Fragmentation.c

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#include "main.h"
#include "802_22.h"
/** In the MAC, the transmitting side has full discretion whether or not to pack 
a group of MAC SDUs into a single MAC PDU. BSs and CPEs shall both have the capability 
of unpacking. If packing is turned on for a connection, the MAC may pack multiple MAC SDUs
into a single MAC PDU. Also, packing makes use of the connection attribute indicating 
whether the connection carries fixed-length or variable-length packets. */
NetSim_PACKET* fn_NetSim_CR_BS_PackPacket(BS_MAC* pstruBSMac,NetSim_PACKET* pstruPacket)
{
    NetSim_PACKET* pstruprevFrag=NULL;
    FRAGMENT_SUB_HEADER* pstruFragHed;
    GMH* pstruGMH = (GMH*)pstruPacket->pstruMacData->Packet_MACProtocol;
    NetSim_PACKET* pstruFragmentList = pstruBSMac->pstruFragmentPacketList;
    if(pstruGMH->sz_Type[FRAGMANET_BIT] == '0')
    {
        return pstruPacket;
    }
    pstruFragHed = pstruGMH->subheader[FRAGMANET_BIT];
    if(pstruFragmentList == NULL)
    {
        pstruBSMac->pstruFragmentPacketList = pstruPacket;
        return NULL;
    }
    while(pstruFragmentList)
    {
        FRAGMENT_SUB_HEADER* pstruFrag = ((GMH*)pstruFragmentList->pstruMacData->Packet_MACProtocol)->subheader[FRAGMANET_BIT];
        if(pstruFrag->nFragmentId == pstruFragHed->nFragmentId)
        {
            pstruFragmentList->pstruMacData->dPacketSize += pstruPacket->pstruMacData->dPacketSize;
            pstruFragmentList->pstruMacData->dPayload += pstruPacket->pstruMacData->dPayload;
            pstruFragmentList->pstruMacData->dOverhead += pstruPacket->pstruMacData->dOverhead;
            pstruFragmentList->pstruMacData->dEndTime = pstruPacket->pstruMacData->dEndTime;
            
            pstruFragmentList->pstruPhyData->dPacketSize += pstruPacket->pstruPhyData->dPacketSize;
            pstruFragmentList->pstruPhyData->dPayload += pstruPacket->pstruPhyData->dPayload;
            pstruFragmentList->pstruPhyData->dOverhead += pstruPacket->pstruPhyData->dOverhead;
            pstruFragmentList->pstruPhyData->dEndTime = pstruPacket->pstruPhyData->dEndTime;
            
            if(pstruFragmentList->pstruAppData && pstruPacket->pstruAppData)
                pstruFragmentList->pstruAppData->dPayload += pstruPacket->pstruAppData->dPayload;
            fn_NetSim_Packet_FreePacket(pstruPacket);
            pstruPacket = NULL;
            if(pstruFragHed->FC == B2_01)
            {
                //Last fragment
                if(pstruprevFrag)
                {
                    pstruprevFrag->pstruNextPacket = pstruFragmentList->pstruNextPacket;
                    pstruFragmentList->pstruNextPacket = NULL;
                }
                else
                {
                    pstruBSMac->pstruFragmentPacketList = pstruFragmentList->pstruNextPacket;
                    pstruFragmentList->pstruNextPacket = NULL;
                }
                break;
            }
            return NULL;
        }
        pstruprevFrag = pstruFragmentList;
        pstruFragmentList = pstruFragmentList->pstruNextPacket;
    }
    if(pstruFragmentList)
    {
        return pstruFragmentList;
    }
    if(pstruPacket)
    {
        if(pstruprevFrag)
        {
            pstruprevFrag->pstruNextPacket = pstruPacket;
        }
    }
    return NULL;
}
/** In the MAC, the transmitting side has full discretion whether or not to pack 
a group of MAC SDUs into a single MAC PDU. BSs and CPEs shall both have the capability 
of unpacking. If packing is turned on for a connection, the MAC may pack multiple MAC SDUs
into a single MAC PDU. Also, packing makes use of the connection attribute indicating 
whether the connection carries fixed-length or variable-length packets. */
int fn_NetSim_CR_CPE_PackPacket()
{
    NetSim_PACKET* pstruprevFrag=NULL;
    FRAGMENT_SUB_HEADER* pstruFragHed;
    CPE_MAC* pstruCPEMAC = (CPE_MAC*)DEVICE_MACVAR(pstruEventDetails->nDeviceId,pstruEventDetails->nInterfaceId);
    NetSim_PACKET* pstruPacket = pstruEventDetails->pPacket;
    GMH* pstruGMH = (GMH*)pstruPacket->pstruMacData->Packet_MACProtocol;
    NetSim_PACKET* pstruFragmentList = pstruCPEMAC->pstruFragmentPacketList;
    if(pstruGMH->sz_Type[FRAGMANET_BIT] == '0')
    {
        //Move packet to network in
        pstruEventDetails->nEventType = NETWORK_IN_EVENT;
        pstruEventDetails->dPacketSize -= pstruPacket->pstruMacData->dOverhead;
        pstruEventDetails->nProtocolId = (NETSIM_ID)fn_NetSim_Stack_GetNWProtocol(pstruEventDetails->nDeviceId);
        pstruEventDetails->nSubEventType = 0;
        fnpAddEvent(pstruEventDetails);
        return 0;
    }
    pstruFragHed = pstruGMH->subheader[FRAGMANET_BIT];
    if(pstruFragmentList == NULL)
    {
        pstruCPEMAC->pstruFragmentPacketList = pstruPacket;
        return 0;
    }
    while(pstruFragmentList)
    {
        FRAGMENT_SUB_HEADER* pstruFrag = ((GMH*)pstruFragmentList->pstruMacData->Packet_MACProtocol)->subheader[FRAGMANET_BIT];
        if(pstruFrag->nFragmentId == pstruFragHed->nFragmentId)
        {
            pstruFragmentList->pstruMacData->dPacketSize += pstruPacket->pstruMacData->dPacketSize;
            pstruFragmentList->pstruMacData->dPayload += pstruPacket->pstruMacData->dPayload;
            pstruFragmentList->pstruMacData->dOverhead += pstruPacket->pstruMacData->dOverhead;
            pstruFragmentList->pstruMacData->dEndTime = pstruPacket->pstruMacData->dEndTime;
 
