/*******************************************************************************
 * Copyright (c) 2009, Rockwell Automation, Inc.
 * All rights reserved.
 *
 ******************************************************************************/

/** @file generic_networkhandler.c
 *  @author Martin Melik Merkumians
 *  @brief This file includes all platform-independent functions of the network handler to reduce code duplication
 *
 *  The generic network handler delegates platform-dependent tasks to the platform network handler
 */

#include <assert.h>
#include <inttypes.h>
#include <stdbool.h>
#include <signal.h>

#include "generic_networkhandler.h"

#include "typedefs.h"
#include "trace.h"
#include "opener_error.h"
#include "encap.h"
#include "ciptcpipinterface.h"
#include "opener_user_conf.h"
#include "cipqos.h"

#define MAX_NO_OF_TCP_SOCKETS 10

/** @brief Ethernet/IP standard port */

/* ----- Windows size_t PRI macros ------------- */
#if defined(__MINGW32__) || defined(HPMICRO) /* This is a Mingw compiler or HPMICRO target (GCC) */
#define PRIuSZT PRIuPTR
#define PRIxSZT PRIxPTR
#else
/* Even the Visual Studio compilers / libraries since VS2015 know that now. */
#define PRIuSZT "zu"
#define PRIxSZT "zx"
#endif /* if defined(__MINGW32__) */

#if defined(_WIN32)
/* Most network functions take their I/O buffers as (char *) pointers that
 *  triggers a warning with our CipOctet (aka unsigned char) buffers. */
#define NWBUF_CAST (void *)
#else
#define NWBUF_CAST
#endif

#ifndef MSG_NOSIGNAL
#define MSG_NOSIGNAL                0
#define MSG_NOSIGNAL_PRAGMA_MESSAGE "MSG_NOSIGNAL not defined. Check if your system stops on SIGPIPE, as this can happen with the send() function"
#if defined(_WIN32)
#pragma message(MSG_NOSIGNAL_PRAGMA_MESSAGE)
#else
#pragma GCC warning MSG_NOSIGNAL_PRAGMA_MESSAGE
#endif /* defined(_WIN32) */
#endif

SocketTimer g_timestamps[OPENER_NUMBER_OF_SUPPORTED_SESSIONS];

//EipUint8 g_ethernet_communication_buffer[PC_OPENER_ETHERNET_BUFFER_SIZE]; /**< communication buffer */
/* global vars */
fd_set master_socket;
fd_set read_socket;

int highest_socket_handle;
int g_current_active_tcp_socket;

struct timeval g_time_value;
MilliSeconds g_actual_time;
MilliSeconds g_last_time;

NetworkStatus g_network_status;

/** @brief Size of the timeout checker function pointer array
 */
#define OPENER_TIMEOUT_CHECKER_ARRAY_SIZE 10

/** @brief function pointer array for timer checker functions
 */
TimeoutCheckerFunction timeout_checker_array[OPENER_TIMEOUT_CHECKER_ARRAY_SIZE];

/** @brief handle any connection request coming in the TCP server socket.
 *
 */
void CheckAndHandleTcpListenerSocket(void);

/** @brief Checks and processes request received via the UDP unicast socket, currently the implementation is port-specific
 *
 */
void CheckAndHandleUdpUnicastSocket(void);

/** @brief Checks and handles incoming messages via UDP broadcast
 *
 */
void CheckAndHandleUdpGlobalBroadcastSocket(void);

/** @brief check if on the UDP consuming socket data has been received and if yes handle it correctly
 *
 */
void CheckAndHandleConsumingUdpSocket(void);

/** @brief Handles data on an established TCP connection, processed connection is given by socket
 *
 *  @param socket The socket to be processed
 *  @return kEipStatusOk on success, or kEipStatusError on failure
 */
EipStatus HandleDataOnTcpSocket(int socket);

void CheckEncapsulationInactivity(int socket_handle);

void RemoveSocketTimerFromList(const int socket_handle);

/*************************************************
* Function implementations from now on
*************************************************/

EipStatus NetworkHandlerInitialize(void)
{
    if (kEipStatusOk != NetworkHandlerInitializePlatform()) {
        return kEipStatusError;
    }

    SocketTimerArrayInitialize(g_timestamps, OPENER_NUMBER_OF_SUPPORTED_SESSIONS);
    /* Activate the current DSCP values to become the used set of values. */
    CipQosUpdateUsedSetQosValues();
    /* Make sure the multicast configuration matches the current IP address. */
    CipTcpIpCalculateMulticastIp(&g_tcpip);
    /* Freeze IP and network mask matching to the socket setup. This is needed
   *  for the off subnet multicast routing check later. */
    g_network_status.ip_address = g_tcpip.interface_configuration.ip_address;
    g_network_status.network_mask = g_tcpip.interface_configuration.network_mask;
    /* Initialize encapsulation layer here because it accesses the IP address. */
    EncapsulationInit();

    /* clear the master and temp sets */
    FD_ZERO(&master_socket);
    FD_ZERO(&read_socket);

