1/* 2 * ppp-comp.h - Definitions for doing PPP packet compression. 3 * 4 * Copyright (c) 1994 Paul Mackerras. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 18 * 3. The name(s) of the authors of this software must not be used to 19 * endorse or promote products derived from this software without 20 * prior written permission. 21 * 22 * 4. Redistributions of any form whatsoever must retain the following 23 * acknowledgment: 24 * "This product includes software developed by Paul Mackerras 25 * <paulus@samba.org>". 26 * 27 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 28 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 29 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 30 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 32 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 33 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 34 * 35 * $Id: ppp-comp.h,v 1.2 2002/12/06 09:49:16 paulus Exp $ 36 */ 37 38#ifndef _NET_PPP_COMP_H 39#define _NET_PPP_COMP_H 40 41/* 42 * The following symbols control whether we include code for 43 * various compression methods. 44 */ 45#ifndef DO_BSD_COMPRESS 46#define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ 47#endif 48#ifndef DO_DEFLATE 49#define DO_DEFLATE 1 /* by default, include Deflate */ 50#endif 51#define DO_PREDICTOR_1 0 52#define DO_PREDICTOR_2 0 53 54/* 55 * Structure giving methods for compression/decompression. 56 */ 57struct compressor { 58 int compress_proto; /* CCP compression protocol number */ 59 60 /* Allocate space for a decompressor (receive side) */ 61 void *(*decomp_alloc) __P((u_char *options, int opt_len)); 62 /* Free space used by a decompressor */ 63 void (*decomp_free) __P((void *state)); 64 /* Initialize a decompressor */ 65 int (*decomp_init) __P((void *state, u_char *options, int opt_len, 66 int unit, int hdrlen, int mru, int debug)); 67 /* Reset a decompressor */ 68 void (*decomp_reset) __P((void *state)); 69 /* Decompress a packet. */ 70 int (*decompress) __P((void *state, u_char *mp, int inlen, 71 u_char *dmp, int *outlen)); 72 /* Update state for an incompressible packet received */ 73 void (*incomp) __P((void *state, u_char *mp, int len)); 74 /* Return decompression statistics */ 75 void (*decomp_stat) __P((void *state, struct compstat *stats)); 76}; 77 78/* 79 * Return values for decompress routine. 80 * We need to make these distinctions so that we can disable certain 81 * useful functionality, namely sending a CCP reset-request as a result 82 * of an error detected after decompression. This is to avoid infringing 83 * a patent held by Motorola. 84 * Don't you just lurve software patents. 85 */ 86#define DECOMP_OK 0 /* everything went OK */ 87#define DECOMP_ERROR 1 /* error detected before decomp. */ 88#define DECOMP_FATALERROR 2 /* error detected after decomp. */ 89 90/* 91 * CCP codes. 92 */ 93#define CCP_CONFREQ 1 94#define CCP_CONFACK 2 95#define CCP_CONFNAK 3 96#define CCP_CONFREJ 4 97#define CCP_TERMREQ 5 98#define CCP_TERMACK 6 99#define CCP_RESETREQ 14 100#define CCP_RESETACK 15 101 102/* 103 * Max # bytes for a CCP option 104 */ 105#define CCP_MAX_OPTION_LENGTH 32 106 107/* 108 * Parts of a CCP packet. 109 */ 110#define CCP_CODE(dp) ((dp)[0]) 111#define CCP_ID(dp) ((dp)[1]) 112#define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3]) 113#define CCP_HDRLEN 4 114 115#define CCP_OPT_CODE(dp) ((dp)[0]) 116#define CCP_OPT_LENGTH(dp) ((dp)[1]) 117#define CCP_OPT_MINLEN 2 118 119/* 120 * Definitions for BSD-Compress. 121 */ 122#define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */ 123#define CILEN_BSD_COMPRESS 3 /* length of config. option */ 124 125/* Macros for handling the 3rd byte of the BSD-Compress config option. */ 126#define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */ 127#define BSD_VERSION(x) ((x) >> 5) /* version of option format */ 128#define BSD_CURRENT_VERSION 1 /* current version number */ 129#define BSD_MAKE_OPT(v, n) (((v) << 5) | (n)) 130 131#define BSD_MIN_BITS 9 /* smallest code size supported */ 132#define BSD_MAX_BITS 15 /* largest code size supported */ 133 134/* 135 * Definitions for Deflate. 136 */ 137#define CI_DEFLATE 26 /* config option for Deflate */ 138#define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */ 139#define CILEN_DEFLATE 4 /* length of its config option */ 140 141#define DEFLATE_MIN_SIZE 8 142#define DEFLATE_MAX_SIZE 15 143#define DEFLATE_METHOD_VAL 8 144#define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE) 145#define DEFLATE_METHOD(x) ((x) & 0x0F) 146#define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \ 147 + DEFLATE_METHOD_VAL) 148#define DEFLATE_CHK_SEQUENCE 0 149 150/* 151 * Definitions for other, as yet unsupported, compression methods. 152 */ 153#define CI_PREDICTOR_1 1 /* config option for Predictor-1 */ 154#define CILEN_PREDICTOR_1 2 /* length of its config option */ 155#define CI_PREDICTOR_2 2 /* config option for Predictor-2 */ 156#define CILEN_PREDICTOR_2 2 /* length of its config option */ 157 158#endif /* _NET_PPP_COMP_H */ 159