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 1.7 1995/05/01 01:43:37 paulus Exp $
30 #ifndef _NET_PPP_COMP_H
31 #define _NET_PPP_COMP_H
34 * The following symbols control whether we include code for
35 * various compression methods.
37 #ifndef DO_BSD_COMPRESS
38 #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */
42 * Structure giving methods for compression/decompression.
46 int compress_proto; /* CCP compression protocol number */
48 /* Allocate space for a compressor (transmit side) */
49 void *(*comp_alloc) __P((u_char *options, int opt_len));
50 /* Free space used by a compressor */
51 void (*comp_free) __P((void *state));
52 /* Initialize a compressor */
53 int (*comp_init) __P((void *state, u_char *options, int opt_len,
54 int unit, int hdrlen, int debug));
55 /* Reset a compressor */
56 void (*comp_reset) __P((void *state));
57 /* Compress a packet */
58 int (*compress) __P((void *state, PACKETPTR *mret,
59 PACKETPTR mp, int orig_len, int max_len));
60 /* Return compression statistics */
61 void (*comp_stat) __P((void *state, struct compstat *stats));
63 /* Allocate space for a decompressor (receive side) */
64 void *(*decomp_alloc) __P((u_char *options, int opt_len));
65 /* Free space used by a decompressor */
66 void (*decomp_free) __P((void *state));
67 /* Initialize a decompressor */
68 int (*decomp_init) __P((void *state, u_char *options, int opt_len,
69 int unit, int hdrlen, int mru, int debug));
70 /* Reset a decompressor */
71 void (*decomp_reset) __P((void *state));
72 /* Decompress a packet. */
73 int (*decompress) __P((void *state, PACKETPTR mp,
75 /* Update state for an incompressible packet received */
76 void (*incomp) __P((void *state, PACKETPTR mp));
77 /* Return decompression statistics */
78 void (*decomp_stat) __P((void *state, struct compstat *stats));
80 #endif /* PACKETPTR */
83 * Return values for decompress routine.
84 * We need to make these distinctions so that we can disable certain
85 * useful functionality, namely sending a CCP reset-request as a result
86 * of an error detected after decompression. This is to avoid infringing
87 * a patent held by Motorola.
88 * Don't you just lurve software patents.
90 #define DECOMP_OK 0 /* everything went OK */
91 #define DECOMP_ERROR 1 /* error detected before decomp. */
92 #define DECOMP_FATALERROR 2 /* error detected after decomp. */
100 #define CCP_TERMACK 6
101 #define CCP_RESETREQ 14
102 #define CCP_RESETACK 15
105 * Max # bytes for a CCP option
107 #define CCP_MAX_OPTION_LENGTH 32
110 * Parts of a CCP packet.
112 #define CCP_CODE(dp) ((dp)[0])
113 #define CCP_ID(dp) ((dp)[1])
114 #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3])
117 #define CCP_OPT_CODE(dp) ((dp)[0])
118 #define CCP_OPT_LENGTH(dp) ((dp)[1])
119 #define CCP_OPT_MINLEN 2
122 * Definitions for BSD-Compress.
124 #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */
125 #define CILEN_BSD_COMPRESS 3 /* length of config. option */
127 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
128 #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */
129 #define BSD_VERSION(x) ((x) >> 5) /* version of option format */
130 #define BSD_CURRENT_VERSION 1 /* current version number */
131 #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n))
133 #define BSD_MIN_BITS 9 /* smallest code size supported */
134 #define BSD_MAX_BITS 15 /* largest code size supported */
136 #endif /* _NET_PPP_COMP_H */