1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
|
/*
* Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1999-2002 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: compress.h,v 1.40 2007/06/19 23:47:16 tbox Exp $ */
#ifndef DNS_COMPRESS_H
#define DNS_COMPRESS_H 1
#include <isc/lang.h>
#include <isc/region.h>
#include <dns/types.h>
ISC_LANG_BEGINDECLS
#define DNS_COMPRESS_NONE 0x00 /*%< no compression */
#define DNS_COMPRESS_GLOBAL14 0x01 /*%< "normal" compression. */
#define DNS_COMPRESS_ALL 0x01 /*%< all compression. */
#define DNS_COMPRESS_CASESENSITIVE 0x02 /*%< case sensitive compression. */
/*! \file dns/compress.h
* Direct manipulation of the structures is strongly discouraged.
*/
#define DNS_COMPRESS_TABLESIZE 64
#define DNS_COMPRESS_INITIALNODES 16
typedef struct dns_compressnode dns_compressnode_t;
struct dns_compressnode {
isc_region_t r;
isc_uint16_t offset;
isc_uint16_t count;
isc_uint8_t labels;
dns_compressnode_t *next;
};
struct dns_compress {
unsigned int magic; /*%< Magic number. */
unsigned int allowed; /*%< Allowed methods. */
int edns; /*%< Edns version or -1. */
/*% Global compression table. */
dns_compressnode_t *table[DNS_COMPRESS_TABLESIZE];
/*% Preallocated nodes for the table. */
dns_compressnode_t initialnodes[DNS_COMPRESS_INITIALNODES];
isc_uint16_t count; /*%< Number of nodes. */
isc_mem_t *mctx; /*%< Memory context. */
};
typedef enum {
DNS_DECOMPRESS_ANY, /*%< Any compression */
DNS_DECOMPRESS_STRICT, /*%< Allowed compression */
DNS_DECOMPRESS_NONE /*%< No compression */
} dns_decompresstype_t;
struct dns_decompress {
unsigned int magic; /*%< Magic number. */
unsigned int allowed; /*%< Allowed methods. */
int edns; /*%< Edns version or -1. */
dns_decompresstype_t type; /*%< Strict checking */
};
isc_result_t
dns_compress_init(dns_compress_t *cctx, int edns, isc_mem_t *mctx);
/*%<
* Inialise the compression context structure pointed to by 'cctx'.
*
* Requires:
* \li 'cctx' is a valid dns_compress_t structure.
* \li 'mctx' is an initialized memory context.
* Ensures:
* \li cctx->global is initialized.
*
* Returns:
* \li #ISC_R_SUCCESS
* \li failures from dns_rbt_create()
*/
void
dns_compress_invalidate(dns_compress_t *cctx);
/*%<
* Invalidate the compression structure pointed to by cctx.
*
* Requires:
*\li 'cctx' to be initialized.
*/
void
dns_compress_setmethods(dns_compress_t *cctx, unsigned int allowed);
/*%<
* Sets allowed compression methods.
*
* Requires:
*\li 'cctx' to be initialized.
*/
unsigned int
dns_compress_getmethods(dns_compress_t *cctx);
/*%<
* Gets allowed compression methods.
*
* Requires:
*\li 'cctx' to be initialized.
*
* Returns:
*\li allowed compression bitmap.
*/
void
dns_compress_setsensitive(dns_compress_t *cctx, isc_boolean_t sensitive);
/*
* Preserve the case of compressed domain names.
*
* Requires:
* 'cctx' to be initialized.
*/
isc_boolean_t
dns_compress_getsensitive(dns_compress_t *cctx);
/*
* Return whether case is to be preservered when compressing
* domain names.
*
* Requires:
* 'cctx' to be initialized.
*/
int
dns_compress_getedns(dns_compress_t *cctx);
/*%<
* Gets edns value.
*
* Requires:
*\li 'cctx' to be initialized.
*
* Returns:
*\li -1 .. 255
*/
isc_boolean_t
dns_compress_findglobal(dns_compress_t *cctx, const dns_name_t *name,
dns_name_t *prefix, isc_uint16_t *offset);
/*%<
* Finds longest possible match of 'name' in the global compression table.
*
* Requires:
*\li 'cctx' to be initialized.
*\li 'name' to be a absolute name.
*\li 'prefix' to be initialized.
*\li 'offset' to point to an isc_uint16_t.
*
* Ensures:
*\li 'prefix' and 'offset' are valid if ISC_TRUE is returned.
*
* Returns:
*\li #ISC_TRUE / #ISC_FALSE
*/
void
dns_compress_add(dns_compress_t *cctx, const dns_name_t *name,
const dns_name_t *prefix, isc_uint16_t offset);
/*%<
* Add compression pointers for 'name' to the compression table,
* not replacing existing pointers.
*
* Requires:
*\li 'cctx' initialized
*
*\li 'name' must be initialized and absolute, and must remain
* valid until the message compression is complete.
*
*\li 'prefix' must be a prefix returned by
* dns_compress_findglobal(), or the same as 'name'.
*/
void
dns_compress_rollback(dns_compress_t *cctx, isc_uint16_t offset);
/*%<
* Remove any compression pointers from global table >= offset.
*
* Requires:
*\li 'cctx' is initialized.
*/
void
dns_decompress_init(dns_decompress_t *dctx, int edns,
dns_decompresstype_t type);
/*%<
* Initializes 'dctx'.
* Records 'edns' and 'type' into the structure.
*
* Requires:
*\li 'dctx' to be a valid pointer.
*/
void
dns_decompress_invalidate(dns_decompress_t *dctx);
/*%<
* Invalidates 'dctx'.
*
* Requires:
*\li 'dctx' to be initialized
*/
void
dns_decompress_setmethods(dns_decompress_t *dctx, unsigned int allowed);
/*%<
* Sets 'dctx->allowed' to 'allowed'.
*
* Requires:
*\li 'dctx' to be initialized
*/
unsigned int
dns_decompress_getmethods(dns_decompress_t *dctx);
/*%<
* Returns 'dctx->allowed'
*
* Requires:
*\li 'dctx' to be initialized
*/
int
dns_decompress_edns(dns_decompress_t *dctx);
/*%<
* Returns 'dctx->edns'
*
* Requires:
*\li 'dctx' to be initialized
*/
dns_decompresstype_t
dns_decompress_type(dns_decompress_t *dctx);
/*%<
* Returns 'dctx->type'
*
* Requires:
*\li 'dctx' to be initialized
*/
ISC_LANG_ENDDECLS
#endif /* DNS_COMPRESS_H */
|
