bsd/net/ppp_comp.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * ppp_comp.h - Definitions for doing PPP packet compression.
  32  *
  33  * Copyright (c) 1994 The Australian National University.
  34  * All rights reserved.
  35  *
  36  * Permission to use, copy, modify, and distribute this software and its
  37  * documentation is hereby granted, provided that the above copyright
  38  * notice appears in all copies.  This software is provided without any
  39  * warranty, express or implied. The Australian National University
  40  * makes no representations about the suitability of this software for
  41  * any purpose.
  42  *
  43  * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
  44  * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  45  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
  46  * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
  47  * OF SUCH DAMAGE.
  48  *
  49  * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  50  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  51  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  52  * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
  53  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  54  * OR MODIFICATIONS.
  55  *
  56  */
  57
  58 #ifndef _NET_PPP_COMP_H
  59 #define _NET_PPP_COMP_H
  60 #ifdef KERNEL_PRIVATE
  61 /*
  62  * The following symbols control whether we include code for
  63  * various compression methods.
  64  */
  65 #ifndef DO_BSD_COMPRESS
  66 #define DO_BSD_COMPRESS 1       /* by default, include BSD-Compress */
  67 #endif
  68 #ifndef DO_DEFLATE
  69 #define DO_DEFLATE      1       /* by default, include Deflate */
  70 #endif
  71 #define DO_PREDICTOR_1  0
  72 #define DO_PREDICTOR_2  0
  73
  74 /*
  75  * Structure giving methods for compression/decompression.
  76  */
  77 #if PACKETPTR
  78 struct compressor {
  79         int     compress_proto; /* CCP compression protocol number */
  80
  81         /* Allocate space for a compressor (transmit side) */
  82         void    *(*comp_alloc)(u_char *options, int opt_len);
  83         /* Free space used by a compressor */
  84         void    (*comp_free)(void *state);
  85         /* Initialize a compressor */
  86         int     (*comp_init)(void *state, u_char *options, int opt_len,
  87                                   int unit, int hdrlen, int debug);
  88         /* Reset a compressor */
  89         void    (*comp_reset)(void *state);
  90         /* Compress a packet */
  91         int     (*compress)(void *state, PACKETPTR *mret,
  92                                  PACKETPTR mp, int orig_len, int max_len);
  93         /* Return compression statistics */
  94         void    (*comp_stat)(void *state, struct compstat *stats);
  95
  96         /* Allocate space for a decompressor (receive side) */
  97         void    *(*decomp_alloc)(u_char *options, int opt_len);
  98         /* Free space used by a decompressor */
  99         void    (*decomp_free)(void *state);
 100         /* Initialize a decompressor */
 101         int     (*decomp_init)(void *state, u_char *options, int opt_len,
 102                                     int unit, int hdrlen, int mru, int debug);
 103         /* Reset a decompressor */
 104         void    (*decomp_reset)(void *state);
 105         /* Decompress a packet. */
 106         int     (*decompress)(void *state, PACKETPTR mp, PACKETPTR *dmpp);
 107         /* Update state for an incompressible packet received */
 108         void    (*incomp)(void *state, PACKETPTR mp);
 109         /* Return decompression statistics */
 110         void    (*decomp_stat)(void *state, struct compstat *stats);
 111 };
 112 #endif /* PACKETPTR */
 113
 114 /*
 115  * Return values for decompress routine.
 116  * We need to make these distinctions so that we can disable certain
 117  * useful functionality, namely sending a CCP reset-request as a result
 118  * of an error detected after decompression.  This is to avoid infringing
 119  * a patent held by Motorola.
 120  * Don't you just lurve software patents.
 121  */
 122 #define DECOMP_OK               0       /* everything went OK */
 123 #define DECOMP_ERROR            1       /* error detected before decomp. */
 124 #define DECOMP_FATALERROR       2       /* error detected after decomp. */
 125
 126 /*
 127  * CCP codes.
 128  */
 129 #define CCP_CONFREQ     1
 130 #define CCP_CONFACK     2
 131 #define CCP_TERMREQ     5
 132 #define CCP_TERMACK     6
 133 #define CCP_RESETREQ    14
 134 #define CCP_RESETACK    15
 135
 136 /*
 137  * Max # bytes for a CCP option
 138  */
 139 #define CCP_MAX_OPTION_LENGTH   32
 140
 141 /*
 142  * Parts of a CCP packet.
 143  */
 144 #define CCP_CODE(dp)            ((dp)[0])
 145 #define CCP_ID(dp)              ((dp)[1])
 146 #define CCP_LENGTH(dp)          (((dp)[2] << 8) + (dp)[3])
 147 #define CCP_HDRLEN              4
 148
 149 #define CCP_OPT_CODE(dp)        ((dp)[0])
 150 #define CCP_OPT_LENGTH(dp)      ((dp)[1])
 151 #define CCP_OPT_MINLEN          2
 152
 153 /*
 154  * Definitions for BSD-Compress.
 155  */
 156 #define CI_BSD_COMPRESS         21      /* config. option for BSD-Compress */
 157 #define CILEN_BSD_COMPRESS      3       /* length of config. option */
 158
 159 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
 160 #define BSD_NBITS(x)            ((x) & 0x1F)    /* number of bits requested */
 161 #define BSD_VERSION(x)          ((x) >> 5)      /* version of option format */
 162 #define BSD_CURRENT_VERSION     1               /* current version number */
 163 #define BSD_MAKE_OPT(v, n)      (((v) << 5) | (n))
 164
 165 #define BSD_MIN_BITS            9       /* smallest code size supported */
 166 #define BSD_MAX_BITS            15      /* largest code size supported */
 167
 168 /*
 169  * Definitions for Deflate.
 170  */
 171 #define CI_DEFLATE              26      /* config option for Deflate */
 172 #define CI_DEFLATE_DRAFT        24      /* value used in original draft RFC */
 173 #define CILEN_DEFLATE           4       /* length of its config option */
 174
 175 #define DEFLATE_MIN_SIZE        8
 176 #define DEFLATE_MAX_SIZE        15
 177 #define DEFLATE_METHOD_VAL      8
 178 #define DEFLATE_SIZE(x)         (((x) >> 4) + DEFLATE_MIN_SIZE)
 179 #define DEFLATE_METHOD(x)       ((x) & 0x0F)
 180 #define DEFLATE_MAKE_OPT(w)     ((((w) - DEFLATE_MIN_SIZE) << 4) \
 181                                  + DEFLATE_METHOD_VAL)
 182 #define DEFLATE_CHK_SEQUENCE    0
 183
 184 /*
 185  * Definitions for other, as yet unsupported, compression methods.
 186  */
 187 #define CI_PREDICTOR_1          1       /* config option for Predictor-1 */
 188 #define CILEN_PREDICTOR_1       2       /* length of its config option */
 189 #define CI_PREDICTOR_2          2       /* config option for Predictor-2 */
 190 #define CILEN_PREDICTOR_2       2       /* length of its config option */
 191
 192 #endif /* KERNEL_PRIVATE */
 193 #endif /* _NET_PPP_COMP_H */