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Refugees from Catacomb: low-level buffer primitives.
[mLib] / buf.h
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800d4c59 1/* -*-c-*-
2 *
3 * $Id$
4 *
5 * Reading and writing packet buffers
6 *
7 * (c) 2001 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of Catacomb.
13 *
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
18 *
19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
23 *
24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
27 * MA 02111-1307, USA.
28 */
29
30#ifndef CATACOMB_BUF_H
31#define CATACOMB_BUF_H
32
33#ifdef __cplusplus
34 extern "C" {
35#endif
36
37/*----- Header files ------------------------------------------------------*/
38
39#include <stddef.h>
40
41#include <mLib/bits.h>
42
43#ifndef CATACOMB_MP_H
44# include "mp.h"
45#endif
46
47#ifndef CATACOMB_EC_H
48# include "ec.h"
49#endif
50
51/*----- Data structures ---------------------------------------------------*/
52
53/* --- Buffers --- *
54 *
55 * Buffers provide a simple stream-like interface for building and parsing
56 * packets.
57 */
58
59typedef struct buf {
60 octet *base, *p, *limit; /* Pointers to the buffer */
61 unsigned f; /* Various flags */
62} buf;
63
64#define BF_BROKEN 1u /* Buffer is broken */
65
66/*----- Useful macros -----------------------------------------------------*/
67
68#define BBASE(b) ((b)->base)
69#define BLIM(b) ((b)->limit)
70#define BCUR(b) ((b)->p)
71#define BSZ(b) ((b)->limit - (b)->base)
72#define BLEN(b) ((b)->p - (b)->base)
73#define BLEFT(b) ((b)->limit - (b)->p)
74#define BSTEP(b, sz) ((b)->p += (sz))
75#define BBAD(b) ((b)->f & BF_BROKEN)
76#define BOK(b) (!BBAD(b))
77
78#define BENSURE(b, sz) \
79 (BBAD(b) ? -1 : (sz) > BLEFT(b) ? (b)->f |= BF_BROKEN, -1 : 0)
80
81/*----- Functions provided ------------------------------------------------*/
82
83/* --- @buf_init@ --- *
84 *
85 * Arguments: @buf *b@ = pointer to a buffer block
86 * @void *p@ = pointer to a buffer
87 * @size_t sz@ = size of the buffer
88 *
89 * Returns: ---
90 *
91 * Use: Initializes the buffer block appropriately.
92 */
93
94extern void buf_init(buf */*b*/, void */*p*/, size_t /*sz*/);
95
96/* --- @buf_break@ --- *
97 *
98 * Arguments: @buf *b@ = pointer to a buffer block
99 *
100 * Returns: Some negative value.
101 *
102 * Use: Marks a buffer as broken.
103 */
104
105extern int buf_break(buf */*b*/);
106
107/* --- @buf_flip@ --- *
108 *
109 * Arguments: @buf *b@ = pointer to a buffer block
110 *
111 * Returns: ---
112 *
113 * Use: Flips a buffer so that if you've just been writing to it,
114 * you can now read from the bit you've written.
115 */
116
117extern void buf_flip(buf */*b*/);
118
119/* --- @buf_ensure@ --- *
120 *
121 * Arguments: @buf *b@ = pointer to a buffer block
122 * @size_t sz@ = size of data wanted
123 *
124 * Returns: Zero if it worked, nonzero if there wasn't enough space.
125 *
126 * Use: Ensures that there are @sz@ bytes still in the buffer.
127 */
128
129extern int buf_ensure(buf */*b*/, size_t /*sz*/);
130
131/* --- @buf_get@ --- *
132 *
133 * Arguments: @buf *b@ = pointer to a buffer block
134 * @size_t sz@ = size of the buffer
135 *
136 * Returns: Pointer to the place in the buffer.
137 *
138 * Use: Reserves a space in the buffer of the requested size, and
139 * returns its start address.
140 */
141
142extern void *buf_get(buf */*b*/, size_t /*sz*/);
143
144/* --- @buf_put@ --- *
145 *
146 * Arguments: @buf *b@ = pointer to a buffer block
147 * @const void *p@ = pointer to a buffer
148 * @size_t sz@ = size of the buffer
149 *
150 * Returns: Zero if it worked, nonzero if there wasn't enough space.