    /* create a new TCP socket */
    if ((g_network_status.tcp_listener = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler tcp_listener: error allocating socket, %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    int set_socket_option_value = 1; //Represents true for used set socket options
    /* Activates address reuse */
    if (setsockopt(g_network_status.tcp_listener, SOL_SOCKET, SO_REUSEADDR, (char *)&set_socket_option_value, sizeof(set_socket_option_value)) == -1) {
        OPENER_TRACE_ERR("networkhandler tcp_listener: error setting socket option SO_REUSEADDR\n");
        return kEipStatusError;
    }

    if (SetSocketToNonBlocking(g_network_status.tcp_listener) < 0) {
        OPENER_TRACE_ERR("networkhandler tcp_listener: error setting socket to non-blocking on new socket\n");
        return kEipStatusError;
    }

    /* create a new UDP socket */
    if ((g_network_status.udp_global_broadcast_listener = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == kEipInvalidSocket) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler udp_global_broadcast_listener: error allocating socket, %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    /* create a new UDP socket */
    if ((g_network_status.udp_unicast_listener = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == kEipInvalidSocket) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler udp_unicast_listener: error allocating socket, %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    /* Activates address reuse */
    set_socket_option_value = 1;
    if (setsockopt(g_network_status.udp_global_broadcast_listener, SOL_SOCKET, SO_REUSEADDR, (char *)&set_socket_option_value,
                   sizeof(set_socket_option_value)) == -1) {
        OPENER_TRACE_ERR("networkhandler udp_global_broadcast_listener: error setting socket option SO_REUSEADDR\n");
        return kEipStatusError;
    }

    if (SetSocketToNonBlocking(g_network_status.udp_global_broadcast_listener) < 0) {
        OPENER_TRACE_ERR("networkhandler udp_global_broadcast_listener: error setting socket to non-blocking on new socket\n");
        return kEipStatusError;
    }

    /* Activates address reuse */
    set_socket_option_value = 1;
    if (setsockopt(g_network_status.udp_unicast_listener, SOL_SOCKET, SO_REUSEADDR, (char *)&set_socket_option_value, sizeof(set_socket_option_value)) == -1) {
        OPENER_TRACE_ERR("networkhandler udp_unicast_listener: error setting socket option SO_REUSEADDR\n");
        return kEipStatusError;
    }

    if (SetSocketToNonBlocking(g_network_status.udp_unicast_listener) < 0) {
        OPENER_TRACE_ERR("networkhandler udp_unicast_listener: error setting socket to non-blocking\n");
        return kEipStatusError;
    }

    struct sockaddr_in my_address = { .sin_family = AF_INET, .sin_port = htons(kOpenerEthernetPort), .sin_addr.s_addr = g_network_status.ip_address };

    /* bind the new socket to port 0xAF12 (CIP) */
    if ((bind(g_network_status.tcp_listener, (struct sockaddr *)&my_address, sizeof(struct sockaddr))) == -1) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler tcp_listener: error with TCP bind: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    if ((bind(g_network_status.udp_unicast_listener, (struct sockaddr *)&my_address, sizeof(struct sockaddr))) == -1) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler udp_unicast_listener: error with UDP bind: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    /* have QoS DSCP explicit appear on UDP responses to unicast messages */
    if (SetQosOnSocket(g_network_status.udp_unicast_listener, CipQosGetDscpPriority(kConnectionObjectPriorityExplicit)) != 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler udp_unicast_listener: error set QoS %d: %d - %s\n", g_network_status.udp_unicast_listener, error_code, error_message);
        FreeErrorMessage(error_message);
        /* print message but don't abort by intent */
    }

    struct sockaddr_in global_broadcast_address = { .sin_family = AF_INET, .sin_port = htons(kOpenerEthernetPort), .sin_addr.s_addr = htonl(INADDR_ANY) };

    /* enable the UDP socket to receive broadcast messages */
    set_socket_option_value = 1;
    if (0 > setsockopt(g_network_status.udp_global_broadcast_listener, SOL_SOCKET, SO_BROADCAST, (char *)&set_socket_option_value, sizeof(int))) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler udp_global_broadcast_listener: error with setting broadcast receive: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    if ((bind(g_network_status.udp_global_broadcast_listener, (struct sockaddr *)&global_broadcast_address, sizeof(struct sockaddr))) == -1) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler udp_global_broadcast_listener: error with UDP bind: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    /* have QoS DSCP explicit appear on UDP responses to broadcast messages */
    if (SetQosOnSocket(g_network_status.udp_global_broadcast_listener, CipQosGetDscpPriority(kConnectionObjectPriorityExplicit)) != 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler udp_global_broadcast_listener: error set QoS %d: %d - %s\n", g_network_status.udp_global_broadcast_listener,
                         error_code, error_message);
        FreeErrorMessage(error_message);
        /* print message but don't abort by intent */
    }

