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1 | /* -*-c-*- |
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2 | * |
3 | * Reading and writing packet buffers |
4 | * |
5 | * (c) 2001 Straylight/Edgeware |
6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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9 | * |
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10 | * This file is part of the mLib utilities library. |
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11 | * |
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12 | * mLib is free software; you can redistribute it and/or modify |
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13 | * it under the terms of the GNU Library General Public License as |
14 | * published by the Free Software Foundation; either version 2 of the |
15 | * License, or (at your option) any later version. |
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16 | * |
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17 | * mLib is distributed in the hope that it will be useful, |
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18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU Library General Public License for more details. |
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21 | * |
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22 | * You should have received a copy of the GNU Library General Public |
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23 | * License along with mLib; if not, write to the Free |
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24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
25 | * MA 02111-1307, USA. |
26 | */ |
27 | |
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28 | #ifndef MLIB_BUF_H |
29 | #define MLIB_BUF_H |
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30 | |
31 | #ifdef __cplusplus |
32 | extern "C" { |
33 | #endif |
34 | |
35 | /*----- Header files ------------------------------------------------------*/ |
36 | |
37 | #include <stddef.h> |
38 | |
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39 | #ifndef MLIB_BITS_H |
40 | # include "bits.h" |
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41 | #endif |
42 | |
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43 | #ifndef MLIB_DSTR_H |
44 | # include "dstr.h" |
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45 | #endif |
46 | |
47 | /*----- Data structures ---------------------------------------------------*/ |
48 | |
49 | /* --- Buffers --- * |
50 | * |
51 | * Buffers provide a simple stream-like interface for building and parsing |
52 | * packets. |
53 | */ |
54 | |
55 | typedef struct buf { |
56 | octet *base, *p, *limit; /* Pointers to the buffer */ |
57 | unsigned f; /* Various flags */ |
58 | } buf; |
59 | |
60 | #define BF_BROKEN 1u /* Buffer is broken */ |
61 | |
62 | /*----- Useful macros -----------------------------------------------------*/ |
63 | |
64 | #define BBASE(b) ((b)->base) |
65 | #define BLIM(b) ((b)->limit) |
66 | #define BCUR(b) ((b)->p) |
67 | #define BSZ(b) ((b)->limit - (b)->base) |
68 | #define BLEN(b) ((b)->p - (b)->base) |
69 | #define BLEFT(b) ((b)->limit - (b)->p) |
70 | #define BSTEP(b, sz) ((b)->p += (sz)) |
71 | #define BBAD(b) ((b)->f & BF_BROKEN) |
72 | #define BOK(b) (!BBAD(b)) |
73 | |
74 | #define BENSURE(b, sz) \ |
75 | (BBAD(b) ? -1 : (sz) > BLEFT(b) ? (b)->f |= BF_BROKEN, -1 : 0) |
76 | |
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77 | #define BUF_DOSUFFIXES(_) DOUINTCONV(_) _(z, z, z) |
78 | |
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79 | /*----- Functions provided ------------------------------------------------*/ |
80 | |
81 | /* --- @buf_init@ --- * |
82 | * |
83 | * Arguments: @buf *b@ = pointer to a buffer block |
84 | * @void *p@ = pointer to a buffer |
85 | * @size_t sz@ = size of the buffer |
86 | * |
87 | * Returns: --- |
88 | * |
89 | * Use: Initializes the buffer block appropriately. |
90 | */ |
91 | |
92 | extern void buf_init(buf */*b*/, void */*p*/, size_t /*sz*/); |
93 | |
94 | /* --- @buf_break@ --- * |
95 | * |
96 | * Arguments: @buf *b@ = pointer to a buffer block |
97 | * |
98 | * Returns: Some negative value. |
99 | * |
100 | * Use: Marks a buffer as broken. |
101 | */ |
102 | |
103 | extern int buf_break(buf */*b*/); |
104 | |
105 | /* --- @buf_flip@ --- * |
106 | * |
107 | * Arguments: @buf *b@ = pointer to a buffer block |
108 | * |
109 | * Returns: --- |
110 | * |
111 | * Use: Flips a buffer so that if you've just been writing to it, |
112 | * you can now read from the bit you've written. |
113 | */ |
114 | |
115 | extern void buf_flip(buf */*b*/); |
116 | |
117 | /* --- @buf_ensure@ --- * |
118 | * |
119 | * Arguments: @buf *b@ = pointer to a buffer block |
120 | * @size_t sz@ = size of data wanted |
121 | * |
122 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
