| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Buffer handling |
| 4 | * |
| 5 | * (c) 2001 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of the mLib utilities library. |
| 11 | * |
| 12 | * mLib is free software; you can redistribute it and/or modify |
| 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. |
| 16 | * |
| 17 | * mLib is distributed in the hope that it will be useful, |
| 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. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Library General Public |
| 23 | * License along with mLib; if not, write to the Free |
| 24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 25 | * MA 02111-1307, USA. |
| 26 | */ |
| 27 | |
| 28 | /*----- Header files ------------------------------------------------------*/ |
| 29 | |
| 30 | #include <assert.h> |
| 31 | #include <string.h> |
| 32 | |
| 33 | #include "buf.h" |
| 34 | |
| 35 | /*----- Main code ---------------------------------------------------------*/ |
| 36 | |
| 37 | /* --- @buf_init@ --- * |
| 38 | * |
| 39 | * Arguments: @buf *b@ = pointer to a buffer block |
| 40 | * @void *p@ = pointer to a buffer |
| 41 | * @size_t sz@ = size of the buffer |
| 42 | * |
| 43 | * Returns: --- |
| 44 | * |
| 45 | * Use: Initializes the buffer block appropriately. |
| 46 | */ |
| 47 | |
| 48 | void buf_init(buf *b, void *p, size_t sz) |
| 49 | { |
| 50 | b->base = b->p = p; |
| 51 | b->limit = b->p + sz; |
| 52 | b->f = 0; |
| 53 | } |
| 54 | |
| 55 | /* --- @buf_break@ --- * |
| 56 | * |
| 57 | * Arguments: @buf *b@ = pointer to a buffer block |
| 58 | * |
| 59 | * Returns: Some negative value. |
| 60 | * |
| 61 | * Use: Marks a buffer as broken. |
| 62 | */ |
| 63 | |
| 64 | int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); } |
| 65 | |
| 66 | /* --- @buf_flip@ --- * |
| 67 | * |
| 68 | * Arguments: @buf *b@ = pointer to a buffer block |
| 69 | * |
| 70 | * Returns: --- |
| 71 | * |
| 72 | * Use: Flips a buffer so that if you've just been writing to it, |
| 73 | * you can now read from the bit you've written. |
| 74 | */ |
| 75 | |
| 76 | void buf_flip(buf *b) |
| 77 | { |
| 78 | b->limit = b->p; |
| 79 | b->p = b->base; |
| 80 | } |
| 81 | |
| 82 | /* --- @buf_ensure@ --- * |
| 83 | * |
| 84 | * Arguments: @buf *b@ = pointer to a buffer block |
| 85 | * @size_t sz@ = size of data wanted |
| 86 | * |
| 87 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 88 | * |
| 89 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
| 90 | */ |
| 91 | |
| 92 | int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); } |
| 93 | |
| 94 | /* --- @buf_get@ --- * |
| 95 | * |
| 96 | * Arguments: @buf *b@ = pointer to a buffer block |
| 97 | * @size_t sz@ = size of the buffer |
| 98 | * |
| 99 | * Returns: Pointer to the place in the buffer. |
| 100 | * |
| 101 | * Use: Reserves a space in the buffer of the requested size, and |
| 102 | * returns its start address. |
| 103 | */ |
| 104 | |
| 105 | void *buf_get(buf *b, size_t sz) |
| 106 | { |
| 107 | void *p; |
| 108 | if (BENSURE(b, sz)) |
| 109 | return (0); |
| 110 | p = BCUR(b); |
| 111 | BSTEP(b, sz); |
| 112 | return (p); |
| 113 | } |
| 114 | |
| 115 | /* --- @buf_put@ --- * |
| 116 | * |
| 117 | * Arguments: @buf *b@ = pointer to a buffer block |
| 118 | * @const void *p@ = pointer to a buffer |
| 119 | * @size_t sz@ = size of the buffer |
| 120 | * |
| 121 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 122 | * |
| 123 | * Use: Fetches data from some place and puts it in the buffer |
