/*

 * atg.c

 *

 * Copyright (C) 2024 - ntop.org

 *

 * 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_ATG

#include "ndpi_api.h"

#include "ndpi_private.h"

static void ndpi_int_atg_add_connection(struct ndpi_detection_module_struct

            *ndpi_struct, struct ndpi_flow_struct *flow) {

  ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_ATG,

           NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);

}

static void ndpi_search_atg(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 for ATG\n");

  if(packet->payload_packet_len >= 8) {

    u_int16_t atg_port = ntohs(10001);

    if((packet->tcp->source == atg_port) || (packet->tcp->dest == atg_port)) {

      if(packet->payload[0] == 0x01 &&

         (packet->payload[1] == 0x49 || packet->payload[1] == 0x69 || packet->payload[1] == 0x53 || packet->payload[1] == 0x73 ) &&

         memcmp(&packet->payload[packet->payload_packet_len - 2], "\r\n", 2) == 0) {

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

        ndpi_int_atg_add_connection(ndpi_struct, flow);

        return;

      }

    }

  }

  NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

}

void init_atg_dissector(struct ndpi_detection_module_struct *ndpi_struct) {

  ndpi_register_dissector("ATG", ndpi_struct,

                     ndpi_search_atg,

                     NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,

                     1, NDPI_PROTOCOL_ATG);

}