            pstruFragmentList->pstruPhyData->dPacketSize += pstruPacket->pstruPhyData->dPacketSize;
            pstruFragmentList->pstruPhyData->dPayload += pstruPacket->pstruPhyData->dPayload;
            pstruFragmentList->pstruPhyData->dOverhead += pstruPacket->pstruPhyData->dOverhead;
            pstruFragmentList->pstruPhyData->dEndTime = pstruPacket->pstruPhyData->dEndTime;
 
 
            if(pstruFragmentList->pstruAppData && pstruPacket->pstruAppData)
                pstruFragmentList->pstruAppData->dPayload += pstruPacket->pstruAppData->dPayload;
            if(pstruFragHed->FC == B2_01)
            {
                //Last fragment
                if(pstruprevFrag)
                {
                    pstruprevFrag->pstruNextPacket = pstruFragmentList->pstruNextPacket;
                    pstruFragmentList->pstruNextPacket = NULL;
                }
                else
                {
                    pstruCPEMAC->pstruFragmentPacketList = pstruFragmentList->pstruNextPacket;
                    pstruFragmentList->pstruNextPacket = NULL;
                }
                break;
            }
            fn_NetSim_Packet_FreePacket(pstruPacket);
            pstruPacket = NULL;
            return 0;
        }
        pstruprevFrag = pstruFragmentList;
        pstruFragmentList = pstruFragmentList->pstruNextPacket;
    }
    if(pstruFragmentList)
    {
        //Move packet to network in
        pstruEventDetails->nEventType = NETWORK_IN_EVENT;
        pstruEventDetails->dPacketSize -= pstruFragmentList->pstruMacData->dOverhead;
        pstruEventDetails->nProtocolId = (NETSIM_ID)fn_NetSim_Stack_GetNWProtocol(pstruEventDetails->nDeviceId);
        pstruEventDetails->nSubEventType = 0;
        pstruEventDetails->pPacket = pstruFragmentList;
        fnpAddEvent(pstruEventDetails);
        return 0;
    }
    if(pstruPacket)
    {
        if(pstruprevFrag)
        {
            pstruprevFrag->pstruNextPacket = pstruPacket;
        }
    }
    return 0;
}
 
/** Fragmentation is the process by which a MAC SDU is divided into one or more MAC PDUs. 
This process is undertaken to allow efficient use of available bandwidth relative to the 
QoS requirements of a connection’s service flow. Upon the creation of a connection by the 
MAC SAP, fragmentation capability is defined. Fragmentation may be initiated by a BS for 
downstream connections and by a CPE for upstream connections. */
int fn_NetSim_CR_FragmentPacket(NetSim_PACKET* pstruPacket,double dSDUSize)
{
    NetSim_PACKET* pstruTempPacket;
    FRAGMENT_SUB_HEADER* pstruFragment;
    GMH* pstruGMH;
    int nCount;
    unsigned int n=0;
    double dSize = pstruPacket->pstruNetworkData->dPacketSize;
    double dAppSize;
    if(dSize <= dSDUSize)
    {
        /* update the MAC header*/
        pstruPacket->pstruMacData->dArrivalTime = pstruEventDetails->dEventTime;
        pstruPacket->pstruMacData->dPayload = pstruPacket->pstruNetworkData->dPacketSize;
        pstruPacket->pstruMacData->dOverhead = GMH_SIZE;
        pstruPacket->pstruMacData->dPacketSize = pstruPacket->pstruMacData->dOverhead + pstruPacket->pstruMacData->dPayload;
        
