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,
30 #ifndef _NET_PPP_COMP_H
31 #define _NET_PPP_COMP_H
34 * Structure giving methods for compression/decompression.
38 int compress_proto; /* CCP compression protocol number */
40 /* Allocate space for a compressor (transmit side) */
41 void *(*comp_alloc)(u_char *options, int opt_len);
42 /* Free space used by a compressor */
43 void (*comp_free)(void *state);
44 /* Initialize a compressor */
45 int (*comp_init)(void *state, u_char *options, int opt_len,
46 int unit, int hdrlen, int debug);
47 /* Reset a compressor */
48 void (*comp_reset)(void *state);
49 /* Compress a packet */
50 int (*compress)(void *state, PACKETPTR *mret, PACKETPTR mp,
51 int orig_len, int max_len);
52 /* Return compression statistics */
53 void (*comp_stat)(void *state, struct compstat *stats);
55 /* Allocate space for a decompressor (receive side) */
56 void *(*decomp_alloc)(u_char *options, int opt_len);
57 /* Free space used by a decompressor */
58 void (*decomp_free)(void *state);
59 /* Initialize a decompressor */
60 int (*decomp_init)(void *state, u_char *options, int opt_len,
61 int unit, int hdrlen, int mru, int debug);
62 /* Reset a decompressor */
63 void (*decomp_reset)(void *state);
64 /* Decompress a packet. */
65 int (*decompress)(void *state, PACKETPTR mp, PACKETPTR *dmpp);
66 /* Update state for an incompressible packet received */
67 void (*incomp)(void *state, PACKETPTR mp);
68 /* Return decompression statistics */
69 void (*decomp_stat)(void *state, struct compstat *stats);
71 #endif /* PACKETPTR */
74 * Return values for decompress routine.
75 * We need to make these distinctions so that we can disable certain
76 * useful functionality, namely sending a CCP reset-request as a result
77 * of an error detected after decompression. This is to avoid infringing
78 * a patent held by Motorola.
79 * Don't you just lurve software patents.
81 #define DECOMP_OK 0 /* everything went OK */
82 #define DECOMP_ERROR 1 /* error detected before decomp. */
83 #define DECOMP_FATALERROR 2 /* error detected after decomp. */
92 #define CCP_RESETREQ 14
93 #define CCP_RESETACK 15
96 * Max # bytes for a CCP option
98 #define CCP_MAX_OPTION_LENGTH 32
101 * Parts of a CCP packet.
103 #define CCP_CODE(dp) ((dp)[0])
104 #define CCP_ID(dp) ((dp)[1])
105 #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3])
108 #define CCP_OPT_CODE(dp) ((dp)[0])
109 #define CCP_OPT_LENGTH(dp) ((dp)[1])
110 #define CCP_OPT_MINLEN 2
113 * Definitions for BSD-Compress.
115 #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */
116 #define CILEN_BSD_COMPRESS 3 /* length of config. option */
118 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
119 #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */
120 #define BSD_VERSION(x) ((x) >> 5) /* version of option format */
121 #define BSD_CURRENT_VERSION 1 /* current version number */
122 #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n))
124 #define BSD_MIN_BITS 9 /* smallest code size supported */
125 #define BSD_MAX_BITS 15 /* largest code size supported */
128 * Definitions for Deflate.
130 #define CI_DEFLATE 26 /* config option for Deflate */
131 #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */
132 #define CILEN_DEFLATE 4 /* length of its config option */
134 #define DEFLATE_MIN_SIZE 8
135 #define DEFLATE_MAX_SIZE 15
136 #define DEFLATE_METHOD_VAL 8
137 #define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE)
138 #define DEFLATE_METHOD(x) ((x) & 0x0F)
139 #define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \
140 + DEFLATE_METHOD_VAL)
141 #define DEFLATE_CHK_SEQUENCE 0
144 * Definitions for other, as yet unsupported, compression methods.
146 #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */
147 #define CILEN_PREDICTOR_1 2 /* length of its config option */
148 #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */
149 #define CILEN_PREDICTOR_2 2 /* length of its config option */
151 #endif /* _NET_PPP_COMP_H */