6b80b6c4 |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: buf.c,v 1.1 2003/10/11 21:02:33 mdw Exp $ |
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 $ |
33 | * Revision 1.1 2003/10/11 21:02:33 mdw |
34 | * Import buf stuff from tripe. |
35 | * |
36 | * Revision 1.4 2001/06/19 22:09:54 mdw |
37 | * Expose interface, for use in the proxy. |
38 | * |
39 | * Revision 1.3 2001/03/03 12:06:48 mdw |
40 | * Use 16-bit lengths on MPs, since there's a packet limit of 64K anyway. |
41 | * |
42 | * Revision 1.2 2001/02/16 21:23:20 mdw |
43 | * Various minor changes. Check that MPs are in canonical form when |
44 | * loading. |
45 | * |
46 | * Revision 1.1 2001/02/03 20:26:37 mdw |
47 | * Initial checkin. |
48 | * |
49 | */ |
50 | |
51 | /*----- Header files ------------------------------------------------------*/ |
52 | |
53 | #include <string.h> |
54 | |
55 | #include <catacomb/mp.h> |
56 | |
57 | #include "buf.h" |
58 | |
59 | /*----- Main code ---------------------------------------------------------*/ |
60 | |
61 | /* --- @buf_init@ --- * |
62 | * |
63 | * Arguments: @buf *b@ = pointer to a buffer block |
64 | * @void *p@ = pointer to a buffer |
65 | * @size_t sz@ = size of the buffer |
66 | * |
67 | * Returns: --- |
68 | * |
69 | * Use: Initializes the buffer block appropriately. |
70 | */ |
71 | |
72 | void buf_init(buf *b, void *p, size_t sz) |
73 | { |
74 | b->base = b->p = p; |
75 | b->limit = b->p + sz; |
76 | b->f = 0; |
77 | } |
78 | |
79 | /* --- @buf_break@ --- * |
80 | * |
81 | * Arguments: @buf *b@ = pointer to a buffer block |
82 | * |
83 | * Returns: Some negative value. |
84 | * |
85 | * Use: Marks a buffer as broken. |
86 | */ |
87 | |
88 | int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); } |
89 | |
90 | /* --- @buf_flip@ --- * |
91 | * |
92 | * Arguments: @buf *b@ = pointer to a buffer block |
93 | * |
94 | * Returns: --- |
95 | * |
96 | * Use: Flips a buffer so that if you've just been writing to it, |
97 | * you can now read from the bit you've written. |
98 | */ |
99 | |
100 | void buf_flip(buf *b) |
101 | { |
102 | b->limit = b->p; |
103 | b->p = b->base; |
104 | } |
105 | |
106 | /* --- @buf_ensure@ --- * |
107 | * |
108 | * Arguments: @buf *b@ = pointer to a buffer block |
109 | * @size_t sz@ = size of data wanted |
110 | * |
111 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
112 | * |
113 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
114 | */ |
115 | |
116 | int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); } |
117 | |
118 | /* --- @buf_get@ --- * |
119 | * |
120 | * Arguments: @buf *b@ = pointer to a buffer block |
121 | * @size_t sz@ = size of the buffer |
122 | * |
123 | * Returns: Pointer to the place in the buffer. |
124 | * |
125 | * Use: Reserves a space in the buffer of the requested size, and |
126 | * returns its start address. |
127 | */ |
128 | |
129 | void *buf_get(buf *b, size_t sz) |
130 | { |
131 | void *p; |
132 | if (BENSURE(b, sz)) |
133 | return (0); |
134 | p = BCUR(b); |
135 | BSTEP(b, sz); |
136 | return (p); |
137 | } |
138 | |
139 | /* --- @buf_put@ --- * |
140 | * |
141 | * Arguments: @buf *b@ = pointer to a buffer block |
142 | * @const void *p@ = pointer to a buffer |
143 | * @size_t sz@ = size of the buffer |
144 | * |
145 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
146 | * |
147 | * Use: Fetches data from some place and puts it in the buffer |
148 | */ |
149 | |
150 | int buf_put(buf *b, const void *p, size_t sz) |
151 | { |
152 | if (BENSURE(b, sz)) |
153 | return (-1); |
154 | memcpy(BCUR(b), p, sz); |
155 | BSTEP(b, sz); |
156 | return (0); |
157 | } |
158 | |
159 | /* --- @buf_getbyte@ --- * |
160 | * |
161 | * Arguments: @buf *b@ = pointer to a buffer block |
162 | * |
163 | * Returns: A byte, or less than zero if there wasn't a byte there. |
