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1da177e4 LT |
1 | /* |
2 | * ppp-comp.h - Definitions for doing PPP packet compression. | |
3 | * | |
4 | * Copyright (c) 1994 The Australian National University. | |
5 | * All rights reserved. | |
6 | * | |
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 | |
12 | * any purpose. | |
13 | * | |
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 | |
18 | * OF SUCH DAMAGE. | |
19 | * | |
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, | |
25 | * OR MODIFICATIONS. | |
1da177e4 LT |
26 | */ |
27 | ||
28 | /* | |
29 | * ==FILEVERSION 980319== | |
30 | * | |
31 | * NOTE TO MAINTAINERS: | |
32 | * If you modify this file at all, please set the above date. | |
33 | * ppp-comp.h is shipped with a PPP distribution as well as with the kernel; | |
34 | * if everyone increases the FILEVERSION number above, then scripts | |
35 | * can do the right thing when deciding whether to install a new ppp-comp.h | |
36 | * file. Don't change the format of that line otherwise, so the | |
37 | * installation script can recognize it. | |
38 | */ | |
39 | ||
40 | #ifndef _NET_PPP_COMP_H | |
41 | #define _NET_PPP_COMP_H | |
42 | ||
43 | struct module; | |
44 | ||
45 | /* | |
46 | * The following symbols control whether we include code for | |
47 | * various compression methods. | |
48 | */ | |
49 | ||
50 | #ifndef DO_BSD_COMPRESS | |
51 | #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ | |
52 | #endif | |
53 | #ifndef DO_DEFLATE | |
54 | #define DO_DEFLATE 1 /* by default, include Deflate */ | |
55 | #endif | |
56 | #define DO_PREDICTOR_1 0 | |
57 | #define DO_PREDICTOR_2 0 | |
58 | ||
59 | /* | |
60 | * Structure giving methods for compression/decompression. | |
61 | */ | |
62 | ||
63 | struct compressor { | |
64 | int compress_proto; /* CCP compression protocol number */ | |
65 | ||
66 | /* Allocate space for a compressor (transmit side) */ | |
67 | void *(*comp_alloc) (unsigned char *options, int opt_len); | |
68 | ||
69 | /* Free space used by a compressor */ | |
70 | void (*comp_free) (void *state); | |
71 | ||
72 | /* Initialize a compressor */ | |
73 | int (*comp_init) (void *state, unsigned char *options, | |
74 | int opt_len, int unit, int opthdr, int debug); | |
75 | ||
76 | /* Reset a compressor */ | |
77 | void (*comp_reset) (void *state); | |
78 | ||
79 | /* Compress a packet */ | |
80 | int (*compress) (void *state, unsigned char *rptr, | |
81 | unsigned char *obuf, int isize, int osize); | |
82 | ||
83 | /* Return compression statistics */ | |
84 | void (*comp_stat) (void *state, struct compstat *stats); | |
85 | ||
86 | /* Allocate space for a decompressor (receive side) */ | |
87 | void *(*decomp_alloc) (unsigned char *options, int opt_len); | |
88 | ||
89 | /* Free space used by a decompressor */ | |
90 | void (*decomp_free) (void *state); | |
91 | ||
92 | /* Initialize a decompressor */ | |
93 | int (*decomp_init) (void *state, unsigned char *options, | |
94 | int opt_len, int unit, int opthdr, int mru, | |
95 | int debug); | |
96 | ||
97 | /* Reset a decompressor */ | |
98 | void (*decomp_reset) (void *state); | |
99 | ||
100 | /* Decompress a packet. */ | |
101 | int (*decompress) (void *state, unsigned char *ibuf, int isize, | |
102 | unsigned char *obuf, int osize); | |
103 | ||
104 | /* Update state for an incompressible packet received */ | |
105 | void (*incomp) (void *state, unsigned char *ibuf, int icnt); | |
106 | ||
107 | /* Return decompression statistics */ | |
108 | void (*decomp_stat) (void *state, struct compstat *stats); | |
109 | ||
110 | /* Used in locking compressor modules */ | |
111 | struct module *owner; | |
b3f9b92a MD |
112 | /* Extra skb space needed by the compressor algorithm */ |
113 | unsigned int comp_extra; | |
