/*
 * thunder.c
 *
 * Copyright (C) 2009-2011 by ipoque GmbH
 * Copyright (C) 2011-18 - 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_THUNDER

#include "ndpi_api.h"

static void ndpi_int_thunder_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
        struct ndpi_flow_struct *flow/* , ndpi_protocol_type_t protocol_type */)
{
    struct ndpi_packet_struct *packet = &flow->packet;
    struct ndpi_id_struct *src = flow->src;
    struct ndpi_id_struct *dst = flow->dst;

    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_THUNDER);

    if (src != NULL) {
        src->thunder_ts = packet->tick_timestamp;
    }
    if (dst != NULL) {
        dst->thunder_ts = packet->tick_timestamp;
    }
}



#if !defined(WIN32)
static inline
#elif defined(MINGW_GCC)
__mingw_forceinline static
#else
__forceinline static
#endif
void ndpi_int_search_thunder_udp(struct ndpi_detection_module_struct
        *ndpi_struct, struct ndpi_flow_struct *flow)
{
    struct ndpi_packet_struct *packet = &flow->packet;

    if (packet->payload_packet_len > 8 && packet->payload[0] >= 0x30
            && packet->payload[0] < 0x40 && packet->payload[1] == 0 && packet->payload[2] == 0 && packet->payload[3] == 0) {
        if (flow->thunder_stage == 3) {
            NDPI_LOG_INFO(ndpi_struct, "found THUNDER udp\n");
            ndpi_int_thunder_add_connection(ndpi_struct, flow);
            return;
        }

        flow->thunder_stage++;
        NDPI_LOG_DBG2(ndpi_struct,
                "maybe thunder udp packet detected, stage increased to %u\n", flow->thunder_stage);
        return;
    }

    NDPI_LOG_DBG(ndpi_struct, "excluding thunder udp at stage %u\n", flow->thunder_stage);
    NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_THUNDER);
}


#if !defined(WIN32)
static inline
#elif defined(MINGW_GCC)
__mingw_forceinline static
#else
__forceinline static
#endif
void ndpi_int_search_thunder_tcp(struct ndpi_detection_module_struct
        *ndpi_struct, struct ndpi_flow_struct *flow)
{
    struct ndpi_packet_struct *packet = &flow->packet;

    if (packet->payload_packet_len > 8 && packet->payload[0] >= 0x30
            && packet->payload[0] < 0x40 && packet->payload[1] == 0 && packet->payload[2] == 0 && packet->payload[3] == 0) {
        if (flow->thunder_stage == 3) {
            NDPI_LOG_INFO(ndpi_struct, "found THUNDER tcp\n");
            ndpi_int_thunder_add_connection(ndpi_struct, flow);
            return;
        }

        flow->thunder_stage++;
        NDPI_LOG_DBG2(ndpi_struct,
                "maybe thunder tcp packet detected, stage increased to %u\n", flow->thunder_stage);
        return;
    }

    if (flow->thunder_stage == 0 && packet->payload_packet_len > 17
            && memcmp(packet->payload, "POST / HTTP/1.1\r\n", 17) == 0) {
        ndpi_parse_packet_line_info(ndpi_struct, flow);

        NDPI_LOG_DBG2(ndpi_struct,
                "maybe thunder http POST packet detected, parsed packet lines: %u, empty line set %u (at: %u)\n",
                packet->parsed_lines, packet->empty_line_position_set, packet->empty_line_position);

        if (packet->empty_line_position_set != 0 &&
                packet->content_line.ptr != NULL &&
                packet->content_line.len == 24 &&
                memcmp(packet->content_line.ptr, "application/octet-stream",
                    24) == 0 && packet->empty_line_position_set < (packet->payload_packet_len - 8)
                && packet->payload[packet->empty_line_position + 2] >= 0x30
                && packet->payload[packet->empty_line_position + 2] < 0x40
                && packet->payload[packet->empty_line_position + 3] == 0x00
                && packet->payload[packet->empty_line_position + 4] == 0x00
                && packet->payload[packet->empty_line_position + 5] == 0x00) {
            NDPI_LOG_INFO(ndpi_struct,
                    "found thunder http POST packet application does match\n");
            ndpi_int_thunder_add_connection(ndpi_struct, flow);
            return;
        }
    }
    NDPI_LOG_DBG(ndpi_struct, "excluding thunder tcp at stage %u\n", flow->thunder_stage);
    NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_THUNDER);
}

#if !defined(WIN32)
static inline
#elif defined(MINGW_GCC)
__mingw_forceinline static
#else
__forceinline static
#endif
void ndpi_int_search_thunder_http(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;

    if (packet->detected_protocol == NDPI_PROTOCOL_THUNDER) {
        if (src != NULL && ((u_int32_t)
                    (packet->tick_timestamp - src->thunder_ts) < ndpi_struct->thunder_timeout)) {
            NDPI_LOG_DBG2(ndpi_struct,
                    "thunder : save src connection packet detected\n");
            src->thunder_ts = packet->tick_timestamp;
        } else if (dst != NULL && ((u_int32_t)
                    (packet->tick_timestamp - dst->thunder_ts) < ndpi_struct->thunder_timeout)) {
            NDPI_LOG_DBG2(ndpi_struct,
                    "thunder : save dst connection packet detected\n");
            dst->thunder_ts = packet->tick_timestamp;
        }
        return;
    }

    if (packet->payload_packet_len > 5
            && memcmp(packet->payload, "GET /", 5) == 0 && NDPI_SRC_OR_DST_HAS_PROTOCOL(src, dst, NDPI_PROTOCOL_THUNDER)) {
        NDPI_LOG_DBG2(ndpi_struct, "HTTP packet detected\n");
        ndpi_parse_packet_line_info(ndpi_struct, flow);

        if (packet->parsed_lines > 7
                && packet->parsed_lines < 11
                && packet->line[1].len > 10
                && memcmp(packet->line[1].ptr, "Accept: */*", 11) == 0
                && packet->line[2].len > 22
                && memcmp(packet->line[2].ptr, "Cache-Control: no-cache",
                    23) == 0 && packet->line[3].len > 16
                && memcmp(packet->line[3].ptr, "Connection: close", 17) == 0
                && packet->line[4].len > 6
                && memcmp(packet->line[4].ptr, "Host: ", 6) == 0
                && packet->line[5].len > 15
                && memcmp(packet->line[5].ptr, "Pragma: no-cache", 16) == 0
                && packet->user_agent_line.ptr != NULL
                && packet->user_agent_line.len > 49
                && memcmp(packet->user_agent_line.ptr,
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)", 50) == 0) {
            NDPI_LOG_INFO(ndpi_struct,
                    "found thunder HTTP download detected\n");
            ndpi_int_thunder_add_connection(ndpi_struct, flow);
        }
    }
}

void ndpi_search_thunder(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;

    if (packet->tcp != NULL) {
        ndpi_int_search_thunder_http(ndpi_struct, flow);
        ndpi_int_search_thunder_tcp(ndpi_struct, flow);
    } else if (packet->udp != NULL) {
        ndpi_int_search_thunder_udp(ndpi_struct, flow);
    }
}


void init_thunder_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
    ndpi_set_bitmask_protocol_detection("Thunder", ndpi_struct, detection_bitmask, *id,
            NDPI_PROTOCOL_THUNDER,
            ndpi_search_thunder,
            NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
            SAVE_DETECTION_BITMASK_AS_UNKNOWN,
            ADD_TO_DETECTION_BITMASK);

    *id += 1;
}
