/*
 * Copyright (C) 2015 Simon Brummer
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @defgroup    net_gnrc_tcp TCP
 * @ingroup     net_gnrc
 * @brief       RIOT's tcp implementation for the gnrc stack
 *
 * @{
 *
 * @file
 * @brief       Transmission Control Block definition
 *
 * @author      Simon Brummer <simon.brummer@haw-hamburg.de>
 */

#ifndef GNRC_TCP_TCB_H
#define GNRC_TCP_TCB_H

#include <stdint.h>
#include <ringbuffer.h>
#include <xtimer.h>
#include <mutex.h>
#include <msg.h>
#include "net/gnrc.h"
#include "config.h"

#ifdef MODULE_GNRC_IPV6
#include "net/gnrc/ipv6.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Size of the tcbs internal message queue
 */
#define GNRC_TCP_TCB_MSG_QUEUE_SIZE (8U)

/**
 * @brief transmission control block of gnrc_tcp
 */
typedef struct _transmission_control_block {
    uint8_t address_family;                        /**< Address Family of local_addr and peer_addr */
#ifdef MODULE_GNRC_IPV6
    uint8_t local_addr[sizeof(ipv6_addr_t)];       /**< local IP address */
    uint8_t peer_addr[sizeof(ipv6_addr_t)];        /**< peer IP address */
#endif
    uint16_t local_port;                           /**< local connections port number */
    uint16_t peer_port;                            /**< port connections port number */
    uint8_t state;                                 /**< Connections state */
    uint8_t status;                                /**< A connections status flags */
    uint32_t snd_una;                              /**< Send Unacknowledged */
    uint32_t snd_nxt;                              /**< Send Next */
    uint16_t snd_wnd;                              /**< Send Window */
    uint32_t snd_wl1;                              /**< SeqNo. Last Windowupdate */
    uint32_t snd_wl2;                              /**< AckNo. Last Windowupdate */
    uint32_t rcv_nxt;                              /**< Receive Next */
    uint16_t rcv_wnd;                              /**< Receive Window */
    uint32_t iss;                                  /**< Initial Sequence Number */
    uint32_t irs;                                  /**< Initial Received Sequence Number */
    uint16_t mss;                                  /**< The peers MSS */
    uint32_t rtt_start;                            /**< Timer value for rtt estimation */
    int32_t rtt_var;                               /**< Round Trip Time variance */
    int32_t srtt;                                  /**< Smoothed Round Trip Time */
    int32_t rto;                                   /**< Retransmission Timeout Duration */
    uint8_t retries;                               /**< Number of Retransmissions */
    xtimer_t tim_tout;                             /**< Timer struct for timeouts */
    msg_t msg_tout;                                /**< Message, sent on timeouts */
    gnrc_pktsnip_t *pkt_retransmit;                /**< Pointer to Packet in "retransmit queue" */
    kernel_pid_t owner;                            /**< PID of this connection handling thread */
    msg_t msg_queue[GNRC_TCP_TCB_MSG_QUEUE_SIZE];  /**< Message queue used for asynchronious operation */
    uint8_t *rcv_buf_raw;                          /**< Pointer to the receive buffer */
    ringbuffer_t rcv_buf;                          /**< Receive Buffer data structure */
    mutex_t fsm_lock;                              /**< Mutex for FSM access synchronization */
    mutex_t function_lock;                         /**< Mutex for Function call synchronization */
    struct _transmission_control_block *next;      /**< Pointer next TCP connection */
} gnrc_tcp_tcb_t;

#ifdef __cplusplus
}
#endif
#endif /* GNRC_TCP_TCB_H */
/** @} */