PIM_Route.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 "IP.h"
#include "PIM_SM.h"
 
typedef struct stru_pim_route
{
    NETSIM_ID d;
    UINT interfaceCount;
    NETSIM_ID* ifList;
    NETSIM_IPAddress dest;
    ptrIP_ROUTINGTABLE table;
    _ele* ele;
}PIM_ROUTE, *ptrPIM_ROUTE;
#define PIM_ROUTE_ALLOC() (ptrPIM_ROUTE)list_alloc(sizeof(PIM_ROUTE),offsetof(PIM_ROUTE,ele))
#define PIM_ROUTE_ADD(ls,m) LIST_ADD_LAST((void**)ls,m)
#define PIM_ROUTE_NEXT(m) (m = LIST_NEXT(m))
static ptrPIM_ROUTE pimRoute = NULL;
 
static ptrPIM_ROUTE find_route(NETSIM_ID d, NETSIM_ID i, NETSIM_IPAddress dest)
{
    ptrPIM_ROUTE r = pimRoute;
    while (r)
    {
        bool fd = false;
        bool fi = false;
        if (r->d == d &&
            !IP_COMPARE(r->dest, dest))
        {
            //Continue further check
        }
        else
        {
            PIM_ROUTE_NEXT(r);
            continue;
        }
        if (i)
        {
            UINT k;
            for (k = 0; k < r->interfaceCount; k++)
            {
                if (r->ifList[k] == i)
                {
                    return r;
                }
            }
        }
        else
        {
            return r;
        }
 
        PIM_ROUTE_NEXT(r);
    }
    return NULL;
}
 
void pim_route_add(NETSIM_ID d,
                   NETSIM_ID i,
                   UINT metric,
                   NETSIM_IPAddress dest)
{
    ptrPIM_ROUTE r = find_route(d, i, dest);
    if (r)
    {
        r->table->Metric = metric;
    }
    else
    {
        if (i)
            r = find_route(d, 0, dest);
        if (r)
        {
            //Add new interface only
            UINT c = r->table->interfaceCount;
            NETSIM_IPAddress* addr = r->table->Interface;
            NETSIM_ID* id = r->table->nInterfaceId;
            NETSIM_ID* rid = r->ifList;
 
            addr = realloc(addr, (c + 1) * sizeof* addr);
            addr[c] = IP_COPY(DEVICE_NWADDRESS(d, i));
            r->table->Interface = addr;
 
            id = realloc(id, (c + 1) * sizeof* id);
            id[c] = i;
            r->table->nInterfaceId = id;
 
            rid = realloc(rid, (c + 1) * sizeof* rid);
            rid[c] = i;
            r->ifList = rid;
 
            r->interfaceCount++;
 
            r->table->interfaceCount++;
 
            r->table->Metric = metric;
        }
        else
        {
            //Add new route
            NETSIM_IPAddress* addr;
            NETSIM_ID* id;
            UINT c;
 
            r = PIM_ROUTE_ALLOC();
            PIM_ROUTE_ADD(&pimRoute, r);
            r->d = d;
            r->dest = dest;
 
            if (i)
            {
                c = 1;
                id = calloc(1, sizeof* id);
                addr = calloc(1, sizeof* addr);
                id[0] = i;
                addr[0] = IP_COPY(DEVICE_NWADDRESS(d, i));
                r->interfaceCount = 1;
                r->ifList = calloc(1, sizeof* r->ifList);
                r->ifList[0] = i;
            }
            else
            {
                c = DEVICE(d)->nNumOfInterface;
                id = calloc(c, sizeof* id);
                addr = calloc(c, sizeof* addr);
                r->interfaceCount = c;
                r->ifList = calloc(c, sizeof* r->ifList);
                UINT k;
                for (k = 0; k < c; k++)
                {
                    id[k] = k + 1;
                    addr[k] = IP_COPY(DEVICE_NWADDRESS(d, k + 1));
                    r->ifList[k] = k + 1;
                }
            }
 
            r->table = iptable_add(IP_WRAPPER_GET(d),
                                   dest,
                                   STR_TO_IP4("255.255.255.255"),
                                   0,
                                   NULL,
                                   c,
                                   addr,
                                   id,
                                   metric,
                                   "PIM-MULTICAST");
        }
    }
}
 
NETSIM_IPAddress pimroute_find_nexthop(NETSIM_ID d, NETSIM_IPAddress dest)
{
    //Create dummy packet
    NetSim_PACKET* packet = fn_NetSim_Packet_CreatePacket(NETWORK_LAYER);
    packet->pstruNetworkData->szDestIP = dest;
    packet->pstruNetworkData->szSourceIP = DEVICE_NWADDRESS(d, 1);
 
    ptrIP_FORWARD_ROUTE route = fn_NetSim_IP_RoutePacket(packet, d);
    NETSIM_IPAddress next = NULL;
    if (!route->nextHop)
    {
        fnNetSimError("Unicast route is not found for dest %s from %s. Please check/enable routing protocol.",
                      dest->str_ip,
                      packet->pstruNetworkData->szSourceIP->str_ip);
    }
    else
    {
        next = route->nextHop[0];
    }
    free(route);
    fn_NetSim_Packet_FreePacket(packet);
    return next;
}