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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 2 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"
static void refresher(struct alarm_list *a, void *data)
{
struct us_conntrack *u = data;
char buf[8192];
int size;
if (nfct_get_attr_u32(u->ct, ATTR_STATUS) & IPS_DYING) {
debug_ct(u->ct, "persistence destroy");
size = build_network_msg(NFCT_Q_DESTROY,
STATE(subsys_event),
u->ct,
buf,
sizeof(buf));
__cache_del(u->cache, u->ct);
mcast_send_netmsg(STATE_SYNC(mcast_client), buf);
} else {
debug_ct(u->ct, "persistence update");
a->expires = random() % CONFIG(refresh) + 1;
size = build_network_msg(NFCT_Q_UPDATE,
STATE(subsys_event),
u->ct,
buf,
sizeof(buf));
mcast_send_netmsg(STATE_SYNC(mcast_client), buf);
}
}
static void cache_notrack_add(struct us_conntrack *u, void *data)
{
struct alarm_list *alarm = data;
init_alarm(alarm);
set_alarm_expiration(alarm, (random() % conf.refresh) + 1);
set_alarm_data(alarm, u);
set_alarm_function(alarm, refresher);
add_alarm(alarm);
}
static void cache_notrack_update(struct us_conntrack *u, void *data)
{
struct alarm_list *alarm = data;
mod_alarm(alarm, (random() % conf.refresh) + 1);
}
static void cache_notrack_destroy(struct us_conntrack *u, void *data)
{
struct alarm_list *alarm = data;
del_alarm(alarm);
}
static struct cache_extra cache_notrack_extra = {
.size = sizeof(struct alarm_list),
.add = cache_notrack_add,
.update = cache_notrack_update,
.destroy = cache_notrack_destroy
};
static int notrack_pre_recv(const struct nlnetwork *net)
{
unsigned int exp_seq;
/*
* Ignore error messages: Although this message type is not ever
* generated in notrack mode, we don't want to crash the daemon
* if someone nuts mixes nack and notrack.
*/
if (net->flags & (NET_RESYNC | NET_NACK))
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;
}
static void notrack_post_send(const struct nlnetwork *n, struct us_conntrack *u)
{
}
struct sync_mode notrack = {
.internal_cache_flags = LIFETIME,
.external_cache_flags = TIMER | LIFETIME,
.internal_cache_extra = &cache_notrack_extra,
.pre_recv = notrack_pre_recv,
.post_send = notrack_post_send,
};
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