    /* Make QoS DSCP explicit already appear on SYN connection establishment.
   * A newly accept()ed TCP socket inherits the setting from this socket.
   */
    if (SetQosOnSocket(g_network_status.tcp_listener, CipQosGetDscpPriority(kConnectionObjectPriorityExplicit)) != 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler tcp_listener: error set QoS %d: %d - %s\n", g_network_status.tcp_listener, error_code, error_message);
        FreeErrorMessage(error_message);
        /* print message but don't abort by intent */
    }

    /* switch socket in listen mode */
    if ((listen(g_network_status.tcp_listener, MAX_NO_OF_TCP_SOCKETS)) == -1) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler tcp_listener: error with listen: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    /* add the listener socket to the master set */
    FD_SET(g_network_status.tcp_listener, &master_socket);
    FD_SET(g_network_status.udp_unicast_listener, &master_socket);
    FD_SET(g_network_status.udp_global_broadcast_listener, &master_socket);

    /* keep track of the biggest file descriptor */
    highest_socket_handle =
        GetMaxSocket(g_network_status.tcp_listener, g_network_status.udp_global_broadcast_listener, 0, g_network_status.udp_unicast_listener);

    g_last_time = GetMilliSeconds(); /* initialize time keeping */
    g_network_status.elapsed_time = 0;

    return kEipStatusOk;
}

void CloseUdpSocket(int socket_handle)
{
    OPENER_TRACE_STATE("Closing UDP socket %d\n", socket_handle);
    CloseSocket(socket_handle);
}

void CloseTcpSocket(int socket_handle)
{
    OPENER_TRACE_STATE("Closing TCP socket %d\n", socket_handle);
    ShutdownSocketPlatform(socket_handle);
    RemoveSocketTimerFromList(socket_handle);
    CloseSocket(socket_handle);
}

void RemoveSocketTimerFromList(const int socket_handle)
{
    SocketTimer *socket_timer = NULL;
    while (NULL != (socket_timer = SocketTimerArrayGetSocketTimer(g_timestamps, OPENER_NUMBER_OF_SUPPORTED_SESSIONS, socket_handle))) {
        SocketTimerClear(socket_timer);
    }
}

EipBool8 CheckSocketSet(int socket)
{
    EipBool8 return_value = false;
    if (FD_ISSET(socket, &read_socket)) {
        if (FD_ISSET(socket, &master_socket)) {
            return_value = true;
        } else {
            OPENER_TRACE_INFO("socket: %d closed with pending message\n", socket);
        }
        FD_CLR(socket, &read_socket);
        /* remove it from the read set so that later checks will not find it */
    }
    return return_value;
}

void CheckAndHandleTcpListenerSocket(void)
{
    int new_socket = kEipInvalidSocket;
    /* see if this is a connection request to the TCP listener*/
    if (true == CheckSocketSet(g_network_status.tcp_listener)) {
        OPENER_TRACE_INFO("networkhandler: new TCP connection\n");

        new_socket = accept(g_network_status.tcp_listener, NULL, NULL);
        if (new_socket == kEipInvalidSocket) {
            int error_code = GetSocketErrorNumber();
            char *error_message = GetErrorMessage(error_code);
            OPENER_TRACE_ERR("networkhandler: error on accept: %d - %s\n", error_code, error_message);
            FreeErrorMessage(error_message);
            return;
        }
        OPENER_TRACE_INFO(">>> network handler: accepting new TCP socket: %d \n", new_socket);

        SocketTimer *socket_timer = SocketTimerArrayGetEmptySocketTimer(g_timestamps, OPENER_NUMBER_OF_SUPPORTED_SESSIONS);

        //    OPENER_TRACE_INFO("Current time stamp: %ld\n", g_actual_time);
        //    for(size_t i = 0; i < OPENER_NUMBER_OF_SUPPORTED_SESSIONS; i++) {
        //      OPENER_TRACE_INFO("Socket: %d - Last Update: %ld\n",
        //                        g_timestamps[i].socket,
        //                        g_timestamps[i].last_update);
        //    }

        OPENER_ASSERT(socket_timer != NULL);

        FD_SET(new_socket, &master_socket);
        /* add newfd to master set */
        if (new_socket > highest_socket_handle) {
            OPENER_TRACE_INFO("New highest socket: %d\n", new_socket);
            highest_socket_handle = new_socket;
        }

        OPENER_TRACE_STATE("networkhandler: opened new TCP connection on fd %d\n", new_socket);
    }
}

