/*

 * avast_securedns.c

 *

 * Copyright (C) 2012-22 - ntop.org

 *

 * This module 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.

 *

 * This module 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.

 * If not, see <http://www.gnu.org/licenses/>.

 *

 */

#include "ndpi_protocol_ids.h"

#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_AVAST_SECUREDNS

#include <stdlib.h>

#include "ndpi_api.h"

#include "ndpi_private.h"

static void ndpi_int_avast_securedns_add_connection(struct ndpi_detection_module_struct *ndpi_struct,

                                                    struct ndpi_flow_struct *flow)

{

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

}

static void ndpi_search_avast_securedns(struct ndpi_detection_module_struct *ndpi_struct,

                                        struct ndpi_flow_struct *flow)

{

  struct ndpi_packet_struct * packet = &ndpi_struct->packet;

  if (packet->payload_packet_len < 34 ||

      ntohl(get_u_int32_t(packet->payload, 11)) != 0x00013209 ||

      flow->packet_counter > 1)

  {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (strncasecmp((char *)&packet->payload[15], "securedns", NDPI_STATICSTRING_LEN("securedns")) == 0)

  {

    ndpi_int_avast_securedns_add_connection(ndpi_struct, flow);

    return;

  }

  NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

}

void init_avast_securedns_dissector(struct ndpi_detection_module_struct *ndpi_struct)

{

  register_dissector("AVAST SecureDNS", ndpi_struct,

                     ndpi_search_avast_securedns,

                     NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_UDP_WITH_PAYLOAD,

                     1, NDPI_PROTOCOL_AVAST_SECUREDNS);

}