initial commit

This patch bootstrap the new nft-sync software. Basically, this
software aims to support two different setups:

1) Rule-set repository server. The software serves the nft rule-set to
   clients that request the ruleset.

   Basically from the system that acts as repository, you have to run:

   # nft-sync -c ../contrib/nft-sync.conf.server

   Then, from the client:

   # nft-sync -c ../contrib/nft-sync.conf.client --fetch

   Which displays the nft rule-set in the standard output, so you
   can inspect the nft rule-set.

   Alternatively, the client can also retrieve and apply the nft
   rule-set using the pull command instead:

   # nft-sync -c ../contrib/nft-sync.conf.client --pull

   [ Note that this command above does not work in this bootstrap yet ]

2) Rule-set synchronization: In case of primary-backup and multiprimary
   firewall configurations, the software makes sure that the firewall
   cluster is deploying the same filtering policy. In this case, you have
   to launch the process:

   # nft-sync -c ../contrib/nft-sync.conf --sync

   [ Note that this command above does not work in this bootstrap yet ]

This bootstrap provides the basic infrastructure as a proof-of-concept.
Many of the necessary features are still lacking:

* Implement --sync and --pull commands.

* Interaction with nft through libnftnl, which allows the software to
  retrieve the local nft rule-set, as well as to parse it and apply it.

* SSL support, specifically the repository mode needs it to make sure
  nobody can steal your filtering policy from the network.

* IPv6 support.

* Allow to serve different rule-sets in the repository mode.

And many others that will be added progressively.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/src/event.c b/src/event.c
new file mode 100644
index 0000000..464b689
--- /dev/null
+++ b/src/event.c
@@ -0,0 +1,79 @@
+/*
+ * (C) 2014 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 Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <event.h>
+
+#include "init.h"
+#include "logging.h"
+
+static int sigtype;
+static struct event_base *ev_base;
+static struct event sigterm_event, sigusr1_event, sigint_event;
+
+static void sigterm_callback(int fd, short event, void *data)
+{
+	sigtype = SIGTERM;
+}
+
+static void sigint_callback(int fd, short event, void *data)
+{
+	sigtype = SIGINT;
+}
+
+static void sigusr1_callback(int fd, short event, void *data)
+{
+	sigtype = SIGUSR1;
+}
+
+int nft_sync_event_init(void)
+{
+	ev_base = event_init();
+	if (ev_base == NULL)
+		return -1;
+
+	signal_set(&sigint_event, SIGINT, sigint_callback, NULL);
+	signal_add(&sigint_event, NULL);
+	signal_set(&sigterm_event, SIGTERM, sigterm_callback, NULL);
+	signal_add(&sigterm_event, NULL);
+	signal_set(&sigusr1_event, SIGUSR1, sigusr1_callback, NULL);
+	signal_add(&sigusr1_event, NULL);
+
+	return 0;
+}
+
+void nft_sync_event_loop(void)
+{
+	while (!sigtype && !nfts_inst.stop)
+		event_loop(EVLOOP_ONCE);
+
+	switch (sigtype) {
+	case SIGINT:
+		nfts_log(NFTS_LOG_NOTICE, "Received SIGINT, closing.");
+		break;
+	case SIGTERM:
+		nfts_log(NFTS_LOG_NOTICE, "Received SIGTERM, closing.");
+		break;
+	case SIGUSR1:
+		nfts_log(NFTS_LOG_NOTICE, "Received SIGUSR1");
+		/* TODO: reload configuration file */
+		break;
+	default:
+		nfts_log(NFTS_LOG_INFO, "Closing process");
+		break;
+	}
+}
+
+void nft_sync_event_fini(void)
+{
+	signal_del(&sigterm_event);
+	signal_del(&sigusr1_event);
+	signal_del(&sigint_event);
+	event_base_free(ev_base);
+}