bsd/net/ppp_comp.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * ppp_comp.h - Definitions for doing PPP packet compression.
  30  *
  31  * Copyright (c) 1994 The Australian National University.
  32  * All rights reserved.
  33  *
  34  * Permission to use, copy, modify, and distribute this software and its
  35  * documentation is hereby granted, provided that the above copyright
  36  * notice appears in all copies.  This software is provided without any
  37  * warranty, express or implied. The Australian National University
  38  * makes no representations about the suitability of this software for
  39  * any purpose.
  40  *
  41  * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
  42  * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  43  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
  44  * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
  45  * OF SUCH DAMAGE.
  46  *
  47  * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  48  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  49  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  50  * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
  51  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  52  * OR MODIFICATIONS.
  53  *
  54  */
  55
  56 #ifndef _NET_PPP_COMP_H
  57 #define _NET_PPP_COMP_H
  58 #ifdef KERNEL_PRIVATE
  59 /*
  60  * The following symbols control whether we include code for
  61  * various compression methods.
  62  */
  63 #ifndef DO_BSD_COMPRESS
  64 #define DO_BSD_COMPRESS 1       /* by default, include BSD-Compress */
  65 #endif
  66 #ifndef DO_DEFLATE
  67 #define DO_DEFLATE      1       /* by default, include Deflate */
  68 #endif
  69 #define DO_PREDICTOR_1  0
  70 #define DO_PREDICTOR_2  0
  71
  72 /*
  73  * Structure giving methods for compression/decompression.
  74  */
  75 #if PACKETPTR
  76 struct compressor {
  77         int     compress_proto; /* CCP compression protocol number */
  78
  79         /* Allocate space for a compressor (transmit side) */
  80         void    *(*comp_alloc)(u_char *options, int opt_len);
  81         /* Free space used by a compressor */
  82         void    (*comp_free)(void *state);
  83         /* Initialize a compressor */
  84         int     (*comp_init)(void *state, u_char *options, int opt_len,
  85             int unit, int hdrlen, int debug);
  86         /* Reset a compressor */
  87         void    (*comp_reset)(void *state);
  88         /* Compress a packet */
  89         int     (*compress)(void *state, PACKETPTR *mret,
  90             PACKETPTR mp, int orig_len, int max_len);
  91         /* Return compression statistics */
  92         void    (*comp_stat)(void *state, struct compstat *stats);
  93
  94         /* Allocate space for a decompressor (receive side) */
  95         void    *(*decomp_alloc)(u_char *options, int opt_len);
  96         /* Free space used by a decompressor */
  97         void    (*decomp_free)(void *state);
  98         /* Initialize a decompressor */
  99         int     (*decomp_init)(void *state, u_char *options, int opt_len,
 100             int unit, int hdrlen, int mru, int debug);
 101         /* Reset a decompressor */
 102         void    (*decomp_reset)(void *state);
 103         /* Decompress a packet. */
 104         int     (*decompress)(void *state, PACKETPTR mp, PACKETPTR *dmpp);
 105         /* Update state for an incompressible packet received */
 106         void    (*incomp)(void *state, PACKETPTR mp);
 107         /* Return decompression statistics */
 108         void    (*decomp_stat)(void *state, struct compstat *stats);
 109 };
 110 #endif /* PACKETPTR */
 111
 112 /*
 113  * Return values for decompress routine.
 114  * We need to make these distinctions so that we can disable certain
 115  * useful functionality, namely sending a CCP reset-request as a result
 116  * of an error detected after decompression.  This is to avoid infringing
 117  * a patent held by Motorola.
 118  * Don't you just lurve software patents.
 119  */
 120 #define DECOMP_OK               0       /* everything went OK */
 121 #define DECOMP_ERROR            1       /* error detected before decomp. */
 122 #define DECOMP_FATALERROR       2       /* error detected after decomp. */
 123
 124 /*
 125  * CCP codes.
 126  */
 127 #define CCP_CONFREQ     1
 128 #define CCP_CONFACK     2
 129 #define CCP_TERMREQ     5
 130 #define CCP_TERMACK     6
 131 #define CCP_RESETREQ    14
 132 #define CCP_RESETACK    15
 133
 134 /*
 135  * Max # bytes for a CCP option
 136  */
 137 #define CCP_MAX_OPTION_LENGTH   32
 138
 139 /*
 140  * Parts of a CCP packet.
 141  */
 142 #define CCP_CODE(dp)            ((dp)[0])
 143 #define CCP_ID(dp)              ((dp)[1])
 144 #define CCP_LENGTH(dp)          (((dp)[2] << 8) + (dp)[3])
 145 #define CCP_HDRLEN              4
 146
 147 #define CCP_OPT_CODE(dp)        ((dp)[0])
 148 #define CCP_OPT_LENGTH(dp)      ((dp)[1])
 149 #define CCP_OPT_MINLEN          2
 150
 151 /*
 152  * Definitions for BSD-Compress.
 153  */
 154 #define CI_BSD_COMPRESS         21      /* config. option for BSD-Compress */
 155 #define CILEN_BSD_COMPRESS      3       /* length of config. option */
 156
 157 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
 158 #define BSD_NBITS(x)            ((x) & 0x1F)    /* number of bits requested */
 159 #define BSD_VERSION(x)          ((x) >> 5)      /* version of option format */
 160 #define BSD_CURRENT_VERSION     1               /* current version number */
 161 #define BSD_MAKE_OPT(v, n)      (((v) << 5) | (n))
 162
 163 #define BSD_MIN_BITS            9       /* smallest code size supported */
 164 #define BSD_MAX_BITS            15      /* largest code size supported */
 165
 166 /*
 167  * Definitions for Deflate.
 168  */
 169 #define CI_DEFLATE              26      /* config option for Deflate */
 170 #define CI_DEFLATE_DRAFT        24      /* value used in original draft RFC */
 171 #define CILEN_DEFLATE           4       /* length of its config option */
 172
 173 #define DEFLATE_MIN_SIZE        8
 174 #define DEFLATE_MAX_SIZE        15
 175 #define DEFLATE_METHOD_VAL      8
 176 #define DEFLATE_SIZE(x)         (((x) >> 4) + DEFLATE_MIN_SIZE)
 177 #define DEFLATE_METHOD(x)       ((x) & 0x0F)
 178 #define DEFLATE_MAKE_OPT(w)     ((((w) - DEFLATE_MIN_SIZE) << 4) \
 179                                  + DEFLATE_METHOD_VAL)
 180 #define DEFLATE_CHK_SEQUENCE    0
 181
 182 /*
 183  * Definitions for other, as yet unsupported, compression methods.
 184  */
 185 #define CI_PREDICTOR_1          1       /* config option for Predictor-1 */
 186 #define CILEN_PREDICTOR_1       2       /* length of its config option */
 187 #define CI_PREDICTOR_2          2       /* config option for Predictor-2 */
 188 #define CILEN_PREDICTOR_2       2       /* length of its config option */
 189
 190 #endif /* KERNEL_PRIVATE */
 191 #endif /* _NET_PPP_COMP_H */