PacketForward.c

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#include "main.h"
#include "802_22.h"
/** This function is used to check whether the destination is present or not.
If it presents,it broadcast the data packet */
int fn_NetSim_CR_BS_ForwardDataPacket()
{
    NetSim_BUFFER* pstruBuffer;
    NETSIM_ID nDeviceId = pstruEventDetails->nDeviceId;
    NETSIM_ID nInterfaceId = pstruEventDetails->nInterfaceId;
    NetSim_PACKET* pstruPacket = pstruEventDetails->pPacket;
    BS_MAC* pstruBSMac = (BS_MAC*)DEVICE_MACVAR(nDeviceId,nInterfaceId);
    //Check the destination
    if(isBroadcastPacket(pstruPacket))
    {
        //Broadcast packet
        NETSIM_ID nloop;
        pstruPacket = fn_NetSim_CR_BS_PackPacket(pstruBSMac,pstruPacket);
        if(!pstruPacket)
            return 1;
        for(nloop = 0;nloop<NETWORK->ppstruDeviceList[nDeviceId-1]->nNumOfInterface;nloop++)
        {
            if(!DEVICE_MAC_NW_INTERFACE(nDeviceId,nloop+1))
                continue;
            if(nloop+1==nInterfaceId)
            {
                NetSim_PACKET* list = pstruBSMac->pstruDSPacketList;
                if(!list)
                {
                    pstruBSMac->pstruDSPacketList = fn_NetSim_Packet_CopyPacket(pstruPacket);
                }
                else
                {
                    while(list->pstruNextPacket)
                        list = list->pstruNextPacket;
                    list->pstruNextPacket = fn_NetSim_Packet_CopyPacket(pstruPacket);
                }
                continue;
            }
            //Place the packet to access interface
            pstruBuffer = DEVICE_MAC_NW_INTERFACE(nDeviceId,nloop+1)->pstruAccessBuffer;
            if(!fn_NetSim_GetBufferStatus(pstruBuffer))
            {
                //Add the MAC out event
                pstruEventDetails->nEventType = MAC_OUT_EVENT;
                pstruEventDetails->nInterfaceId = nloop+1;
                pstruEventDetails->nProtocolId = fn_NetSim_Stack_GetMacProtocol(nDeviceId,nloop+1);
                pstruEventDetails->nSubEventType = 0;
                pstruEventDetails->pPacket = NULL;
                fnpAddEvent(pstruEventDetails);
            }
            fn_NetSim_Packet_AddPacketToList(pstruBuffer,fn_NetSim_Packet_CopyPacket(pstruPacket),0);
        }
        fn_NetSim_Packet_FreePacket(pstruPacket);
    }
    else
    {
        UINT destCount;
        NETSIM_ID* dest = get_dest_from_packet(pstruPacket, &destCount);
        UINT i;
        int nSID = 0;
        for (i = 0; i < destCount; i++)
        {
            nSID = pstruBSMac->anSIDFromDevId[dest[i]];
            if (nSID)
                break;
        }
        if(nSID)
        {
            NetSim_PACKET* list = pstruBSMac->pstruDSPacketList;
            if(!list)
            {
                pstruBSMac->pstruDSPacketList = pstruPacket;
            }
            else
            {
                while(list->pstruNextPacket)
                    list = list->pstruNextPacket;
                list->pstruNextPacket = pstruPacket;
            }
            pstruPacket->nTransmitterId = pstruPacket->nReceiverId;
            pstruPacket->nReceiverId = destCount > 1 ? 0 : dest[0];
        }
        
        if(isMulticastPacket(pstruPacket) || !nSID)
        {
            //Broadcasting to other port
            NETSIM_ID nloop;
            pstruPacket = fn_NetSim_CR_BS_PackPacket(pstruBSMac,pstruPacket);
            if(!pstruPacket)
                return 1;
            for(nloop = 0;nloop<NETWORK->ppstruDeviceList[nDeviceId-1]->nNumOfInterface;nloop++)
            {
                if(nloop == nInterfaceId-1)
                    continue;
                //Place the packet to access interface
                pstruBuffer = DEVICE_MAC_NW_INTERFACE(nDeviceId,nloop+1)->pstruAccessBuffer;
                if(!fn_NetSim_GetBufferStatus(pstruBuffer))
                {
                    //Add the MAC out event
                    pstruEventDetails->nEventType = MAC_OUT_EVENT;
                    pstruEventDetails->nInterfaceId = nloop+1;
                    pstruEventDetails->nProtocolId = fn_NetSim_Stack_GetMacProtocol(nDeviceId,nloop+1);
                    pstruEventDetails->nSubEventType = 0;
                    pstruEventDetails->pPacket = NULL;
                    fnpAddEvent(pstruEventDetails);
                }
                fn_NetSim_CR_FreePacket_F(pstruPacket);
                fn_NetSim_Packet_AddPacketToList(pstruBuffer,pstruPacket,0);
            }
        }
    }
    return 0;
}