RIP.c

/************************************************************************************
* Copyright (C) 2023                                                               *
* TETCOS, Bangalore. India                                                         *
*                                                                                  *
* Tetcos owns the intellectual property rights in the Product and its content.     *
* The copying, redistribution, reselling or publication of any or all of the       *
* Product or its content without express prior written consent of Tetcos is        *
* prohibited. Ownership and / or any other right relating to the software and all *
* intellectual property rights therein shall remain at all times with Tetcos.      *
*                                                                                  *
* Author:    Thangarasu                                                       *
*                                                                                  *
* ---------------------------------------------------------------------------------*/
#define _CRT_SECURE_NO_DEPRECATE
#include "main.h"
#include "Routing.h"
/**
    This function is called by NetworkStack.dll, while configuring the device 
    Application layer for RIP protocol. 
*/
_declspec(dllexport)int fn_NetSim_RIP_Configure(void** var)
{
    return fn_NetSim_RIP_Configure_F(var);
}
/**
    This functon initializes the RIP parameters.
*/
_declspec (dllexport) int fn_NetSim_RIP_Init(struct stru_NetSim_Network *NETWORK_Formal,\
    NetSim_EVENTDETAILS *pstruEventDetails_Formal,char *pszAppPath_Formal,\
    char *pszWritePath_Formal,int nVersion_Type,void **fnPointer)
{
    fn_NetSim_RIP_Init_F(NETWORK_Formal,pstruEventDetails_Formal,pszAppPath_Formal,\
        pszWritePath_Formal,nVersion_Type,fnPointer);
    return 0;
}
/**
    This function is called by NetworkStack.dll, once simulation end to free the 
    allocated memory for the network.   
*/
_declspec(dllexport) int fn_NetSim_RIP_Finish()
{
    fn_NetSim_RIP_Finish_F();
    return 0;
}
/**
    This function is called by NetworkStack.dll, while writing the evnt trace 
    to get the sub event as a string.
*/
_declspec (dllexport) char *fn_NetSim_RIP_Trace(int nSubEvent)
{
    return (fn_NetSim_RIP_Trace_F(nSubEvent));
}
/**
    This function is called by NetworkStack.dll, to free the packet of RIP protocol
*/
_declspec(dllexport) int fn_NetSim_RIP_FreePacket(NetSim_PACKET* pstruPacket)
{
    return fn_NetSim_RIP_FreePacket_F(pstruPacket); 
}
/**
    This function is called by NetworkStack.dll, to copy the packet of RIP protocol
    from source to destination.
*/
_declspec(dllexport) int fn_NetSim_RIP_CopyPacket(NetSim_PACKET* pstruDestPacket,NetSim_PACKET* pstruSrcPacket)
{
    return fn_NetSim_RIP_CopyPacket_F(pstruDestPacket,pstruSrcPacket);  
}
/**
    This function write the Metrics in Metrics.txt  
*/
_declspec(dllexport) int fn_NetSim_RIP_Metrics(PMETRICSWRITER metricsWriter)
{
    return fn_NetSim_RIP_Metrics_F(metricsWriter);  
}
/**
    This function will return the string to write packet trace heading.
*/
_declspec(dllexport)char* fn_NetSim_RIP_ConfigPacketTrace()
{
    return "";
}
/**
   This function will return the string to write packet trace.                                                                                                  
*/
_declspec(dllexport)char* fn_NetSim_RIP_WritePacketTrace()
{
    return "";
}
/**
    This function is called by NetworkStack.dll, whenever the event gets triggered  <br/>
    inside the NetworkStack.dll for the Application layer RIP protocol<br/>
    It includes APPLICATION_IN,NETWORK_OUT,NETWORK_IN and TIMER_EVENT.<br/>
        
 */
_declspec(dllexport)int fn_NetSim_RIP_Run()
{
    if(pstruEventDetails->pPacket && !fnCheckRoutingPacket())
        return 0; //Not routing packet
    return fnRouter[pstruEventDetails->nProtocolId?pstruEventDetails->nProtocolId%100:pstruEventDetails->pPacket->nControlDataType/100%100]();
}
/** This function is used to send the RIP updates whenever routing table is updated*/ 
_declspec(dllexport)int fn_NetSim_RIP_TriggeredUpdate(struct stru_NetSim_Network *pstruNETWORK,NetSim_EVENTDETAILS *pstruEventDetails)
{
    int nLoop1=0,nLink_Id=0;
    NETSIM_ID nConnectedDevId=0,nDeviceid;
    NETSIM_ID nConnectedInterfaceId=0;
    NETSIM_ID nInterfaceId,nLoop=0;
    NETSIM_ID nInterfaceCount;
    DEVICE_ROUTER *pstruRouter;
    RIP_PACKET *pstruRIPPacket = NULL;
    NetSim_PACKET* pstruControlPacket=NULL;
    RIP_ROUTING_DATABASE *pstrudatabase;
    RIP_ENTRY *pstruRIPNewEntry,*pstruRIPCurrentEntry;
    NETWORK=pstruNETWORK;
    nDeviceid=pstruEventDetails->nDeviceId;
    nInterfaceCount=NETWORK->ppstruDeviceList[nDeviceid-1]->nNumOfInterface;
 
