/*

 * cassandra.c

 *

 * Apache Cassandra CQL Binary protocol

 * 

 * Copyright (C) 2023 - ntop.org

 * Copyright (C) 2023 - V.G <v.gavrilov@securitycode.ru>

 *

 * 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_CASSANDRA

#include "ndpi_api.h"

#include "ndpi_private.h"

static inline int ndpi_validate_cassandra_response(u_int8_t response)

{

  return (response >= 0x81 && response <= 0x85) ? 1 : -1;

}

static inline int ndpi_validate_cassandra_request(u_int8_t request)

{

  return (request >= 0x01 && request <= 0x05) ? 1 : -1;

}

static void ndpi_int_cassandra_add_connection(struct ndpi_detection_module_struct *ndpi_struct,

                                              struct ndpi_flow_struct *flow)

{

  NDPI_LOG_INFO(ndpi_struct, "found Cassandra CQL\n");

  ndpi_set_detected_protocol(ndpi_struct, flow,

                             NDPI_PROTOCOL_CASSANDRA, NDPI_PROTOCOL_UNKNOWN,

                             NDPI_CONFIDENCE_DPI);

}

static void ndpi_search_cassandra(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 Cassandra CQL\n");

  if (packet->payload_packet_len == 19 &&

      ntohl(get_u_int32_t(packet->payload, 0)) == 0xCA552DFA)

  {

    NDPI_LOG_INFO(ndpi_struct, "found Cassandra Internode Communication\n");

    ndpi_int_cassandra_add_connection(ndpi_struct, flow);

    return;

  }

  if ((packet->payload_packet_len < 9) ||

      (flow->packet_counter >= 8) ||

      (!ndpi_validate_cassandra_response(packet->payload[0]) ||

       !ndpi_validate_cassandra_request(packet->payload[0])))

  {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (flow->packet_direction_counter[packet->packet_direction] > 2) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  /* Looking for a 'STARTUP' message from the client,

   * which should always contain the CQL_VERSION string

   */

  if (packet->payload_packet_len > 60 &&

      memcmp(&packet->payload[packet->payload_packet_len-20], "CQL_VERSION", 11) == 0)

  {

    NDPI_LOG_INFO(ndpi_struct, "found Cassandra CQL\n");

    ndpi_int_cassandra_add_connection(ndpi_struct, flow);

    return;

  }

}

void init_cassandra_dissector(struct ndpi_detection_module_struct *ndpi_struct) {

  register_dissector("Cassandra", ndpi_struct,

                     ndpi_search_cassandra,

                     NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,

                     1, NDPI_PROTOCOL_CASSANDRA);

}