ppp-comp.h

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/*
 * ppp-comp.h - Definitions for doing PPP packet compression.
 *
 * Copyright 1994-1998 Paul Mackerras.
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  version 2 as published by the Free Software Foundation.
 */
#ifndef _UAPI_NET_PPP_COMP_H
#define _UAPI_NET_PPP_COMP_H


/*
 * CCP codes.
 */

#define CCP_CONFREQ 1
#define CCP_CONFACK 2
#define CCP_TERMREQ 5
#define CCP_TERMACK 6
#define CCP_RESETREQ    14
#define CCP_RESETACK    15

/*
 * Max # bytes for a CCP option
 */

#define CCP_MAX_OPTION_LENGTH   32

/*
 * Parts of a CCP packet.
 */

#define CCP_CODE(dp)        ((dp)[0])
#define CCP_ID(dp)      ((dp)[1])
#define CCP_LENGTH(dp)      (((dp)[2] << 8) + (dp)[3])
#define CCP_HDRLEN      4

#define CCP_OPT_CODE(dp)    ((dp)[0])
#define CCP_OPT_LENGTH(dp)  ((dp)[1])
#define CCP_OPT_MINLEN      2

/*
 * Definitions for BSD-Compress.
 */

#define CI_BSD_COMPRESS     21  /* config. option for BSD-Compress */
#define CILEN_BSD_COMPRESS  3   /* length of config. option */

/* Macros for handling the 3rd byte of the BSD-Compress config option. */
#define BSD_NBITS(x)        ((x) & 0x1F)    /* number of bits requested */
#define BSD_VERSION(x)      ((x) >> 5)  /* version of option format */
#define BSD_CURRENT_VERSION 1       /* current version number */
#define BSD_MAKE_OPT(v, n)  (((v) << 5) | (n))

#define BSD_MIN_BITS        9   /* smallest code size supported */
#define BSD_MAX_BITS        15  /* largest code size supported */

/*
 * Definitions for Deflate.
 */

#define CI_DEFLATE      26  /* config option for Deflate */
#define CI_DEFLATE_DRAFT    24  /* value used in original draft RFC */
#define CILEN_DEFLATE       4   /* length of its config option */

#define DEFLATE_MIN_SIZE    9
#define DEFLATE_MAX_SIZE    15
#define DEFLATE_METHOD_VAL  8
#define DEFLATE_SIZE(x)     (((x) >> 4) + 8)
#define DEFLATE_METHOD(x)   ((x) & 0x0F)
#define DEFLATE_MAKE_OPT(w) ((((w) - 8) << 4) + DEFLATE_METHOD_VAL)
#define DEFLATE_CHK_SEQUENCE    0

/*
 * Definitions for MPPE.
 */

#define CI_MPPE                18      /* config option for MPPE */
#define CILEN_MPPE              6      /* length of config option */

/*
 * Definitions for other, as yet unsupported, compression methods.
 */

#define CI_PREDICTOR_1      1   /* config option for Predictor-1 */
#define CILEN_PREDICTOR_1   2   /* length of its config option */
#define CI_PREDICTOR_2      2   /* config option for Predictor-2 */
#define CILEN_PREDICTOR_2   2   /* length of its config option */


#endif /* _UAPI_NET_PPP_COMP_H */