/*
 * sopcast.c
 *
 * Copyright (C) 2009-2011 by ipoque GmbH
 * Copyright (C) 2011-19 - 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_SOPCAST

#include "ndpi_api.h"


static void ndpi_int_sopcast_add_connection(struct ndpi_detection_module_struct
					    *ndpi_struct, struct ndpi_flow_struct *flow)
{
  ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_SOPCAST, NDPI_PROTOCOL_UNKNOWN);
}

/**
 * this function checks for sopcast tcp pattern
 *
 * NOTE: if you add more patterns please keep the number of if levels
 * low, it is already complex enough
 */
	
#if !defined(WIN32)
static inline
#elif defined(MINGW_GCC)
__mingw_forceinline static
#else
__forceinline static
#endif
u_int8_t ndpi_int_is_sopcast_tcp(const u_int8_t * payload, const u_int16_t payload_len)
{
  if (payload_len != 54)
    return 0;

  if (payload[2] != payload[3] - 4 && payload[2] != payload[3] + 4)
    return 0;

  if (payload[2] != payload[4] - 1 && payload[2] != payload[4] + 1)
    return 0;

  if (payload[25] != payload[25 + 16 - 1] + 1 && payload[25] != payload[25 + 16 - 1] - 1) {

    if (payload[3] != payload[25] &&
	payload[3] != payload[25] - 4 && payload[3] != payload[25] + 4 && payload[3] != payload[25] - 21) {
      return 0;
    }
  }

  if (payload[4] != payload[28] ||
      payload[28] != payload[30] ||
      payload[30] != payload[31] ||
      get_u_int16_t(payload, 30) != get_u_int16_t(payload, 32) || get_u_int16_t(payload, 32) != get_u_int16_t(payload, 34)) {

    if ((payload[2] != payload[5] - 1 && payload[2] != payload[5] + 1) ||
	payload[2] != payload[25] ||
	payload[4] != payload[28] ||
	payload[4] != payload[31] ||
	payload[4] != payload[32] ||
	payload[4] != payload[33] ||
	payload[4] != payload[34] ||
	payload[4] != payload[35] || payload[4] != payload[30] || payload[2] != payload[36]) {
      return 0;
    }
  }

  if (payload[42] != payload[53])
    return 0;

  if (payload[45] != payload[46] + 1 && payload[45] != payload[46] - 1)
    return 0;

  if (payload[45] != payload[49] || payload[46] != payload[50] || payload[47] != payload[51])
    return 0;

  return 1;
}

static void ndpi_search_sopcast_tcp(struct ndpi_detection_module_struct
				    *ndpi_struct, struct ndpi_flow_struct *flow)
{

  struct ndpi_packet_struct *packet = &flow->packet;
	
  if (flow->packet_counter == 1 && packet->payload_packet_len == 54 && get_u_int16_t(packet->payload, 0) == ntohs(0x0036)) {
    if (ndpi_int_is_sopcast_tcp(packet->payload, packet->payload_packet_len)) {
      NDPI_LOG_INFO(ndpi_struct, "found sopcast TCP \n");
      ndpi_int_sopcast_add_connection(ndpi_struct, flow);
      return;
    }
  }

  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);

}

static void ndpi_search_sopcast_udp(struct ndpi_detection_module_struct
				    *ndpi_struct, struct ndpi_flow_struct *flow)
{
  struct ndpi_packet_struct *packet = &flow->packet;
	
  NDPI_LOG_DBG(ndpi_struct, "search sopcast.  \n");

