/*

 * armagetron.c

 *

 * Copyright (C) 2009-11 - ipoque GmbH

 * Copyright (C) 2011-22 - 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_ARMAGETRON

#include "ndpi_api.h"

static void ndpi_int_armagetron_add_connection(struct ndpi_detection_module_struct *ndpi_struct,

                 struct ndpi_flow_struct *flow)

{

  ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_ARMAGETRON, NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);

}

static void ndpi_search_armagetron_udp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)

{

  struct ndpi_packet_struct *packet = &ndpi_struct->packet;

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

  if (packet->payload_packet_len > 10) {

    /* login request */

    if (get_u_int32_t(packet->payload, 0) == htonl(0x000b0000)) {

      const u_int16_t dataLength = ntohs(get_u_int16_t(packet->payload, 4));

      if (dataLength == 0 || dataLength * 2 + 8 != packet->payload_packet_len)

  goto exclude;

      if (get_u_int16_t(packet->payload, 6) == htons(0x0008)

    && get_u_int16_t(packet->payload, packet->payload_packet_len - 2) == 0) {

  NDPI_LOG_INFO(ndpi_struct, "found armagetron\n");

  ndpi_int_armagetron_add_connection(ndpi_struct, flow);

  return;

      }

    }

    /* sync_msg */

    if (packet->payload_packet_len == 16 && get_u_int16_t(packet->payload, 0) == htons(0x001c)

  && get_u_int16_t(packet->payload, 2) != 0) {

      const u_int16_t dataLength = ntohs(get_u_int16_t(packet->payload, 4));

      if (dataLength != 4)

  goto exclude;

      if (get_u_int32_t(packet->payload, 6) == htonl(0x00000500) && get_u_int32_t(packet->payload, 6 + 4) == htonl(0x00010000)

    && get_u_int16_t(packet->payload, packet->payload_packet_len - 2) == 0) {

  NDPI_LOG_INFO(ndpi_struct, "found armagetron\n");

  ndpi_int_armagetron_add_connection(ndpi_struct, flow);

  return;

      }

    }

    /* net_sync combination */

    if (packet->payload_packet_len > 50 && get_u_int16_t(packet->payload, 0) == htons(0x0018)

  && get_u_int16_t(packet->payload, 2) != 0) {

      u_int16_t val;

      const u_int16_t dataLength = ntohs(get_u_int16_t(packet->payload, 4));

      if (dataLength == 0 || dataLength * 2 + 8 > packet->payload_packet_len)

  goto exclude;

      val = get_u_int16_t(packet->payload, 6 + 2);

      if (val == get_u_int16_t(packet->payload, 6 + 6)) {

  val = ntohs(get_u_int16_t(packet->payload, 6 + 8));

  if ((6 + 10 + val + 4) < packet->payload_packet_len

      && (get_u_int32_t(packet->payload, 6 + 10 + val) == htonl(0x00010000)

    || get_u_int32_t(packet->payload, 6 + 10 + val) == htonl(0x00000001))

      && get_u_int16_t(packet->payload, packet->payload_packet_len - 2) == 0) {

    NDPI_LOG_INFO(ndpi_struct, "found armagetron\n");

    ndpi_int_armagetron_add_connection(ndpi_struct, flow);

    return;

  }

      }

    }

  }

 exclude:

  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);

}

void init_armagetron_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id)

{

  ndpi_set_bitmask_protocol_detection("Armagetron", ndpi_struct, *id,

              NDPI_PROTOCOL_ARMAGETRON,

              ndpi_search_armagetron_udp,

              NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_UDP_WITH_PAYLOAD,

              SAVE_DETECTION_BITMASK_AS_UNKNOWN,

              ADD_TO_DETECTION_BITMASK);

  *id += 1;

}