/*

 * Copyright (c) 2003+ Evgeniy Polyakov <johnpol@2ka.mxt.ru>

 *

 *

 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 */

#ifndef _XT_OSF_H

#define _XT_OSF_H

#include <linux/types.h>

#define MAXGENRELEN		32

#define XT_OSF_GENRE		(1<<0)

#define	XT_OSF_TTL		(1<<1)

#define XT_OSF_LOG		(1<<2)

#define XT_OSF_INVERT		(1<<3)

#define XT_OSF_LOGLEVEL_ALL	0	/* log all matched fingerprints */

#define XT_OSF_LOGLEVEL_FIRST	1	/* log only the first matced fingerprint */

#define XT_OSF_LOGLEVEL_ALL_KNOWN	2 /* do not log unknown packets */

#define XT_OSF_TTL_TRUE		0	/* True ip and fingerprint TTL comparison */

#define XT_OSF_TTL_LESS		1	/* Check if ip TTL is less than fingerprint one */

#define XT_OSF_TTL_NOCHECK	2	/* Do not compare ip and fingerprint TTL at all */

struct xt_osf_info {

	char			genre[MAXGENRELEN];

	__u32			len;

	__u32			flags;

	__u32			loglevel;

	__u32			ttl;

};

/*

 * Wildcard MSS (kind of).

 * It is used to implement a state machine for the different wildcard values

 * of the MSS and window sizes.

 */

struct xt_osf_wc {

	__u32			wc;

	__u32			val;

};

/*

 * This struct represents IANA options

 * http://www.iana.org/assignments/tcp-parameters

 */

struct xt_osf_opt {

	__u16			kind, length;

	struct xt_osf_wc	wc;

};

struct xt_osf_user_finger {

	struct xt_osf_wc	wss;

	__u8			ttl, df;

	__u16			ss, mss;

	__u16			opt_num;

	char			genre[MAXGENRELEN];

	char			version[MAXGENRELEN];

	char			subtype[MAXGENRELEN];

	/* MAX_IPOPTLEN is maximum if all options are NOPs or EOLs */

	struct xt_osf_opt	opt[MAX_IPOPTLEN];

};

struct xt_osf_nlmsg {

	struct xt_osf_user_finger	f;

	struct iphdr		ip;

	struct tcphdr		tcp;

};

/* Defines for IANA option kinds */

enum iana_options {

	OSFOPT_EOL = 0,		/* End of options */

	OSFOPT_NOP, 		/* NOP */

	OSFOPT_MSS, 		/* Maximum segment size */

	OSFOPT_WSO, 		/* Window scale option */

	OSFOPT_SACKP,		/* SACK permitted */

	OSFOPT_SACK,		/* SACK */

	OSFOPT_ECHO,

	OSFOPT_ECHOREPLY,

	OSFOPT_TS,		/* Timestamp option */

	OSFOPT_POCP,		/* Partial Order Connection Permitted */

	OSFOPT_POSP,		/* Partial Order Service Profile */

	/* Others are not used in the current OSF */

	OSFOPT_EMPTY = 255,

};

/*

 * Initial window size option state machine: multiple of mss, mtu or

 * plain numeric value. Can also be made as plain numeric value which

 * is not a multiple of specified value.

 */

enum xt_osf_window_size_options {

	OSF_WSS_PLAIN	= 0,

	OSF_WSS_MSS,

	OSF_WSS_MTU,

	OSF_WSS_MODULO,

	OSF_WSS_MAX,

};

/*

 * Add/remove fingerprint from the kernel.

 */

enum xt_osf_msg_types {

	OSF_MSG_ADD,

	OSF_MSG_REMOVE,

	OSF_MSG_MAX,

};

enum xt_osf_attr_type {

	OSF_ATTR_UNSPEC,

	OSF_ATTR_FINGER,

	OSF_ATTR_MAX,

};

#endif				/* _XT_OSF_H */