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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: buf.c,v 1.4 2001/06/19 22:09:54 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 Trivial IP Encryption (TrIPE). |
13 | * |
14 | * TrIPE is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * TrIPE 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 General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with TrIPE; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: buf.c,v $ |
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32 | * Revision 1.4 2001/06/19 22:09:54 mdw |
33 | * Expose interface, for use in the proxy. |
34 | * |
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35 | * Revision 1.3 2001/03/03 12:06:48 mdw |
36 | * Use 16-bit lengths on MPs, since there's a packet limit of 64K anyway. |
37 | * |
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38 | * Revision 1.2 2001/02/16 21:23:20 mdw |
39 | * Various minor changes. Check that MPs are in canonical form when |
40 | * loading. |
41 | * |
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42 | * Revision 1.1 2001/02/03 20:26:37 mdw |
43 | * Initial checkin. |
44 | * |
45 | */ |
46 | |
47 | /*----- Header files ------------------------------------------------------*/ |
48 | |
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49 | #include <string.h> |
50 | |
51 | #include <catacomb/mp.h> |
52 | |
53 | #include "buf.h" |
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54 | |
55 | /*----- Main code ---------------------------------------------------------*/ |
56 | |
57 | /* --- @buf_init@ --- * |
58 | * |
59 | * Arguments: @buf *b@ = pointer to a buffer block |
60 | * @void *p@ = pointer to a buffer |
61 | * @size_t sz@ = size of the buffer |
62 | * |
63 | * Returns: --- |
64 | * |
65 | * Use: Initializes the buffer block appropriately. |
66 | */ |
67 | |
68 | void buf_init(buf *b, void *p, size_t sz) |
69 | { |
70 | b->base = b->p = p; |
71 | b->limit = b->p + sz; |
72 | b->f = 0; |
73 | } |
74 | |
75 | /* --- @buf_break@ --- * |
76 | * |
77 | * Arguments: @buf *b@ = pointer to a buffer block |
78 | * |
79 | * Returns: Some negative value. |
80 | * |
81 | * Use: Marks a buffer as broken. |
82 | */ |
83 | |
84 | int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); } |
85 | |
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86 | /* --- @buf_flip@ --- * |
87 | * |
88 | * Arguments: @buf *b@ = pointer to a buffer block |
89 | * |
90 | * Returns: --- |
91 | * |
92 | * Use: Flips a buffer so that if you've just been writing to it, |
93 | * you can now read from the bit you've written. |
94 | */ |
95 | |
96 | void buf_flip(buf *b) |
97 | { |
98 | b->limit = b->p; |
99 | b->p = b->base; |
100 | } |
101 | |
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102 | /* --- @buf_ensure@ --- * |
103 | * |
104 | * Arguments: @buf *b@ = pointer to a buffer block |
105 | * @size_t sz@ = size of data wanted |
106 | * |
107 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
108 | * |
109 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
110 | */ |
111 | |
112 | int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); } |
113 | |
114 | /* --- @buf_get@ --- * |
115 | * |
116 | * Arguments: @buf *b@ = pointer to a buffer block |
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117 | * @size_t sz@ = size of the buffer |
118 | * |
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119 | * Returns: Pointer to the place in the buffer. |
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120 | * |
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121 | * Use: Reserves a space in the buffer of the requested size, and |
122 | * returns its start address. |
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123 | */ |
124 | |
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125 | void *buf_get(buf *b, size_t sz) |
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126 | { |
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127 | void *p; |
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128 | if (BENSURE(b, sz)) |
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129 | return (0); |
130 | p = BCUR(b); |
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131 | BSTEP(b, sz); |
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132 | return (p); |
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133 | } |
134 | |
135 | /* --- @buf_put@ --- * |
136 | * |
137 | * Arguments: @buf *b@ = pointer to a buffer block |
138 | * @const void *p@ = pointer to a buffer |
139 | * @size_t sz@ = size of the buffer |
140 | * |
141 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
142 | * |
143 | * Use: Fetches data from some place and puts it in the buffer |
144 | */ |
145 | |
146 | int buf_put(buf *b, const void *p, size_t sz) |
147 | { |
148 | if (BENSURE(b, sz)) |
149 | return (-1); |
150 | memcpy(BCUR(b), p, sz); |
151 | BSTEP(b, sz); |
152 | return (0); |
153 | } |
154 | |
155 | /* --- @buf_getbyte@ --- * |
156 | * |
