linux/include/linux/ppp-comp.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * ppp-comp.h - Definitions for doing PPP packet compression.
 *
 * Copyright 1994-1998 Paul Mackerras.
 */
#ifndef _NET_PPP_COMP_H
#define _NET_PPP_COMP_H

#include <uapi/linux/ppp-comp.h>

struct compstat;
struct module;

/*
 * The following symbols control whether we include code for
 * various compression methods.
 */

#ifndef DO_BSD_COMPRESS
#define DO_BSD_COMPRESS …
#endif
#ifndef DO_DEFLATE
#define DO_DEFLATE …
#endif
#define DO_PREDICTOR_1 …
#define DO_PREDICTOR_2 …

/*
 * Structure giving methods for compression/decompression.
 */

struct compressor { … };

/*
 * The return value from decompress routine is the length of the
 * decompressed packet if successful, otherwise DECOMP_ERROR
 * or DECOMP_FATALERROR if an error occurred.
 * 
 * We need to make this distinction so that we can disable certain
 * useful functionality, namely sending a CCP reset-request as a result
 * of an error detected after decompression.  This is to avoid infringing
 * a patent held by Motorola.
 * Don't you just lurve software patents.
 */

#define DECOMP_ERROR …
#define DECOMP_FATALERROR …

extern int ppp_register_compressor(struct compressor *);
extern void ppp_unregister_compressor(struct compressor *);
#endif /* _NET_PPP_COMP_H */