/* * ppp-comp.h - Definitions for doing PPP packet compression. * * Copyright (c) 1994 The Australian National University. * All rights reserved. * * Permission to use, copy, modify, and distribute this software and its * documentation is hereby granted, provided that the above copyright * notice appears in all copies.  This software is provided without any * warranty, express or implied. The Australian National University * makes no representations about the suitability of this software for * any purpose. * * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, * OR MODIFICATIONS. * * $Id: ppp-comp.h,v 1.6 1997/11/27 06:04:44 paulus Exp $ *//* *  ==FILEVERSION 980319== * *  NOTE TO MAINTAINERS: *     If you modify this file at all, please set the above date. *     ppp-comp.h is shipped with a PPP distribution as well as with the kernel; *     if everyone increases the FILEVERSION number above, then scripts *     can do the right thing when deciding whether to install a new ppp-comp.h *     file.  Don't change the format of that line otherwise, so the *     installation script can recognize it. */#ifndef _NET_PPP_COMP_H#define _NET_PPP_COMP_H/* * The following symbols control whether we include code for * various compression methods. */#ifndef DO_BSD_COMPRESS#define DO_BSD_COMPRESS	1	/* by default, include BSD-Compress */#endif#ifndef DO_DEFLATE#define DO_DEFLATE	1	/* by default, include Deflate */#endif#define DO_PREDICTOR_1	0#define DO_PREDICTOR_2	0/* * Structure giving methods for compression/decompression. */struct compressor {	int	compress_proto;	/* CCP compression protocol number */	/* Allocate space for a compressor (transmit side) */	void	*(*comp_alloc) (unsigned char *options, int opt_len);	/* Free space used by a compressor */	void	(*comp_free) (void *state);	/* Initialize a compressor */	int	(*comp_init) (void *state, unsigned char *options,			      int opt_len, int unit, int opthdr, int debug);	/* Reset a compressor */	void	(*comp_reset) (void *state);	/* Compress a packet */	int     (*compress) (void *state, unsigned char *rptr,			      unsigned char *obuf, int isize, int osize);	/* Return compression statistics */	void	(*comp_stat) (void *state, struct compstat *stats);	/* Allocate space for a decompressor (receive side) */	void	*(*decomp_alloc) (unsigned char *options, int opt_len);	/* Free space used by a decompressor */	void	(*decomp_free) (void *state);	/* Initialize a decompressor */	int	(*decomp_init) (void *state, unsigned char *options,				int opt_len, int unit, int opthdr, int mru,				int debug);	/* Reset a decompressor */	void	(*decomp_reset) (void *state);	/* Decompress a packet. */	int	(*decompress) (void *state, unsigned char *ibuf, int isize,				unsigned char *obuf, int osize);	/* Update state for an incompressible packet received */	void	(*incomp) (void *state, unsigned char *ibuf, int icnt);	/* Return decompression statistics */	void	(*decomp_stat) (void *state, struct compstat *stats);};/* * 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		-1	/* error detected before decomp. */#define DECOMP_FATALERROR	-2	/* error detected after decomp. *//* * CCP codes. */#define CCP_CONFREQ	1#define CCP_CONFACK	2#define CCP_TERMREQ	5#define CCP_TERMACK	6#define CCP_RESETREQ	14#define CCP_RESETACK	15/* * Max # bytes for a CCP option */#define CCP_MAX_OPTION_LENGTH	32/* * Parts of a CCP packet. */#define CCP_CODE(dp)		((dp)[0])#define CCP_ID(dp)		((dp)[1])#define CCP_LENGTH(dp)		(((dp)[2] << 8) + (dp)[3])#define CCP_HDRLEN		4#define CCP_OPT_CODE(dp)	((dp)[0])#define CCP_OPT_LENGTH(dp)	((dp)[1])#define CCP_OPT_MINLEN		2/* * Definitions for BSD-Compress. */#define CI_BSD_COMPRESS		21	/* config. option for BSD-Compress */#define CILEN_BSD_COMPRESS	3	/* length of config. option *//* Macros for handling the 3rd byte of the BSD-Compress config option. */#define BSD_NBITS(x)		((x) & 0x1F)	/* number of bits requested */#define BSD_VERSION(x)		((x) >> 5)	/* version of option format */#define BSD_CURRENT_VERSION	1		/* current version number */#define BSD_MAKE_OPT(v, n)	(((v) << 5) | (n))#define BSD_MIN_BITS		9	/* smallest code size supported */#define BSD_MAX_BITS		15	/* largest code size supported *//* * Definitions for Deflate. */#define CI_DEFLATE		26	/* config option for Deflate */#define CI_DEFLATE_DRAFT	24	/* value used in original draft RFC */#define CILEN_DEFLATE		4	/* length of its config option */#define DEFLATE_MIN_SIZE	8#define DEFLATE_MAX_SIZE	15#define DEFLATE_METHOD_VAL	8#define DEFLATE_SIZE(x)		(((x) >> 4) + DEFLATE_MIN_SIZE)#define DEFLATE_METHOD(x)	((x) & 0x0F)#define DEFLATE_MAKE_OPT(w)	((((w) - DEFLATE_MIN_SIZE) << 4) \				 + DEFLATE_METHOD_VAL)#define DEFLATE_CHK_SEQUENCE	0/* * Definitions for other, as yet unsupported, compression methods. */#define CI_PREDICTOR_1		1	/* config option for Predictor-1 */#define CILEN_PREDICTOR_1	2	/* length of its config option */#define CI_PREDICTOR_2		2	/* config option for Predictor-2 */#define CILEN_PREDICTOR_2	2	/* length of its config option */#endif /* _NET_PPP_COMP_H */