123 | * |
124 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
125 | */ |
126 | |
127 | extern int buf_ensure(buf */*b*/, size_t /*sz*/); |
128 | |
129 | /* --- @buf_get@ --- * |
130 | * |
131 | * Arguments: @buf *b@ = pointer to a buffer block |
132 | * @size_t sz@ = size of the buffer |
133 | * |
134 | * Returns: Pointer to the place in the buffer. |
135 | * |
136 | * Use: Reserves a space in the buffer of the requested size, and |
137 | * returns its start address. |
138 | */ |
139 | |
140 | extern void *buf_get(buf */*b*/, size_t /*sz*/); |
141 | |
142 | /* --- @buf_put@ --- * |
143 | * |
144 | * Arguments: @buf *b@ = pointer to a buffer block |
145 | * @const void *p@ = pointer to a buffer |
146 | * @size_t sz@ = size of the buffer |
147 | * |
148 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
149 | * |
150 | * Use: Fetches data from some place and puts it in the buffer |
151 | */ |
152 | |
153 | extern int buf_put(buf */*b*/, const void */*p*/, size_t /*sz*/); |
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 | extern int buf_getbyte(buf */*b*/); |
165 | |
166 | /* --- @buf_putbyte@ --- * |
167 | * |
168 | * Arguments: @buf *b@ = pointer to a buffer block |
169 | * @int ch@ = byte to write |
170 | * |
171 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
172 | * |
173 | * Use: Puts a single byte in a buffer. |
174 | */ |
175 | |
176 | extern int buf_putbyte(buf */*b*/, int /*ch*/); |
177 | |
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178 | /* --- @buf_getu{8,{16,24,32,64}{,l,b}}@ --- * |
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179 | * |
180 | * Arguments: @buf *b@ = pointer to a buffer block |
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181 | * @uintSZ *w@ = where to put the word |
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182 | * |
183 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
184 | * |
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185 | * Use: Gets a word of appropriate size and order from a buffer. |
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186 | */ |
187 | |
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188 | #define BUF_DECL_GETU_(n, W, w) \ |
189 | extern int buf_getu##w(buf */*b*/, uint##n */*w*/); |
190 | DOUINTCONV(BUF_DECL_GETU_) |
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191 | |
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192 | /* --- @buf_putu{8,{16,24,32,64}{,l,b}}@ --- * |
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193 | * |
194 | * Arguments: @buf *b@ = pointer to a buffer block |
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195 | * @uintSZ w@ = word to write |
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196 | * |
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197 | * Returns: Zero if OK, or nonzero if there wasn't enough space |
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198 | * |
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199 | * Use: Puts a word into a buffer with appropriate size and order. |
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200 | */ |
201 | |
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202 | #define BUF_DECL_PUTU_(n, W, w) \ |
203 | extern int buf_putu##w(buf */*b*/, uint##n /*w*/); |
204 | DOUINTCONV(BUF_DECL_PUTU_) |
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205 | |
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206 | /* --- @buf_getmem{8,{16,24,32,64}{,l,b},z} --- * |
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207 | * |
208 | * Arguments: @buf *b@ = pointer to a buffer block |
209 | * @size_t *nn@ = where to put the length |
210 | * |
211 | * Returns: Pointer to the buffer data, or null. |
212 | * |
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213 | * Use: Gets a chunk of memory from a buffer. The suffix is the |
214 | * width and byte order of the length; @z@ means null- |
215 | * terminated. |
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216 | */ |
217 | |
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218 | #define BUF_DECL_GETMEM_(n, W, w) \ |
219 | extern void *buf_getmem##w(buf */*b*/, size_t */*nn*/); |
220 | BUF_DOSUFFIXES(BUF_DECL_GETMEM_) |
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221 | |
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222 | /* --- @buf_putmem{8,{16,24,32,64}{,l,b},z} --- * |
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223 | * |
224 | * Arguments: @buf *b@ = pointer to a buffer block |
225 | * @const void *p@ = pointer to data to write |
226 | * @size_t n@ = length to write |
227 | * |
228 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
229 | * |
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230 | * Use: Writes a chunk of data to a buffer. The suffix is the |
231 | * width and byte order of the length; @z@ means null- |
