bsd/net/ppp_comp.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * ppp_comp.h - Definitions for doing PPP packet compression.
  24  *
  25  * Copyright (c) 1994 The Australian National University.
  26  * All rights reserved.
  27  *
  28  * Permission to use, copy, modify, and distribute this software and its
  29  * documentation is hereby granted, provided that the above copyright
  30  * notice appears in all copies.  This software is provided without any
  31  * warranty, express or implied. The Australian National University
  32  * makes no representations about the suitability of this software for
  33  * any purpose.
  34  *
  35  * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
  36  * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  37  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
  38  * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
  39  * OF SUCH DAMAGE.
  40  *
  41  * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  42  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  43  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  44  * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
  45  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  46  * OR MODIFICATIONS.
  47  *
  48  */
  49
  50 #ifndef _NET_PPP_COMP_H
  51 #define _NET_PPP_COMP_H
  52 #ifdef KERNEL_PRIVATE
  53 /*
  54  * The following symbols control whether we include code for
  55  * various compression methods.
  56  */
  57 #ifndef DO_BSD_COMPRESS
  58 #define DO_BSD_COMPRESS 1       /* by default, include BSD-Compress */
  59 #endif
  60 #ifndef DO_DEFLATE
  61 #define DO_DEFLATE      1       /* by default, include Deflate */
  62 #endif
  63 #define DO_PREDICTOR_1  0
  64 #define DO_PREDICTOR_2  0
  65
  66 /*
  67  * Structure giving methods for compression/decompression.
  68  */
  69 #if PACKETPTR
  70 struct compressor {
  71         int     compress_proto; /* CCP compression protocol number */
  72
  73         /* Allocate space for a compressor (transmit side) */
  74         void    *(*comp_alloc)(u_char *options, int opt_len);
  75         /* Free space used by a compressor */
  76         void    (*comp_free)(void *state);
  77         /* Initialize a compressor */
  78         int     (*comp_init)(void *state, u_char *options, int opt_len,
  79                                   int unit, int hdrlen, int debug);
  80         /* Reset a compressor */
  81         void    (*comp_reset)(void *state);
  82         /* Compress a packet */
  83         int     (*compress)(void *state, PACKETPTR *mret,
  84                                  PACKETPTR mp, int orig_len, int max_len);
  85         /* Return compression statistics */
  86         void    (*comp_stat)(void *state, struct compstat *stats);
  87
  88         /* Allocate space for a decompressor (receive side) */
  89         void    *(*decomp_alloc)(u_char *options, int opt_len);
  90         /* Free space used by a decompressor */
  91         void    (*decomp_free)(void *state);
  92         /* Initialize a decompressor */
  93         int     (*decomp_init)(void *state, u_char *options, int opt_len,
  94                                     int unit, int hdrlen, int mru, int debug);
  95         /* Reset a decompressor */
  96         void    (*decomp_reset)(void *state);
  97         /* Decompress a packet. */
  98         int     (*decompress)(void *state, PACKETPTR mp, PACKETPTR *dmpp);
  99         /* Update state for an incompressible packet received */
 100         void    (*incomp)(void *state, PACKETPTR mp);
 101         /* Return decompression statistics */
 102         void    (*decomp_stat)(void *state, struct compstat *stats);
 103 };
 104 #endif /* PACKETPTR */
 105
 106 /*
 107  * Return values for decompress routine.
 108  * We need to make these distinctions so that we can disable certain
 109  * useful functionality, namely sending a CCP reset-request as a result
 110  * of an error detected after decompression.  This is to avoid infringing
 111  * a patent held by Motorola.
 112  * Don't you just lurve software patents.
 113  */
 114 #define DECOMP_OK               0       /* everything went OK */
 115 #define DECOMP_ERROR            1       /* error detected before decomp. */
 116 #define DECOMP_FATALERROR       2       /* error detected after decomp. */
 117
 118 /*
 119  * CCP codes.
 120  */
 121 #define CCP_CONFREQ     1
 122 #define CCP_CONFACK     2
 123 #define CCP_TERMREQ     5
 124 #define CCP_TERMACK     6
 125 #define CCP_RESETREQ    14
 126 #define CCP_RESETACK    15
 127
 128 /*
 129  * Max # bytes for a CCP option
 130  */
 131 #define CCP_MAX_OPTION_LENGTH   32
 132
 133 /*
 134  * Parts of a CCP packet.
 135  */
 136 #define CCP_CODE(dp)            ((dp)[0])
 137 #define CCP_ID(dp)              ((dp)[1])
 138 #define CCP_LENGTH(dp)          (((dp)[2] << 8) + (dp)[3])
 139 #define CCP_HDRLEN              4
 140
 141 #define CCP_OPT_CODE(dp)        ((dp)[0])
 142 #define CCP_OPT_LENGTH(dp)      ((dp)[1])
 143 #define CCP_OPT_MINLEN          2
 144
 145 /*
 146  * Definitions for BSD-Compress.
 147  */
 148 #define CI_BSD_COMPRESS         21      /* config. option for BSD-Compress */
 149 #define CILEN_BSD_COMPRESS      3       /* length of config. option */
 150
 151 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
 152 #define BSD_NBITS(x)            ((x) & 0x1F)    /* number of bits requested */
 153 #define BSD_VERSION(x)          ((x) >> 5)      /* version of option format */
 154 #define BSD_CURRENT_VERSION     1               /* current version number */
 155 #define BSD_MAKE_OPT(v, n)      (((v) << 5) | (n))
 156
 157 #define BSD_MIN_BITS            9       /* smallest code size supported */
 158 #define BSD_MAX_BITS            15      /* largest code size supported */
 159
 160 /*
 161  * Definitions for Deflate.
 162  */
 163 #define CI_DEFLATE              26      /* config option for Deflate */
 164 #define CI_DEFLATE_DRAFT        24      /* value used in original draft RFC */
 165 #define CILEN_DEFLATE           4       /* length of its config option */
 166
 167 #define DEFLATE_MIN_SIZE        8
 168 #define DEFLATE_MAX_SIZE        15
 169 #define DEFLATE_METHOD_VAL      8
 170 #define DEFLATE_SIZE(x)         (((x) >> 4) + DEFLATE_MIN_SIZE)
 171 #define DEFLATE_METHOD(x)       ((x) & 0x0F)
 172 #define DEFLATE_MAKE_OPT(w)     ((((w) - DEFLATE_MIN_SIZE) << 4) \
 173                                  + DEFLATE_METHOD_VAL)
 174 #define DEFLATE_CHK_SEQUENCE    0
 175
 176 /*
 177  * Definitions for other, as yet unsupported, compression methods.
 178  */
 179 #define CI_PREDICTOR_1          1       /* config option for Predictor-1 */
 180 #define CILEN_PREDICTOR_1       2       /* length of its config option */
 181 #define CI_PREDICTOR_2          2       /* config option for Predictor-2 */
 182 #define CILEN_PREDICTOR_2       2       /* length of its config option */
 183
 184 #endif /* KERNEL_PRIVATE */
 185 #endif /* _NET_PPP_COMP_H */