SourceRoute.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 "List.h"
#include "DSR.h"
/**
This function adds the source route option
*/
int fn_NetSim_DSR_AddSourceRouteOption(NetSim_PACKET* packet,DSR_ROUTE_CACHE* cache)
{
//  unsigned int loop;
    unsigned int length;
    DSR_OPTION_HEADER* option;
    DSR_SOURCE_ROUTE_OPTION* srcRouteOption;
    option = (DSR_OPTION_HEADER*)packet->pstruNetworkData->Packet_RoutingProtocol;
    if(option && option->optType == optType_SourceRoute)
    {
        //Already added and processed
        return 1;
    }
    option = calloc(1,sizeof* option);
    srcRouteOption=calloc(1,sizeof* srcRouteOption);
    option->options = srcRouteOption;
    option->nNextHeader = NO_NEXT_HEADER;
    option->optType = optType_SourceRoute;
    srcRouteOption->F = cache->F;
    srcRouteOption->L = cache->L;
    srcRouteOption->nSalvage = 0;
    srcRouteOption->nOptionType = optType_SourceRoute;
    srcRouteOption->nReserved = 0;
    length = fn_NetSim_DSR_FillAddress(srcRouteOption,cache,dsr_get_curr_ip(),packet->pstruNetworkData->szDestIP);
    srcRouteOption->nSegsLeft = length;
    srcRouteOption->nOptDataLen = length*4+2;
    packet->pstruNetworkData->Packet_RoutingProtocol = option;
    packet->pstruNetworkData->nRoutingProtocol = NW_PROTOCOL_DSR;
    option->nPayloadLength = DSR_SOURCEROUTE_SIZE_FIXED+length*4;
    packet->pstruNetworkData->dOverhead = DSR_OPTION_HEADER_SIZE+option->nPayloadLength;
    if(packet->pstruTransportData)
        packet->pstruNetworkData->dPayload = packet->pstruTransportData->dPacketSize;
    packet->pstruNetworkData->dPacketSize = packet->pstruNetworkData->dOverhead +
        packet->pstruNetworkData->dPayload;
    return 1;
}
/**
This function process the data packet. it the device is the intended target, 
it adds a Transport_In_Event. Else it adds Network_Out_Event
*/
int fn_NetSim_DSR_ProcessSourceRouteOption(NetSim_EVENTDETAILS* pstruEventDetails)
{
    NetSim_PACKET* packet = pstruEventDetails->pPacket;
    DSR_OPTION_HEADER* option;
    DSR_SOURCE_ROUTE_OPTION* srcRouteOption;
    option = (DSR_OPTION_HEADER*)packet->pstruNetworkData->Packet_RoutingProtocol;
    if(!option)
        return 0;
    if(option->ackRequestOption)
        DSR_PROCESS_ACK_REQUEST(packet);
    if(option && option->optType == optType_SourceRoute)
    {
        //update the metrics
        DSR_DEV_VAR(pstruEventDetails->nDeviceId)->dsrMetrics.packetReceived++;
        srcRouteOption = option->options;
 
        if (!IP_COMPARE(packet->pstruNetworkData->szDestIP, dsr_get_curr_ip()))
        {
            fn_NetSim_DSR_FreePacket(packet);
            packet->pstruNetworkData->Packet_RoutingProtocol = NULL;
        }
        return 1;
 
    }
    return 0;
}