EipStatus NetworkHandlerProcessCyclic(void)
{
    read_socket = master_socket;

    g_time_value.tv_sec = 0;
    g_time_value.tv_usec =
        (g_network_status.elapsed_time < kOpenerTimerTickInMilliSeconds ? kOpenerTimerTickInMilliSeconds - g_network_status.elapsed_time : 0) *
        1000; /* 10 ms */

    int ready_socket = select(highest_socket_handle + 1, &read_socket, 0, 0, &g_time_value);

    if (ready_socket == kEipInvalidSocket) {
        if (EINTR == errno) /* we have somehow been interrupted. The default behavior is to go back into the select loop. */
        {
            return kEipStatusOk;
        } else {
            int error_code = GetSocketErrorNumber();
            char *error_message = GetErrorMessage(error_code);
            OPENER_TRACE_ERR("networkhandler: error with select: %d - %s\n", error_code, error_message);
            FreeErrorMessage(error_message);
            return kEipStatusError;
        }
    }

    if (ready_socket > 0) {
        CheckAndHandleTcpListenerSocket();
        CheckAndHandleUdpUnicastSocket();
        CheckAndHandleUdpGlobalBroadcastSocket();
        CheckAndHandleConsumingUdpSocket();

        for (int socket = 0; socket <= highest_socket_handle; socket++) {
            if (true == CheckSocketSet(socket)) {
                /* if it is still checked it is a TCP receive */
                if (kEipStatusError == HandleDataOnTcpSocket(socket)) /* if error */
                {
                    CloseTcpSocket(socket);
                    RemoveSession(socket); /* clean up session and close the socket */
                }
            }
        }
    }

    for (int socket = 0; socket <= highest_socket_handle; socket++) {
        CheckEncapsulationInactivity(socket);
    }

    /* Check if all connections from one originator times out */
    //CheckForTimedOutConnectionsAndCloseTCPConnections();
    //OPENER_TRACE_INFO("Socket Loop done\n");
    g_actual_time = GetMilliSeconds();
    g_network_status.elapsed_time += g_actual_time - g_last_time;
    g_last_time = g_actual_time;
    //OPENER_TRACE_INFO("Elapsed time: %u\n", g_network_status.elapsed_time);

    /* check if we had been not able to update the connection manager for several kOpenerTimerTickInMilliSeconds.
   * This should compensate the jitter of the windows timer
   */
    if (g_network_status.elapsed_time >= kOpenerTimerTickInMilliSeconds) {
        /* call manage_connections() in connection manager every kOpenerTimerTickInMilliSeconds ms */
        ManageConnections(g_network_status.elapsed_time);

        /* Call timeout checker functions registered in timeout_checker_array */
        for (size_t i = 0; i < OPENER_TIMEOUT_CHECKER_ARRAY_SIZE; i++) {
            if (NULL != timeout_checker_array[i]) {
                (timeout_checker_array[i])(g_network_status.elapsed_time);
            }
        }

        g_network_status.elapsed_time = 0;
    }
    return kEipStatusOk;
}

EipStatus NetworkHandlerFinish(void)
{
    CloseTcpSocket(g_network_status.tcp_listener);
    CloseUdpSocket(g_network_status.udp_unicast_listener);
    CloseUdpSocket(g_network_status.udp_global_broadcast_listener);
    return kEipStatusOk;
}

void CheckAndHandleUdpGlobalBroadcastSocket(void)
{
    /* see if this is an unsolicited inbound UDP message */
    if (true == CheckSocketSet(g_network_status.udp_global_broadcast_listener)) {
        struct sockaddr_in from_address = { 0 };
        socklen_t from_address_length = sizeof(from_address);

        OPENER_TRACE_STATE("networkhandler: unsolicited UDP message on EIP global broadcast socket\n");

        /* Handle UDP broadcast messages */
        CipOctet incoming_message[PC_OPENER_ETHERNET_BUFFER_SIZE] = { 0 };
        int received_size = recvfrom(g_network_status.udp_global_broadcast_listener, NWBUF_CAST incoming_message, sizeof(incoming_message), 0,
                                     (struct sockaddr *)&from_address, &from_address_length);

        if (received_size <= 0) { /* got error */
            int error_code = GetSocketErrorNumber();
            char *error_message = GetErrorMessage(error_code);
            OPENER_TRACE_ERR("networkhandler: error on recvfrom UDP global broadcast port: %d - %s\n", error_code, error_message);
            FreeErrorMessage(error_message);
            return;
        }

        OPENER_TRACE_INFO("Data received on global broadcast UDP:\n");

        const EipUint8 *receive_buffer = &incoming_message[0];
        int remaining_bytes = 0;
        ENIPMessage outgoing_message;
        InitializeENIPMessage(&outgoing_message);
        EipStatus need_to_send = HandleReceivedExplictUdpData(g_network_status.udp_unicast_listener,
                                                              /* sending from unicast port, due to strange behavior of the broadcast port */
                                                              &from_address, receive_buffer, received_size, &remaining_bytes, false, &outgoing_message);

        receive_buffer += received_size - remaining_bytes;
        received_size = remaining_bytes;

        if (need_to_send > 0) {
            OPENER_TRACE_INFO("UDP broadcast reply sent:\n");

