/*
 * IP compression header declations
 *
 * Copyright (C) 2003 Michael Richardson <mcr@sandelman.ottawa.on.ca>
 *
 * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * 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.
 */

#ifndef IPSEC_IPCOMP_H
#define IPSEC_IPCOMP_H

#include "libreswan/ipsec_auth.h"

/* Prefix all global deflate symbols with "ipcomp_" to avoid collisions with ppp_deflate & ext2comp */
#ifndef IPCOMP_PREFIX
#define IPCOMP_PREFIX
#endif /* IPCOMP_PREFIX */

#ifndef IPPROTO_COMP
#define IPPROTO_COMP 108
#endif /* IPPROTO_COMP */

extern int sysctl_ipsec_debug_ipcomp;

struct ipcomphdr {              /* IPCOMP header */
	__u8 ipcomp_nh;         /* Next header (protocol) */
	__u8 ipcomp_flags;      /* Reserved, must be 0 */
	__u16 ipcomp_cpi;       /* Compression Parameter Index */
};

#ifndef CONFIG_XFRM_ALTERNATE_STACK
extern struct inet_protocol comp_protocol;
#endif /* CONFIG_XFRM_ALTERNATE_STACK */

extern int sysctl_ipsec_debug_ipcomp;

#define IPCOMP_UNCOMPRESSABLE     0x000000001
#define IPCOMP_COMPRESSIONERROR   0x000000002
#define IPCOMP_PARMERROR          0x000000004
#define IPCOMP_DECOMPRESSIONERROR 0x000000008

#define IPCOMP_ADAPT_INITIAL_TRIES      8
#define IPCOMP_ADAPT_INITIAL_SKIP       4
#define IPCOMP_ADAPT_SUBSEQ_TRIES       2
#define IPCOMP_ADAPT_SUBSEQ_SKIP        8

/* Function prototypes */
struct sk_buff *skb_compress(struct sk_buff *skb, struct ipsec_sa *ips,
			     unsigned int *flags);
struct sk_buff *skb_decompress(struct sk_buff *skb, struct ipsec_sa *ips,
			       unsigned int *flags);

extern struct xform_functions ipcomp_xform_funcs[];

#endif /* IPSEC_IPCOMP_H */