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1 | /* -*-c-*- |
2 | * |
3 | * $Id$ |
4 | * |
5 | * Buffer handling |
6 | * |
7 | * (c) 2001 Straylight/Edgeware |
8 | */ |
9 | |
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10 | /*----- Licensing notice --------------------------------------------------* |
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11 | * |
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12 | * This file is part of the mLib utilities library. |
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13 | * |
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14 | * mLib is free software; you can redistribute it and/or modify |
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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. |
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18 | * |
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19 | * mLib is distributed in the hope that it will be useful, |
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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. |
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23 | * |
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24 | * You should have received a copy of the GNU Library General Public |
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25 | * License along with mLib; if not, write to the Free |
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26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Header files ------------------------------------------------------*/ |
31 | |
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32 | #include <assert.h> |
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33 | #include <string.h> |
34 | |
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35 | #include "buf.h" |
36 | |
37 | /*----- Main code ---------------------------------------------------------*/ |
38 | |
39 | /* --- @buf_init@ --- * |
40 | * |
41 | * Arguments: @buf *b@ = pointer to a buffer block |
42 | * @void *p@ = pointer to a buffer |
43 | * @size_t sz@ = size of the buffer |
44 | * |
45 | * Returns: --- |
46 | * |
47 | * Use: Initializes the buffer block appropriately. |
48 | */ |
49 | |
50 | void buf_init(buf *b, void *p, size_t sz) |
51 | { |
52 | b->base = b->p = p; |
53 | b->limit = b->p + sz; |
54 | b->f = 0; |
55 | } |
56 | |
57 | /* --- @buf_break@ --- * |
58 | * |
59 | * Arguments: @buf *b@ = pointer to a buffer block |
60 | * |
61 | * Returns: Some negative value. |
62 | * |
63 | * Use: Marks a buffer as broken. |
64 | */ |
65 | |
66 | int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); } |
67 | |
68 | /* --- @buf_flip@ --- * |
69 | * |
70 | * Arguments: @buf *b@ = pointer to a buffer block |
71 | * |
72 | * Returns: --- |
73 | * |
74 | * Use: Flips a buffer so that if you've just been writing to it, |
75 | * you can now read from the bit you've written. |
76 | */ |
77 | |
78 | void buf_flip(buf *b) |
79 | { |
80 | b->limit = b->p; |
81 | b->p = b->base; |
82 | } |
83 | |
84 | /* --- @buf_ensure@ --- * |
85 | * |
86 | * Arguments: @buf *b@ = pointer to a buffer block |
87 | * @size_t sz@ = size of data wanted |
88 | * |
89 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
90 | * |
91 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
92 | */ |
93 | |
94 | int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); } |
95 | |
96 | /* --- @buf_get@ --- * |
97 | * |
98 | * Arguments: @buf *b@ = pointer to a buffer block |
99 | * @size_t sz@ = size of the buffer |
100 | * |
101 | * Returns: Pointer to the place in the buffer. |
102 | * |
103 | * Use: Reserves a space in the buffer of the requested size, and |
104 | * returns its start address. |
105 | */ |
106 | |
107 | void *buf_get(buf *b, size_t sz) |
108 | { |
109 | void *p; |
110 | if (BENSURE(b, sz)) |
111 | return (0); |
112 | p = BCUR(b); |
113 | BSTEP(b, sz); |
114 | return (p); |
115 | } |
116 | |
117 | /* --- @buf_put@ --- * |
118 | * |
119 | * Arguments: @buf *b@ = pointer to a buffer block |
120 | * @const void *p@ = pointer to a buffer |
121 | * @size_t sz@ = size of the buffer |
122 | * |
123 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
124 | * |
125 | * Use: Fetches data from some place and puts it in the buffer |
126 | */ |
127 | |
128 | int buf_put(buf *b, const void *p, size_t sz) |
129 | { |
130 | if (BENSURE(b, sz)) |
131 | return (-1); |
132 | memcpy(BCUR(b), p, sz); |
133 | BSTEP(b, sz); |
134 | return (0); |
135 | } |
136 | |
137 | /* --- @buf_getbyte@ --- * |
138 | * |
139 | * Arguments: @buf *b@ = pointer to a buffer block |
140 | * |
141 | * Returns: A byte, or less than zero if there wasn't a byte there. |
142 | * |
143 | * Use: Gets a single byte from a buffer. |