            /* if the active socket matches a registered UDP callback, handle a UDP packet */
            if (sendto(g_network_status.udp_unicast_listener, /* sending from unicast port, due to strange behavior of the broadcast port */
                       (char *)outgoing_message.message_buffer, outgoing_message.used_message_length, 0, (struct sockaddr *)&from_address,
                       sizeof(from_address)) != outgoing_message.used_message_length) {
                OPENER_TRACE_INFO("networkhandler: UDP response was not fully sent\n");
            }
        }
        if (remaining_bytes > 0) {
            OPENER_TRACE_ERR("Request on broadcast UDP port had too many data (%d)", remaining_bytes);
        }
    }
}

void CheckAndHandleUdpUnicastSocket(void)
{
    /* see if this is an unsolicited inbound UDP message */
    if (true == CheckSocketSet(g_network_status.udp_unicast_listener)) {
        struct sockaddr_in from_address = { 0 };
        socklen_t from_address_length = sizeof(from_address);

        OPENER_TRACE_STATE("networkhandler: unsolicited UDP message on EIP unicast socket\n");

        /* Handle UDP broadcast messages */
        CipOctet incoming_message[PC_OPENER_ETHERNET_BUFFER_SIZE] = { 0 };
        int received_size = recvfrom(g_network_status.udp_unicast_listener, NWBUF_CAST incoming_message, sizeof(incoming_message), 0,
                                     (struct sockaddr *)&from_address, &from_address_length);

        if (received_size <= 0) { /* got error */
            int error_code = GetSocketErrorNumber();
            char *error_message = GetErrorMessage(error_code);
            OPENER_TRACE_ERR("networkhandler: error on recvfrom UDP unicast port: %d - %s\n", error_code, error_message);
            FreeErrorMessage(error_message);
            return;
        }

        OPENER_TRACE_INFO("Data received on UDP unicast:\n");

        EipUint8 *receive_buffer = &incoming_message[0];
        int remaining_bytes = 0;
        ENIPMessage outgoing_message;
        InitializeENIPMessage(&outgoing_message);
        EipStatus need_to_send = HandleReceivedExplictUdpData(g_network_status.udp_unicast_listener, &from_address, receive_buffer, received_size,
                                                              &remaining_bytes, true, &outgoing_message);

        receive_buffer += received_size - remaining_bytes;
        received_size = remaining_bytes;

        if (need_to_send > 0) {
            OPENER_TRACE_INFO("UDP unicast reply sent:\n");

            /* if the active socket matches a registered UDP callback, handle a UDP packet */
            if (sendto(g_network_status.udp_unicast_listener, (char *)outgoing_message.message_buffer, outgoing_message.used_message_length, 0,
                       (struct sockaddr *)&from_address, sizeof(from_address)) != outgoing_message.used_message_length) {
                OPENER_TRACE_INFO("networkhandler: UDP unicast response was not fully sent\n");
            }
        }
        if (remaining_bytes > 0) {
            OPENER_TRACE_ERR("Request on broadcast UDP port had too many data (%d)", remaining_bytes);
        }
    }
}

EipStatus SendUdpData(const struct sockaddr_in *const address, const ENIPMessage *const outgoing_message)
{
#if defined(OPENER_TRACE_ENABLED)
    static char ip_str[INET_ADDRSTRLEN];
    OPENER_TRACE_INFO("UDP packet to be sent to: %s:%d\n", inet_ntop(AF_INET, &address->sin_addr, ip_str, sizeof ip_str), ntohs(address->sin_port));
#endif

    int sent_length = sendto(g_network_status.udp_io_messaging, (char *)outgoing_message->message_buffer, outgoing_message->used_message_length, 0,
                             (struct sockaddr *)address, sizeof(*address));
    if (sent_length < 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler: error with sendto in SendUDPData: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    if (sent_length != outgoing_message->used_message_length) {
        OPENER_TRACE_WARN("data length sent_length mismatch; probably not all data was sent in SendUdpData, sent %d of %d\n", sent_length,
                          outgoing_message->used_message_length);
        return kEipStatusError;
    }

    return kEipStatusOk;
}

EipStatus HandleDataOnTcpSocket(int socket)
{
    OPENER_TRACE_INFO("Entering HandleDataOnTcpSocket for socket: %d\n", socket);
    int remaining_bytes = 0;
    long data_sent = PC_OPENER_ETHERNET_BUFFER_SIZE;

    /* We will handle just one EIP packet here the rest is done by the select
   * method which will inform us if more data is available in the socket
     because of the current implementation of the main loop this may not be
     the fastest way and a loop here with a non blocking socket would better
     fit*/

    /*Check how many data is here -- read the first four bytes from the connection */
    CipOctet incoming_message[PC_OPENER_ETHERNET_BUFFER_SIZE] = { 0 };

    long number_of_read_bytes = recv(socket, NWBUF_CAST incoming_message, 4, 0); /*TODO we may have to set the socket to a non blocking socket */