| 124 | */ |
| 125 | |
| 126 | int buf_put(buf *b, const void *p, size_t sz) |
| 127 | { |
| 128 | if (BENSURE(b, sz)) |
| 129 | return (-1); |
| 130 | memcpy(BCUR(b), p, sz); |
| 131 | BSTEP(b, sz); |
| 132 | return (0); |
| 133 | } |
| 134 | |
| 135 | /* --- @buf_getbyte@ --- * |
| 136 | * |
| 137 | * Arguments: @buf *b@ = pointer to a buffer block |
| 138 | * |
| 139 | * Returns: A byte, or less than zero if there wasn't a byte there. |
| 140 | * |
| 141 | * Use: Gets a single byte from a buffer. |
| 142 | */ |
| 143 | |
| 144 | int buf_getbyte(buf *b) |
| 145 | { |
| 146 | if (BENSURE(b, 1)) |
| 147 | return (-1); |
| 148 | return (*b->p++); |
| 149 | } |
| 150 | |
| 151 | /* --- @buf_putbyte@ --- * |
| 152 | * |
| 153 | * Arguments: @buf *b@ = pointer to a buffer block |
| 154 | * @int ch@ = byte to write |
| 155 | * |
| 156 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
| 157 | * |
| 158 | * Use: Puts a single byte in a buffer. |
| 159 | */ |
| 160 | |
| 161 | int buf_putbyte(buf *b, int ch) |
| 162 | { |
| 163 | if (BENSURE(b, 1)) |
| 164 | return (-1); |
| 165 | *b->p++ = ch; |
| 166 | return (0); |
| 167 | } |
| 168 | |
| 169 | /* --- @buf_getu{8,{16,24,32,64}{,l,b}}@ --- * |
| 170 | * |
| 171 | * Arguments: @buf *b@ = pointer to a buffer block |
| 172 | * @uintSZ *w@ = where to put the word |
| 173 | * |
| 174 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
| 175 | * |
| 176 | * Use: Gets a word of appropriate size and order from a buffer. |
| 177 | */ |
| 178 | |
| 179 | #define BUF_GETU_(n, W, w) \ |
| 180 | int buf_getu##w(buf *b, uint##n *ww) \ |
| 181 | { \ |
| 182 | if (BENSURE(b, SZ_##W)) return (-1); \ |
| 183 | *ww = LOAD##W(b->p); \ |
| 184 | BSTEP(b, SZ_##W); \ |
| 185 | return (0); \ |
| 186 | } |
| 187 | DOUINTCONV(BUF_GETU_) |
| 188 | |
| 189 | /* --- @buf_putu{8,{16,24,32,64}{,l,b}}@ --- * |
| 190 | * |
| 191 | * Arguments: @buf *b@ = pointer to a buffer block |
| 192 | * @uintSZ w@ = word to write |
| 193 | * |
| 194 | * Returns: Zero if OK, or nonzero if there wasn't enough space |
| 195 | * |
| 196 | * Use: Puts a word into a buffer with appropriate size and order. |
| 197 | */ |
| 198 | |
| 199 | #define BUF_PUTU_(n, W, w) \ |
| 200 | int buf_putu##w(buf *b, uint##n ww) \ |
| 201 | { \ |
| 202 | if (BENSURE(b, SZ_##W)) return (-1); \ |
| 203 | STORE##W(b->p, ww); \ |
| 204 | BSTEP(b, SZ_##W); \ |
| 205 | return (0); \ |
| 206 | } |
| 207 | DOUINTCONV(BUF_PUTU_) |
| 208 | |
| 209 | /* --- @findz@ --- * |
| 210 | * |
| 211 | * Arguments: @buf *b@ = pointer to a buffer block |
| 212 | * @size_t *nn@ = where to put the length |
| 213 | * |
| 214 | * Returns: Zero if OK, nonzero if there wasn't a null byte to be found. |
| 215 | * |
| 216 | * Use: Finds a terminating null byte. The length includes this |
| 217 | * terminator. |
| 218 | */ |
| 219 | |
| 220 | static int findz(buf *b, size_t *nn) |
| 221 | { |
| 222 | octet *p; |
| 223 | |
| 224 | if ((p = memchr(BCUR(b), 0, BLEFT(b))) == 0) { |
| 225 | buf_break(b); |
| 226 | return (-1); |
| 227 | } |
| 228 | *nn = p - BCUR(b) + 1; |
| 229 | return (0); |
| 230 | } |
| 231 | |
| 232 | /* --- @buf_getmem{8,{16,24,32,64}{,l,b},z} --- * |
| 233 | * |
| 234 | * Arguments: @buf *b@ = pointer to a buffer block |
| 235 | * @size_t *nn@ = where to put the length |
| 236 | * |
| 237 | * Returns: Pointer to the buffer data, or null. |
| 238 | * |
| 239 | * Use: Gets a chunk of memory from a buffer. The suffix is the |
| 240 | * width and byte order of the length; @z@ means null- |
