AODV_RouteError.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 "AODV.h"
#include "List.h"
/**
This function Generates a route error and sends it to the previous HOP.
*/
int fn_NetSim_AODV_GenerateRERR(NETSIM_ID nDeviceId,
    NETSIM_IPAddress UnreachableIP,
    NetSim_EVENTDETAILS* pstruEventDetails)
{
    int DestCount=0;
    NETSIM_IPAddress* DestinationList=NULL;
    unsigned int* DestinationSequence=NULL;
    AODV_DEVICE_VAR* pstruDeviceVar = AODV_DEV_VAR(nDeviceId);
    AODV_ROUTETABLE* routeTable = pstruDeviceVar->routeTable;
    AODV_PRECURSORS_LIST* precursorList = pstruDeviceVar->precursorsList;
    while(routeTable)
    {
        if(!IP_COMPARE(routeTable->NextHop,UnreachableIP))
        {
            routeTable->routingFlags = AODV_RoutingFlag_InValid;
            routeTable->Lifetime = pstruEventDetails->dEventTime+AODV_DELETE_PERIOD;
            DestCount++;
            DestinationList = realloc(DestinationList,DestCount*(sizeof* DestinationList));
            DestinationSequence = realloc(DestinationSequence,DestCount*(sizeof* DestinationSequence));
            DestinationList[DestCount-1] = IP_COPY(routeTable->DestinationIPAddress);
            DestinationSequence[DestCount-1] = routeTable->DestinationSequenceNumber;
        }
        routeTable = LIST_NEXT(routeTable);
    }
    if(precursorList->count)
    {
        int loop;
        bool flag=false;
        for(loop=0;loop<precursorList->count;loop++)
        {
            if(!IP_COMPARE(precursorList->list[loop],UnreachableIP))
            {
                IP_FREE(precursorList->list[loop]);
                precursorList->count--;
                flag = true;
            }
            if(flag)
                precursorList->list[loop] = precursorList->list[loop+1];
        }
    }
    if(DestCount)
    {
        NetSim_EVENTDETAILS pevent;
        AODV_RERR* rerr;
        NetSim_PACKET* packet = fn_NetSim_AODV_GenerateCtrlPacket(nDeviceId,
            0,0,
            pstruEventDetails->dEventTime,
            AODVctrlPacket_RERR);
        if(DEVICE_NWPROTOCOL(pstruEventDetails->nDeviceId,1) == NW_PROTOCOL_IPV4)
        {
            packet->pstruNetworkData->dOverhead = AODV_RERR_SIZE_FIXED+8*DestCount;
            packet->pstruNetworkData->dPacketSize = AODV_RERR_SIZE_FIXED+8*DestCount;
        }
        else
        {
            packet->pstruNetworkData->dOverhead = AODV_RERR_SIZE_FIXED+20*DestCount;
            packet->pstruNetworkData->dPacketSize = AODV_RERR_SIZE_FIXED+20*DestCount;
        }
        packet->pstruNetworkData->nTTL = AODV_NET_DIAMETER;
        rerr = calloc(1,sizeof* rerr);
        packet->pstruNetworkData->Packet_RoutingProtocol = rerr;
        rerr->DestCount = DestCount;
        rerr->Type = 3;
        rerr->UnreachableDestinationIPAddress = DestinationList;
        rerr->UnreachableDestinationSequenceNumber = DestinationSequence;
 
        //Add Network out event to transmit packet
        memcpy(&pevent,pstruEventDetails,sizeof pevent);
        pevent.dPacketSize = packet->pstruNetworkData->dPacketSize;
        pevent.nApplicationId = 0;
        pevent.nEventType = NETWORK_OUT_EVENT;
        pevent.nPacketId = 0;
        pevent.nProtocolId = NW_PROTOCOL_AODV;
        pevent.nSegmentId = 0;
        pevent.nSubEventType = 0;
        pevent.pPacket = packet;
        pevent.szOtherDetails = NULL;
        pevent.pPacket->pstruNetworkData->szNextHopIp=NULL;
        fnpAddEvent(&pevent);
        //update the metrics
        AODV_METRICS_VAR(pevent.nDeviceId).rerrSent++;
        AODV_METRICS_VAR(pevent.nDeviceId).routeBreak++;
    }
    return 1;
}
/**
This function Processess a route error. It deletes the entry to the target in the Route Table
and forwards the REER packet to previous HOP if any.
*/
int fn_NetSim_AODV_ProcessRERR(NetSim_EVENTDETAILS* pstruEventDetails)
{
    bool flag = false;
    NETSIM_IPAddress nextHop = pstruEventDetails->pPacket->pstruNetworkData->szSourceIP;
    AODV_RERR* rerr = (AODV_RERR*)pstruEventDetails->pPacket->pstruNetworkData->Packet_RoutingProtocol;
    AODV_ROUTETABLE* routeTable = AODV_DEV_VAR(pstruEventDetails->nDeviceId)->routeTable;
    while(routeTable)
    {
        unsigned int loop;
        for(loop=0;loop<rerr->DestCount;loop++)
        {
            if(!IP_COMPARE(rerr->UnreachableDestinationIPAddress[loop],routeTable->DestinationIPAddress) &&
                !IP_COMPARE(nextHop,routeTable->NextHop))
            {
                flag = true; //Forward the rerr packet
                routeTable->routingFlags = AODV_RoutingFlag_InValid;
                routeTable->Lifetime = pstruEventDetails->dEventTime + AODV_DELETE_PERIOD;
                break;
            }
 
        }
        routeTable = LIST_NEXT(routeTable);
    }
    if(flag)
    {
        IP_FREE(pstruEventDetails->pPacket->pstruNetworkData->szSourceIP);
        pstruEventDetails->pPacket->pstruNetworkData->szSourceIP = aodv_get_curr_ip();
        pstruEventDetails->nEventType = NETWORK_OUT_EVENT;
        fnpAddEvent(pstruEventDetails);
        AODV_METRICS_VAR(pstruEventDetails->nDeviceId).rerrForwarded++;
    }
    return 1;
}