CSMACDMac.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:    Shashi Kant Suman                                                     *
*                                                                                  *
* ---------------------------------------------------------------------------------*/
#include "main.h"
#include "CSMACD.h"
 
#define check_for_retry_limit(mac) (mac->nRetryLimit>mac->nRetryCount)
 
void wait_for_random_time()
{
    double ran = fn_NetSim_Utilities_GenerateRandomNo(DEVICE_SEED(pstruEventDetails->nDeviceId))/NETSIM_RAND_MAX;
 
    ran *= 16;
    if(file_contention != NULL)
    {
        fprintf(file_contention,"%d\t%d\t%f\n",pstruEventDetails->nDeviceId,(int)ran,pstruEventDetails->dEventTime);
    }
    pstruEventDetails->dEventTime+= (int)ran*CSMACD_CURRMAC->dSlotTime;
}
 
void send_to_phy()
{
    NetSim_PACKET* packet = fn_NetSim_Packet_CopyPacket(CSMACD_CURRMAC->currentPacket);
 
    packet->pstruMacData->dArrivalTime = packet->pstruNetworkData->dEndTime;
    packet->pstruMacData->dStartTime = pstruEventDetails->dEventTime;
    packet->pstruMacData->dEndTime = pstruEventDetails->dEventTime;
 
    packet->pstruMacData->dPayload=packet->pstruNetworkData->dPacketSize;
    packet->pstruMacData->dOverhead=CSMACD_MAC_OVERHEAD;
    packet->pstruMacData->dPacketSize = 
        packet->pstruMacData->dPayload+
        packet->pstruMacData->dOverhead;
 
    pstruEventDetails->dPacketSize=fnGetPacketSize(packet);
    if(packet->pstruAppData)
    {
        pstruEventDetails->nApplicationId=packet->pstruAppData->nApplicationId;
        pstruEventDetails->nSegmentId=packet->pstruAppData->nSegmentId;
    }
    else
    {
        pstruEventDetails->nApplicationId=0;
        pstruEventDetails->nSegmentId=0;
    }
    pstruEventDetails->nEventType=PHYSICAL_OUT_EVENT;
    pstruEventDetails->nPacketId=packet->nPacketId;
    pstruEventDetails->nProtocolId=MAC_PROTOCOL_CSMACD;
    pstruEventDetails->nSubEventType=0;
    pstruEventDetails->pPacket=packet;
    pstruEventDetails->szOtherDetails=NULL;
    fnpAddEvent(pstruEventDetails);
}
 
void fn_NetSim_CSMACD_MacOut()
{
    NetSim_BUFFER* buffer= DEVICE_MAC_NW_INTERFACE(pstruEventDetails->nDeviceId,pstruEventDetails->nInterfaceId)->pstruAccessBuffer;
    PCSMACD_MACVAR mac = CSMACD_CURRMAC;
    NetSim_PACKET* packet;
 
    if(mac->macState || !isMediumIdle())
        return;
 
    if(mac->currentPacket && !mac->iswaited)
    {
        if(check_for_retry_limit(mac))
        {
            mac->macState=Busy;
            wait_for_random_time();
            pstruEventDetails->nEventType = TIMER_EVENT;
            pstruEventDetails->nSubEventType = WAIT_FOR_RANDOM_TIME;
            fnpAddEvent(pstruEventDetails);
            return;
        }
        else
        {
            fn_NetSim_Packet_FreePacket(mac->currentPacket);
            mac->currentPacket=NULL;
            mac->nRetryCount=0;
            goto FIRST_TRANSMISSION;
        }
    }
FIRST_TRANSMISSION:
    mac->iswaited = false;
 
    packet = mac->currentPacket;
 
    if(fn_NetSim_GetBufferStatus(buffer) || packet)
    {
        if(isMediumIdle())
        {
            double ran;
            mac->macState=Busy;
            ran = fn_NetSim_Utilities_GenerateRandomNo(DEVICE_SEED(pstruEventDetails->nDeviceId))/NETSIM_RAND_MAX;
            if(ran<=mac->dPersistance)
            {
                if(!packet) //Take new packet from buffer
                    packet = fn_NetSim_Packet_GetPacketFromBuffer(buffer,1);
                mac->currentPacket = packet;
                send_to_phy();
            }
            else
            {
                pstruEventDetails->dEventTime +=mac->dSlotTime;
                pstruEventDetails->nEventType = TIMER_EVENT;
                pstruEventDetails->nSubEventType = PERSISTANCE_WAIT;
                fnpAddEvent(pstruEventDetails);
            }
        }
    }
}
 
void fn_NetSim_CSMACD_MacIn()
{
    pstruEventDetails->nEventType = NETWORK_IN_EVENT;
    fnpAddEvent(pstruEventDetails);
}
 
void fn_NetSim_CSMACS_PersistanceWait()
{
    double ran;
    PCSMACD_MACVAR mac=CSMACD_CURRMAC;
    NetSim_PACKET* packet;
    NetSim_BUFFER* buffer= DEVICE_MAC_NW_INTERFACE(pstruEventDetails->nDeviceId,pstruEventDetails->nInterfaceId)->pstruAccessBuffer;
 
    if(!isMediumIdle())
    {
        mac->macState=Idle;
        mac->iswaited = true;
        return;
    }
 
    ran = fn_NetSim_Utilities_GenerateRandomNo(DEVICE_SEED(pstruEventDetails->nDeviceId))/NETSIM_RAND_MAX;
    if(ran<=mac->dPersistance)
    {
        if(!mac->currentPacket)
        {
            packet = fn_NetSim_Packet_GetPacketFromBuffer(buffer,1);
            mac->currentPacket = packet;
        }
        send_to_phy();
    }
    else
    {
        pstruEventDetails->dEventTime +=mac->dSlotTime;
        pstruEventDetails->nEventType = TIMER_EVENT;
        pstruEventDetails->nSubEventType = PERSISTANCE_WAIT;
        fnpAddEvent(pstruEventDetails);
    }
}