| 241 | * terminated. |
| 242 | */ |
| 243 | |
| 244 | #define BUF_GETMEM_(n, W, w) \ |
| 245 | void *buf_getmem##w(buf *b, size_t *nn) \ |
| 246 | { \ |
| 247 | uint##n sz; \ |
| 248 | if (buf_getu##w(b, &sz)) return (0); \ |
| 249 | *nn = sz; \ |
| 250 | return (buf_get(b, sz)); \ |
| 251 | } |
| 252 | DOUINTCONV(BUF_GETMEM_) |
| 253 | |
| 254 | void *buf_getmemz(buf *b, size_t *nn) |
| 255 | { |
| 256 | if (findz(b, nn)) return (0); |
| 257 | return (buf_get(b, *nn)); |
| 258 | } |
| 259 | |
| 260 | /* --- @buf_putmem{8,{16,24,32,64}{,l,b},z} --- * |
| 261 | * |
| 262 | * Arguments: @buf *b@ = pointer to a buffer block |
| 263 | * @const void *p@ = pointer to data to write |
| 264 | * @size_t n@ = length to write |
| 265 | * |
| 266 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
| 267 | * |
| 268 | * Use: Writes a chunk of data to a buffer. The suffix is the |
| 269 | * width and byte order of the length; @z@ means null- |
| 270 | * terminated. |
| 271 | */ |
| 272 | |
| 273 | #define BUF_PUTMEM_(n, W, w) \ |
| 274 | int buf_putmem##w(buf *b, const void *p, size_t sz) \ |
| 275 | { \ |
| 276 | assert(sz <= MASK##W); \ |
| 277 | if (buf_putu##w(b, sz) || buf_put(b, p, sz)) \ |
| 278 | return (-1); \ |
| 279 | return (0); \ |
| 280 | } |
| 281 | DOUINTCONV(BUF_PUTMEM_) |
| 282 | |
| 283 | int buf_putmemz(buf *b, const void *p, size_t n) |
| 284 | { |
| 285 | octet *q; |
| 286 | |
| 287 | assert(!memchr(p, 0, n)); |
| 288 | if ((q = buf_get(b, n + 1)) == 0) |
| 289 | return (-1); |
| 290 | memcpy(q, p, n); |
| 291 | q[n] = 0; |
| 292 | return (0); |
| 293 | } |
| 294 | |
| 295 | /* --- @buf_getbuf{8,{16,24,32,64}{,l,b},z} --- * |
| 296 | * |
| 297 | * Arguments: @buf *b@ = pointer to a buffer block |
| 298 | * @buf *bb@ = where to put the result |
| 299 | * |
| 300 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 301 | * |
| 302 | * Use: Gets a block of data from a buffer, and writes its bounds to |
| 303 | * another buffer. |
| 304 | */ |
| 305 | |
| 306 | #define BUF_GETBUF_(n, W, w) \ |
| 307 | int buf_getbuf##w(buf *b, buf *bb) \ |
| 308 | { \ |
| 309 | void *p; \ |
| 310 | size_t sz; \ |
| 311 | \ |
| 312 | if ((p = buf_getmem##w(b, &sz)) == 0) \ |
| 313 | return (-1); \ |
| 314 | buf_init(bb, p, sz); \ |
| 315 | return (0); \ |
| 316 | } |
| 317 | BUF_DOSUFFIXES(BUF_GETBUF_) |
| 318 | |
| 319 | /* --- @buf_putbuf{8,{16,24,32,64}{,l,b},z} --- * |
| 320 | * |
| 321 | * Arguments: @buf *b@ = pointer to a buffer block |
| 322 | * @buf *bb@ = buffer to write |
| 323 | * |
| 324 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 325 | * |
| 326 | * Use: Puts the contents of a buffer to a buffer. |
| 327 | */ |
| 328 | |
| 329 | #define BUF_PUTBUF_(n, W, w) \ |
| 330 | int buf_putbuf##w(buf *b, buf *bb) \ |
| 331 | { return (buf_putmem##w(b, BBASE(bb), BLEN(bb))); } |
| 332 | BUF_DOSUFFIXES(BUF_PUTBUF_) |
| 333 | |
| 334 | /* --- @buf_putstr{8,{16,24,32,64}{,l,b},z} --- * |
| 335 | * |
| 336 | * Arguments: @buf *b@ = pointer to a buffer block |
| 337 | * @const char *p@ = string to write |
| 338 | * |
| 339 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 340 | * |
| 341 | * Use: Puts a null-terminated string to a buffer. |
| 342 | */ |
| 343 | |
| 344 | #define BUF_PUTSTR_(n, W, w) \ |
| 345 | int buf_putstr##w(buf *b, const char *p) \ |
| 346 | { return (buf_putmem##w(b, p, strlen(p))); } |
| 347 | BUF_DOSUFFIXES(BUF_PUTSTR_) |
| 348 | |
| 349 | /*----- That's all, folks -------------------------------------------------*/ |