151 *
152 * Use: Fetches data from some place and puts it in the buffer
153 */
154
155extern int buf_put(buf */*b*/, const void */*p*/, size_t /*sz*/);
156
157/* --- @buf_getbyte@ --- *
158 *
159 * Arguments: @buf *b@ = pointer to a buffer block
160 *
161 * Returns: A byte, or less than zero if there wasn't a byte there.
162 *
163 * Use: Gets a single byte from a buffer.
164 */
165
166extern int buf_getbyte(buf */*b*/);
167
168/* --- @buf_putbyte@ --- *
169 *
170 * Arguments: @buf *b@ = pointer to a buffer block
171 * @int ch@ = byte to write
172 *
173 * Returns: Zero if OK, nonzero if there wasn't enough space.
174 *
175 * Use: Puts a single byte in a buffer.
176 */
177
178extern int buf_putbyte(buf */*b*/, int /*ch*/);
179
180/* --- @buf_getu16@ --- *
181 *
182 * Arguments: @buf *b@ = pointer to a buffer block
183 * @uint16 *w@ = where to put the word
184 *
185 * Returns: Zero if OK, or nonzero if there wasn't a word there.
186 *
187 * Use: Gets a 16-bit word from a buffer.
188 */
189
190extern int buf_getu16(buf */*b*/, uint16 */*w*/);
191
192/* --- @buf_putu16@ --- *
193 *
194 * Arguments: @buf *b@ = pointer to a buffer block
195 * @uint16 w@ = word to write
196 *
197 * Returns: Zero if OK, nonzero if there wasn't enough space.
198 *
199 * Use: Puts a 16-but word in a buffer.
200 */
201
202extern int buf_putu16(buf */*b*/, uint16 /*w*/);
203
204/* --- @buf_getu32@ --- *
205 *
206 * Arguments: @buf *b@ = pointer to a buffer block
207 * @uint32 *w@ = where to put the word
208 *
209 * Returns: Zero if OK, or nonzero if there wasn't a word there.
210 *
211 * Use: Gets a 32-bit word from a buffer.
212 */
213
214extern int buf_getu32(buf */*b*/, uint32 */*w*/);
215
216/* --- @buf_putu32@ --- *
217 *
218 * Arguments: @buf *b@ = pointer to a buffer block
219 * @uint32 w@ = word to write
220 *
221 * Returns: Zero if OK, nonzero if there wasn't enough space.
222 *
223 * Use: Puts a 32-but word in a buffer.
224 */
225
226extern int buf_putu32(buf */*b*/, uint32 /*w*/);
227
228/* --- @buf_getmem{8,16,32,z} --- *
229 *
230 * Arguments: @buf *b@ = pointer to a buffer block
231 * @size_t *nn@ = where to put the length
232 *
233 * Returns: Pointer to the buffer data, or null.
234 *
235 * Use: Gets a chunk of memory from a buffer. The number, @16@ or
236 * @32@, is the width of the length; @z@ means null-terminated.
237 */
238
239extern void *buf_getmem8(buf */*b*/, size_t */*nn*/);
240extern void *buf_getmem16(buf */*b*/, size_t */*nn*/);
241extern void *buf_getmem32(buf */*b*/, size_t */*nn*/);
242extern void *buf_getmemz(buf */*b*/, size_t */*nn*/);
243
244/* --- @buf_putmem{8,16,32,z} --- *
245 *
246 * Arguments: @buf *b@ = pointer to a buffer block
247 * @const void *p@ = pointer to data to write
248 * @size_t n@ = length to write
249 *
250 * Returns: Zero if OK, nonzero if there wasn't enough space.
251 *
252 * Use: Writes a chunk of data to a buffer. The number, @16@ or
253 * @32@, is the width of the length; @z@ means null-terminated.
254 */
255
256extern int buf_putmem8(buf */*b*/, const void */*p*/, size_t /*n*/);
257extern int buf_putmem16(buf */*b*/, const void */*p*/, size_t /*n*/);
258extern int buf_putmem32(buf */*b*/, const void */*p*/, size_t /*n*/);
259extern int buf_putmemz(buf */*b*/, const void */*p*/, size_t /*n*/);
260
261/* --- @buf_getbuf{8,16,32,z}@ --- *
262 *
263 * Arguments: @buf *b@ = pointer to a buffer block
264 * @buf *bb@ = where to put the result
265 *
266 * Returns: Zero if it worked, nonzero if there wasn't enough space.
267 *
268 * Use: Gets a block of data from a buffer, and writes its bounds to
269 * another buffer. The number, @16@ or @32@, is the width of
270 * the length; @z@ means null-terminated.