144 | */ |
145 | |
146 | int buf_getbyte(buf *b) |
147 | { |
148 | if (BENSURE(b, 1)) |
149 | return (-1); |
150 | return (*b->p++); |
151 | } |
152 | |
153 | /* --- @buf_putbyte@ --- * |
154 | * |
155 | * Arguments: @buf *b@ = pointer to a buffer block |
156 | * @int ch@ = byte to write |
157 | * |
158 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
159 | * |
160 | * Use: Puts a single byte in a buffer. |
161 | */ |
162 | |
163 | int buf_putbyte(buf *b, int ch) |
164 | { |
165 | if (BENSURE(b, 1)) |
166 | return (-1); |
167 | *b->p++ = ch; |
168 | return (0); |
169 | } |
170 | |
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171 | /* --- @buf_getu{8,{16,24,32,64}{,l,b}}@ --- * |
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172 | * |
173 | * Arguments: @buf *b@ = pointer to a buffer block |
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174 | * @uintSZ *w@ = where to put the word |
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175 | * |
176 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
177 | * |
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178 | * Use: Gets a word of appropriate size and order from a buffer. |
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179 | */ |
180 | |
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181 | #define BUF_GETU_(n, W, w) \ |
182 | int buf_getu##w(buf *b, uint##n *ww) \ |
183 | { \ |
184 | if (BENSURE(b, SZ_##W)) return (-1); \ |
185 | *ww = LOAD##W(b->p); \ |
186 | BSTEP(b, SZ_##W); \ |
187 | return (0); \ |
188 | } |
189 | DOUINTCONV(BUF_GETU_) |
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190 | |
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191 | /* --- @buf_putu{8,{16,24,32,64}{,l,b}}@ --- * |
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192 | * |
193 | * Arguments: @buf *b@ = pointer to a buffer block |
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194 | * @uintSZ w@ = word to write |
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195 | * |
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196 | * Returns: Zero if OK, or nonzero if there wasn't enough space |
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197 | * |
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198 | * Use: Puts a word into a buffer with appropriate size and order. |
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199 | */ |
200 | |
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201 | #define BUF_PUTU_(n, W, w) \ |
202 | int buf_putu##w(buf *b, uint##n ww) \ |
203 | { \ |
204 | if (BENSURE(b, SZ_##W)) return (-1); \ |
205 | STORE##W(b->p, ww); \ |
206 | BSTEP(b, SZ_##W); \ |
207 | return (0); \ |
208 | } |
209 | DOUINTCONV(BUF_PUTU_) |
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210 | |
211 | /* --- @findz@ --- * |
212 | * |
213 | * Arguments: @buf *b@ = pointer to a buffer block |
214 | * @size_t *nn@ = where to put the length |
215 | * |
216 | * Returns: Zero if OK, nonzero if there wasn't a null byte to be found. |
217 | * |
218 | * Use: Finds a terminating null byte. |
219 | */ |
220 | |
221 | static int findz(buf *b, size_t *nn) |
222 | { |
223 | octet *p; |
224 | |
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225 | if ((p = memchr(BCUR(b), 0, BLEFT(b))) == 0) { |
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226 | buf_break(b); |
227 | return (-1); |
228 | } |
229 | *nn = p - BCUR(b); |
230 | return (0); |
231 | } |
232 | |
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233 | /* --- @buf_getmem{8,{16,24,32,64}{,l,b},z} --- * |
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234 | * |
235 | * Arguments: @buf *b@ = pointer to a buffer block |
236 | * @size_t *nn@ = where to put the length |
237 | * |
238 | * Returns: Pointer to the buffer data, or null. |
239 | * |
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240 | * Use: Gets a chunk of memory from a buffer. The suffix is the |
241 | * width and byte order of the length; @z@ means null- |
242 | * terminated. |
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243 | */ |
244 | |
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245 | #define BUF_GETMEM_(n, W, w) \ |
246 | void *buf_getmem##w(buf *b, size_t *nn) \ |
247 | { \ |
248 | uint##n sz; \ |
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249 | if (buf_getu##w(b, &sz)) return (0); \ |
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250 | *nn = sz; \ |
251 | return (buf_get(b, sz)); \ |
252 | } |
253 | DOUINTCONV(BUF_GETMEM_) |
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254 | |
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255 | void *buf_getmemz(buf *b, size_t *nn) |
256 | { |