    SocketTimer *const socket_timer = SocketTimerArrayGetSocketTimer(g_timestamps, OPENER_NUMBER_OF_SUPPORTED_SESSIONS, socket);
    if (number_of_read_bytes == 0) {
        OPENER_TRACE_ERR("networkhandler: socket: %d - connection closed by client.\n", socket);
        RemoveSocketTimerFromList(socket);
        RemoveSession(socket);
        return kEipStatusError;
    }
    if (number_of_read_bytes < 0) {
        int error_code = GetSocketErrorNumber();
        if (OPENER_SOCKET_WOULD_BLOCK == error_code) {
            return kEipStatusOk;
        }
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler: error on recv: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    const EipUint8 *read_buffer = &incoming_message[2];                                    /* at this place EIP stores the data length */
    size_t data_size = GetUintFromMessage(&read_buffer) + ENCAPSULATION_HEADER_LENGTH - 4; /* -4 is for the 4 bytes we have already read*/
    /* (NOTE this advances the buffer pointer) */
    if ((PC_OPENER_ETHERNET_BUFFER_SIZE - 4) < data_size) { /*TODO can this be handled in a better way?*/
        OPENER_TRACE_ERR("too large packet received will be ignored, will drop the data\n");
        /* Currently we will drop the whole packet */

        do {
            OPENER_TRACE_INFO("Entering consumption loop, remaining data to receive: %ld\n", data_sent);
            number_of_read_bytes = recv(socket, NWBUF_CAST & incoming_message[0], data_sent, 0);

            if (number_of_read_bytes == 0) /* got error or connection closed by client */
            {
                int error_code = GetSocketErrorNumber();
                char *error_message = GetErrorMessage(error_code);
                OPENER_TRACE_ERR("networkhandler: socket: %d - connection closed by client: %d - %s\n", socket, error_code, error_message);
                FreeErrorMessage(error_message);
                RemoveSocketTimerFromList(socket);
                return kEipStatusError;
            }
            if (number_of_read_bytes < 0) {
                int error_code = GetSocketErrorNumber();
                char *error_message = GetErrorMessage(error_code);
                if (OPENER_SOCKET_WOULD_BLOCK == error_code) {
                    return kEipStatusOk;
                }
                OPENER_TRACE_ERR("networkhandler: error on recv: %d - %s\n", error_code, error_message);
                FreeErrorMessage(error_message);
                return kEipStatusError;
            }
            data_size -= number_of_read_bytes;
            if ((data_size < PC_OPENER_ETHERNET_BUFFER_SIZE) && (data_size != 0)) {
                data_sent = data_size;
            }
        } while (0 < data_size);
        SocketTimerSetLastUpdate(socket_timer, g_actual_time);
        return kEipStatusOk;
    }

    number_of_read_bytes = recv(socket, NWBUF_CAST & incoming_message[4], data_size, 0);

    if (0 == number_of_read_bytes) /* got error or connection closed by client */
    {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler: socket: %d - connection closed by client: %d - %s\n", socket, error_code, error_message);
        FreeErrorMessage(error_message);
        RemoveSocketTimerFromList(socket);
        RemoveSession(socket);
        return kEipStatusError;
    }
    if (number_of_read_bytes < 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        if (OPENER_SOCKET_WOULD_BLOCK == error_code) {
            return kEipStatusOk;
        }
        OPENER_TRACE_ERR("networkhandler: error on recv: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipStatusError;
    }

    if ((unsigned)number_of_read_bytes == data_size) {
        /*we got the right amount of data */
        data_size += 4;
        /*TODO handle partial packets*/
        OPENER_TRACE_INFO("Data received on TCP: %" PRIuSZT "\n", data_size);

        g_current_active_tcp_socket = socket;

        struct sockaddr sender_address;
        memset(&sender_address, 0, sizeof(sender_address));
        socklen_t fromlen = sizeof(sender_address);
        if (getpeername(socket, (struct sockaddr *)&sender_address, &fromlen) < 0) {
            int error_code = GetSocketErrorNumber();
            char *error_message = GetErrorMessage(error_code);
            OPENER_TRACE_ERR("networkhandler: could not get peername: %d - %s\n", error_code, error_message);
            FreeErrorMessage(error_message);
        }

        ENIPMessage outgoing_message;
        InitializeENIPMessage(&outgoing_message);
        EipStatus need_to_send = HandleReceivedExplictTcpData(socket, incoming_message, data_size, &remaining_bytes, &sender_address, &outgoing_message);
        if (NULL != socket_timer) {
            SocketTimerSetLastUpdate(socket_timer, g_actual_time);
        }

        g_current_active_tcp_socket = kEipInvalidSocket;

        if (remaining_bytes != 0) {
            OPENER_TRACE_WARN("Warning: received packet was to long: %d Bytes left!\n", remaining_bytes);
        }

        if (need_to_send > 0) {
            OPENER_TRACE_INFO("TCP reply: send %" PRIuSZT " bytes on %d\n", outgoing_message.used_message_length, socket);

            data_sent = send(socket, (char *)outgoing_message.message_buffer, outgoing_message.used_message_length, MSG_NOSIGNAL);
            SocketTimerSetLastUpdate(socket_timer, g_actual_time);
            if (data_sent != outgoing_message.used_message_length) {
                OPENER_TRACE_WARN("TCP response was not fully sent: exp %" PRIuSZT ", sent %ld\n", outgoing_message.used_message_length, data_sent);
            }
        }

        return kEipStatusOk;
    } else {
        /* we got a fragmented packet currently we cannot handle this will
     * for this we would need a network buffer per TCP socket
     *
     * However with typical packet sizes of EIP this shouldn't be a big issue.
     */
        /*TODO handle fragmented packets */
    }
    return kEipStatusError;
}

