IGMP_Host.c

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/************************************************************************************
* Copyright (C) 2020                                                               *
* 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 "IGMP.h"
 
static ptrIGMP_HOST_DB find_or_alloc_multicast_db_host(NETSIM_ID d, NETSIM_IPAddress group)
{
    ptrIGMP_HOST_DB r = GET_IGMP_HOST(d)->database;
 
    while (r)
    {
        if (!IP_COMPARE(r->group, group))
            return r;
        r = LIST_NEXT(r);
    }
 
    r = (ptrIGMP_HOST_DB)IGMP_HOST_DB_ALLOC();
    r->group = IP_COPY(group);
    r->state = HostState_IdleMember;
 
    IGMP_HOST_DB_ADD(d, r);
 
    return r;
}
 
static void host_join_multicast_group(NETSIM_ID d, NETSIM_IPAddress group)
{
    find_or_alloc_multicast_db_host(d, group);
}
 
ptrIGMP_HOST_DB host_get_multicast_db(NETSIM_ID d, NETSIM_IPAddress addr)
{
    ptrIGMP_HOST_DB r = GET_IGMP_HOST(d)->database;
 
    while (r)
    {
        if (!IP_COMPARE(r->group, addr))
            return r;
        r = LIST_NEXT(r);
    }
    return NULL;
}
 
void igmp_host_init(NETSIM_ID d)
{
    ptrIGMP_HOST host = GET_IGMP_HOST(d);
 
    print_igmp_log("\nHost %d, Time 0: joining multicast group %s.",
                   d,
                   "224.0.0.1");
 
    host_join_multicast_group(d, STR_TO_IP4("224.0.0.1"));
}
 
IP_PROTOCOL_ACTION host_is_ip_present_in_db(NETSIM_ID d, NETSIM_IPAddress ip, NetSim_PACKET* packet)
{
    IP_DEVVAR* dip = GET_IP_DEVVAR(d);
    ptrIGMP_HOST_DB db = dip->isIGMPConfigured ? GET_IGMP_HOST(d)->database : NULL;
    while (db)
    {
        if (!IP_COMPARE(db->group, ip))
            return ACTION_MOVEUP;
        db = LIST_NEXT(db);
    }
    return ACTION_DROP;
}
 
bool host_process_query(NetSim_PACKET* packet,
                        ptrIGMP_MSG msg,
                        NETSIM_ID d)
{
    bool isTimerReqd = false;
    ptrIGMP_HOST_DB db = host_get_multicast_db(d, msg->GroupAddress);
 
    print_igmp_log("\nHost %d, Time %0.0lf: Query received for group address %s.",
                   d,
                   pstruEventDetails->dEventTime,
                   msg->GroupAddress->str_ip);
 
    if (!db->isReportreqd ||
        pstruEventDetails->dEventTime -
        db->queryRecvTime - 
        db->delayTime >=
        msg->MaxRespTime*0.1*SECOND)
        isTimerReqd = true;
 
    db->maxResponseTime = msg->MaxRespTime;
    db->queryRecvTime = pstruEventDetails->dEventTime;
 
    if (isTimerReqd)
    {
        print_igmp_log("Starting Delay timer.");
        igmp_start_timer(d,
            EVENT_IGMP_DelayTimer,
            msg->GroupAddress,
            pstruEventDetails->dEventTime);
        db->isReportreqd = true;
        print_igmp_log("Changing host state to delaying member");
        db->state = HostState_DelayingMember;
    }
 
    return false;
}
 
void host_send_report()
{
    NETSIM_IPAddress g = pstruEventDetails->szOtherDetails;
    ptrIGMP_HOST_DB db = host_get_multicast_db(pstruEventDetails->nDeviceId,
                                               g);
 
    if (db->isReportreqd)
    {
        print_igmp_log("\nHost %d, Time %0.0lf: Sending report for group address %s.",
                       pstruEventDetails->nDeviceId,
                       pstruEventDetails->dEventTime,
                       g->str_ip);
 
        send_membership_report(pstruEventDetails->nDeviceId,
                               g);
        db->isReportreqd = false;
        print_igmp_log("Changing host state to idle member");
        db->state = HostState_IdleMember;
    }
}
 
bool host_process_report(NetSim_PACKET* packet,
                         ptrIGMP_MSG msg,
                         NETSIM_ID d)
{
    ptrIGMP_HOST_DB db = host_get_multicast_db(d, msg->GroupAddress);
    if (db)
    {
        print_igmp_log("\nHost %d, Time %0.0lf: report received for group address %s.",
                       d,
                       pstruEventDetails->dEventTime,
                       msg->GroupAddress->str_ip);
        print_igmp_log("Report is not required.");
        db->isReportreqd = false;
        print_igmp_log("Changing host state to Idle member");
        db->state = HostState_IdleMember;
    }
    return false;
}
 
void igmp_host_join_group(NETSIM_ID d, NETSIM_IPAddress group)
{
    if (!isHost(d))
        fnNetSimError("%s is called for Non-Host device %d.\n", __FUNCTION__, d);
 
    print_igmp_log("\nHost %d, Time %0.0lf: Joining multicast group %s.",
                   d,
                   pstruEventDetails->dEventTime,
                   group->str_ip);
    print_igmp_log("Sending membership report.");
 
    ptrIGMP_HOST_DB db = find_or_alloc_multicast_db_host(d, group);
 
    send_membership_report(d, group);
    db->reportSentCount++;
    print_igmp_log("Changing host state to delaying member");
    db->state = HostState_DelayingMember;
    print_igmp_log("Starting Unsolicited report timer");
    igmp_start_timer(d,
        EVENT_IGMP_Unsolicited_report,
        group,
        pstruEventDetails->dEventTime);
}
 
void host_handle_unsolicited_report_timer()
{
    NETSIM_ID d = pstruEventDetails->nDeviceId;
    NETSIM_IPAddress group = pstruEventDetails->szOtherDetails;
 
    ptrIGMP_HOST_DB db = find_or_alloc_multicast_db_host(d, group);
 
    if (db->reportSentCount < 2 && db->isReportreqd)
    {
        print_igmp_log("\nHost %d, Time %0.0lf: Unsolicited report timer triggered. Sending membership report.");
        send_membership_report(d, group);
        db->reportSentCount++;
        print_igmp_log("Changing host state to delaying member");
        db->state = HostState_DelayingMember;
        print_igmp_log("Starting Unsolicited report timer");
        igmp_start_timer(d,
            EVENT_IGMP_Unsolicited_report,
            group,
            pstruEventDetails->dEventTime);
    }
}
 
void host_free(NETSIM_ID d)
{
    ptrIGMP_HOST h = GET_IGMP_HOST(d);
    ptrIGMP_HOST_DB db = h->database;
    while (db)
    {
        LIST_FREE(&db, db);
    }
    free(h);
    SET_IGMP_HOST(d, NULL);
}