Component 3/IP/Multicast.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 "IP.h"
#include "List.h"
#include "IGMP.h"
 
static NETSIM_IPAddress ALL_IN_SUBNET;
static NETSIM_IPAddress ALL_ROUTER_IN_SUBNET;
static NETSIM_IPAddress ALL_PIM_ROUTER;
static NETSIM_IPAddress ALL_SPF_ROUTERS;
static NETSIM_IPAddress ALL_D_ROUTERS;
 
void multicast_join_group()
{
    NETSIM_IPAddress ip = pstruEventDetails->szOtherDetails;
 
    IP_DEVVAR* dev = GET_IP_DEVVAR(pstruEventDetails->nDeviceId);
    if (!dev->isIGMPConfigured)
    {
        fnNetSimError("%s is called for device %d without IGMP enable. Please enable IGMP to run multicast\n",
                      __FUNCTION__,
                      pstruEventDetails->nDeviceId);
        return;
    }
    //Call IPGMP to join group
    igmp_host_join_group(pstruEventDetails->nDeviceId, ip);
}
 
static bool isOSPFPacket(NetSim_PACKET* packet)
{
    if (!ALL_SPF_ROUTERS)
    {
        ALL_SPF_ROUTERS = STR_TO_IP4("224.0.0.5");
        ALL_D_ROUTERS = STR_TO_IP4("224.0.0.6");
    }
 
    NETSIM_IPAddress ip = packet->pstruNetworkData->szDestIP;
    if (!IP_COMPARE(ip, ALL_SPF_ROUTERS))
        return true;
 
    if (!IP_COMPARE(ip, ALL_D_ROUTERS))
        return true;
 
    return false;
}
 
IP_PROTOCOL_ACTION check_ip_in_multicastgroup(NETSIM_IPAddress ip, NETSIM_ID d, NetSim_PACKET* packet)
{
    if (isRouter(d) && isOSPFPacket(packet))
        return ACTION_MOVEUP;
 
    if (isIGMPPacket(packet))
        return ACTION_MOVEUP;
 
    if (isPIMPacket(packet))
    {
        if (isHost(d))
            return ACTION_DROP;
        else if (isRouter(d))
            return ACTION_MOVEUP;
    }
 
    if (isRouter(d))
        return ACTION_REROUTE;
    //return router_is_ip_present_in_db(d, ip, packet);
    else if (isHost(d))
        return host_is_ip_present_in_db(d, ip, packet);
    else if (isL3Device(d))
        return ACTION_REROUTE;
    else
        return ACTION_DROP; //Unknown type of device.
}
 
bool is_reserved_multicast_address(NETSIM_IPAddress ip)
{
    static bool init = false;
    if (!init)
    {
        init = true;
        ALL_PIM_ROUTER = STR_TO_IP4("224.0.0.13");
        ALL_IN_SUBNET = STR_TO_IP4("224.0.0.1");
        ALL_ROUTER_IN_SUBNET = STR_TO_IP4("224.0.0.2");
        ALL_SPF_ROUTERS = STR_TO_IP4("224.0.0.5");
        ALL_D_ROUTERS = STR_TO_IP4("224.0.0.6");
    }
 
    if (!IP_COMPARE(ip, ALL_IN_SUBNET ))
        return true;
    
    if (!IP_COMPARE(ip, ALL_PIM_ROUTER))
        return true;
 
    if (!IP_COMPARE(ip, ALL_ROUTER_IN_SUBNET))
        return true;
 
    if (!IP_COMPARE(ip, ALL_SPF_ROUTERS))
        return true;
    
    if (!IP_COMPARE(ip, ALL_D_ROUTERS))
        return true;
    
    return false;
}
 
IP_ROUTINGTABLE* tab = NULL;
static bool isCorrectRouteForSubnet(IP_ROUTINGTABLE** table, NETSIM_IPAddress dest, NETSIM_IPAddress src)
{
    if (!tab)
        tab = IPROUTINGTABLE_ALLOC();
    
    if (IP_COMPARE((*table)->networkDestination, dest))
        return false;
 
    memcpy(tab, *table, sizeof* tab);
    tab->interfaceCount = 0;
 
    UINT k = 0;
    UINT i;
    for (i = 0; i < (*table)->interfaceCount; i++)
    {
        if (IP_IS_IN_SAME_NETWORK_IPV4(src, (*table)->Interface[i], (*table)->netMask))
        {
            tab->interfaceCount++;
            tab->Interface[k] = (*table)->Interface[i];
            tab->nInterfaceId[k] = (*table)->nInterfaceId[i];
            k++;
        }
    }
    if (k)
    {
        *table = tab;
        return true;
    }
    else
    {
        *table = NULL;
        return false;
    }
}
 
bool isCorrectRoute(pptrIP_ROUTINGTABLE table, NETSIM_IPAddress dest, NETSIM_IPAddress src)
{
    if (!IP_COMPARE(dest, ALL_IN_SUBNET))
        return isCorrectRouteForSubnet(table, dest, src);
 
    if (!IP_COMPARE(dest, ALL_PIM_ROUTER))
        return true;
 
    return true;
}