/** @brief Create the UDP socket for the implicit IO messaging, one socket handles all connections
 *
 * @return the socket handle if successful, else kEipInvalidSocket */
int CreateUdpSocket(void)
{
    /* create a new UDP socket */
    g_network_status.udp_io_messaging = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

    if (g_network_status.udp_io_messaging == kEipInvalidSocket) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler: cannot create UDP socket: %d- %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return kEipInvalidSocket;
    }

    if (SetSocketToNonBlocking(g_network_status.udp_io_messaging) < 0) {
        OPENER_TRACE_ERR("networkhandler udp_io_messaging: error setting socket to non-blocking on new socket\n");
        CloseUdpSocket(g_network_status.udp_io_messaging);
        OPENER_ASSERT(false); /* This should never happen! */
        return kEipInvalidSocket;
    }

    OPENER_TRACE_INFO("networkhandler: UDP socket %d\n", g_network_status.udp_io_messaging);

    int option_value = 1;
    if (setsockopt(g_network_status.udp_io_messaging, SOL_SOCKET, SO_REUSEADDR, (char *)&option_value, sizeof(option_value)) < 0) {
        OPENER_TRACE_ERR("error setting socket option SO_REUSEADDR on %s UDP socket\n");
        CloseUdpSocket(g_network_status.udp_io_messaging);
        return kEipInvalidSocket;
    }

    /* The bind on UDP sockets is necessary as the ENIP spec wants the source port to be specified to 2222 */
    struct sockaddr_in source_addr = { .sin_family = AF_INET, .sin_addr.s_addr = htonl(INADDR_ANY), .sin_port = htons(kOpenerEipIoUdpPort) };

    if (bind(g_network_status.udp_io_messaging, (struct sockaddr *)&source_addr, sizeof(source_addr)) < 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("error on bind UDP for producing messages: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        CloseUdpSocket(g_network_status.udp_io_messaging);
        return kEipInvalidSocket;
    }

    /* add new socket to the master list */
    FD_SET(g_network_status.udp_io_messaging, &master_socket);

    if (g_network_status.udp_io_messaging > highest_socket_handle) {
        OPENER_TRACE_INFO("New highest socket: %d\n", g_network_status.udp_io_messaging);
        highest_socket_handle = g_network_status.udp_io_messaging;
    }
    return g_network_status.udp_io_messaging;
}

/** @brief Set the Qos the socket for implicit IO messaging
 *
 * @return 0 if successful, else the error code */
int SetQos(CipUsint qos_for_socket)
{
    if (SetQosOnSocket(g_network_status.udp_io_messaging, CipQosGetDscpPriority(qos_for_socket)) != 0) { /* got error */
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler: error on set QoS on socket: %d - %s\n", error_code, error_message);
        return error_code;
    }
    return 0;
}

/** @brief Set the socket options for Multicast Producer
 *
 * @return 0 if successful, else the error code */
int SetSocketOptionsMulticastProduce(void)
{
    if (g_tcpip.mcast_ttl_value != 1) {
        /* we need to set a TTL value for the socket */
        if (setsockopt(g_network_status.udp_io_messaging, IPPROTO_IP, IP_MULTICAST_TTL, NWBUF_CAST & g_tcpip.mcast_ttl_value, sizeof(g_tcpip.mcast_ttl_value)) <
            0) {
            int error_code = GetSocketErrorNumber();
            char *error_message = GetErrorMessage(error_code);
            OPENER_TRACE_ERR("networkhandler: could not set the TTL to: %d, error: %d - %s\n", g_tcpip.mcast_ttl_value, error_code, error_message);
            FreeErrorMessage(error_message);
            return error_code;
        }
    }
    /* Need to specify the interface for outgoing multicast packets on a
     device with multiple interfaces. */
    struct in_addr my_addr = { .s_addr = g_network_status.ip_address };
    if (setsockopt(g_network_status.udp_io_messaging, IPPROTO_IP, IP_MULTICAST_IF, NWBUF_CAST & my_addr.s_addr, sizeof my_addr.s_addr) < 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler: could not set the multicast interface, error: %d "
                         "- %s\n",
                         error_code, error_message);
        FreeErrorMessage(error_message);
        return error_code;
    }
    return 0;
}

