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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: buf.c,v 1.2 2003/11/10 22:18:30 mdw Exp $ |
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4 | * |
5 | * Buffer handling |
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 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: buf.c,v $ |
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33 | * Revision 1.2 2003/11/10 22:18:30 mdw |
34 | * Build fixes. |
35 | * |
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36 | * Revision 1.1 2003/10/11 21:02:33 mdw |
37 | * Import buf stuff from tripe. |
38 | * |
39 | * Revision 1.4 2001/06/19 22:09:54 mdw |
40 | * Expose interface, for use in the proxy. |
41 | * |
42 | * Revision 1.3 2001/03/03 12:06:48 mdw |
43 | * Use 16-bit lengths on MPs, since there's a packet limit of 64K anyway. |
44 | * |
45 | * Revision 1.2 2001/02/16 21:23:20 mdw |
46 | * Various minor changes. Check that MPs are in canonical form when |
47 | * loading. |
48 | * |
49 | * Revision 1.1 2001/02/03 20:26:37 mdw |
50 | * Initial checkin. |
51 | * |
52 | */ |
53 | |
54 | /*----- Header files ------------------------------------------------------*/ |
55 | |
56 | #include <string.h> |
57 | |
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58 | #include "mp.h" |
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59 | #include "buf.h" |
60 | |
61 | /*----- Main code ---------------------------------------------------------*/ |
62 | |
63 | /* --- @buf_init@ --- * |
64 | * |
65 | * Arguments: @buf *b@ = pointer to a buffer block |
66 | * @void *p@ = pointer to a buffer |
67 | * @size_t sz@ = size of the buffer |
68 | * |
69 | * Returns: --- |
70 | * |
71 | * Use: Initializes the buffer block appropriately. |
72 | */ |
73 | |
74 | void buf_init(buf *b, void *p, size_t sz) |
75 | { |
76 | b->base = b->p = p; |
77 | b->limit = b->p + sz; |
78 | b->f = 0; |
79 | } |
80 | |
81 | /* --- @buf_break@ --- * |
82 | * |
83 | * Arguments: @buf *b@ = pointer to a buffer block |
84 | * |
85 | * Returns: Some negative value. |
86 | * |
87 | * Use: Marks a buffer as broken. |
88 | */ |
89 | |
90 | int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); } |
91 | |
92 | /* --- @buf_flip@ --- * |
93 | * |
94 | * Arguments: @buf *b@ = pointer to a buffer block |
95 | * |
96 | * Returns: --- |
97 | * |
98 | * Use: Flips a buffer so that if you've just been writing to it, |
99 | * you can now read from the bit you've written. |
100 | */ |
101 | |
102 | void buf_flip(buf *b) |
103 | { |
104 | b->limit = b->p; |
105 | b->p = b->base; |
106 | } |
107 | |
108 | /* --- @buf_ensure@ --- * |
109 | * |
110 | * Arguments: @buf *b@ = pointer to a buffer block |
111 | * @size_t sz@ = size of data wanted |
112 | * |
113 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
114 | * |
115 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
116 | */ |
117 | |
118 | int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); } |
119 | |
120 | /* --- @buf_get@ --- * |
121 | * |
122 | * Arguments: @buf *b@ = pointer to a buffer block |
123 | * @size_t sz@ = size of the buffer |
124 | * |
125 | * Returns: Pointer to the place in the buffer. |
126 | * |
127 | * Use: Reserves a space in the buffer of the requested size, and |
128 | * returns its start address. |
129 | */ |
130 | |
131 | void *buf_get(buf *b, size_t sz) |
132 | { |
133 | void *p; |
134 | if (BENSURE(b, sz)) |
135 | return (0); |
136 | p = BCUR(b); |
137 | BSTEP(b, sz); |
138 | return (p); |
139 | } |
140 | |
141 | /* --- @buf_put@ --- * |
142 | * |
143 | * Arguments: @buf *b@ = pointer to a buffer block |
144 | * @const void *p@ = pointer to a buffer |
145 | * @size_t sz@ = size of the buffer |
146 | * |
147 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
148 | * |
149 | * Use: Fetches data from some place and puts it in the buffer |
150 | */ |
151 | |
152 | int buf_put(buf *b, const void *p, size_t sz) |
153 | { |
154 | if (BENSURE(b, sz)) |
155 | return (-1); |
156 | memcpy(BCUR(b), p, sz); |
157 | BSTEP(b, sz); |
