2 * ppp-comp.h - Definitions for doing PPP packet compression.
4 * Copyright (c) 1994 Paul Mackerras. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
18 * 3. The name(s) of the authors of this software must not be used to
19 * endorse or promote products derived from this software without
20 * prior written permission.
22 * 4. Redistributions of any form whatsoever must retain the following
24 * "This product includes software developed by Paul Mackerras
25 * <paulus@samba.org>".
27 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
28 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
29 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
30 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
32 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
33 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
35 * $Id: ppp-comp.h,v 1.2 2002/12/06 09:49:16 paulus Exp $
38 #ifndef _NET_PPP_COMP_H
39 #define _NET_PPP_COMP_H
42 * The following symbols control whether we include code for
43 * various compression methods.
45 #ifndef DO_BSD_COMPRESS
46 #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */
49 #define DO_DEFLATE 1 /* by default, include Deflate */
51 #define DO_PREDICTOR_1 0
52 #define DO_PREDICTOR_2 0
55 #include <net/ppp_defs.h>
57 #include <linux/ppp_defs.h>
61 * Structure giving methods for compression/decompression.
64 int compress_proto; /* CCP compression protocol number */
66 /* Allocate space for a decompressor (receive side) */
67 void *(*decomp_alloc)(u_char *options, int opt_len);
68 /* Free space used by a decompressor */
69 void (*decomp_free)(void *state);
70 /* Initialize a decompressor */
71 int (*decomp_init)(void *state, u_char *options, int opt_len,
72 int unit, int hdrlen, int mru, int debug);
73 /* Reset a decompressor */
74 void (*decomp_reset)(void *state);
75 /* Decompress a packet. */
76 int (*decompress)(void *state, u_char *mp, int inlen,
77 u_char *dmp, int *outlen);
78 /* Update state for an incompressible packet received */
79 void (*incomp)(void *state, u_char *mp, int len);
80 /* Return decompression statistics */
81 void (*decomp_stat)(void *state, struct compstat *stats);
85 * Return values for decompress routine.
86 * We need to make these distinctions so that we can disable certain
87 * useful functionality, namely sending a CCP reset-request as a result
88 * of an error detected after decompression. This is to avoid infringing
89 * a patent held by Motorola.
90 * Don't you just lurve software patents.
92 #define DECOMP_OK 0 /* everything went OK */
93 #define DECOMP_ERROR 1 /* error detected before decomp. */
94 #define DECOMP_FATALERROR 2 /* error detected after decomp. */
100 #define CCP_CONFACK 2
101 #define CCP_CONFNAK 3
102 #define CCP_CONFREJ 4
103 #define CCP_TERMREQ 5
104 #define CCP_TERMACK 6
105 #define CCP_RESETREQ 14
106 #define CCP_RESETACK 15
109 * Max # bytes for a CCP option
111 #define CCP_MAX_OPTION_LENGTH 32
114 * Parts of a CCP packet.
116 #define CCP_CODE(dp) ((dp)[0])
117 #define CCP_ID(dp) ((dp)[1])
118 #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3])
121 #define CCP_OPT_CODE(dp) ((dp)[0])
122 #define CCP_OPT_LENGTH(dp) ((dp)[1])
123 #define CCP_OPT_MINLEN 2
126 * Definitions for BSD-Compress.
128 #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */
129 #define CILEN_BSD_COMPRESS 3 /* length of config. option */
131 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
132 #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */
133 #define BSD_VERSION(x) ((x) >> 5) /* version of option format */
134 #define BSD_CURRENT_VERSION 1 /* current version number */
135 #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n))
137 #define BSD_MIN_BITS 9 /* smallest code size supported */
138 #define BSD_MAX_BITS 15 /* largest code size supported */
141 * Definitions for Deflate.
143 #define CI_DEFLATE 26 /* config option for Deflate */
144 #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */
145 #define CILEN_DEFLATE 4 /* length of its config option */
147 #define DEFLATE_MIN_SIZE 8
148 #define DEFLATE_MAX_SIZE 15
149 #define DEFLATE_METHOD_VAL 8
150 #define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE)
151 #define DEFLATE_METHOD(x) ((x) & 0x0F)
152 #define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \
153 + DEFLATE_METHOD_VAL)
154 #define DEFLATE_CHK_SEQUENCE 0
157 * Definitions for other, as yet unsupported, compression methods.
159 #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */
160 #define CILEN_PREDICTOR_1 2 /* length of its config option */
161 #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */
162 #define CILEN_PREDICTOR_2 2 /* length of its config option */
164 #endif /* _NET_PPP_COMP_H */