157 | * Arguments: @buf *b@ = pointer to a buffer block |
158 | * |
159 | * Returns: A byte, or less than zero if there wasn't a byte there. |
160 | * |
161 | * Use: Gets a single byte from a buffer. |
162 | */ |
163 | |
164 | int buf_getbyte(buf *b) |
165 | { |
166 | if (BENSURE(b, 1)) |
167 | return (-1); |
168 | return (*b->p++); |
169 | } |
170 | |
171 | /* --- @buf_putbyte@ --- * |
172 | * |
173 | * Arguments: @buf *b@ = pointer to a buffer block |
174 | * @int ch@ = byte to write |
175 | * |
176 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
177 | * |
178 | * Use: Puts a single byte in a buffer. |
179 | */ |
180 | |
181 | int buf_putbyte(buf *b, int ch) |
182 | { |
183 | if (BENSURE(b, 1)) |
184 | return (-1); |
185 | *b->p++ = ch; |
186 | return (0); |
187 | } |
188 | |
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189 | /* --- @buf_getu16@ --- * |
190 | * |
191 | * Arguments: @buf *b@ = pointer to a buffer block |
192 | * @uint16 *w@ = where to put the word |
193 | * |
194 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
195 | * |
196 | * Use: Gets a 16-bit word from a buffer. |
197 | */ |
198 | |
199 | int buf_getu16(buf *b, uint16 *w) |
200 | { |
201 | if (BENSURE(b, 2)) |
202 | return (-1); |
203 | *w = LOAD16(b->p); |
204 | BSTEP(b, 2); |
205 | return (0); |
206 | } |
207 | |
208 | /* --- @buf_putu16@ --- * |
209 | * |
210 | * Arguments: @buf *b@ = pointer to a buffer block |
211 | * @uint16 w@ = word to write |
212 | * |
213 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
214 | * |
215 | * Use: Puts a 16-but word in a buffer. |
216 | */ |
217 | |
218 | int buf_putu16(buf *b, uint16 w) |
219 | { |
220 | if (BENSURE(b, 2)) |
221 | return (-1); |
222 | STORE16(b->p, w); |
223 | BSTEP(b, 2); |
224 | return (0); |
225 | } |
226 | |
227 | /* --- @buf_getu32@ --- * |
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228 | * |
229 | * Arguments: @buf *b@ = pointer to a buffer block |
230 | * @uint32 *w@ = where to put the word |
231 | * |
232 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
233 | * |
234 | * Use: Gets a 32-bit word from a buffer. |
235 | */ |
236 | |
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237 | int buf_getu32(buf *b, uint32 *w) |
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238 | { |
239 | if (BENSURE(b, 4)) |
240 | return (-1); |
241 | *w = LOAD32(b->p); |
242 | BSTEP(b, 4); |
243 | return (0); |
244 | } |
245 | |
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246 | /* --- @buf_putu32@ --- * |
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247 | * |
248 | * Arguments: @buf *b@ = pointer to a buffer block |
249 | * @uint32 w@ = word to write |
250 | * |
251 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
252 | * |
253 | * Use: Puts a 32-but word in a buffer. |
254 | */ |
255 | |
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256 | int buf_putu32(buf *b, uint32 w) |
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257 | { |
258 | if (BENSURE(b, 4)) |
259 | return (-1); |
260 | STORE32(b->p, w); |
261 | BSTEP(b, 4); |
262 | return (0); |
263 | } |
264 | |
265 | /* --- @buf_getmp@ --- * |
266 | * |
267 | * Arguments: @buf *b@ = pointer to a buffer block |
268 | * |
269 | * Returns: A multiprecision integer, or null if there wasn't one there. |
270 | * |
271 | * Use: Gets a multiprecision integer from a buffer. |
272 | */ |
273 | |
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274 | mp *buf_getmp(buf *b) |
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275 | { |
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276 | uint16 sz; |
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277 | mp *m; |
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278 | if (buf_getu16(b, &sz) || buf_ensure(b, sz)) |
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279 | return (0); |
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280 | m = mp_loadb(MP_NEW, BCUR(b), sz); |
281 | if (mp_octets(m) != sz) { |
282 | mp_drop(m); |
283 | return (0); |
284 | } |
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285 | BSTEP(b, sz); |
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286 | return (m); |
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287 | } |
288 | |
289 | /* --- @buf_putmp@ --- * |
290 | * |
291 | * Arguments: @buf *b@ = pointer to a buffer block |
292 | * @mp *m@ = a multiprecision integer |
293 | * |
294 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
295 | * |
296 | * Use: Puts a multiprecision integer to a buffer. |
297 | */ |
298 | |
299 | int buf_putmp(buf *b, mp *m) |
300 | { |
301 | size_t sz = mp_octets(m); |
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302 | assert(sz < MASK16); |
303 | if (buf_putu16(b, sz) || buf_ensure(b, sz)) |
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304 | return (-1); |
305 | mp_storeb(m, BCUR(b), sz); |
306 | BSTEP(b, sz); |
307 | return (0); |
308 | } |
309 | |
310 | /*----- That's all, folks -------------------------------------------------*/ |