/***************************************************************************
 *   Copyright (C) 04/2007 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <libnfnetlink/libnfnetlink.h>
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>

#include "logging.h"
#include "plugins.h"
#include "probe.h"

#define DS_L3PROTO	1
#define DS_L4PROTO	2
#define DS_TCP		3

struct sammler_plugin plugin;

static struct nfct_handle *cth;
struct ct_values {
	int	total;
	int	local;
	int	nated;
	int	unreplied;

	int	proto_tcp;
	int	proto_udp;
	int	proto_unknown;

	int	tcp_state[10];
};

static const char *l3proto_ds_def = {
	"DS:total:GAUGE:15:0:U "
	"DS:local:GAUGE:15:0:U "
	"DS:nated:GAUGE:15:0:U "
	"DS:unreplied:GAUGE:15:0:U "
};

static const char *l4proto_ds_def = {
	"DS:tcp:GAUGE:15:0:U "
	"DS:udp:GAUGE:15:0:U "
	"DS:unknown:GAUGE:15:0:U "
};

static const char *tcp_ds_def = {
	"DS:none:GAUGE:15:0:U "
	"DS:syn_sent:GAUGE:15:0:U "
	"DS:syn_recv:GAUGE:15:0:U "
	"DS:established:GAUGE:15:0:U "
	"DS:fin_wait:GAUGE:15:0:U "
	"DS:close_wait:GAUGE:15:0:U "
	"DS:last_ack:GAUGE:15:0:U "
	"DS:time_wait:GAUGE:15:0:U "
	"DS:close:GAUGE:15:0:U "
	"DS:listen:GAUGE:15:0:U "
};

static const char * get_ds(int ds_id)
{
	switch (ds_id) {
	case DS_L3PROTO:
		return l3proto_ds_def;

	case DS_L4PROTO:
		return l4proto_ds_def;

	case DS_TCP:
		return tcp_ds_def;

	default:
		return NULL;
	}
}

static int probe_cb(void *arg, unsigned int flags, int type, void *privdata)
{
	struct nfct_conntrack *ct = (struct nfct_conntrack *)arg;
	struct ct_values *data = (struct ct_values *)privdata;

	data->total++;

	if (ct->status & IPS_NAT_MASK)
		data->nated++;
	else
		data->local++;

	if (!(ct->status & IPS_SEEN_REPLY))
		data->unreplied++;

	switch (ct->tuple[NFCT_DIR_ORIGINAL].protonum) {
	case IPPROTO_TCP:
		data->proto_tcp++;
		data->tcp_state[ct->protoinfo.tcp.state]++;
		break;

	case IPPROTO_UDP:
		data->proto_udp++;
		break;

	default:
		data->proto_unknown++;
		break;
	}

	return 0;
}

static int probe(void)
{
	struct ct_values data;
	memset(&data, 0, sizeof(data));

	nfct_register_callback(cth, probe_cb, &data);

	if (nfct_dump_conntrack_table(cth, AF_INET) < 0) {
		log_print(LOG_WARN, "plugin conntrack: nfct_dump_conntrack_table()");
		return -1;
	}

	probe_submit(&plugin, "conntrack.rrd", DS_L3PROTO, "%d:%d:%d:%d",
			data.total, data.local, data.nated, data.unreplied);

	probe_submit(&plugin, "conntrack-proto.rrd", DS_L4PROTO, "%d:%d:%d",
			data.proto_tcp, data.proto_udp, data.proto_unknown);

	probe_submit(&plugin, "conntrack-tcp.rrd", DS_TCP, "%d:%d:%d:%d:%d:%d:%d:%d:%d:%d",
			data.tcp_state[0], data.tcp_state[1], data.tcp_state[2], data.tcp_state[3],
			data.tcp_state[4], data.tcp_state[5], data.tcp_state[6], data.tcp_state[7],
			data.tcp_state[8], data.tcp_state[9]);

	return 0;
}

static int init(void)
{
	cth = nfct_open(CONNTRACK, 0);
	if (cth == NULL) {
		log_print(LOG_WARN, "plugin conntrack: nfct_open()");
		return -1;
	}
	return 0;
}

static int fini(void)
{
	nfct_close(cth);
	return 0;
}

struct sammler_plugin plugin = {
	.name		= "conntrack",
	.interval	= 10,
	.init		= &init,
	.fini		= &fini,
	.probe		= &probe,
	.get_ds		= &get_ds,
};