[u/mdw/catacomb] / buf.h

/* -*-c-*-
 *
 * $Id: buf.h,v 1.4 2004/04/08 01:36:15 mdw Exp $
 *
 * Reading and writing packet buffers
 *
 * (c) 2001 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of Catacomb.
 *
 * Catacomb is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * Catacomb is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with Catacomb; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

#ifndef CATACOMB_BUF_H
#define CATACOMB_BUF_H

#ifdef __cplusplus
  extern "C" {
#endif

/*----- Header files ------------------------------------------------------*/

#include <stddef.h>

#include <mLib/bits.h>

#ifndef CATACOMB_MP_H
#  include "mp.h"
#endif

#ifndef CATACOMB_EC_H
#  include "ec.h"
#endif

/*----- Data structures ---------------------------------------------------*/

/* --- Buffers --- *
 *
 * Buffers provide a simple stream-like interface for building and parsing
 * packets.
 */

typedef struct buf {
  octet *base, *p, *limit;		/* Pointers to the buffer */
  unsigned f;				/* Various flags */
} buf;

#define BF_BROKEN 1u			/* Buffer is broken */

/*----- Useful macros -----------------------------------------------------*/

#define BBASE(b) ((b)->base)
#define BLIM(b) ((b)->limit)
#define BCUR(b) ((b)->p)
#define BSZ(b) ((b)->limit - (b)->base)
#define BLEN(b) ((b)->p - (b)->base)
#define BLEFT(b) ((b)->limit - (b)->p)
#define BSTEP(b, sz) ((b)->p += (sz))
#define BBAD(b) ((b)->f & BF_BROKEN)
#define BOK(b) (!BBAD(b))

#define BENSURE(b, sz)							\
  (BBAD(b) ? -1 : (sz) > BLEFT(b) ? (b)->f |= BF_BROKEN, -1 : 0)

/*----- Functions provided ------------------------------------------------*/

/* --- @buf_init@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@void *p@ = pointer to a buffer
 *		@size_t sz@ = size of the buffer
 *
 * Returns:	---
 *
 * Use:		Initializes the buffer block appropriately.
 */

extern void buf_init(buf */*b*/, void */*p*/, size_t /*sz*/);

/* --- @buf_break@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *
 * Returns:	Some negative value.
 *
 * Use:		Marks a buffer as broken.
 */

extern int buf_break(buf */*b*/);

/* --- @buf_flip@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *
 * Returns:	---
 *
 * Use:		Flips a buffer so that if you've just been writing to it,
 *		you can now read from the bit you've written.
 */

extern void buf_flip(buf */*b*/);

/* --- @buf_ensure@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@size_t sz@ = size of data wanted
 *
 * Returns:	Zero if it worked, nonzero if there wasn't enough space.
 *
 * Use:		Ensures that there are @sz@ bytes still in the buffer.
 */

extern int buf_ensure(buf */*b*/, size_t /*sz*/);

/* --- @buf_get@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@size_t sz@ = size of the buffer
 *
 * Returns:	Pointer to the place in the buffer.
 *
 * Use:		Reserves a space in the buffer of the requested size, and
 *		returns its start address.
 */

extern void *buf_get(buf */*b*/, size_t /*sz*/);

/* --- @buf_put@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@const void *p@ = pointer to a buffer
 *		@size_t sz@ = size of the buffer
 *
 * Returns:	Zero if it worked, nonzero if there wasn't enough space.
 *
 * Use:		Fetches data from some place and puts it in the buffer
 */

extern int buf_put(buf */*b*/, const void */*p*/, size_t /*sz*/);

/* --- @buf_getbyte@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *
 * Returns:	A byte, or less than zero if there wasn't a byte there.
 *
 * Use:		Gets a single byte from a buffer.
 */

extern int buf_getbyte(buf */*b*/);

/* --- @buf_putbyte@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@int ch@ = byte to write
 *
 * Returns:	Zero if OK, nonzero if there wasn't enough space.
 *
 * Use:		Puts a single byte in a buffer.
 */

extern int buf_putbyte(buf */*b*/, int /*ch*/);

/* --- @buf_getu16@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@uint16 *w@ = where to put the word
 *
 * Returns:	Zero if OK, or nonzero if there wasn't a word there.
 *
 * Use:		Gets a 16-bit word from a buffer.
 */

extern int buf_getu16(buf */*b*/, uint16 */*w*/);

/* --- @buf_putu16@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@uint16 w@ = word to write
 *
 * Returns:	Zero if OK, nonzero if there wasn't enough space.
 *
 * Use:		Puts a 16-but word in a buffer.
 */

extern int buf_putu16(buf */*b*/, uint16 /*w*/);

