LXR linux/include/uapi/linux/ppp-comp.h

   1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2/*
   3 * ppp-comp.h - Definitions for doing PPP packet compression.
   4 *
   5 * Copyright 1994-1998 Paul Mackerras.
   6 *
   7 *  This program is free software; you can redistribute it and/or
   8 *  modify it under the terms of the GNU General Public License
   9 *  version 2 as published by the Free Software Foundation.
  10 */
  11#ifndef _UAPI_NET_PPP_COMP_H
  12#define _UAPI_NET_PPP_COMP_H
  13
  14
  15/*
  16 * CCP codes.
  17 */
  18
  19#define CCP_CONFREQ     1
  20#define CCP_CONFACK     2
  21#define CCP_TERMREQ     5
  22#define CCP_TERMACK     6
  23#define CCP_RESETREQ    14
  24#define CCP_RESETACK    15
  25
  26/*
  27 * Max # bytes for a CCP option
  28 */
  29
  30#define CCP_MAX_OPTION_LENGTH   32
  31
  32/*
  33 * Parts of a CCP packet.
  34 */
  35
  36#define CCP_CODE(dp)            ((dp)[0])
  37#define CCP_ID(dp)              ((dp)[1])
  38#define CCP_LENGTH(dp)          (((dp)[2] << 8) + (dp)[3])
  39#define CCP_HDRLEN              4
  40
  41#define CCP_OPT_CODE(dp)        ((dp)[0])
  42#define CCP_OPT_LENGTH(dp)      ((dp)[1])
  43#define CCP_OPT_MINLEN          2
  44
  45/*
  46 * Definitions for BSD-Compress.
  47 */
  48
  49#define CI_BSD_COMPRESS         21      /* config. option for BSD-Compress */
  50#define CILEN_BSD_COMPRESS      3       /* length of config. option */
  51
  52/* Macros for handling the 3rd byte of the BSD-Compress config option. */
  53#define BSD_NBITS(x)            ((x) & 0x1F)    /* number of bits requested */
  54#define BSD_VERSION(x)          ((x) >> 5)      /* version of option format */
  55#define BSD_CURRENT_VERSION     1               /* current version number */
  56#define BSD_MAKE_OPT(v, n)      (((v) << 5) | (n))
  57
  58#define BSD_MIN_BITS            9       /* smallest code size supported */
  59#define BSD_MAX_BITS            15      /* largest code size supported */
  60
  61/*
  62 * Definitions for Deflate.
  63 */
  64
  65#define CI_DEFLATE              26      /* config option for Deflate */
  66#define CI_DEFLATE_DRAFT        24      /* value used in original draft RFC */
  67#define CILEN_DEFLATE           4       /* length of its config option */
  68
  69#define DEFLATE_MIN_SIZE        9
  70#define DEFLATE_MAX_SIZE        15
  71#define DEFLATE_METHOD_VAL      8
  72#define DEFLATE_SIZE(x)         (((x) >> 4) + 8)
  73#define DEFLATE_METHOD(x)       ((x) & 0x0F)
  74#define DEFLATE_MAKE_OPT(w)     ((((w) - 8) << 4) + DEFLATE_METHOD_VAL)
  75#define DEFLATE_CHK_SEQUENCE    0
  76
  77/*
  78 * Definitions for MPPE.
  79 */
  80
  81#define CI_MPPE                18      /* config option for MPPE */
  82#define CILEN_MPPE              6      /* length of config option */
  83
  84/*
  85 * Definitions for other, as yet unsupported, compression methods.
  86 */
  87
  88#define CI_PREDICTOR_1          1       /* config option for Predictor-1 */
  89#define CILEN_PREDICTOR_1       2       /* length of its config option */
  90#define CI_PREDICTOR_2          2       /* config option for Predictor-2 */
  91#define CILEN_PREDICTOR_2       2       /* length of its config option */
  92
  93
  94#endif /* _UAPI_NET_PPP_COMP_H */
  95