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/*
* (C) 2006-2007 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "conntrackd.h"
#include "sync.h"
#include "network.h"
#include "us-conntrack.h"
#include "alarm.h"
#include "cache.h"
#include "debug.h"
#include <stdlib.h>
#include <string.h>
static void refresher(struct alarm_block *a, void *data)
{
size_t len;
struct nethdr *net;
struct us_conntrack *u = data;
debug_ct(u->ct, "persistence update");
add_alarm(a,
random() % CONFIG(refresh) + 1,
((random() % 5 + 1) * 200000) - 1);
net = BUILD_NETMSG(u->ct, NFCT_Q_UPDATE);
len = prepare_send_netmsg(STATE_SYNC(mcast_client), net);
mcast_buffered_send_netmsg(STATE_SYNC(mcast_client), net, len);
}
static void cache_alarm_add(struct us_conntrack *u, void *data)
{
struct alarm_block *alarm = data;
init_alarm(alarm, u, refresher);
add_alarm(alarm,
random() % CONFIG(refresh) + 1,
((random() % 5 + 1) * 200000) - 1);
}
static void cache_alarm_update(struct us_conntrack *u, void *data)
{
struct alarm_block *alarm = data;
add_alarm(alarm,
random() % CONFIG(refresh) + 1,
((random() % 5 + 1) * 200000) - 1);
}
static void cache_alarm_destroy(struct us_conntrack *u, void *data)
{
struct alarm_block *alarm = data;
del_alarm(alarm);
}
static struct cache_extra cache_alarm_extra = {
.size = sizeof(struct alarm_block),
.add = cache_alarm_add,
.update = cache_alarm_update,
.destroy = cache_alarm_destroy
};
static int alarm_recv(const struct nethdr *net)
{
unsigned int exp_seq;
/*
* Ignore error messages: Although this message type is not ever
* generated in alarm mode, we don't want to crash the daemon
* if someone nuts mixes ftfw and alarm.
*/
if (net->flags)
return 1;
/*
* Multicast sequence tracking: we keep track of multicast messages
* although we don't do any explicit message recovery. So, why do
* we do sequence tracking? Just to let know the sysadmin.
*
* Let t be 1 < t < RefreshTime. To ensure consistency, conntrackd
* retransmit every t seconds a message with the state of a certain
* entry even if such entry did not change. This mechanism also
* provides passive resynchronization, in other words, there is
* no facility to request a full synchronization from new nodes that
* just joined the cluster, instead they just get resynchronized in
* RefreshTime seconds at worst case.
*/
mcast_track_seq(net->seq, &exp_seq);
return 0;
}
struct sync_mode sync_alarm = {
.internal_cache_flags = LIFETIME,
.external_cache_flags = TIMER | LIFETIME,
.internal_cache_extra = &cache_alarm_extra,
.recv = alarm_recv,
};
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