    for(nLoop=0;nLoop<nInterfaceCount;nLoop++)
    {
        if(NETWORK->ppstruDeviceList[nDeviceid-1]->ppstruInterfaceList[nLoop]->szAddress &&
            NETWORK->ppstruDeviceList[nDeviceid-1]->ppstruInterfaceList[nLoop]->nInterfaceType==INTERFACE_WAN_ROUTER)
        {
            nLink_Id = fn_NetSim_Stack_GetConnectedDevice(nDeviceid,nLoop+1,&nConnectedDevId,&nConnectedInterfaceId);
            if(!nLink_Id)
                continue;
            if(NETWORK->ppstruDeviceList[nDeviceid-1]->pstruApplicationLayer)
            {
                pstruRouter = get_RIP_var(nDeviceid);
                if(pstruRouter && pstruRouter->RoutingProtocol[nLoop] == APP_PROTOCOL_RIP)
                {
                    //Creating the RIP packet
                    pstruRIPPacket=calloc(1,sizeof(RIP_PACKET));
                    //Assign the Version type
                    pstruRIPPacket->nVersion=pstruRouter->uniInteriorRouting.struRIP.n_RIP_Version;
                    pstrudatabase=pstruRouter->pstruRoutingTables->pstruRIP_RoutingTable;
                    //Add all the entries in routing database to RIP packet
                    while(pstrudatabase!=NULL)
                    {       
                        pstruRIPNewEntry=calloc(1,sizeof(struct stru_RIPEntry));
                        pstruRIPNewEntry->szIPv4_address=IP_COPY(pstrudatabase->szAddress);
                        pstruRIPNewEntry->szNext_Hop=IP_COPY(pstrudatabase->szRouter);
                        pstruRIPNewEntry->nAddress_family_identifier=2; // The Address family identifier value is 2 for IP
                        pstruRIPNewEntry->szSubnet_Mask=IP_COPY(pstrudatabase->szSubnetmask);
                        pstruRIPNewEntry->nMetric=pstrudatabase->nMetric;
                        if(pstruRIPPacket->pstruRIPEntry)
                        {
                            pstruRIPCurrentEntry = pstruRIPPacket->pstruRIPEntry;
                            while(pstruRIPCurrentEntry->pstru_RIP_NextEntry != NULL)
                                pstruRIPCurrentEntry = pstruRIPCurrentEntry->pstru_RIP_NextEntry;
                            pstruRIPCurrentEntry->pstru_RIP_NextEntry = pstruRIPNewEntry;
                        }
                        else
                            pstruRIPPacket->pstruRIPEntry = pstruRIPNewEntry;
 
