| /* 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 module; |
| |
| /* |
| * 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); |
| |
| /* Used in locking compressor modules */ |
| struct module *owner; |
| /* Extra skb space needed by the compressor algorithm */ |
| unsigned int comp_extra; |
| }; |
| |
| /* |
| * 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. */ |
| |
| extern int ppp_register_compressor(struct compressor *); |
| extern void ppp_unregister_compressor(struct compressor *); |
| #endif /* _NET_PPP_COMP_H */ |