/*	$OpenBSD: if_pfsync.h,v 1.6 2003/12/15 21:49:38 deraadt Exp $	*/

/*
 * Copyright (c) 2001 Michael Shalayeff
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _NET_IF_PFSYNC_H_
#define _NET_IF_PFSYNC_H_

struct pfsync_state_scrub {
	u_int16_t	pfss_flags;
	u_int8_t	pfss_ttl;	/* stashed TTL		*/
	u_int8_t	scrub_flag;
	u_int32_t	pfss_ts_mod;	/* timestamp modulation	*/
} __packed;

struct pfsync_state_host {
	struct pf_addr	addr;
	u_int16_t	port;
	u_int16_t	pad[3];
} __packed;

struct pfsync_state_peer {
	struct pfsync_state_scrub scrub;	/* state is scrubbed	*/
	u_int32_t	seqlo;		/* Max sequence number sent	*/
	u_int32_t	seqhi;		/* Max the other end ACKd + win	*/
	u_int32_t	seqdiff;	/* Sequence number modulator	*/
	u_int16_t	max_win;	/* largest window (pre scaling)	*/
	u_int16_t	mss;		/* Maximum segment size option	*/
	u_int8_t	state;		/* active state level		*/
	u_int8_t	wscale;		/* window scaling factor	*/
	u_int8_t	scrub_flag;
	u_int8_t	pad[5];
} __packed;

struct pfsync_state {
	u_int64_t	 id;
	struct pfsync_state_host lan;
	struct pfsync_state_host gwy;
	struct pfsync_state_host ext;
	struct pfsync_state_peer src;
	struct pfsync_state_peer dst;
	struct pf_addr	 rt_addr;
	u_int32_t	 rule;
	u_int32_t	 anchor;
	u_int32_t	 nat_rule;
	u_int32_t	 creation;
	u_int32_t	 expire;
	u_int32_t	 packets[2];
	u_int32_t	 bytes[2];
	u_int32_t	 creatorid;
	sa_family_t	 af;
	u_int8_t	 proto;
	u_int8_t	 direction;
	u_int8_t	 log;
	u_int8_t	 allow_opts;
	u_int8_t	 timeout;
	u_int8_t	 sync_flags;
	u_int8_t	 updates;
} __packed;

struct pfsync_state_upd {
	u_int64_t		id;
	struct pfsync_state_peer	src;
	struct pfsync_state_peer	dst;
	u_int32_t		creatorid;
	u_int32_t		expire;
	u_int8_t		updates;
	u_int8_t		pad[7];
} __packed;

struct pfsync_state_del {
	u_int64_t		id;
	u_int32_t		creatorid;
	struct {
		u_int8_t	state;
	} src;
	struct {
		u_int8_t	state;
	} dst;
	u_int8_t		pad[2];
} __packed;

struct pfsync_state_clr {
	u_int32_t		creatorid;
	u_int32_t		pad;
} __packed;

#ifdef _KERNEL

union sc_statep {
	struct pfsync_state	*s;
	struct pfsync_state_upd	*u;
	struct pfsync_state_del	*d;
	struct pfsync_state_clr	*c;
};

struct pfsync_softc {
	struct ifnet		 sc_if;
	struct ifnet		*sc_sync_ifp;

	struct ip_moptions	 sc_imo;
	struct timeout		 sc_tmo;
	struct mbuf		*sc_mbuf;	/* current cummulative mbuf */
	struct mbuf		*sc_mbuf_net;	/* current cummulative mbuf */
	union sc_statep		 sc_statep;
	union sc_statep		 sc_statep_net;
	int			 sc_maxcount;	/* number of states in mtu */
	int			 sc_maxupdates;	/* number of updates/state */
};
#endif


struct pfsync_header {
	u_int8_t version;
#define	PFSYNC_VERSION	1
	u_int8_t af;
	u_int8_t action;
#define	PFSYNC_ACT_CLR		0	/* clear all states */
#define	PFSYNC_ACT_INS		1	/* insert state */
#define	PFSYNC_ACT_UPD		2	/* update state */
#define	PFSYNC_ACT_DEL		3	/* delete state */
#define	PFSYNC_ACT_UPD_C	4	/* "compressed" state update */
#define	PFSYNC_ACT_DEL_C	5	/* "compressed" state delete */
#define	PFSYNC_ACT_INS_F	6	/* insert fragment */
#define	PFSYNC_ACT_DEL_F	7	/* delete fragments */
#define	PFSYNC_ACT_MAX		8
	u_int8_t count;
} __packed;