164 | * |
165 | * Use: Gets a single byte from a buffer. |
166 | */ |
167 | |
168 | int buf_getbyte(buf *b) |
169 | { |
170 | if (BENSURE(b, 1)) |
171 | return (-1); |
172 | return (*b->p++); |
173 | } |
174 | |
175 | /* --- @buf_putbyte@ --- * |
176 | * |
177 | * Arguments: @buf *b@ = pointer to a buffer block |
178 | * @int ch@ = byte to write |
179 | * |
180 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
181 | * |
182 | * Use: Puts a single byte in a buffer. |
183 | */ |
184 | |
185 | int buf_putbyte(buf *b, int ch) |
186 | { |
187 | if (BENSURE(b, 1)) |
188 | return (-1); |
189 | *b->p++ = ch; |
190 | return (0); |
191 | } |
192 | |
193 | /* --- @buf_getu16@ --- * |
194 | * |
195 | * Arguments: @buf *b@ = pointer to a buffer block |
196 | * @uint16 *w@ = where to put the word |
197 | * |
198 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
199 | * |
200 | * Use: Gets a 16-bit word from a buffer. |
201 | */ |
202 | |
203 | int buf_getu16(buf *b, uint16 *w) |
204 | { |
205 | if (BENSURE(b, 2)) |
206 | return (-1); |
207 | *w = LOAD16(b->p); |
208 | BSTEP(b, 2); |
209 | return (0); |
210 | } |
211 | |
212 | /* --- @buf_putu16@ --- * |
213 | * |
214 | * Arguments: @buf *b@ = pointer to a buffer block |
215 | * @uint16 w@ = word to write |
216 | * |
217 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
218 | * |
219 | * Use: Puts a 16-but word in a buffer. |
220 | */ |
221 | |
222 | int buf_putu16(buf *b, uint16 w) |
223 | { |
224 | if (BENSURE(b, 2)) |
225 | return (-1); |
226 | STORE16(b->p, w); |
227 | BSTEP(b, 2); |
228 | return (0); |
229 | } |
230 | |
231 | /* --- @buf_getu32@ --- * |
232 | * |
233 | * Arguments: @buf *b@ = pointer to a buffer block |
234 | * @uint32 *w@ = where to put the word |
235 | * |
236 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
237 | * |
238 | * Use: Gets a 32-bit word from a buffer. |
239 | */ |
240 | |
241 | int buf_getu32(buf *b, uint32 *w) |
242 | { |
243 | if (BENSURE(b, 4)) |
244 | return (-1); |
245 | *w = LOAD32(b->p); |
246 | BSTEP(b, 4); |
247 | return (0); |
248 | } |
249 | |
250 | /* --- @buf_putu32@ --- * |
251 | * |
252 | * Arguments: @buf *b@ = pointer to a buffer block |
253 | * @uint32 w@ = word to write |
254 | * |
255 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
256 | * |
257 | * Use: Puts a 32-but word in a buffer. |
258 | */ |
259 | |
260 | int buf_putu32(buf *b, uint32 w) |
261 | { |
262 | if (BENSURE(b, 4)) |
263 | return (-1); |
264 | STORE32(b->p, w); |
265 | BSTEP(b, 4); |
266 | return (0); |
267 | } |
268 | |
269 | /* --- @buf_getmp@ --- * |
270 | * |
271 | * Arguments: @buf *b@ = pointer to a buffer block |
272 | * |
273 | * Returns: A multiprecision integer, or null if there wasn't one there. |
274 | * |
275 | * Use: Gets a multiprecision integer from a buffer. |
276 | */ |
277 | |
278 | mp *buf_getmp(buf *b) |
279 | { |
280 | uint16 sz; |
281 | mp *m; |
282 | if (buf_getu16(b, &sz) || buf_ensure(b, sz)) |
283 | return (0); |
284 | m = mp_loadb(MP_NEW, BCUR(b), sz); |
285 | if (mp_octets(m) != sz) { |
286 | mp_drop(m); |
287 | return (0); |
288 | } |
289 | BSTEP(b, sz); |
290 | return (m); |
291 | } |
292 | |
293 | /* --- @buf_putmp@ --- * |
294 | * |
295 | * Arguments: @buf *b@ = pointer to a buffer block |
296 | * @mp *m@ = a multiprecision integer |
297 | * |
298 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
299 | * |
300 | * Use: Puts a multiprecision integer to a buffer. |
301 | */ |
302 | |
303 | int buf_putmp(buf *b, mp *m) |
304 | { |
305 | size_t sz = mp_octets(m); |
306 | assert(sz < MASK16); |
307 | if (buf_putu16(b, sz) || buf_ensure(b, sz)) |
308 | return (-1); |
309 | mp_storeb(m, BCUR(b), sz); |
310 | BSTEP(b, sz); |
311 | return (0); |
312 | } |
313 | |
314 | /*----- That's all, folks -------------------------------------------------*/ |