1 /* $OpenBSD: ppp-comp.h,v 1.8 2002/09/13 00:12:07 deraadt Exp $ */
2
3 /*
4 * ppp-comp.h - Definitions for doing PPP packet compression.
5 *
6 * Copyright (c) 1989-2002 Paul Mackerras. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. The name(s) of the authors of this software must not be used to
21 * endorse or promote products derived from this software without
22 * prior written permission.
23 *
24 * 4. Redistributions of any form whatsoever must retain the following
25 * acknowledgment:
26 * "This product includes software developed by Paul Mackerras
27 * <paulus@samba.org>".
28 *
29 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
30 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
31 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
32 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
33 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
34 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
35 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
36 */
37
38 #ifndef _NET_PPP_COMP_H_
39 #define _NET_PPP_COMP_H_
40
41 /*
42 * The following symbols control whether we include code for
43 * various compression methods.
44 */
45 #ifndef DO_BSD_COMPRESS
46 #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */
47 #endif
48 #ifndef DO_DEFLATE
49 #define DO_DEFLATE 1 /* by default, include Deflate */
50 #endif
51 #define DO_PREDICTOR_1 0
52 #define DO_PREDICTOR_2 0
53
54 /*
55 * Structure giving methods for compression/decompression.
56 */
57 #ifdef PACKETPTR
58 struct compressor {
59 int compress_proto; /* CCP compression protocol number */
60
61 /* Allocate space for a compressor (transmit side) */
62 void *(*comp_alloc)(u_char *options, int opt_len);
63 /* Free space used by a compressor */
64 void (*comp_free)(void *state);
65 /* Initialize a compressor */
66 int (*comp_init)(void *state, u_char *options, int opt_len,
67 int unit, int hdrlen, int debug);
68 /* Reset a compressor */
69 void (*comp_reset)(void *state);
70 /* Compress a packet */
71 int (*compress)(void *state, PACKETPTR *mret,
72 PACKETPTR mp, int orig_len, int max_len);
73 /* Return compression statistics */
74 void (*comp_stat)(void *state, struct compstat *stats);
75
76 /* Allocate space for a decompressor (receive side) */
77 void *(*decomp_alloc)(u_char *options, int opt_len);
78 /* Free space used by a decompressor */
79 void (*decomp_free)(void *state);
80 /* Initialize a decompressor */
81 int (*decomp_init)(void *state, u_char *options, int opt_len,
82 int unit, int hdrlen, int mru, int debug);
83 /* Reset a decompressor */
84 void (*decomp_reset)(void *state);
85 /* Decompress a packet. */
86 int (*decompress)(void *state, PACKETPTR mp,
87 PACKETPTR *dmpp);
88 /* Update state for an incompressible packet received */
89 void (*incomp)(void *state, PACKETPTR mp);
90 /* Return decompression statistics */
91 void (*decomp_stat)(void *state, struct compstat *stats);
92 };
93 #endif /* PACKETPTR */
94
95 /*
96 * Return values for decompress routine.
97 * We need to make these distinctions so that we can disable certain
98 * useful functionality, namely sending a CCP reset-request as a result
99 * of an error detected after decompression. This is to avoid infringing
100 * a patent held by Motorola.
101 * Don't you just lurve software patents.
102 */
103 #define DECOMP_OK 0 /* everything went OK */
104 #define DECOMP_ERROR 1 /* error detected before decomp. */
105 #define DECOMP_FATALERROR 2 /* error detected after decomp. */
106
107 /*
108 * CCP codes.
109 */
110 #define CCP_CONFREQ 1
111 #define CCP_CONFACK 2
112 #define CCP_TERMREQ 5
113 #define CCP_TERMACK 6
114 #define CCP_RESETREQ 14
115 #define CCP_RESETACK 15
116
117 /*
118 * Max # bytes for a CCP option
119 */
120 #define CCP_MAX_OPTION_LENGTH 32
121
122 /*
123 * Parts of a CCP packet.
124 */
125 #define CCP_CODE(dp) ((dp)[0])
126 #define CCP_ID(dp) ((dp)[1])
127 #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3])
128 #define CCP_HDRLEN 4
129
130 #define CCP_OPT_CODE(dp) ((dp)[0])
131 #define CCP_OPT_LENGTH(dp) ((dp)[1])
132 #define CCP_OPT_MINLEN 2
133
134 /*
135 * Definitions for BSD-Compress.
136 */
137 #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */
138 #define CILEN_BSD_COMPRESS 3 /* length of config. option */
139
140 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
141 #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */
142 #define BSD_VERSION(x) ((x) >> 5) /* version of option format */
143 #define BSD_CURRENT_VERSION 1 /* current version number */
144 #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n))
145
146 #define BSD_MIN_BITS 9 /* smallest code size supported */
147 #define BSD_MAX_BITS 15 /* largest code size supported */
148
149 /*
150 * Definitions for Deflate.
151 */
152 #define CI_DEFLATE 26 /* config option for Deflate */
153 #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */
154 #define CILEN_DEFLATE 4 /* length of its config option */
155
156 #define DEFLATE_MIN_SIZE 8
157 #define DEFLATE_MAX_SIZE 15
158 #define DEFLATE_METHOD_VAL 8
159 #define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE)
160 #define DEFLATE_METHOD(x) ((x) & 0x0F)
161 #define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \
162 + DEFLATE_METHOD_VAL)
163 #define DEFLATE_CHK_SEQUENCE 0
164
165 /*
166 * Definitions for other, as yet unsupported, compression methods.
167 */
168 #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */
169 #define CILEN_PREDICTOR_1 2 /* length of its config option */
170 #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */
171 #define CILEN_PREDICTOR_2 2 /* length of its config option */
172
173 #endif /* _NET_PPP_COMP_H_ */