release/src/router/pppd/include/net/ppp-comp.h

   1 /*
   2  * ppp-comp.h - Definitions for doing PPP packet compression.
   3  *
   4  * Copyright (c) 1984 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 1.13 2002/12/06 09:49:15 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  */
  57 #ifdef PACKETPTR
  58 struct compressor {
  59         int     compress_proto; /* CCP compression protocol number */
  60
  61         /* Allocate space for a compressor (transmit side) */
  62         void    *(*comp_alloc) __P((u_char *options, int opt_len));
  63         /* Free space used by a compressor */
  64         void    (*comp_free) __P((void *state));
  65         /* Initialize a compressor */
  66         int     (*comp_init) __P((void *state, u_char *options, int opt_len,
  67                                   int unit, int hdrlen, int debug));
  68         /* Reset a compressor */
  69         void    (*comp_reset) __P((void *state));
  70         /* Compress a packet */
  71         int     (*compress) __P((void *state, PACKETPTR *mret,
  72                                  PACKETPTR mp, int orig_len, int max_len));
  73         /* Return compression statistics */
  74         void    (*comp_stat) __P((void *state, struct compstat *stats));
  75
  76         /* Allocate space for a decompressor (receive side) */
  77         void    *(*decomp_alloc) __P((u_char *options, int opt_len));
  78         /* Free space used by a decompressor */
  79         void    (*decomp_free) __P((void *state));
  80         /* Initialize a decompressor */
  81         int     (*decomp_init) __P((void *state, u_char *options, int opt_len,
  82                                     int unit, int hdrlen, int mru, int debug));
  83         /* Reset a decompressor */
  84         void    (*decomp_reset) __P((void *state));
  85         /* Decompress a packet. */
  86         int     (*decompress) __P((void *state, PACKETPTR mp,
  87                                    PACKETPTR *dmpp));
  88         /* Update state for an incompressible packet received */
  89         void    (*incomp) __P((void *state, PACKETPTR mp));
  90         /* Return decompression statistics */
  91         void    (*decomp_stat) __P((void *state, struct compstat *stats));
  92 };
  93 #endif /* PACKETPTR */
  94
  95 /*
  96  * Return values for decompress routine.
  97  * We need to make these distinctions so that we can disable certain
  98  * useful functionality, namely sending a CCP reset-request as a result
  99  * of an error detected after decompression.  This is to avoid infringing
 100  * a patent held by Motorola.
 101  * Don't you just lurve software patents.
 102  */
 103 #define DECOMP_OK               0       /* everything went OK */
 104 #define DECOMP_ERROR            1       /* error detected before decomp. */
 105 #define DECOMP_FATALERROR       2       /* error detected after decomp. */
 106
 107 /*
 108  * CCP codes.
 109  */
 110 #define CCP_CONFREQ     1
 111 #define CCP_CONFACK     2
 112 #define CCP_TERMREQ     5
 113 #define CCP_TERMACK     6
 114 #define CCP_RESETREQ    14
 115 #define CCP_RESETACK    15
 116
 117 /*
 118  * Max # bytes for a CCP option
 119  */
 120 #define CCP_MAX_OPTION_LENGTH   32
 121
 122 /*
 123  * Parts of a CCP packet.
 124  */
 125 #define CCP_CODE(dp)            ((dp)[0])
 126 #define CCP_ID(dp)              ((dp)[1])
 127 #define CCP_LENGTH(dp)          (((dp)[2] << 8) + (dp)[3])
 128 #define CCP_HDRLEN              4
 129
 130 #define CCP_OPT_CODE(dp)        ((dp)[0])
 131 #define CCP_OPT_LENGTH(dp)      ((dp)[1])
 132 #define CCP_OPT_MINLEN          2
 133
 134 /*
 135  * Definitions for BSD-Compress.
 136  */
 137 #define CI_BSD_COMPRESS         21      /* config. option for BSD-Compress */
 138 #define CILEN_BSD_COMPRESS      3       /* length of config. option */
 139
 140 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
 141 #define BSD_NBITS(x)            ((x) & 0x1F)    /* number of bits requested */
 142 #define BSD_VERSION(x)          ((x) >> 5)      /* version of option format */
 143 #define BSD_CURRENT_VERSION     1               /* current version number */
 144 #define BSD_MAKE_OPT(v, n)      (((v) << 5) | (n))
 145
 146 #define BSD_MIN_BITS            9       /* smallest code size supported */
 147 #define BSD_MAX_BITS            15      /* largest code size supported */
 148
 149 /*
 150  * Definitions for Deflate.
 151  */
 152 #define CI_DEFLATE              26      /* config option for Deflate */
 153 #define CI_DEFLATE_DRAFT        24      /* value used in original draft RFC */
 154 #define CILEN_DEFLATE           4       /* length of its config option */
 155
 156 #define DEFLATE_MIN_SIZE        8
 157 #define DEFLATE_MAX_SIZE        15
 158 #define DEFLATE_METHOD_VAL      8
 159 #define DEFLATE_SIZE(x)         (((x) >> 4) + DEFLATE_MIN_SIZE)
 160 #define DEFLATE_METHOD(x)       ((x) & 0x0F)
 161 #define DEFLATE_MAKE_OPT(w)     ((((w) - DEFLATE_MIN_SIZE) << 4) \
 162                                  + DEFLATE_METHOD_VAL)
 163 #define DEFLATE_CHK_SEQUENCE    0
 164
 165 /*
 166  * Definitions for MPPE.
 167  */
 168 #define CI_MPPE                 18      /* config option for MPPE */
 169 #define CILEN_MPPE              6       /* length of config option */
 170
 171 /* MPPE/MPPC definitions by J.D.*/
 172 #define MPPE_STATELESS          MPPE_H_BIT      /* configuration bit H */
 173 #define MPPE_40BIT              MPPE_L_BIT      /* configuration bit L */
 174 #define MPPE_56BIT              MPPE_M_BIT      /* configuration bit M */
 175 #define MPPE_128BIT             MPPE_S_BIT      /* configuration bit S */
 176 #define MPPE_MPPC               MPPE_C_BIT      /* configuration bit C */
 177
 178 /*
 179  * Definitions for Stac LZS.
 180  */
 181
 182 #define CI_LZS                  17      /* config option for Stac LZS */
 183 #define CILEN_LZS               5       /* length of config option */
 184
 185 #define LZS_OVHD                4       /* max. LZS overhead */
 186 #define LZS_HIST_LEN            2048    /* LZS history size */
 187 #define LZS_MAX_CCOUNT          0x0FFF  /* max. coherency counter value */
 188
 189 #define LZS_MODE_NONE           0
 190 #define LZS_MODE_LCB            1
 191 #define LZS_MODE_CRC            2
 192 #define LZS_MODE_SEQ            3
 193 #define LZS_MODE_EXT            4
 194
 195 #define LZS_EXT_BIT_FLUSHED     0x80    /* bit A */
 196 #define LZS_EXT_BIT_COMP        0x20    /* bit C */
 197
 198 /*
 199  * Definitions for other, as yet unsupported, compression methods.
 200  */
 201 #define CI_PREDICTOR_1          1       /* config option for Predictor-1 */
 202 #define CILEN_PREDICTOR_1       2       /* length of its config option */
 203 #define CI_PREDICTOR_2          2       /* config option for Predictor-2 */
 204 #define CILEN_PREDICTOR_2       2       /* length of its config option */
 205
 206 #endif /* _NET_PPP_COMP_H */