232 | * terminated. |
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233 | */ |
234 | |
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235 | #define BUF_DECL_PUTMEM_(n, W, w) \ |
236 | extern int buf_putmem##w(buf */*b*/, const void */*p*/, size_t /*nn*/); |
237 | BUF_DOSUFFIXES(BUF_DECL_PUTMEM_) |
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238 | |
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239 | /* --- @buf_getbuf{8,{16,24,32,64}{,l,b},z} --- * |
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240 | * |
241 | * Arguments: @buf *b@ = pointer to a buffer block |
242 | * @buf *bb@ = where to put the result |
243 | * |
244 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
245 | * |
246 | * Use: Gets a block of data from a buffer, and writes its bounds to |
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247 | * another buffer. |
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248 | */ |
249 | |
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250 | #define BUF_DECL_GETBUF_(n, W, w) \ |
251 | extern int buf_getbuf##w(buf */*b*/, buf */*bb*/); |
252 | BUF_DOSUFFIXES(BUF_DECL_GETBUF_) |
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253 | |
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254 | /* --- @buf_putbuf{8,{16,24,32,64}{,l,b},z} --- * |
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255 | * |
256 | * Arguments: @buf *b@ = pointer to a buffer block |
257 | * @buf *bb@ = buffer to write |
258 | * |
259 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
260 | * |
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261 | * Use: Puts the contents of a buffer to a buffer. |
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262 | */ |
263 | |
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264 | #define BUF_DECL_PUTBUF_(n, W, w) \ |
265 | extern int buf_putbuf##w(buf */*b*/, buf */*bb*/); |
266 | BUF_DOSUFFIXES(BUF_DECL_PUTBUF_) |
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267 | |
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268 | /* --- @buf_getdstr{8,{16,24,32,64}{,l,b},z} --- * |
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269 | * |
270 | * Arguments: @buf *b@ = pointer to a buffer block |
271 | * @dstr *d@ = where to put the result |
272 | * |
273 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
274 | * |
275 | * Use: Gets a block of data from a buffer, and writes its contents |
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276 | * to a string. |
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277 | */ |
278 | |
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279 | #define BUF_DECL_GETDSTR_(n, W, w) \ |
280 | extern int buf_getdstr##w(buf */*b*/, dstr */*d*/); |
281 | BUF_DOSUFFIXES(BUF_DECL_GETDSTR_) |
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282 | |
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283 | /* --- @buf_putdstr{8,{16,24,32,64}{,l,b},z} --- * |
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284 | * |
285 | * Arguments: @buf *b@ = pointer to a buffer block |
286 | * @dstr *d@ = string to write |
287 | * |
288 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
289 | * |
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290 | * Use: Puts a dynamic string to a buffer. |
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291 | */ |
292 | |
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293 | #define BUF_DECL_PUTDSTR_(n, W, w) \ |
294 | extern int buf_putdstr##w(buf */*b*/, dstr */*d*/); |
295 | BUF_DOSUFFIXES(BUF_DECL_PUTDSTR_) |
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296 | |
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297 | /* --- @buf_putstr{8,{16,24,32,64}{,l,b},z} --- * |
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298 | * |
299 | * Arguments: @buf *b@ = pointer to a buffer block |
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300 | * @const char *p@ = string to write |
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301 | * |
302 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
303 | * |
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304 | * Use: Puts a null-terminated string to a buffer. |
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305 | */ |
306 | |
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307 | #define BUF_DECL_PUTSTR_(n, W, w) \ |
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308 | extern int buf_putstr##w(buf */*b*/, const char */*p*/); |
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309 | BUF_DOSUFFIXES(BUF_DECL_PUTSTR_) |
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310 | |
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311 | /*----- That's all, folks -------------------------------------------------*/ |
312 | |
313 | #ifdef __cplusplus |
314 | } |
315 | #endif |
316 | |
317 | #endif |