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d2912cb1 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
1da177e4 LT |
2 | /* |
3 | * ppp-comp.h - Definitions for doing PPP packet compression. | |
4 | * | |
784db3f0 | 5 | * Copyright 1994-1998 Paul Mackerras. |
1da177e4 | 6 | */ |
1da177e4 LT |
7 | #ifndef _NET_PPP_COMP_H |
8 | #define _NET_PPP_COMP_H | |
9 | ||
607ca46e DH |
10 | #include <uapi/linux/ppp-comp.h> |
11 | ||
5f10376b | 12 | struct compstat; |
1da177e4 LT |
13 | struct module; |
14 | ||
15 | /* | |
16 | * The following symbols control whether we include code for | |
17 | * various compression methods. | |
18 | */ | |
19 | ||
20 | #ifndef DO_BSD_COMPRESS | |
21 | #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ | |
22 | #endif | |
23 | #ifndef DO_DEFLATE | |
24 | #define DO_DEFLATE 1 /* by default, include Deflate */ | |
25 | #endif | |
26 | #define DO_PREDICTOR_1 0 | |
27 | #define DO_PREDICTOR_2 0 | |
28 | ||
29 | /* | |
30 | * Structure giving methods for compression/decompression. | |
31 | */ | |
32 | ||
33 | struct compressor { | |
34 | int compress_proto; /* CCP compression protocol number */ | |
35 | ||
36 | /* Allocate space for a compressor (transmit side) */ | |
37 | void *(*comp_alloc) (unsigned char *options, int opt_len); | |
38 | ||
39 | /* Free space used by a compressor */ | |
40 | void (*comp_free) (void *state); | |
41 | ||
42 | /* Initialize a compressor */ | |
43 | int (*comp_init) (void *state, unsigned char *options, | |
44 | int opt_len, int unit, int opthdr, int debug); | |
45 | ||
46 | /* Reset a compressor */ | |
47 | void (*comp_reset) (void *state); | |
48 | ||
49 | /* Compress a packet */ | |
50 | int (*compress) (void *state, unsigned char *rptr, | |
51 | unsigned char *obuf, int isize, int osize); | |
52 | ||
53 | /* Return compression statistics */ | |
54 | void (*comp_stat) (void *state, struct compstat *stats); | |
55 | ||
56 | /* Allocate space for a decompressor (receive side) */ | |
57 | void *(*decomp_alloc) (unsigned char *options, int opt_len); | |
58 | ||
59 | /* Free space used by a decompressor */ | |
60 | void (*decomp_free) (void *state); | |
61 | ||
62 | /* Initialize a decompressor */ | |
63 | int (*decomp_init) (void *state, unsigned char *options, | |
64 | int opt_len, int unit, int opthdr, int mru, | |
65 | int debug); | |
66 | ||
67 | /* Reset a decompressor */ | |
68 | void (*decomp_reset) (void *state); | |
69 | ||
70 | /* Decompress a packet. */ | |
71 | int (*decompress) (void *state, unsigned char *ibuf, int isize, | |
72 | unsigned char *obuf, int osize); | |
73 | ||
74 | /* Update state for an incompressible packet received */ | |
75 | void (*incomp) (void *state, unsigned char *ibuf, int icnt); | |
76 | ||
77 | /* Return decompression statistics */ | |
78 | void (*decomp_stat) (void *state, struct compstat *stats); | |
79 | ||
80 | /* Used in locking compressor modules */ | |
81 | struct module *owner; | |
b3f9b92a MD |
82 | /* Extra skb space needed by the compressor algorithm */ |
83 | unsigned int comp_extra; | |
1da177e4 LT |
84 | }; |
85 | ||
86 | /* | |
87 | * The return value from decompress routine is the length of the | |
88 | * decompressed packet if successful, otherwise DECOMP_ERROR | |
89 | * or DECOMP_FATALERROR if an error occurred. | |
90 | * | |
91 | * We need to make this distinction so that we can disable certain | |
92 | * useful functionality, namely sending a CCP reset-request as a result | |
93 | * of an error detected after decompression. This is to avoid infringing | |
94 | * a patent held by Motorola. | |
95 | * Don't you just lurve software patents. | |
96 | */ | |
97 | ||
98 | #define DECOMP_ERROR -1 /* error detected before decomp. */ | |
99 | #define DECOMP_FATALERROR -2 /* error detected after decomp. */ | |
100 | ||
1da177e4 LT |
101 | extern int ppp_register_compressor(struct compressor *); |
102 | extern void ppp_unregister_compressor(struct compressor *); | |
1da177e4 | 103 | #endif /* _NET_PPP_COMP_H */ |