104 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0-only */
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| /*
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|  * ppp-comp.h - Definitions for doing PPP packet compression.
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|  *
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|  * Copyright 1994-1998 Paul Mackerras.
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|  */
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| #ifndef _NET_PPP_COMP_H
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| #define _NET_PPP_COMP_H
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| 
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| #include <uapi/linux/ppp-comp.h>
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| 
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| struct compstat;
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| struct module;
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| 
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| /*
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|  * The following symbols control whether we include code for
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|  * various compression methods.
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|  */
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| 
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| #ifndef DO_BSD_COMPRESS
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| #define DO_BSD_COMPRESS	1	/* by default, include BSD-Compress */
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| #endif
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| #ifndef DO_DEFLATE
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| #define DO_DEFLATE	1	/* by default, include Deflate */
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| #endif
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| #define DO_PREDICTOR_1	0
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| #define DO_PREDICTOR_2	0
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| 
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| /*
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|  * Structure giving methods for compression/decompression.
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|  */
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| 
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| struct compressor {
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| 	int	compress_proto;	/* CCP compression protocol number */
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| 
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| 	/* Allocate space for a compressor (transmit side) */
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| 	void	*(*comp_alloc) (unsigned char *options, int opt_len);
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| 
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| 	/* Free space used by a compressor */
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| 	void	(*comp_free) (void *state);
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| 
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| 	/* Initialize a compressor */
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| 	int	(*comp_init) (void *state, unsigned char *options,
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| 			      int opt_len, int unit, int opthdr, int debug);
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| 
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| 	/* Reset a compressor */
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| 	void	(*comp_reset) (void *state);
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| 
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| 	/* Compress a packet */
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| 	int     (*compress) (void *state, unsigned char *rptr,
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| 			      unsigned char *obuf, int isize, int osize);
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| 
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| 	/* Return compression statistics */
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| 	void	(*comp_stat) (void *state, struct compstat *stats);
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| 
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| 	/* Allocate space for a decompressor (receive side) */
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| 	void	*(*decomp_alloc) (unsigned char *options, int opt_len);
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| 
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| 	/* Free space used by a decompressor */
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| 	void	(*decomp_free) (void *state);
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| 
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| 	/* Initialize a decompressor */
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| 	int	(*decomp_init) (void *state, unsigned char *options,
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| 				int opt_len, int unit, int opthdr, int mru,
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| 				int debug);
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| 
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| 	/* Reset a decompressor */
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| 	void	(*decomp_reset) (void *state);
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| 
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| 	/* Decompress a packet. */
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| 	int	(*decompress) (void *state, unsigned char *ibuf, int isize,
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| 				unsigned char *obuf, int osize);
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| 
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| 	/* Update state for an incompressible packet received */
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| 	void	(*incomp) (void *state, unsigned char *ibuf, int icnt);
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| 
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| 	/* Return decompression statistics */
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| 	void	(*decomp_stat) (void *state, struct compstat *stats);
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| 
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| 	/* Used in locking compressor modules */
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| 	struct module *owner;
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| 	/* Extra skb space needed by the compressor algorithm */
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| 	unsigned int comp_extra;
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| };
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| 
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| /*
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|  * The return value from decompress routine is the length of the
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|  * decompressed packet if successful, otherwise DECOMP_ERROR
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|  * or DECOMP_FATALERROR if an error occurred.
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|  * 
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|  * We need to make this distinction so that we can disable certain
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|  * useful functionality, namely sending a CCP reset-request as a result
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|  * of an error detected after decompression.  This is to avoid infringing
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|  * a patent held by Motorola.
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|  * Don't you just lurve software patents.
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|  */
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| 
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| #define DECOMP_ERROR		-1	/* error detected before decomp. */
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| #define DECOMP_FATALERROR	-2	/* error detected after decomp. */
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| 
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| extern int ppp_register_compressor(struct compressor *);
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| extern void ppp_unregister_compressor(struct compressor *);
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| #endif /* _NET_PPP_COMP_H */
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