| /* |
| * ppp-comp.h - Definitions for doing PPP packet compression. |
| * |
| * Copyright (c) 1994 The Australian National University. |
| * All rights reserved. |
| * |
| * Permission to use, copy, modify, and distribute this software and its |
| * documentation is hereby granted, provided that the above copyright |
| * notice appears in all copies. This software is provided without any |
| * warranty, express or implied. The Australian National University |
| * makes no representations about the suitability of this software for |
| * any purpose. |
| * |
| * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY |
| * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES |
| * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF |
| * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY |
| * OF SUCH DAMAGE. |
| * |
| * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY |
| * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS |
| * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO |
| * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, |
| * OR MODIFICATIONS. |
| */ |
| |
| /* |
| * ==FILEVERSION 980319== |
| * |
| * NOTE TO MAINTAINERS: |
| * If you modify this file at all, please set the above date. |
| * ppp-comp.h is shipped with a PPP distribution as well as with the kernel; |
| * if everyone increases the FILEVERSION number above, then scripts |
| * can do the right thing when deciding whether to install a new ppp-comp.h |
| * file. Don't change the format of that line otherwise, so the |
| * installation script can recognize it. |
| */ |
| |
| #ifndef _NET_PPP_COMP_H |
| #define _NET_PPP_COMP_H |
| |
| struct module; |
| |
| /* |
| * The following symbols control whether we include code for |
| * various compression methods. |
| */ |
| |
| #ifndef DO_BSD_COMPRESS |
| #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ |
| #endif |
| #ifndef DO_DEFLATE |
| #define DO_DEFLATE 1 /* by default, include Deflate */ |
| #endif |
| #define DO_PREDICTOR_1 0 |
| #define DO_PREDICTOR_2 0 |
| |
| /* |
| * Structure giving methods for compression/decompression. |
| */ |
| |
| struct compressor { |
| int compress_proto; /* CCP compression protocol number */ |
| |
| /* Allocate space for a compressor (transmit side) */ |
| void *(*comp_alloc) (unsigned char *options, int opt_len); |
| |
| /* Free space used by a compressor */ |
| void (*comp_free) (void *state); |
| |
| /* Initialize a compressor */ |
| int (*comp_init) (void *state, unsigned char *options, |
| int opt_len, int unit, int opthdr, int debug); |
| |
| /* Reset a compressor */ |
| void (*comp_reset) (void *state); |
| |
| /* Compress a packet */ |
| int (*compress) (void *state, unsigned char *rptr, |
| unsigned char *obuf, int isize, int osize); |
| |
| /* Return compression statistics */ |
| void (*comp_stat) (void *state, struct compstat *stats); |
| |
| /* Allocate space for a decompressor (receive side) */ |
| void *(*decomp_alloc) (unsigned char *options, int opt_len); |
| |
| /* Free space used by a decompressor */ |
| void (*decomp_free) (void *state); |
| |
| /* Initialize a decompressor */ |
| int (*decomp_init) (void *state, unsigned char *options, |
| int opt_len, int unit, int opthdr, int mru, |
| int debug); |
| |
| /* Reset a decompressor */ |
| void (*decomp_reset) (void *state); |
| |
| /* Decompress a packet. */ |
| int (*decompress) (void *state, unsigned char *ibuf, int isize, |
| unsigned char *obuf, int osize); |
| |
| /* Update state for an incompressible packet received */ |
| void (*incomp) (void *state, unsigned char *ibuf, int icnt); |
| |
| /* Return decompression statistics */ |
| void (*decomp_stat) (void *state, struct compstat *stats); |
| |
| /* Used in locking compressor modules */ |
| struct module *owner; |
| /* Extra skb space needed by the compressor algorithm */ |
| unsigned int comp_extra; |
| }; |
| |
| /* |
| * The return value from decompress routine is the length of the |
| * decompressed packet if successful, otherwise DECOMP_ERROR |
| * or DECOMP_FATALERROR if an error occurred. |
| * |
| * We need to make this distinction so that we can disable certain |
| * useful functionality, namely sending a CCP reset-request as a result |
| * of an error detected after decompression. This is to avoid infringing |
| * a patent held by Motorola. |
| * Don't you just lurve software patents. |
| */ |
| |
| #define DECOMP_ERROR -1 /* error detected before decomp. */ |
| #define DECOMP_FATALERROR -2 /* error detected after decomp. */ |
| |
| /* |
| * 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 /* _NET_PPP_COMP_H */ |