271 */
272
273extern int buf_getbuf8(buf */*b*/, buf */*bb*/);
274extern int buf_getbuf16(buf */*b*/, buf */*bb*/);
275extern int buf_getbuf32(buf */*b*/, buf */*bb*/);
276extern int buf_getbufz(buf */*b*/, buf */*bb*/);
277
278/* --- @buf_putbuf{8,16,32,z}@ --- *
279 *
280 * Arguments: @buf *b@ = pointer to a buffer block
281 * @buf *bb@ = buffer to write
282 *
283 * Returns: Zero if it worked, nonzero if there wasn't enough space.
284 *
285 * Use: Puts the contents of a buffer to a buffer. The number, @16@
286 * or @32@, is the width of the length; @z@ means null-
287 * terminated.
288 */
289
290extern int buf_putbuf8(buf */*b*/, buf */*bb*/);
291extern int buf_putbuf16(buf */*b*/, buf */*bb*/);
292extern int buf_putbuf32(buf */*b*/, buf */*bb*/);
293extern int buf_putbufz(buf */*b*/, buf */*bb*/);
294
295/* --- @buf_getstr{8,16,32,z}@ --- *
296 *
297 * Arguments: @buf *b@ = pointer to a buffer block
298 * @dstr *d@ = where to put the result
299 *
300 * Returns: Zero if it worked, nonzero if there wasn't enough space.
301 *
302 * Use: Gets a block of data from a buffer, and writes its contents
303 * to a string. The number, @16@ or @32@, is the width of the
304 * length; @z@ means null-terminated.
305 */
306
307extern int buf_getstr8(buf */*b*/, dstr */*d*/);
308extern int buf_getstr16(buf */*b*/, dstr */*d*/);
309extern int buf_getstr32(buf */*b*/, dstr */*d*/);
310extern int buf_getstrz(buf */*b*/, dstr */*d*/);
311
312/* --- @buf_putstr{8,16,32,z}@ --- *
313 *
314 * Arguments: @buf *b@ = pointer to a buffer block
315 * @dstr *d@ = string to write
316 *
317 * Returns: Zero if it worked, nonzero if there wasn't enough space.
318 *
319 * Use: Puts a string to a buffer, and writes its bounds to
320 * another buffer. The number, @16@ or @32@, is the width of
321 * the length; @z@ means null-terminated.
322 */
323
324extern int buf_putstr8(buf */*b*/, dstr */*d*/);
325extern int buf_putstr16(buf */*b*/, dstr */*d*/);
326extern int buf_putstr32(buf */*b*/, dstr */*d*/);
327extern int buf_putstrz(buf */*b*/, dstr */*d*/);
328
329/* --- @buf_getmp@ --- *
330 *
331 * Arguments: @buf *b@ = pointer to a buffer block
332 *
333 * Returns: A multiprecision integer, or null if there wasn't one there.
334 *
335 * Use: Gets a multiprecision integer from a buffer.
336 */
337
338extern mp *buf_getmp(buf */*b*/);
339
340/* --- @buf_putmp@ --- *
341 *
342 * Arguments: @buf *b@ = pointer to a buffer block
343 * @mp *m@ = a multiprecision integer
344 *
345 * Returns: Zero if it worked, nonzero if there wasn't enough space.
346 *
347 * Use: Puts a multiprecision integer to a buffer.
348 */
349
350extern int buf_putmp(buf */*b*/, mp */*m*/);
351
352/* --- @buf_getec@ --- *
353 *
354 * Arguments: @buf *b@ = pointer to a buffer block
355 * @ec *p@ = where to put the point
356 *
357 * Returns: Zero if it worked, nonzero if it failed.
358 *
359 * Use: Gets a multiprecision integer from a buffer. The point must
360 * be initialized.
361 */
362
363extern int buf_getec(buf */*b*/, ec */*p*/);
364
365/* --- @buf_putec@ --- *
366 *
367 * Arguments: @buf *b@ = pointer to a buffer block
368 * @ec *p@ = an elliptic curve point
369 *
370 * Returns: Zero if it worked, nonzero if there wasn't enough space.
371 *
372 * Use: Puts an elliptic curve point to a buffer.
373 */
374
375extern int buf_putec(buf */*b*/, ec */*p*/);
376
377/*----- That's all, folks -------------------------------------------------*/
378
379#ifdef __cplusplus
380 }
381#endif
382
383#endif