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1 | /* | |
2 | * ppp-comp.h - Definitions for doing PPP packet compression. | |
3 | * | |
4 | * Copyright 1994-1998 Paul Mackerras. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * version 2 as published by the Free Software Foundation. | |
9 | */ | |
10 | #ifndef _NET_PPP_COMP_H | |
11 | #define _NET_PPP_COMP_H | |
12 | ||
13 | #include <uapi/linux/ppp-comp.h> | |
14 | ||
15 | ||
16 | struct module; | |
17 | ||
18 | /* | |
19 | * The following symbols control whether we include code for | |
20 | * various compression methods. | |
21 | */ | |
22 | ||
23 | #ifndef DO_BSD_COMPRESS | |
24 | #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ | |
25 | #endif | |
26 | #ifndef DO_DEFLATE | |
27 | #define DO_DEFLATE 1 /* by default, include Deflate */ | |
28 | #endif | |
29 | #define DO_PREDICTOR_1 0 | |
30 | #define DO_PREDICTOR_2 0 | |
31 | ||
32 | /* | |
33 | * Structure giving methods for compression/decompression. | |
34 | */ | |
35 | ||
36 | struct compressor { | |
37 | int compress_proto; /* CCP compression protocol number */ | |
38 | ||
39 | /* Allocate space for a compressor (transmit side) */ | |
40 | void *(*comp_alloc) (unsigned char *options, int opt_len); | |
41 | ||
42 | /* Free space used by a compressor */ | |
43 | void (*comp_free) (void *state); | |
44 | ||
45 | /* Initialize a compressor */ | |
46 | int (*comp_init) (void *state, unsigned char *options, | |
47 | int opt_len, int unit, int opthdr, int debug); | |
48 | ||
49 | /* Reset a compressor */ | |
50 | void (*comp_reset) (void *state); | |
51 | ||
52 | /* Compress a packet */ | |
53 | int (*compress) (void *state, unsigned char *rptr, | |
54 | unsigned char *obuf, int isize, int osize); | |
55 | ||
56 | /* Return compression statistics */ | |
57 | void (*comp_stat) (void *state, struct compstat *stats); | |
58 | ||
59 | /* Allocate space for a decompressor (receive side) */ | |
60 | void *(*decomp_alloc) (unsigned char *options, int opt_len); | |
61 | ||
62 | /* Free space used by a decompressor */ | |
63 | void (*decomp_free) (void *state); | |
64 | ||
65 | /* Initialize a decompressor */ | |
66 | int (*decomp_init) (void *state, unsigned char *options, | |
67 | int opt_len, int unit, int opthdr, int mru, | |
68 | int debug); | |
69 | ||
70 | /* Reset a decompressor */ | |
71 | void (*decomp_reset) (void *state); | |
72 | ||
73 | /* Decompress a packet. */ | |
74 | int (*decompress) (void *state, unsigned char *ibuf, int isize, | |
75 | unsigned char *obuf, int osize); | |
76 | ||
77 | /* Update state for an incompressible packet received */ | |
78 | void (*incomp) (void *state, unsigned char *ibuf, int icnt); | |
79 | ||
80 | /* Return decompression statistics */ | |
81 | void (*decomp_stat) (void *state, struct compstat *stats); | |
82 | ||
83 | /* Used in locking compressor modules */ | |
84 | struct module *owner; | |
85 | /* Extra skb space needed by the compressor algorithm */ | |
86 | unsigned int comp_extra; | |
87 | }; | |
88 | ||
89 | /* | |
90 | * The return value from decompress routine is the length of the | |
91 | * decompressed packet if successful, otherwise DECOMP_ERROR | |
92 | * or DECOMP_FATALERROR if an error occurred. | |
93 | * | |
94 | * We need to make this distinction so that we can disable certain | |
95 | * useful functionality, namely sending a CCP reset-request as a result | |
96 | * of an error detected after decompression. This is to avoid infringing | |
97 | * a patent held by Motorola. | |
98 | * Don't you just lurve software patents. | |
99 | */ | |
100 | ||
101 | #define DECOMP_ERROR -1 /* error detected before decomp. */ | |
102 | #define DECOMP_FATALERROR -2 /* error detected after decomp. */ | |
103 | ||
104 | extern int ppp_register_compressor(struct compressor *); | |
105 | extern void ppp_unregister_compressor(struct compressor *); | |
106 | #endif /* _NET_PPP_COMP_H */ |