        pstruPacket->pstruPhyData->dPayload = pstruPacket->pstruMacData->dPacketSize;
        pstruPacket->pstruPhyData->dOverhead = 0;
        pstruPacket->pstruPhyData->dPacketSize = pstruPacket->pstruPhyData->dOverhead + pstruPacket->pstruPhyData->dPayload;
        
        pstruGMH = fnpAllocateMemory(1,sizeof *pstruGMH);
        pstruGMH->n_Length = (int)pstruPacket->pstruMacData->dPacketSize;
        pstruGMH->n_UCS = 0;
        pstruGMH->sz_Type[FRAGMANET_BIT] = '0';
        pstruPacket->pstruMacData->Packet_MACProtocol =pstruGMH;
        pstruPacket->pstruMacData->nMACProtocol = MAC_PROTOCOL_IEEE802_22;
        return 0;
    }
    ++g_FragmentId;
    nCount = (int)ceil(dSize/dSDUSize);
    if(pstruPacket->pstruAppData)
        dAppSize = pstruPacket->pstruAppData->dPayload/nCount;
    else
        dAppSize = 0;
    /* update the MAC header*/
    pstruPacket->pstruMacData->dArrivalTime = pstruEventDetails->dEventTime;
    pstruPacket->pstruMacData->dPayload = dSDUSize;
    pstruPacket->pstruMacData->dOverhead = GMH_SIZE + FRAGMENT_SIZE;
    pstruPacket->pstruMacData->dPacketSize = pstruPacket->pstruMacData->dOverhead + pstruPacket->pstruMacData->dPayload;
    
    pstruPacket->pstruPhyData->dPayload = pstruPacket->pstruMacData->dPacketSize;
    pstruPacket->pstruPhyData->dOverhead = 0;
    pstruPacket->pstruPhyData->dPacketSize = pstruPacket->pstruPhyData->dOverhead + pstruPacket->pstruPhyData->dPayload;
    
    if(pstruPacket->pstruAppData)
        pstruPacket->pstruAppData->dPayload = dAppSize;
    pstruGMH = fnpAllocateMemory(1,sizeof *pstruGMH);
    pstruGMH->n_Length = (int)pstruPacket->pstruMacData->dPacketSize;
    pstruGMH->n_UCS = 0;
    pstruPacket->pstruMacData->Packet_MACProtocol =pstruGMH;
    pstruPacket->pstruMacData->nMACProtocol = MAC_PROTOCOL_IEEE802_22;
    pstruFragment = fnpAllocateMemory(1,sizeof *pstruFragment);
    pstruFragment->purpos = 0;
    pstruFragment->FC = B2_10;
    pstruFragment->length = (unsigned int)dSDUSize;
    pstruFragment->FSN = ++n;
    pstruFragment->nFragmentId = g_FragmentId;
    pstruGMH->subheader[FRAGMANET_BIT] = pstruFragment;
    pstruGMH->sz_Type[FRAGMANET_BIT] = '1';
    dSize -= dSDUSize;
    nCount--;
    while(nCount)
    {
        pstruTempPacket = fn_NetSim_Packet_CopyPacket(pstruPacket);
        pstruTempPacket->pstruNextPacket = NULL;
        pstruPacket->pstruNextPacket = pstruTempPacket;
        pstruPacket = pstruPacket->pstruNextPacket;
        pstruPacket->pstruMacData->dArrivalTime = pstruEventDetails->dEventTime;
        pstruPacket->pstruMacData->dOverhead = GMH_SIZE + FRAGMENT_SIZE;
        pstruPacket->pstruMacData->dPacketSize = pstruPacket->pstruMacData->dOverhead + pstruPacket->pstruMacData->dPayload;
        
        pstruPacket->pstruPhyData->dPayload = pstruPacket->pstruMacData->dPacketSize;
        pstruPacket->pstruPhyData->dOverhead = 0;
        pstruPacket->pstruPhyData->dPacketSize = pstruPacket->pstruPhyData->dOverhead + pstruPacket->pstruPhyData->dPayload;
        
        pstruGMH = PACKET_MACPROTOCOLDATA(pstruPacket);
        pstruGMH->n_Length = (int)pstruPacket->pstruMacData->dPacketSize;
        pstruGMH->n_UCS = 0;
        pstruPacket->pstruMacData->Packet_MACProtocol =pstruGMH;
        pstruPacket->pstruMacData->nMACProtocol = MAC_PROTOCOL_IEEE802_22;
        pstruFragment = pstruGMH->subheader[FRAGMANET_BIT];
        pstruFragment->purpos = 0;
        pstruFragment->length = (unsigned int)dSDUSize;
        pstruFragment->FSN = ++n;
        pstruFragment->nFragmentId = g_FragmentId;
        if(dSize>dSDUSize)
        {
            pstruPacket->pstruMacData->dPayload = dSDUSize;
            pstruFragment->FC = B2_11;
        }
        else
        {
            pstruPacket->pstruMacData->dPayload = dSize;
            pstruFragment->FC = B2_01;
        }
        pstruGMH->sz_Type[FRAGMANET_BIT] = '1';
        dSize -= dSDUSize;
        nCount--;
    }
    return 0;
}