/*

 * mpegts.c (MPEG Transport Stream)

 *          https://en.wikipedia.org/wiki/MPEG_transport_stream

 *

 * Copyright (C) 2015-22 - 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_MPEGTS

#include "ndpi_api.h"

#include "ndpi_private.h"

static void ndpi_search_mpegts(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 MPEGTS\n");

  if((packet->udp != NULL) && ((packet->payload_packet_len % 188) == 0)) {

    u_int i, num_chunks = packet->payload_packet_len / 188;

    for(i=0; i<num_chunks; i++) {

      u_int offset = 188 * i;

      if(packet->payload[offset] != 0x47) goto no_mpegts;

    }

    /* This looks MPEG TS */

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

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

    return;

  }    

 no_mpegts:

  NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

}

void init_mpegts_dissector(struct ndpi_detection_module_struct *ndpi_struct)

{

  ndpi_register_dissector("MPEG_TS", ndpi_struct,

                     ndpi_search_mpegts,

                     NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_UDP_WITH_PAYLOAD,

                      1, NDPI_PROTOCOL_MPEGTS);

}