                        pstrudatabase=pstrudatabase->pstru_Router_NextEntry;
                    }
                    nInterfaceId=nLoop+1;
                    //Create the Application layer packet to carry the RIP packet
                    pstruControlPacket=fn_NetSim_Packet_CreatePacket(APPLICATION_LAYER);
                    pstruControlPacket->nControlDataType=RIP_Packet;
                    pstruControlPacket->nPacketId=0;
                    pstruControlPacket->nPacketType=PacketType_Control;
                    pstruControlPacket->nSourceId=nDeviceid;
                    add_dest_to_packet(pstruControlPacket, nConnectedDevId);
                    pstruControlPacket->nTransmitterId=nDeviceid;
                    pstruControlPacket->nReceiverId=nConnectedDevId;
                    //Assign the Application layer details of the packet
                    pstruControlPacket->pstruAppData->dArrivalTime=pstruEventDetails->dEventTime;
                    pstruControlPacket->pstruAppData->dEndTime=pstruEventDetails->dEventTime;
                    pstruControlPacket->pstruAppData->dStartTime=pstruEventDetails->dEventTime;
                    pstruControlPacket->pstruAppData->dPayload=RIP_PACKET_SIZE_WITH_HEADER;
                    pstruControlPacket->pstruAppData->dOverhead=0;
                    pstruControlPacket->pstruAppData->dPacketSize=pstruControlPacket->pstruAppData->dPayload+pstruControlPacket->pstruAppData->dOverhead;
                    pstruControlPacket->pstruAppData->nApplicationProtocol=APP_PROTOCOL_RIP;
                    pstruControlPacket->pstruAppData->Packet_AppProtocol=pstruRIPPacket;
                    //Assign the Network layer details of the packet
                    pstruControlPacket->pstruNetworkData->nNetworkProtocol=NW_PROTOCOL_IPV4;
                    pstruControlPacket->pstruNetworkData->nTTL = 1;
                    pstruControlPacket->pstruNetworkData->szSourceIP=IP_COPY(fn_NetSim_Stack_GetIPAddressAsId(nDeviceid,nInterfaceId));
                    pstruControlPacket->pstruNetworkData->szDestIP=IP_COPY(fn_NetSim_Stack_GetIPAddressAsId(nConnectedDevId,nConnectedInterfaceId));
                    if(!pstruControlPacket->pstruNetworkData->szDestIP)
                    {
                        char str[5000];
                        sprintf(str,"Unable to get the connected device IP address for Router %d Interface %d",nDeviceid,nInterfaceId);
                        fnNetSimError(str);
                    }
                    //Assign the Transport layer details of the packet
                    pstruControlPacket->pstruTransportData->nSourcePort=RIP_PORT+1;
                    pstruControlPacket->pstruTransportData->nDestinationPort=RIP_PORT;
                    if(NETWORK->ppstruDeviceList[nDeviceid-1]->pstruTransportLayer->isUDP)
                        pstruControlPacket->pstruTransportData->nTransportProtocol=TX_PROTOCOL_UDP;
                    else if(NETWORK->ppstruDeviceList[nDeviceid-1]->pstruTransportLayer->isTCP)
                        pstruControlPacket->pstruTransportData->nTransportProtocol=TX_PROTOCOL_TCP;
                    else
                        pstruControlPacket->pstruTransportData->nTransportProtocol=0;
                    //Add the packets to the socket buffer
                    if(!fn_NetSim_Socket_GetBufferStatus(pstruRouter->sock))
                    {
                        fn_NetSim_Socket_PassPacketToInterface(nDeviceid, pstruControlPacket, pstruRouter->sock);
                        pstruEventDetails->dEventTime=pstruEventDetails->dEventTime;
                        pstruEventDetails->dPacketSize=pstruControlPacket->pstruAppData->dPacketSize;
                        pstruEventDetails->nApplicationId=0;
                        pstruEventDetails->nProtocolId=pstruControlPacket->pstruTransportData->nTransportProtocol;
                        pstruEventDetails->nDeviceId=nDeviceid;
                        pstruEventDetails->nInterfaceId=0;
                        pstruEventDetails->nEventType=TRANSPORT_OUT_EVENT;
                        pstruEventDetails->nSubEventType=0;
                        pstruEventDetails->pPacket=NULL;
                        pstruEventDetails->szOtherDetails = pstruRouter->sock;
                        fnpAddEvent(pstruEventDetails); 
                    }
                    else
                    {
                        fn_NetSim_Socket_PassPacketToInterface(nDeviceid, pstruControlPacket, pstruRouter->sock);
                    }   
                }
            }
        }
    }
    return 0;
}
/** This function is used to execute the RIP functionalities.*/
int fn_NetSim_RIP_Run_F()
{
    SUB_EVENT nSub_Event_Type;
 
    nEventType=pstruEventDetails->nEventType;
 
    nSub_Event_Type = pstruEventDetails->nSubEventType;
    //  
    //Check  the event type
    switch(nEventType)  
    {           
    case APPLICATION_IN_EVENT:
        switch(nSub_Event_Type)
        {
        case ROUTING_TABLE_UPDATION:
            fn_NetSim_RIP_DistanceVectorAlgorithm(NETWORK,pstruEventDetails);
#ifdef _RIP_Trace
            fn_NetSim_RIPTrace(NETWORK,pstruEventDetails->nDeviceId,1);
#endif      
            break;
        default:
            fn_NetSim_RIP_ReceivingOf_RIP_Message(NETWORK,pstruEventDetails);
            break;
        }
        break;
    case TIMER_EVENT:
        switch(nSub_Event_Type)
        {
        case SEND_RIP_UPDATE_PKT:
            fn_NetSim_RIP_Update_Timer(NETWORK,pstruEventDetails);
            break;
        case RIP_TIMEOUT:
            fn_NetSim_RIP_Timeout_Timer(NETWORK,pstruEventDetails); 
            break;
        case RIP_GARBAGE_COLLECTION:
            fn_NetSim_RIP_Garbage_Collection_Timer(NETWORK,pstruEventDetails);
            break;
        default:
            printf("\nInvalid sub event");
            break;
        }
        break;
    default:    
        printf("\nInvalid event");
        break;  
    }   
 
    return 0;
}