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-rw-r--r--src/sync-notrack.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/src/sync-notrack.c b/src/sync-notrack.c
new file mode 100644
index 0000000..2b5ae38
--- /dev/null
+++ b/src/sync-notrack.c
@@ -0,0 +1,127 @@
+/*
+ * (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,
+};