/* --- @buf_getu32@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@uint32 *w@ = where to put the word
 *
 * Returns:	Zero if OK, or nonzero if there wasn't a word there.
 *
 * Use:		Gets a 32-bit word from a buffer.
 */

extern int buf_getu32(buf */*b*/, uint32 */*w*/);

/* --- @buf_putu32@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@uint32 w@ = word to write
 *
 * Returns:	Zero if OK, nonzero if there wasn't enough space.
 *
 * Use:		Puts a 32-but word in a buffer.
 */

extern int buf_putu32(buf */*b*/, uint32 /*w*/);

/* --- @buf_getmp@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *
 * Returns:	A multiprecision integer, or null if there wasn't one there.
 *
 * Use:		Gets a multiprecision integer from a buffer.
 */

extern mp *buf_getmp(buf */*b*/);

/* --- @buf_putmp@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@mp *m@ = a multiprecision integer
 *
 * Returns:	Zero if it worked, nonzero if there wasn't enough space.
 *
 * Use:		Puts a multiprecision integer to a buffer.
 */

extern int buf_putmp(buf */*b*/, mp */*m*/);

/* --- @buf_getec@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@ec *p@ = where to put the point
 *
 * Returns:	Zero if it worked, nonzero if it failed.
 *
 * Use:		Gets a multiprecision integer from a buffer.  The point must
 *		be initialized.
 */

extern int buf_getec(buf */*b*/, ec */*p*/);

/* --- @buf_putec@ --- *
 *
 * Arguments:	@buf *b@ = pointer to a buffer block
 *		@ec *p@ = an elliptic curve point
 *
 * Returns:	Zero if it worked, nonzero if there wasn't enough space.
 *
 * Use:		Puts an elliptic curve point to a buffer.
 */

extern int buf_putec(buf */*b*/, ec */*p*/);

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif
Commit	Line	Data
6b80b6c4	1	/* --c--
6b80b6c4	2	*
b817bfc6	3	* $Id: buf.h,v 1.4 2004/04/08 01:36:15 mdw Exp $
5ff5e658	4	*
5ff5e658	5	* Reading and writing packet buffers
6b80b6c4	6	*
6b80b6c4	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
5ff5e658	30	#ifndef CATACOMB_BUF_H
5ff5e658	31	#define CATACOMB_BUF_H
6b80b6c4	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
5ff5e658	43	#ifndef CATACOMB_MP_H
	44	# include "mp.h"
	45	#endif
6b80b6c4	46
34e4f738	47	#ifndef CATACOMB_EC_H
	48	# include "ec.h"
	49	#endif
	50
6b80b6c4	51	/----- Data structures ---------------------------------------------------/
	52
	53	/* --- Buffers --- *
	54	*
	55	* Buffers provide a simple stream-like interface for building and parsing
	56	* packets.
	57	*/
	58
	59	typedef 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
	94	extern 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
	105	extern 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
117	extern 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
129	extern 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
142	extern 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
155	extern 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
166	extern 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
178	extern 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
190	extern 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
202	extern 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
214	extern 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
226	extern int buf_putu32(buf /b/, uint32 /w*/);
227
228	/* --- @buf_getmp@ --- *
229	*
230	* Arguments: @buf *b@ = pointer to a buffer block
231	*
232	* Returns: A multiprecision integer, or null if there wasn't one there.
233	*
234	* Use: Gets a multiprecision integer from a buffer.
235	*/
236
237	extern mp buf_getmp(buf /b/);
238
239	/* --- @buf_putmp@ --- *
240	*
241	* Arguments: @buf *b@ = pointer to a buffer block
242	* @mp *m@ = a multiprecision integer
243	*
244	* Returns: Zero if it worked, nonzero if there wasn't enough space.
245	*
246	* Use: Puts a multiprecision integer to a buffer.
247	*/
248
249	extern int buf_putmp(buf /b/, mp /m/);
250
34e4f738	251	/* --- @buf_getec@ --- *
	252	*
	253	* Arguments: @buf *b@ = pointer to a buffer block
	254	* @ec *p@ = where to put the point
	255	*
	256	* Returns: Zero if it worked, nonzero if it failed.
	257	*
	258	* Use: Gets a multiprecision integer from a buffer. The point must
	259	* be initialized.
	260	*/
	261
	262	extern int buf_getec(buf /b/, ec /p/);
	263
	264	/* --- @buf_putec@ --- *
	265	*
	266	* Arguments: @buf *b@ = pointer to a buffer block
	267	* @ec *p@ = an elliptic curve point
	268	*
	269	* Returns: Zero if it worked, nonzero if there wasn't enough space.
	270	*
	271	* Use: Puts an elliptic curve point to a buffer.
	272	*/
	273
	274	extern int buf_putec(buf /b/, ec /p/);
	275
6b80b6c4	276	/----- That's all, folks -------------------------------------------------/
	277
	278	#ifdef __cplusplus
	279	}
	280	#endif
	281
	282	#endif