/*	$NetBSD: nattraversal.h,v 1.8 2018/05/19 18:51:59 maxv Exp $	*/

/*
 * Copyright (C) 2004 SuSE Linux AG, Nuernberg, Germany.
 * Contributed by: Michal Ludvig <mludvig@suse.cz>, SUSE Labs
 * 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.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``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 PROJECT OR CONTRIBUTORS 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 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 _NATTRAVERSAL_H
#define _NATTRAVERSAL_H

#include "vendorid.h"

#define	NAT_ANNOUNCED		(1L<<0)
#define	NAT_DETECTED_ME		(1L<<1)
#define	NAT_DETECTED_PEER	(1L<<2)
#define	NAT_PORTS_CHANGED	(1L<<3)
#define	NAT_KA_QUEUED		(1L<<4)
#define	NAT_ADD_NON_ESP_MARKER	(1L<<5)

#define	NATT_AVAILABLE(_ph1)	((_ph1)->natt_flags & NAT_ANNOUNCED)

#define	NAT_DETECTED	(NAT_DETECTED_ME | NAT_DETECTED_PEER)

#define	NON_ESP_MARKER_LEN	sizeof(u_int32_t)
#define	NON_ESP_MARKER_USE(_ph1)	((_ph1)->natt_flags & NAT_ADD_NON_ESP_MARKER)

/*
 * These are the values from parsing "remote {}" block of the config file.
 */
#define NATT_OFF	FLASE	/* = 0 */
#define NATT_ON		TRUE	/* = 1 */
#define NATT_FORCE	2

struct ph1natt_options {
	int version;
	u_int16_t float_port;
	u_int16_t mode_udp_tunnel;
	u_int16_t mode_udp_transport;
	u_int16_t encaps_type; /* ESPINUDP / ESPINUDP_NON_IKE */
	u_int16_t mode_udp_diff;
	u_int16_t payload_nat_d;
	u_int16_t payload_nat_oa;
};

struct ph2natt {
	u_int8_t type;
	u_int16_t sport;
	u_int16_t dport;
	struct sockaddr *oa;
	u_int16_t frag;
};

int natt_vendorid(int vid);
vchar_t *natt_hash_addr(struct ph1handle *iph1, struct sockaddr *addr);
int natt_compare_addr_hash(struct ph1handle *iph1, vchar_t *natd_received, int natd_seq);
int natt_udp_encap(int encmode);
int natt_fill_options(struct ph1natt_options *opts, int version);
void natt_float_ports(struct ph1handle *iph1);
void natt_handle_vendorid(struct ph1handle *iph1, int vid_numeric);

struct payload_list *
isakmp_plist_append_natt_vids(struct payload_list *plist, vchar_t *vid_natt[MAX_NATT_VID_COUNT]);

/* NAT keepalive functions */
void natt_keepalive_init(void);
int natt_keepalive_add(struct sockaddr *src, struct sockaddr *dst);
int natt_keepalive_add_ph1(struct ph1handle *iph1);
void natt_keepalive_remove(struct sockaddr *src, struct sockaddr *dst);

/* Walk through all rmconfigs and tell if NAT-T is enabled in at least one. */
int natt_enabled_in_rmconf(void);

#endif /* _NATTRAVERSAL_H */