/*
 * Copyright 2013-2019 Software Radio Systems Limited
 *
 * This file is part of srsLTE.
 *
 * srsLTE is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * srsLTE 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 Affero General Public License for more details.
 *
 * A copy of the GNU Affero General Public License can be found in
 * the LICENSE file in the top-level directory of this distribution
 * and at http://www.gnu.org/licenses/.
 *
 */

/******************************************************************************
 * File:        mbms-gw.h
 * Description: Top-level MBMS-GW class. Creates and links all
 *              interfaces and helpers.
 *****************************************************************************/

#ifndef MBMS_GW_H
#define MBMS_GW_H

#include "srslte/asn1/gtpc.h"
#include "srslte/common/buffer_pool.h"
#include "srslte/common/log.h"
#include "srslte/common/log_filter.h"
#include "srslte/common/logger_file.h"
#include "srslte/common/threads.h"
#include "srslte/srslte.h"
#include <cstddef>

namespace srsepc{


const uint16_t GTPU_RX_PORT = 2152;

typedef struct {
  std::string name;
  std::string sgi_mb_if_name;
  std::string sgi_mb_if_addr;
  std::string sgi_mb_if_mask;
  std::string m1u_multi_addr;
  std::string m1u_multi_if;
  int         m1u_multi_ttl;
} mbms_gw_args_t;

struct pseudo_hdr
{
  uint32_t  src_addr;
  uint32_t  dst_addr;
  uint8_t   placeholder;
  uint8_t   protocol;
  uint16_t  udp_len;
};

class mbms_gw:
  public thread
{
public:
  static mbms_gw* get_instance(void);
  static void cleanup(void);
  int init(mbms_gw_args_t* args, srslte::log_filter *mbms_gw_log);
  void stop();
  void run_thread();

private:

  /* Methods */
  mbms_gw();
  virtual ~mbms_gw();
  static mbms_gw *m_instance;

  srslte::error_t init_sgi_mb_if(mbms_gw_args_t *args);
  srslte::error_t init_m1_u(mbms_gw_args_t *args);
  void handle_sgi_md_pdu(srslte::byte_buffer_t *msg);
  uint16_t in_cksum(uint16_t *iphdr, int count);

  /* Members */
  bool m_running;
  srslte::byte_buffer_pool *m_pool;
  srslte::log_filter  *m_mbms_gw_log;

  bool m_sgi_mb_up;
  int m_sgi_mb_if;

  bool m_m1u_up;
  int m_m1u;
  struct sockaddr_in m_m1u_multi_addr;
};

} // namespace srsepc

#endif // SGW_H