1da177e4 LT |
114 | }; |
115 | ||
116 | /* | |
117 | * The return value from decompress routine is the length of the | |
118 | * decompressed packet if successful, otherwise DECOMP_ERROR | |
119 | * or DECOMP_FATALERROR if an error occurred. | |
120 | * | |
121 | * We need to make this distinction so that we can disable certain | |
122 | * useful functionality, namely sending a CCP reset-request as a result | |
123 | * of an error detected after decompression. This is to avoid infringing | |
124 | * a patent held by Motorola. | |
125 | * Don't you just lurve software patents. | |
126 | */ | |
127 | ||
128 | #define DECOMP_ERROR -1 /* error detected before decomp. */ | |
129 | #define DECOMP_FATALERROR -2 /* error detected after decomp. */ | |
130 | ||
131 | /* | |
132 | * CCP codes. | |
133 | */ | |
134 | ||
135 | #define CCP_CONFREQ 1 | |
136 | #define CCP_CONFACK 2 | |
137 | #define CCP_TERMREQ 5 | |
138 | #define CCP_TERMACK 6 | |
139 | #define CCP_RESETREQ 14 | |
140 | #define CCP_RESETACK 15 | |
141 | ||
142 | /* | |
143 | * Max # bytes for a CCP option | |
144 | */ | |
145 | ||
146 | #define CCP_MAX_OPTION_LENGTH 32 | |
147 | ||
148 | /* | |
149 | * Parts of a CCP packet. | |
150 | */ | |
151 | ||
152 | #define CCP_CODE(dp) ((dp)[0]) | |
153 | #define CCP_ID(dp) ((dp)[1]) | |
154 | #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3]) | |
155 | #define CCP_HDRLEN 4 | |
156 | ||
157 | #define CCP_OPT_CODE(dp) ((dp)[0]) | |
158 | #define CCP_OPT_LENGTH(dp) ((dp)[1]) | |
159 | #define CCP_OPT_MINLEN 2 | |
160 | ||
161 | /* | |
162 | * Definitions for BSD-Compress. | |
163 | */ | |
164 | ||
165 | #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */ | |
166 | #define CILEN_BSD_COMPRESS 3 /* length of config. option */ | |
167 | ||
168 | /* Macros for handling the 3rd byte of the BSD-Compress config option. */ | |
169 | #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */ | |
170 | #define BSD_VERSION(x) ((x) >> 5) /* version of option format */ | |
171 | #define BSD_CURRENT_VERSION 1 /* current version number */ | |
172 | #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n)) | |
173 | ||
174 | #define BSD_MIN_BITS 9 /* smallest code size supported */ | |
175 | #define BSD_MAX_BITS 15 /* largest code size supported */ | |
176 | ||
177 | /* | |
178 | * Definitions for Deflate. | |
179 | */ | |
180 | ||
181 | #define CI_DEFLATE 26 /* config option for Deflate */ | |
182 | #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */ | |
183 | #define CILEN_DEFLATE 4 /* length of its config option */ | |
184 | ||
185 | #define DEFLATE_MIN_SIZE 9 | |
186 | #define DEFLATE_MAX_SIZE 15 | |
187 | #define DEFLATE_METHOD_VAL 8 | |
188 | #define DEFLATE_SIZE(x) (((x) >> 4) + 8) | |
189 | #define DEFLATE_METHOD(x) ((x) & 0x0F) | |
190 | #define DEFLATE_MAKE_OPT(w) ((((w) - 8) << 4) + DEFLATE_METHOD_VAL) | |
191 | #define DEFLATE_CHK_SEQUENCE 0 | |
192 | ||
b3f9b92a MD |
193 | /* |
194 | * Definitions for MPPE. | |
195 | */ | |
196 | ||
197 | #define CI_MPPE 18 /* config option for MPPE */ | |
198 | #define CILEN_MPPE 6 /* length of config option */ | |
199 | ||
1da177e4 LT |
200 | /* |
201 | * Definitions for other, as yet unsupported, compression methods. | |
202 | */ | |
203 | ||
204 | #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */ | |
205 | #define CILEN_PREDICTOR_1 2 /* length of its config option */ | |
206 | #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */ | |
207 | #define CILEN_PREDICTOR_2 2 /* length of its config option */ | |
208 | ||
209 | #ifdef __KERNEL__ | |
210 | extern int ppp_register_compressor(struct compressor *); | |
211 | extern void ppp_unregister_compressor(struct compressor *); | |
212 | #endif /* __KERNEL__ */ | |
213 | ||
214 | #endif /* _NET_PPP_COMP_H */ |