1 /* 2 * ppp-comp.h - Definitions for doing PPP packet compression. 3 * 4 * Copyright 1994-1998 Paul Mackerras. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * version 2 as published by the Free Software Foundation. 9 */ 10 #ifndef _NET_PPP_COMP_H 11 #define _NET_PPP_COMP_H 12 13 #include <uapi/linux/ppp-comp.h> 14 15 16 struct module; 17 18 /* 19 * The following symbols control whether we include code for 20 * various compression methods. 21 */ 22 23 #ifndef DO_BSD_COMPRESS 24 #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ 25 #endif 26 #ifndef DO_DEFLATE 27 #define DO_DEFLATE 1 /* by default, include Deflate */ 28 #endif 29 #define DO_PREDICTOR_1 0 30 #define DO_PREDICTOR_2 0 31 32 /* 33 * Structure giving methods for compression/decompression. 34 */ 35 36 struct compressor { 37 int compress_proto; /* CCP compression protocol number */ 38 39 /* Allocate space for a compressor (transmit side) */ 40 void *(*comp_alloc) (unsigned char *options, int opt_len); 41 42 /* Free space used by a compressor */ 43 void (*comp_free) (void *state); 44 45 /* Initialize a compressor */ 46 int (*comp_init) (void *state, unsigned char *options, 47 int opt_len, int unit, int opthdr, int debug); 48 49 /* Reset a compressor */ 50 void (*comp_reset) (void *state); 51 52 /* Compress a packet */ 53 int (*compress) (void *state, unsigned char *rptr, 54 unsigned char *obuf, int isize, int osize); 55 56 /* Return compression statistics */ 57 void (*comp_stat) (void *state, struct compstat *stats); 58 59 /* Allocate space for a decompressor (receive side) */ 60 void *(*decomp_alloc) (unsigned char *options, int opt_len); 61 62 /* Free space used by a decompressor */ 63 void (*decomp_free) (void *state); 64 65 /* Initialize a decompressor */ 66 int (*decomp_init) (void *state, unsigned char *options, 67 int opt_len, int unit, int opthdr, int mru, 68 int debug); 69 70 /* Reset a decompressor */ 71 void (*decomp_reset) (void *state); 72 73 /* Decompress a packet. */ 74 int (*decompress) (void *state, unsigned char *ibuf, int isize, 75 unsigned char *obuf, int osize); 76 77 /* Update state for an incompressible packet received */ 78 void (*incomp) (void *state, unsigned char *ibuf, int icnt); 79 80 /* Return decompression statistics */ 81 void (*decomp_stat) (void *state, struct compstat *stats); 82 83 /* Used in locking compressor modules */ 84 struct module *owner; 85 /* Extra skb space needed by the compressor algorithm */ 86 unsigned int comp_extra; 87 }; 88 89 /* 90 * The return value from decompress routine is the length of the 91 * decompressed packet if successful, otherwise DECOMP_ERROR 92 * or DECOMP_FATALERROR if an error occurred. 93 * 94 * We need to make this distinction so that we can disable certain 95 * useful functionality, namely sending a CCP reset-request as a result 96 * of an error detected after decompression. This is to avoid infringing 97 * a patent held by Motorola. 98 * Don't you just lurve software patents. 99 */ 100 101 #define DECOMP_ERROR -1 /* error detected before decomp. */ 102 #define DECOMP_FATALERROR -2 /* error detected after decomp. */ 103 104 extern int ppp_register_compressor(struct compressor *); 105 extern void ppp_unregister_compressor(struct compressor *); 106 #endif /* _NET_PPP_COMP_H */ 107