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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - include/linux/ppp-comp.h
2 * ppp-comp.h - Definitions for doing PPP packet compression.
4 * Copyright (c) 1994 The Australian National University.
7 * Permission to use, copy, modify, and distribute this software and its
8 * documentation is hereby granted, provided that the above copyright
9 * notice appears in all copies. This software is provided without any
10 * warranty, express or implied. The Australian National University
11 * makes no representations about the suitability of this software for
14 * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
15 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
17 * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
20 * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
21 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
22 * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
24 * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
27 * $Id: ppp-comp.h,v 1.6 1997/11/27 06:04:44 paulus Exp $
31 * ==FILEVERSION 980319==
33 * NOTE TO MAINTAINERS:
34 * If you modify this file at all, please set the above date.
35 * ppp-comp.h is shipped with a PPP distribution as well as with the kernel;
36 * if everyone increases the FILEVERSION number above, then scripts
37 * can do the right thing when deciding whether to install a new ppp-comp.h
38 * file. Don't change the format of that line otherwise, so the
39 * installation script can recognize it.
42 #ifndef _NET_PPP_COMP_H
43 #define _NET_PPP_COMP_H
48 * The following symbols control whether we include code for
49 * various compression methods.
52 #ifndef DO_BSD_COMPRESS
53 #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */
56 #define DO_DEFLATE 1 /* by default, include Deflate */
58 #define DO_PREDICTOR_1 0
59 #define DO_PREDICTOR_2 0
62 * Structure giving methods for compression/decompression.
66 int compress_proto
; /* CCP compression protocol number */
68 /* Allocate space for a compressor (transmit side) */
69 void *(*comp_alloc
) (unsigned char *options
, int opt_len
);
71 /* Free space used by a compressor */
72 void (*comp_free
) (void *state
);
74 /* Initialize a compressor */
75 int (*comp_init
) (void *state
, unsigned char *options
,
76 int opt_len
, int unit
, int opthdr
, int debug
);
78 /* Reset a compressor */
79 void (*comp_reset
) (void *state
);
81 /* Compress a packet */
82 int (*compress
) (void *state
, unsigned char *rptr
,
83 unsigned char *obuf
, int isize
, int osize
);
85 /* Return compression statistics */
86 void (*comp_stat
) (void *state
, struct compstat
*stats
);
88 /* Allocate space for a decompressor (receive side) */
89 void *(*decomp_alloc
) (unsigned char *options
, int opt_len
);
91 /* Free space used by a decompressor */
92 void (*decomp_free
) (void *state
);
94 /* Initialize a decompressor */
95 int (*decomp_init
) (void *state
, unsigned char *options
,
96 int opt_len
, int unit
, int opthdr
, int mru
,
99 /* Reset a decompressor */
100 void (*decomp_reset
) (void *state
);
102 /* Decompress a packet. */
103 int (*decompress
) (void *state
, unsigned char *ibuf
, int isize
,
104 unsigned char *obuf
, int osize
);
106 /* Update state for an incompressible packet received */
107 void (*incomp
) (void *state
, unsigned char *ibuf
, int icnt
);
109 /* Return decompression statistics */
110 void (*decomp_stat
) (void *state
, struct compstat
*stats
);
112 /* Used in locking compressor modules */
113 struct module
*owner
;
114 /* Extra skb space needed by the compressor algorithm */
115 unsigned int comp_extra
;
119 * The return value from decompress routine is the length of the
120 * decompressed packet if successful, otherwise DECOMP_ERROR
121 * or DECOMP_FATALERROR if an error occurred.
123 * We need to make this distinction so that we can disable certain
124 * useful functionality, namely sending a CCP reset-request as a result
125 * of an error detected after decompression. This is to avoid infringing
126 * a patent held by Motorola.
127 * Don't you just lurve software patents.
130 #define DECOMP_ERROR -1 /* error detected before decomp. */
131 #define DECOMP_FATALERROR -2 /* error detected after decomp. */
137 #define CCP_CONFREQ 1
138 #define CCP_CONFACK 2
139 #define CCP_TERMREQ 5
140 #define CCP_TERMACK 6
141 #define CCP_RESETREQ 14
142 #define CCP_RESETACK 15
145 * Max # bytes for a CCP option
148 #define CCP_MAX_OPTION_LENGTH 32
151 * Parts of a CCP packet.
154 #define CCP_CODE(dp) ((dp)[0])
155 #define CCP_ID(dp) ((dp)[1])
156 #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3])
159 #define CCP_OPT_CODE(dp) ((dp)[0])
160 #define CCP_OPT_LENGTH(dp) ((dp)[1])
161 #define CCP_OPT_MINLEN 2
164 * Definitions for BSD-Compress.
167 #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */
168 #define CILEN_BSD_COMPRESS 3 /* length of config. option */
170 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
171 #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */
172 #define BSD_VERSION(x) ((x) >> 5) /* version of option format */
173 #define BSD_CURRENT_VERSION 1 /* current version number */
174 #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n))
176 #define BSD_MIN_BITS 9 /* smallest code size supported */
177 #define BSD_MAX_BITS 15 /* largest code size supported */
180 * Definitions for Deflate.
183 #define CI_DEFLATE 26 /* config option for Deflate */
184 #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */
185 #define CILEN_DEFLATE 4 /* length of its config option */
187 #define DEFLATE_MIN_SIZE 9
188 #define DEFLATE_MAX_SIZE 15
189 #define DEFLATE_METHOD_VAL 8
190 #define DEFLATE_SIZE(x) (((x) >> 4) + 8)
191 #define DEFLATE_METHOD(x) ((x) & 0x0F)
192 #define DEFLATE_MAKE_OPT(w) ((((w) - 8) << 4) + DEFLATE_METHOD_VAL)
193 #define DEFLATE_CHK_SEQUENCE 0
196 * Definitions for MPPE.
199 #define CI_MPPE 18 /* config option for MPPE */
200 #define CILEN_MPPE 6 /* length of config option */
203 * Definitions for other, as yet unsupported, compression methods.
206 #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */
207 #define CILEN_PREDICTOR_1 2 /* length of its config option */
208 #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */
209 #define CILEN_PREDICTOR_2 2 /* length of its config option */
212 extern int ppp_register_compressor(struct compressor
*);
213 extern void ppp_unregister_compressor(struct compressor
*);
214 #endif /* __KERNEL__ */
216 #endif /* _NET_PPP_COMP_H */