#define PFSYNC_HDRLEN	sizeof(struct pfsync_header)
#define	PFSYNC_ACTIONS \
	"CLR ST", "INS ST", "UPD ST", "DEL ST", \
	"UPD ST COMP", "DEL ST COMP", "INS FR", "DEL FR"

#define PFSYNC_DFLTTL		255

struct pfsyncstats {
	u_long	pfsyncs_ipackets;	/* total input packets, IPv4 */
	u_long	pfsyncs_ipackets6;	/* total input packets, IPv6 */
	u_long	pfsyncs_badif;		/* not the right interface */
	u_long	pfsyncs_badttl;		/* TTL is not PFSYNC_DFLTTL */
	u_long	pfsyncs_hdrops;		/* packets shorter than header */
	u_long	pfsyncs_badver;		/* bad (incl unsupp) version */
	u_long	pfsyncs_badact;		/* bad action */
	u_long	pfsyncs_badlen;		/* data length does not match */
	u_long	pfsyncs_badauth;	/* bad authentication */
	u_long	pfsyncs_badstate;	/* insert/lookup failed */

	u_long	pfsyncs_opackets;	/* total output packets, IPv4 */
	u_long	pfsyncs_opackets6;	/* total output packets, IPv6 */
	u_long	pfsyncs_onomem;		/* no memory for an mbuf for a send */
	u_long	pfsyncs_oerrors;	/* ip output error */
};

/*
 * Configuration structure for SIOCSETPFSYNC SIOCGETPFSYNC
 */
struct pfsyncreq {
	char	pfsyncr_syncif[IFNAMSIZ];
	int	pfsyncr_maxupdates;
	int	pfsyncr_authlevel;
};
#define SIOCSETPFSYNC	_IOW('i', 247, struct ifreq)
#define SIOCGETPFSYNC	_IOWR('i', 248, struct ifreq)


#define pf_state_peer_hton(s,d) do {		\
	(d)->seqlo = htonl((s)->seqlo);		\
	(d)->seqhi = htonl((s)->seqhi);		\
	(d)->seqdiff = htonl((s)->seqdiff);	\
	(d)->max_win = htons((s)->max_win);	\
	(d)->mss = htons((s)->mss);		\
	(d)->state = (s)->state;		\
	(d)->wscale = (s)->wscale;		\
} while (0)

#define pf_state_peer_ntoh(s,d) do {		\
	(d)->seqlo = ntohl((s)->seqlo);		\
	(d)->seqhi = ntohl((s)->seqhi);		\
	(d)->seqdiff = ntohl((s)->seqdiff);	\
	(d)->max_win = ntohs((s)->max_win);	\
	(d)->mss = ntohs((s)->mss);		\
	(d)->state = (s)->state;		\
	(d)->wscale = (s)->wscale;		\
} while (0)

#define pf_state_host_hton(s,d) do {				\
	bcopy(&(s)->addr, &(d)->addr, sizeof((d)->addr));	\
	(d)->port = htons((s)->port);				\
} while (0)

#define pf_state_host_ntoh(s,d) do {				\
	bcopy(&(s)->addr, &(d)->addr, sizeof((d)->addr));	\
	(d)->port = ntohs((s)->port);				\
} while (0)

#ifdef _KERNEL
void pfsync_input(struct mbuf *, ...);
int pfsync_clear_states(u_int32_t);
int pfsync_pack_state(u_int8_t, struct pf_state *);
#define pfsync_insert_state(st)	do {			\
	if (st->rule.ptr->rule_flag & PFRULE_NOSYNC)	\
		st->sync_flags |= PFSTATE_NOSYNC;	\
	else if (!st->sync_flags)			\
		pfsync_pack_state(PFSYNC_ACT_INS, (st));\
	st->sync_flags &= ~PFSTATE_FROMSYNC;		\
} while (0)
#define pfsync_update_state(st) do {			\
	if (!st->sync_flags)				\
		pfsync_pack_state(PFSYNC_ACT_UPD, (st));\
	st->sync_flags &= ~PFSTATE_FROMSYNC;		\
} while (0)
#define pfsync_delete_state(st) do {			\
	if (!st->sync_flags)				\
		pfsync_pack_state(PFSYNC_ACT_DEL, (st));\
	st->sync_flags &= ~PFSTATE_FROMSYNC;		\
} while (0)
#endif

#endif /* _NET_IF_PFSYNC_H_ */