add best effort replication protocol (aka NOTRACK)

1 files changed, 184 insertions, 0 deletions

diff --git a/src/sync-notrack.c b/src/sync-notrack.c
new file mode 100644
index 0000000..2b1bc13
--- /dev/null
+++ b/src/sync-notrack.c
@@ -0,0 +1,184 @@
+/*
+ * (C) 2008 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 "us-conntrack.h"
+#include "queue.h"
+#include "debug.h"
+#include "network.h"
+#include "log.h"
+#include "cache.h"
+#include "event.h"
+
+#include <string.h>
+
+static LIST_HEAD(tx_list);
+static unsigned int tx_list_len;
+static struct queue *tx_queue;
+
+struct cache_notrack {
+	struct list_head	tx_list;
+};
+
+static struct cache_extra cache_notrack_extra = {
+	.size 		= sizeof(struct cache_notrack),
+};
+
+static void tx_queue_add_ctlmsg(uint32_t flags, uint32_t from, uint32_t to)
+{
+	struct nethdr_ack ack = {
+		.flags = flags,
+		.from  = from,
+		.to    = to,
+	};
+
+	queue_add(tx_queue, &ack, NETHDR_ACK_SIZ);
+	write_evfd(STATE_SYNC(evfd));
+}
+
+static int notrack_init(void)
+{
+	tx_queue = queue_create(~0U);
+	if (tx_queue == NULL) {
+		dlog(LOG_ERR, "cannot create tx queue");
+		return -1;
+	}
+
+	return 0;
+}
+
+static void notrack_kill(void)
+{
+	queue_destroy(tx_queue);
+}
+
+static int do_cache_to_tx(void *data1, void *data2)
+{
+	struct us_conntrack *u = data2;
+	struct cache_notrack *cn = cache_get_extra(STATE_SYNC(internal), u);
+
+	/* add to tx list */
+	list_add_tail(&cn->tx_list, &tx_list);
+	tx_list_len++;
+
+	write_evfd(STATE_SYNC(evfd));
+
+	return 0;
+}
+
+static int notrack_local(int fd, int type, void *data)
+{
+	int ret = 1;
+
+	switch(type) {
+	case REQUEST_DUMP:
+		dlog(LOG_NOTICE, "request resync");
+		tx_queue_add_ctlmsg(NET_F_RESYNC, 0, 0);
+		break;
+	case SEND_BULK:
+		dlog(LOG_NOTICE, "sending bulk update");
+		cache_iterate(STATE_SYNC(internal), NULL, do_cache_to_tx);
+		break;
+	default:
+		ret = 0;
+		break;
+	}
+
+	return ret;
+}
+
+static int digest_msg(const struct nethdr *net)
+{
+	if (IS_DATA(net))
+		return MSG_DATA;
+
+	if (IS_RESYNC(net)) {
+		cache_iterate(STATE_SYNC(internal), NULL, do_cache_to_tx);
+		return MSG_CTL;
+	}
+
+	return MSG_BAD;
+}
+
+static int notrack_recv(const struct nethdr *net)
+{
+	int ret;
+	unsigned int exp_seq;
+
+	mcast_track_seq(net->seq, &exp_seq);
+
+	ret = digest_msg(net);
+
+	if (ret != MSG_BAD)
+		mcast_track_update_seq(net->seq);
+
+	return ret;
+}
+
+static int tx_queue_xmit(void *data1, const void *data2)
+{
+	struct nethdr *net = data1;
+	size_t len = prepare_send_netmsg(STATE_SYNC(mcast_client), net);
+
+	mcast_buffered_send_netmsg(STATE_SYNC(mcast_client), net, len);
+	queue_del(tx_queue, net);
+
+	return 0;
+}
+
+static int tx_list_xmit(struct list_head *i, struct us_conntrack *u, int type)
+{
+	int ret;
+	struct nethdr *net = BUILD_NETMSG(u->ct, type);
+	size_t len = prepare_send_netmsg(STATE_SYNC(mcast_client), net);
+
+	list_del_init(i);
+	tx_list_len--;
+
+	ret = mcast_buffered_send_netmsg(STATE_SYNC(mcast_client), net, len);
+
+	return ret;
+}
+
+static void notrack_run(void)
+{
+	struct cache_notrack *cn, *tmp;
+
+	/* send messages in the tx_queue */
+	queue_iterate(tx_queue, NULL, tx_queue_xmit);
+
+	/* send conntracks in the tx_list */
+	list_for_each_entry_safe(cn, tmp, &tx_list, tx_list) {
+		struct us_conntrack *u;
+
+		u = cache_get_conntrack(STATE_SYNC(internal), cn);
+		tx_list_xmit(&cn->tx_list, u, NFCT_Q_UPDATE);
+	}
+}
+
+struct sync_mode sync_notrack = {
+	.internal_cache_flags	= LIFETIME,
+	.external_cache_flags	= LIFETIME,
+	.internal_cache_extra	= &cache_notrack_extra,
+	.init			= notrack_init,
+	.kill			= notrack_kill,
+	.local			= notrack_local,
+	.recv			= notrack_recv,
+	.run			= notrack_run,
+};