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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: buf.h,v 1.4 2004/04/08 01:36:15 mdw Exp $ |
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4 | * |
5 | * Reading and writing packet buffers |
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6 | * |
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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 | |
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30 | #ifndef CATACOMB_BUF_H |
31 | #define CATACOMB_BUF_H |
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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 | |
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43 | #ifndef CATACOMB_MP_H |
44 | # include "mp.h" |
45 | #endif |
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46 | |
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47 | #ifndef CATACOMB_EC_H |
48 | # include "ec.h" |
49 | #endif |
50 | |
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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 | |
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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 | |
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276 | /*----- That's all, folks -------------------------------------------------*/ |
277 | |
278 | #ifdef __cplusplus |
279 | } |
280 | #endif |
281 | |
282 | #endif |