OSPF_Interface.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 "OSPF.h"
#include "OSPF_enum.h"
#include "OSPF_Interface.h"
#include "OSPF_List.h"
#include "OSPF_Msg.h"
 
OSPFIFTYPE OSPFIFTYPE_FROM_STR(char* val)
{
    UINT i;
    UINT len = sizeof(strOSPFIFTYPE) / sizeof(strOSPFIFTYPE[0]);
    for (i = 0; i < len; i++)
    {
        if (!_stricmp(strOSPFIFTYPE[i], val))
            return (OSPFIFTYPE)i;
    }
    return (OSPFIFTYPE)0;
}
 
ptrOSPF_IF OSPF_IF_GET(ptrOSPF_PDS ospf, NETSIM_ID ifId)
{
    UINT i;
    for (i = 0; i < ospf->ifCount; i++)
    {
        if (ospf->ospfIf[i]->id == ifId)
            return ospf->ospfIf[i];
    }
    return NULL;
}
 
static void ospf_interface_change_state(ptrOSPF_PDS ospf,
                                        ptrOSPF_IF thisInterface,
                                        OSPFIFSTATE newState)
{
    OSPFIFSTATE oldState = thisInterface->State;
    print_ospf_log(OSPF_LOG, "Interface state changed to %s from %s",
                   strOSPFIFSTATE[newState],
                   strOSPFIFSTATE[oldState]);
    thisInterface->State = newState;
 
    ptrOSPFAREA_DS area = OSPF_AREA_GET_ID(ospf, thisInterface->areaId);
    ospf_lsa_schedule_routerLSA(ospf, area, false);
 
    if (oldState != OSPFIFSTATE_DR &&
        newState == OSPFIFSTATE_DR)
    {
        print_ospf_log(OSPF_LOG, "I am new DR. Producing network LSA for this network");
        ospf_lsa_scheduleNWLSA(ospf, thisInterface, area, false);
    }
    else if (oldState == OSPFIFSTATE_DR &&
             newState != OSPFIFSTATE_DR)
    {
        print_ospf_log(OSPF_LOG, "I am no longer DR. Flush previously originated network LSA");
        ospf_lsa_scheduleNWLSA(ospf, thisInterface, area, true);
    }
}
 
void ospf_handle_interfaceUp_event()
{
    ptrOSPF_PDS ospf = OSPF_PDS_CURRENT();
    ptrOSPF_IF thisInterface = OSPF_IF_CURRENT();
 
    if (thisInterface->State != OSPFIFSTATE_DOWN)
        return;
 
    // Start Hello timer & enabling periodic sending of Hello packet
    if (thisInterface->Type == OSPFIFTYPE_P2P ||
        thisInterface->Type == OSPFIFTYPE_P2MP ||
        thisInterface->Type == OSPFIFTYPE_VIRTUALLINK)
        ospf_interface_change_state(ospf, thisInterface, OSPFIFSTATE_P2P);
    else if (thisInterface->RouterPriority == 0)
        ospf_interface_change_state(ospf, thisInterface, OSPFIFSTATE_DR);
    else
    {
        ospf_interface_change_state(ospf, thisInterface, OSPFIFSTATE_WAITING);
        ospf_event_add(OSPF_CURR_TIME() +
                       thisInterface->routerDeadInterval*SECOND,
                       pstruEventDetails->nDeviceId,
                       pstruEventDetails->nInterfaceId,
                       OSPF_WAITTIMER,
                       NULL,
                       NULL);
    }
    start_interval_hello_timer();
}
 
void ospf_interface_init(ptrOSPF_PDS ospf, ptrOSPF_IF thisInterface)
{
    ospf;
    thisInterface->updateLSAList = ospf_list_init(OSPF_LSA_MSG_FREE, OSPF_LSA_MSG_COPY);
    thisInterface->delayedAckList = ospf_list_init(OSPF_LSA_MSG_FREE, OSPF_LSA_MSG_COPY);
}
 
void ospf_interface_handleMultipleInterfaceEvent()
{
    OSPF_Subevent e = pstruEventDetails->nSubEventType;
    ptrOSPF_PDS ospf = OSPF_PDS_CURRENT();
    ptrOSPF_IF thisInterface = OSPF_IF_CURRENT();
    OSPFIFSTATE oldState = thisInterface->State;
    OSPFIFSTATE newState = OSPFIFSTATE_DOWN;
 
    if(((e == OSPF_BACKUPSEEN || e == OSPF_WAITTIMER) &&
        thisInterface->State != OSPFIFSTATE_WAITING) ||
        (e == OSPF_NEIGHBORCHANGE) &&
       (thisInterface->State != OSPFIFSTATE_DROther &&
        thisInterface->State != OSPFIFSTATE_BACKUP &&
        thisInterface->State != OSPFIFSTATE_DR))
    {
        newState = oldState;
    }
    else
    {
        newState = ospf_DR_election(ospf, thisInterface);
    }
 
    if (newState != oldState)
        ospf_interface_change_state(ospf, thisInterface, newState);
}
 
void ospf_handle_interfaceDown_event()
{
    ptrOSPF_PDS ospf = OSPF_PDS_CURRENT();
    ptrOSPF_IF thisInterface = OSPF_IF_CURRENT();
    UINT n;
    for (n = 0; n < thisInterface->neighborRouterCount; n++)
    {
        ptrOSPF_NEIGHBOR neigh = thisInterface->neighborRouterList[n];
        ospf_event_set_and_call(OSPF_KillNbr,
                                neigh);
    }
 
    thisInterface->designaterRouter = NULL;
    thisInterface->designaterRouterAddr = NULL;
    thisInterface->backupDesignaterRouter = NULL;
    thisInterface->backupDesignaterRouterAddr = NULL;
 
    thisInterface->isFloodTimerSet = false;
    thisInterface->delayedAckTimer = false;
    
    ospf_list_delete_all(thisInterface->updateLSAList);
    ospf_list_delete_all(thisInterface->delayedAckList);
 
    ospf_interface_change_state(ospf, thisInterface, OSPFIFSTATE_DOWN);
}