_bitmask, *id,
            NDPI_PROTOCOL_ZATTOO,
            ndpi_search_zattoo,
            NDPI_SELECTION_BITMASK_PROTOCOL_TCP_OR_UDP_WITH_PAYLOAD,
            SAVE_DETECTION_BITMASK_AS_UNKNOWN,
            ADD_TO_DETECTION_BITMASK);

    *id += 1;
}