158 | return (0); |
159 | } |
160 | |
161 | /* --- @buf_getbyte@ --- * |
162 | * |
163 | * Arguments: @buf *b@ = pointer to a buffer block |
164 | * |
165 | * Returns: A byte, or less than zero if there wasn't a byte there. |
166 | * |
167 | * Use: Gets a single byte from a buffer. |
168 | */ |
169 | |
170 | int buf_getbyte(buf *b) |
171 | { |
172 | if (BENSURE(b, 1)) |
173 | return (-1); |
174 | return (*b->p++); |
175 | } |
176 | |
177 | /* --- @buf_putbyte@ --- * |
178 | * |
179 | * Arguments: @buf *b@ = pointer to a buffer block |
180 | * @int ch@ = byte to write |
181 | * |
182 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
183 | * |
184 | * Use: Puts a single byte in a buffer. |
185 | */ |
186 | |
187 | int buf_putbyte(buf *b, int ch) |
188 | { |
189 | if (BENSURE(b, 1)) |
190 | return (-1); |
191 | *b->p++ = ch; |
192 | return (0); |
193 | } |
194 | |
195 | /* --- @buf_getu16@ --- * |
196 | * |
197 | * Arguments: @buf *b@ = pointer to a buffer block |
198 | * @uint16 *w@ = where to put the word |
199 | * |
200 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
201 | * |
202 | * Use: Gets a 16-bit word from a buffer. |
203 | */ |
204 | |
205 | int buf_getu16(buf *b, uint16 *w) |
206 | { |
207 | if (BENSURE(b, 2)) |
208 | return (-1); |
209 | *w = LOAD16(b->p); |
210 | BSTEP(b, 2); |
211 | return (0); |
212 | } |
213 | |
214 | /* --- @buf_putu16@ --- * |
215 | * |
216 | * Arguments: @buf *b@ = pointer to a buffer block |
217 | * @uint16 w@ = word to write |
218 | * |
219 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
220 | * |
221 | * Use: Puts a 16-but word in a buffer. |
222 | */ |
223 | |
224 | int buf_putu16(buf *b, uint16 w) |
225 | { |
226 | if (BENSURE(b, 2)) |
227 | return (-1); |
228 | STORE16(b->p, w); |
229 | BSTEP(b, 2); |
230 | return (0); |
231 | } |
232 | |
233 | /* --- @buf_getu32@ --- * |
234 | * |
235 | * Arguments: @buf *b@ = pointer to a buffer block |
236 | * @uint32 *w@ = where to put the word |
237 | * |
238 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
239 | * |
240 | * Use: Gets a 32-bit word from a buffer. |
241 | */ |
242 | |
243 | int buf_getu32(buf *b, uint32 *w) |
244 | { |
245 | if (BENSURE(b, 4)) |
246 | return (-1); |
247 | *w = LOAD32(b->p); |
248 | BSTEP(b, 4); |
249 | return (0); |
250 | } |
251 | |
252 | /* --- @buf_putu32@ --- * |
253 | * |
254 | * Arguments: @buf *b@ = pointer to a buffer block |
255 | * @uint32 w@ = word to write |
256 | * |
257 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
258 | * |
259 | * Use: Puts a 32-but word in a buffer. |
260 | */ |
261 | |
262 | int buf_putu32(buf *b, uint32 w) |
263 | { |
264 | if (BENSURE(b, 4)) |
265 | return (-1); |
266 | STORE32(b->p, w); |
267 | BSTEP(b, 4); |
268 | return (0); |
269 | } |
270 | |
271 | /* --- @buf_getmp@ --- * |
272 | * |
273 | * Arguments: @buf *b@ = pointer to a buffer block |
274 | * |
275 | * Returns: A multiprecision integer, or null if there wasn't one there. |
276 | * |
277 | * Use: Gets a multiprecision integer from a buffer. |
278 | */ |
279 | |
280 | mp *buf_getmp(buf *b) |
281 | { |
282 | uint16 sz; |
283 | mp *m; |
284 | if (buf_getu16(b, &sz) || buf_ensure(b, sz)) |
285 | return (0); |
286 | m = mp_loadb(MP_NEW, BCUR(b), sz); |
287 | if (mp_octets(m) != sz) { |
288 | mp_drop(m); |
289 | return (0); |
290 | } |
291 | BSTEP(b, sz); |
292 | return (m); |
293 | } |
294 | |
295 | /* --- @buf_putmp@ --- * |
296 | * |
297 | * Arguments: @buf *b@ = pointer to a buffer block |
298 | * @mp *m@ = a multiprecision integer |
299 | * |
300 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
301 | * |
302 | * Use: Puts a multiprecision integer to a buffer. |
303 | */ |
304 | |
305 | int buf_putmp(buf *b, mp *m) |
306 | { |
307 | size_t sz = mp_octets(m); |
308 | assert(sz < MASK16); |
309 | if (buf_putu16(b, sz) || buf_ensure(b, sz)) |
310 | return (-1); |
311 | mp_storeb(m, BCUR(b), sz); |
312 | BSTEP(b, sz); |
313 | return (0); |
314 | } |
315 | |
316 | /*----- That's all, folks -------------------------------------------------*/ |