RouteCache.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 "DSR.h"
#include "List.h"
/**
This function adds a route to the route cache. This is the entire list of address from
the device to the target in sequence
*/
int fn_NetSim_DSR_UpdateRouteCache(unsigned int length,
    NETSIM_IPAddress* address,
    double dTime)
{
    NETSIM_ID nDeviceId = pstruEventDetails->nDeviceId;
    DSR_DEVICE_VAR* devVar = DSR_DEV_VAR(nDeviceId);
    DSR_ROUTE_CACHE* cache = ROUTECACHE_ALLOC();
    unsigned int count = 0;
    while(count<length)
    {
        if(!IP_COMPARE(address[count],dsr_get_curr_ip()))
            break;
        count++;
    }
    count = length-count;
    cache->nLength = count;
    cache->dTimeOutTime = dTime+ROUTE_CACHE_TIMEOUT;
    cache->address = calloc(count,sizeof* cache->address);
    while(count--)
    {
        cache->address[count] = IP_COPY(address[--length]);
    }
    LIST_ADD_LAST(&devVar->pstruRouteCache,cache);
    return 0;
}
/**
This function searches the route cache for a route to the target from the device.
If route is found, it returns the route.
*/
DSR_ROUTE_CACHE* fn_NetSim_DSR_FindCache(DSR_DEVICE_VAR* devVar,NETSIM_IPAddress address,double dTime)
{
    DSR_ROUTE_CACHE* cache=devVar->pstruRouteCache;
    while(cache)
    {
        unsigned int nLoop;
        if(cache->dTimeOutTime <= dTime)
        {
            DSR_ROUTE_CACHE* temp = cache;
            cache = (DSR_ROUTE_CACHE*)LIST_NEXT(cache);
            LIST_FREE((void**)&devVar->pstruRouteCache,temp);
            continue; //cache expired
        }
        for(nLoop=0;nLoop<cache->nLength;nLoop++)
        {
            if(!IP_COMPARE(cache->address[nLoop],address))
            {
                cache->dTimeOutTime = dTime+ROUTE_CACHE_TIMEOUT;
                return cache;
            }
        }
        cache = LIST_NEXT(cache);
    }
    return NULL;
}
/**
If the route cache contains the address in the addList, it returns a false.
*/
bool fn_NetSim_DSR_ValidateRouteCache(DSR_ROUTE_CACHE* cache,NETSIM_IPAddress* addList,int count)
{
    unsigned int loop;
    int loop2;
    for(loop=0;loop<cache->nLength;loop++)
    {
        for(loop2=0;loop2<count;loop2++)
        {
            if(!IP_COMPARE(cache->address[loop],addList[loop2]))
                return false;
        }
    }
    return true;
}
/**
This function deletes an entry from the route cache.
*/
int fn_NetSim_DSR_DeleteEntryFromRouteCache(DSR_ROUTE_CACHE** ppcache,
    NETSIM_IPAddress ip1,
    NETSIM_IPAddress ip2)
{
    DSR_ROUTE_CACHE* cache = *ppcache;
    while(cache)
    {
        unsigned int loop;
        int flag = 0;
        for(loop=0;loop<cache->nLength-1;loop++)
        {
            if(!IP_COMPARE(ip1,cache->address[loop]) &&
                !IP_COMPARE(ip2,cache->address[loop+1]))
 
            {
                unsigned int loop2;
                //cache found
                for(loop2=0;loop2<cache->nLength;loop2++)
                    IP_FREE(cache->address[loop2]);
                free(cache->address);
                LIST_FREE((void**)ppcache,cache);
                cache=*ppcache;
                flag=1;
                break;
            }
        }
        if(flag)
            continue;
        cache = (DSR_ROUTE_CACHE*)LIST_NEXT(cache);
    }
    return 1;
}