bsd/net/ppp_comp.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * ppp_comp.h - Definitions for doing PPP packet compression.
  25  *
  26  * Copyright (c) 1994 The Australian National University.
  27  * All rights reserved.
  28  *
  29  * Permission to use, copy, modify, and distribute this software and its
  30  * documentation is hereby granted, provided that the above copyright
  31  * notice appears in all copies.  This software is provided without any
  32  * warranty, express or implied. The Australian National University
  33  * makes no representations about the suitability of this software for
  34  * any purpose.
  35  *
  36  * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
  37  * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  38  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
  39  * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
  40  * OF SUCH DAMAGE.
  41  *
  42  * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  43  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  44  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  45  * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
  46  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  47  * OR MODIFICATIONS.
  48  *
  49  */
  50
  51 #ifndef _NET_PPP_COMP_H
  52 #define _NET_PPP_COMP_H
  53 #ifdef KERNEL_PRIVATE
  54 /*
  55  * The following symbols control whether we include code for
  56  * various compression methods.
  57  */
  58 #ifndef DO_BSD_COMPRESS
  59 #define DO_BSD_COMPRESS 1       /* by default, include BSD-Compress */
  60 #endif
  61 #ifndef DO_DEFLATE
  62 #define DO_DEFLATE      1       /* by default, include Deflate */
  63 #endif
  64 #define DO_PREDICTOR_1  0
  65 #define DO_PREDICTOR_2  0
  66
  67 /*
  68  * Structure giving methods for compression/decompression.
  69  */
  70 #if PACKETPTR
  71 struct compressor {
  72         int     compress_proto; /* CCP compression protocol number */
  73
  74         /* Allocate space for a compressor (transmit side) */
  75         void    *(*comp_alloc)(u_char *options, int opt_len);
  76         /* Free space used by a compressor */
  77         void    (*comp_free)(void *state);
  78         /* Initialize a compressor */
  79         int     (*comp_init)(void *state, u_char *options, int opt_len,
  80                                   int unit, int hdrlen, int debug);
  81         /* Reset a compressor */
  82         void    (*comp_reset)(void *state);
  83         /* Compress a packet */
  84         int     (*compress)(void *state, PACKETPTR *mret,
  85                                  PACKETPTR mp, int orig_len, int max_len);
  86         /* Return compression statistics */
  87         void    (*comp_stat)(void *state, struct compstat *stats);
  88
  89         /* Allocate space for a decompressor (receive side) */
  90         void    *(*decomp_alloc)(u_char *options, int opt_len);
  91         /* Free space used by a decompressor */
  92         void    (*decomp_free)(void *state);
  93         /* Initialize a decompressor */
  94         int     (*decomp_init)(void *state, u_char *options, int opt_len,
  95                                     int unit, int hdrlen, int mru, int debug);
  96         /* Reset a decompressor */
  97         void    (*decomp_reset)(void *state);
  98         /* Decompress a packet. */
  99         int     (*decompress)(void *state, PACKETPTR mp, PACKETPTR *dmpp);
 100         /* Update state for an incompressible packet received */
 101         void    (*incomp)(void *state, PACKETPTR mp);
 102         /* Return decompression statistics */
 103         void    (*decomp_stat)(void *state, struct compstat *stats);
 104 };
 105 #endif /* PACKETPTR */
 106
 107 /*
 108  * Return values for decompress routine.
 109  * We need to make these distinctions so that we can disable certain
 110  * useful functionality, namely sending a CCP reset-request as a result
 111  * of an error detected after decompression.  This is to avoid infringing
 112  * a patent held by Motorola.
 113  * Don't you just lurve software patents.
 114  */
 115 #define DECOMP_OK               0       /* everything went OK */
 116 #define DECOMP_ERROR            1       /* error detected before decomp. */
 117 #define DECOMP_FATALERROR       2       /* error detected after decomp. */
 118
 119 /*
 120  * CCP codes.
 121  */
 122 #define CCP_CONFREQ     1
 123 #define CCP_CONFACK     2
 124 #define CCP_TERMREQ     5
 125 #define CCP_TERMACK     6
 126 #define CCP_RESETREQ    14
 127 #define CCP_RESETACK    15
 128
 129 /*
 130  * Max # bytes for a CCP option
 131  */
 132 #define CCP_MAX_OPTION_LENGTH   32
 133
 134 /*
 135  * Parts of a CCP packet.
 136  */
 137 #define CCP_CODE(dp)            ((dp)[0])
 138 #define CCP_ID(dp)              ((dp)[1])
 139 #define CCP_LENGTH(dp)          (((dp)[2] << 8) + (dp)[3])
 140 #define CCP_HDRLEN              4
 141
 142 #define CCP_OPT_CODE(dp)        ((dp)[0])
 143 #define CCP_OPT_LENGTH(dp)      ((dp)[1])
 144 #define CCP_OPT_MINLEN          2
 145
 146 /*
 147  * Definitions for BSD-Compress.
 148  */
 149 #define CI_BSD_COMPRESS         21      /* config. option for BSD-Compress */
 150 #define CILEN_BSD_COMPRESS      3       /* length of config. option */
 151
 152 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
 153 #define BSD_NBITS(x)            ((x) & 0x1F)    /* number of bits requested */
 154 #define BSD_VERSION(x)          ((x) >> 5)      /* version of option format */
 155 #define BSD_CURRENT_VERSION     1               /* current version number */
 156 #define BSD_MAKE_OPT(v, n)      (((v) << 5) | (n))
 157
 158 #define BSD_MIN_BITS            9       /* smallest code size supported */
 159 #define BSD_MAX_BITS            15      /* largest code size supported */
 160
 161 /*
 162  * Definitions for Deflate.
 163  */
 164 #define CI_DEFLATE              26      /* config option for Deflate */
 165 #define CI_DEFLATE_DRAFT        24      /* value used in original draft RFC */
 166 #define CILEN_DEFLATE           4       /* length of its config option */
 167
 168 #define DEFLATE_MIN_SIZE        8
 169 #define DEFLATE_MAX_SIZE        15
 170 #define DEFLATE_METHOD_VAL      8
 171 #define DEFLATE_SIZE(x)         (((x) >> 4) + DEFLATE_MIN_SIZE)
 172 #define DEFLATE_METHOD(x)       ((x) & 0x0F)
 173 #define DEFLATE_MAKE_OPT(w)     ((((w) - DEFLATE_MIN_SIZE) << 4) \
 174                                  + DEFLATE_METHOD_VAL)
 175 #define DEFLATE_CHK_SEQUENCE    0
 176
 177 /*
 178  * Definitions for other, as yet unsupported, compression methods.
 179  */
 180 #define CI_PREDICTOR_1          1       /* config option for Predictor-1 */
 181 #define CILEN_PREDICTOR_1       2       /* length of its config option */
 182 #define CI_PREDICTOR_2          2       /* config option for Predictor-2 */
 183 #define CILEN_PREDICTOR_2       2       /* length of its config option */
 184
 185 #endif /* KERNEL_PRIVATE */
 186 #endif /* _NET_PPP_COMP_H */