From 5bac4f06e8ebc81ed16ec93a0db8682e6a359608 Mon Sep 17 00:00:00 2001 From: "/C=EU/ST=EU/CN=Pablo Neira Ayuso/emailAddress=pablo@netfilter.org" Date: Fri, 21 Dec 2007 18:04:49 +0000 Subject: o Use more appropriate names for the existing synchronization modes: o rename `persistent' mode to `alarm' o rename `nack' mode to `ftfw' o Now default synchronization mode is ftfw instead of alarm --- src/sync-alarm.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 src/sync-alarm.c (limited to 'src/sync-alarm.c') diff --git a/src/sync-alarm.c b/src/sync-alarm.c new file mode 100644 index 0000000..a0791ac --- /dev/null +++ b/src/sync-alarm.c @@ -0,0 +1,104 @@ +/* + * (C) 2006-2007 by Pablo Neira Ayuso + * + * 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) +{ + int len; + struct nethdr *net; + struct us_conntrack *u = data; + + debug_ct(u->ct, "persistence update"); + + a->expires = random() % CONFIG(refresh) + 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_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_alarm_update(struct us_conntrack *u, void *data) +{ + struct alarm_list *alarm = data; + mod_alarm(alarm, (random() % conf.refresh) + 1); +} + +static void cache_alarm_destroy(struct us_conntrack *u, void *data) +{ + struct alarm_list *alarm = data; + del_alarm(alarm); +} + +static struct cache_extra cache_alarm_extra = { + .size = sizeof(struct alarm_list), + .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 alarm = { + .internal_cache_flags = LIFETIME, + .external_cache_flags = TIMER | LIFETIME, + .internal_cache_extra = &cache_alarm_extra, + .recv = alarm_recv, +}; -- cgit v1.2.3