/** @brief Get the peer address
 *
 * @return peer address if successful, else any address (0) */
EipUint32 GetPeerAddress(void)
{
    struct sockaddr_in peer_address;
    socklen_t peer_address_length = sizeof(peer_address);

    if (getpeername(g_current_active_tcp_socket, (struct sockaddr *)&peer_address, &peer_address_length) < 0) {
        int error_code = GetSocketErrorNumber();
        char *error_message = GetErrorMessage(error_code);
        OPENER_TRACE_ERR("networkhandler: could not get peername: %d - %s\n", error_code, error_message);
        FreeErrorMessage(error_message);
        return htonl(INADDR_ANY);
    }
    return peer_address.sin_addr.s_addr;
}

void CheckAndHandleConsumingUdpSocket(void)
{
    DoublyLinkedListNode *iterator = connection_list.first;

    CipConnectionObject *current_connection_object = NULL;

    /* see a message of the registered UDP socket has been received     */
    while (NULL != iterator) {
        current_connection_object = (CipConnectionObject *)iterator->data;
        iterator = iterator->next; /* do this at the beginning as the close function may can make the entry invalid */

        if ((kEipInvalidSocket != current_connection_object->socket[kUdpCommuncationDirectionConsuming]) &&
            (true == CheckSocketSet(current_connection_object->socket[kUdpCommuncationDirectionConsuming]))) {
            OPENER_TRACE_INFO("Processing UDP consuming message\n");
            struct sockaddr_in from_address = { 0 };
            socklen_t from_address_length = sizeof(from_address);
            CipOctet incoming_message[PC_OPENER_ETHERNET_BUFFER_SIZE] = { 0 };

            int received_size = recvfrom(g_network_status.udp_io_messaging, NWBUF_CAST incoming_message, sizeof(incoming_message), 0,
                                         (struct sockaddr *)&from_address, &from_address_length);
            if (0 == received_size) {
                int error_code = GetSocketErrorNumber();
                char *error_message = GetErrorMessage(error_code);
                OPENER_TRACE_ERR("networkhandler: socket: %d - connection closed by client: %d - %s\n",
                                 current_connection_object->socket[kUdpCommuncationDirectionConsuming], error_code, error_message);
                FreeErrorMessage(error_message);
                current_connection_object->connection_close_function(current_connection_object);
                continue;
            }

            if (0 > received_size) {
                int error_code = GetSocketErrorNumber();
                char *error_message = GetErrorMessage(error_code);
                if (OPENER_SOCKET_WOULD_BLOCK == error_code) {
                    return; // No fatal error, resume execution
                }
                OPENER_TRACE_ERR("networkhandler: error on recv: %d - %s\n", error_code, error_message);
                FreeErrorMessage(error_message);
                current_connection_object->connection_close_function(current_connection_object);
                continue;
            }

            HandleReceivedConnectedData(incoming_message, received_size, &from_address);
        }
    }
}

void CloseSocket(const int socket_handle)
{
    OPENER_TRACE_INFO("networkhandler: closing socket %d\n", socket_handle);

    if (kEipInvalidSocket != socket_handle) {
        FD_CLR(socket_handle, &master_socket);
        CloseSocketPlatform(socket_handle);
    }
    OPENER_TRACE_INFO("networkhandler: closing socket done %d\n", socket_handle);
}

int GetMaxSocket(int socket1, int socket2, int socket3, int socket4)
{
    if ((socket1 > socket2) && (socket1 > socket3) && (socket1 > socket4)) {
        return socket1;
    }

    if ((socket2 > socket1) && (socket2 > socket3) && (socket2 > socket4)) {
        return socket2;
    }

    if ((socket3 > socket1) && (socket3 > socket2) && (socket3 > socket4)) {
        return socket3;
    }

    return socket4;
}

void CheckEncapsulationInactivity(int socket_handle)
{
    if (0 < g_tcpip.encapsulation_inactivity_timeout) { //*< Encapsulation inactivity timeout is enabled
        SocketTimer *socket_timer = SocketTimerArrayGetSocketTimer(g_timestamps, OPENER_NUMBER_OF_SUPPORTED_SESSIONS, socket_handle);

        if (NULL != socket_timer) {
            MilliSeconds diff_milliseconds = g_actual_time - SocketTimerGetLastUpdate(socket_timer);

            if (diff_milliseconds >= (MilliSeconds)(1000UL * g_tcpip.encapsulation_inactivity_timeout)) {
                CipSessionHandle encapsulation_session_handle = GetSessionFromSocket(socket_handle);

                CloseClass3ConnectionBasedOnSession(encapsulation_session_handle);

                CloseTcpSocket(socket_handle);
                RemoveSession(socket_handle);
            }
        }
    }
}

void RegisterTimeoutChecker(TimeoutCheckerFunction timeout_checker_function)
{
    for (size_t i = 0; i < OPENER_TIMEOUT_CHECKER_ARRAY_SIZE; i++) {
        if (NULL == timeout_checker_array[i]) {                  // find empty array element
            timeout_checker_array[i] = timeout_checker_function; // add function pointer to array
            break;
        }
    }
}