257 | if (findz(b, nn)) return (0); |
258 | return (buf_get(b, *nn)); |
259 | } |
260 | |
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261 | /* --- @buf_putmem{8,{16,24,32,64}{,l,b},z} --- * |
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262 | * |
263 | * Arguments: @buf *b@ = pointer to a buffer block |
264 | * @const void *p@ = pointer to data to write |
265 | * @size_t n@ = length to write |
266 | * |
267 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
268 | * |
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269 | * Use: Writes a chunk of data to a buffer. The suffix is the |
270 | * width and byte order of the length; @z@ means null- |
271 | * terminated. |
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272 | */ |
273 | |
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274 | #define BUF_PUTMEM_(n, W, w) \ |
275 | int buf_putmem##w(buf *b, const void *p, size_t sz) \ |
276 | { \ |
277 | assert(sz <= MASK##W); \ |
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278 | if (buf_putu##w(b, sz) || buf_put(b, p, sz)) \ |
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279 | return (-1); \ |
280 | return (0); \ |
281 | } |
282 | DOUINTCONV(BUF_PUTMEM_) |
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283 | |
284 | int buf_putmemz(buf *b, const void *p, size_t n) |
285 | { |
286 | octet *q; |
287 | |
288 | assert(!memchr(p, 0, n)); |
289 | if ((q = buf_get(b, n + 1)) == 0) |
290 | return (-1); |
291 | memcpy(q, p, n); |
292 | q[n] = 0; |
293 | return (0); |
294 | } |
295 | |
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296 | /* --- @buf_getbuf{8,{16,24,32,64}{,l,b},z} --- * |
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297 | * |
298 | * Arguments: @buf *b@ = pointer to a buffer block |
299 | * @buf *bb@ = where to put the result |
300 | * |
301 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
302 | * |
303 | * Use: Gets a block of data from a buffer, and writes its bounds to |
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304 | * another buffer. |
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305 | */ |
306 | |
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307 | #define BUF_GETBUF_(n, W, w) \ |
308 | int buf_getbuf##w(buf *b, buf *bb) \ |
309 | { \ |
310 | void *p; \ |
311 | size_t sz; \ |
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312 | \ |
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313 | if ((p = buf_getmem##w(b, &sz)) == 0) \ |
314 | return (-1); \ |
315 | buf_init(bb, p, sz); \ |
316 | return (0); \ |
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317 | } |
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318 | BUF_DOSUFFIXES(BUF_GETBUF_) |
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319 | |
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320 | /* --- @buf_putbuf{8,{16,24,32,64}{,l,b},z} --- * |
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321 | * |
322 | * Arguments: @buf *b@ = pointer to a buffer block |
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323 | * @buf *bb@ = buffer to write |
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324 | * |
325 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
326 | * |
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327 | * Use: Puts the contents of a buffer to a buffer. |
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328 | */ |
329 | |
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330 | #define BUF_PUTBUF_(n, W, w) \ |
331 | int buf_putbuf##w(buf *b, buf *bb) \ |
332 | { return (buf_putmem##w(b, BBASE(bb), BLEN(bb))); } |
333 | BUF_DOSUFFIXES(BUF_PUTBUF_) |
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334 | |
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335 | /* --- @buf_putstr{8,{16,24,32,64}{,l,b},z} --- * |
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336 | * |
337 | * Arguments: @buf *b@ = pointer to a buffer block |
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338 | * @const char *p@ = string to write |
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339 | * |
340 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
341 | * |
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342 | * Use: Puts a null-terminated string to a buffer. |
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343 | */ |
344 | |
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345 | #define BUF_PUTSTR_(n, W, w) \ |
346 | int buf_putstr##w(buf *b, const char *p) \ |
347 | { return (buf_putmem##w(b, p, strlen(p))); } |
348 | BUF_DOSUFFIXES(BUF_PUTSTR_) |
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349 | |
350 | /*----- That's all, folks -------------------------------------------------*/ |