  if (packet->payload_packet_len == 52 && packet->payload[0] == 0xff
      && packet->payload[1] == 0xff && packet->payload[2] == 0x01
      && packet->payload[8] == 0x02 && packet->payload[9] == 0xff
      && packet->payload[10] == 0x00 && packet->payload[11] == 0x2c
      && packet->payload[12] == 0x00 && packet->payload[13] == 0x00 && packet->payload[14] == 0x00) {
    NDPI_LOG_INFO(ndpi_struct, "found sopcast with if I.  \n");
    ndpi_int_sopcast_add_connection(ndpi_struct, flow);
    return;
  }
  if ((packet->payload_packet_len == 80 || packet->payload_packet_len == 28 || packet->payload_packet_len == 94)
      && packet->payload[0] == 0x00 && (packet->payload[2] == 0x02 || packet->payload[2] == 0x01)
      && packet->payload[8] == 0x01 && packet->payload[9] == 0xff
      && packet->payload[10] == 0x00 && packet->payload[11] == 0x14
      && packet->payload[12] == 0x00 && packet->payload[13] == 0x00) {
    NDPI_LOG_INFO(ndpi_struct, "found sopcast with if II.  \n");
    ndpi_int_sopcast_add_connection(ndpi_struct, flow);
    return;
  }
  /* this case has been seen once. Please remove this comment, if you see it another time */
  if (packet->payload_packet_len == 60 && packet->payload[0] == 0x00
      && packet->payload[2] == 0x01
      && packet->payload[8] == 0x03 && packet->payload[9] == 0xff
      && packet->payload[10] == 0x00 && packet->payload[11] == 0x34
      && packet->payload[12] == 0x00 && packet->payload[13] == 0x00 && packet->payload[14] == 0x00) {
    NDPI_LOG_INFO(ndpi_struct, "found sopcast with if III.  \n");
    ndpi_int_sopcast_add_connection(ndpi_struct, flow);
    return;
  }
  if (packet->payload_packet_len == 42 && packet->payload[0] == 0x00
      && packet->payload[1] == 0x02 && packet->payload[2] == 0x01
      && packet->payload[3] == 0x07 && packet->payload[4] == 0x03
      && packet->payload[8] == 0x06
      && packet->payload[9] == 0x01 && packet->payload[10] == 0x00
      && packet->payload[11] == 0x22 && packet->payload[12] == 0x00 && packet->payload[13] == 0x00) {
    NDPI_LOG_INFO(ndpi_struct, "found sopcast with if IV.  \n");
    ndpi_int_sopcast_add_connection(ndpi_struct, flow);
    return;
  }
  if (packet->payload_packet_len == 28 && packet->payload[0] == 0x00
      && packet->payload[1] == 0x0c && packet->payload[2] == 0x01
      && packet->payload[3] == 0x07 && packet->payload[4] == 0x00
      && packet->payload[8] == 0x01
      && packet->payload[9] == 0x01 && packet->payload[10] == 0x00
      && packet->payload[11] == 0x14 && packet->payload[12] == 0x00 && packet->payload[13] == 0x00) {
    NDPI_LOG_INFO(ndpi_struct, "found sopcast with if V.  \n");
    ndpi_int_sopcast_add_connection(ndpi_struct, flow);
    return;
  }
  /* this case has been seen once. Please remove this comment, if you see it another time */
  if (packet->payload_packet_len == 286 && packet->payload[0] == 0x00
      && packet->payload[1] == 0x02 && packet->payload[2] == 0x01
      && packet->payload[3] == 0x07 && packet->payload[4] == 0x03
      && packet->payload[8] == 0x06
      && packet->payload[9] == 0x01 && packet->payload[10] == 0x01
      && packet->payload[11] == 0x16 && packet->payload[12] == 0x00 && packet->payload[13] == 0x00) {
    NDPI_LOG_INFO(ndpi_struct, "found sopcast with if VI.  \n");
    ndpi_int_sopcast_add_connection(ndpi_struct, flow);
    return;
  }
  if (packet->payload_packet_len == 76 && packet->payload[0] == 0xff
      && packet->payload[1] == 0xff && packet->payload[2] == 0x01
      && packet->payload[8] == 0x0c && packet->payload[9] == 0xff
      && packet->payload[10] == 0x00 && packet->payload[11] == 0x44
      && packet->payload[16] == 0x01 && packet->payload[15] == 0x01
      && packet->payload[12] == 0x00 && packet->payload[13] == 0x00 && packet->payload[14] == 0x00) {
    NDPI_LOG_INFO(ndpi_struct, "found sopcast with if VII.  \n");
    ndpi_int_sopcast_add_connection(ndpi_struct, flow);
    return;
  }

  /* Attention please: no asymmetric detection necessary. This detection works asymmetrically as well. */

  NDPI_LOG_DBG(ndpi_struct, "exclude sopcast.  \n");
  NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_SOPCAST);

}

void ndpi_search_sopcast(struct ndpi_detection_module_struct
			 *ndpi_struct, struct ndpi_flow_struct *flow)
{
  struct ndpi_packet_struct *packet = &flow->packet;

  if (packet->udp != NULL)
    ndpi_search_sopcast_udp(ndpi_struct, flow);
  if (packet->tcp != NULL)
    ndpi_search_sopcast_tcp(ndpi_struct, flow);

}


void init_sopcast_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
  ndpi_set_bitmask_protocol_detection("Sopcast", ndpi_struct, detection_bitmask, *id,
				      NDPI_PROTOCOL_SOPCAST,
				      ndpi_search_sopcast,
				      NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD,
				      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
				      ADD_TO_DETECTION_BITMASK);

  *id += 1;
}