src/helper/binarybuffer.c

   1 /***************************************************************************
   2  *   Copyright (C) 2004, 2005 by Dominic Rath                              *
   3  *   Dominic.Rath@gmx.de                                                   *
   4  *                                                                         *
   5  *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
   6  *   oyvind.harboe@zylin.com                                               *
   7  *                                                                         *
   8  *   This program is free software; you can redistribute it and/or modify  *
   9  *   it under the terms of the GNU General Public License as published by  *
  10  *   the Free Software Foundation; either version 2 of the License, or     *
  11  *   (at your option) any later version.                                   *
  12  *                                                                         *
  13  *   This program is distributed in the hope that it will be useful,       *
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  16  *   GNU General Public License for more details.                          *
  17  *                                                                         *
  18  *   You should have received a copy of the GNU General Public License     *
  19  *   along with this program; if not, write to the                         *
  20  *   Free Software Foundation, Inc.,                                       *
  21  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  22  ***************************************************************************/
  23 #ifdef HAVE_CONFIG_H
  24 #include "config.h"
  25 #endif
  26
  27 #include "log.h"
  28 #include "binarybuffer.h"
  29
  30 static const unsigned char bit_reverse_table256[] =
  31 {
  32   0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
  33   0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
  34   0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
  35   0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
  36   0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
  37   0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
  38   0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
  39   0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
  40   0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
  41   0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
  42   0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
  43   0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
  44   0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
  45   0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
  46   0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
  47   0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
  48 };
  49
  50
  51 void* buf_cpy(const void *from, void *_to, unsigned size)
  52 {
  53         if (NULL == from || NULL == _to)
  54                 return NULL;
  55
  56         // copy entire buffer
  57         memcpy(_to, from, DIV_ROUND_UP(size, 8));
  58
  59         /* mask out bits that don't belong to the buffer */
  60         unsigned trailing_bits = size % 8;
  61         if (trailing_bits)
  62         {
  63                 uint8_t *to = _to;
  64                 to[size / 8] &= (1 << trailing_bits) - 1;
  65         }
  66         return _to;
  67 }
  68
  69 static bool buf_cmp_masked(uint8_t a, uint8_t b, uint8_t m)
  70 {
  71         return (a & m) != (b & m);
  72 }
  73 static bool buf_cmp_trailing(uint8_t a, uint8_t b, uint8_t m, unsigned trailing)
  74 {
  75         uint8_t mask = (1 << trailing) - 1;
  76         return buf_cmp_masked(a, b, mask & m);
  77 }
  78
  79 bool buf_cmp(const void *_buf1, const void *_buf2, unsigned size)
  80 {
  81         if (!_buf1 || !_buf2)
  82                 return _buf1 != _buf2;
  83
  84         unsigned last = size / 8;
  85         if (memcmp(_buf1, _buf2, last) != 0)
  86                 return false;
  87
  88         unsigned trailing = size % 8;
  89         if (!trailing)
  90                 return false;
  91
  92         const uint8_t *buf1 = _buf1, *buf2 = _buf2;
  93         return buf_cmp_trailing(buf1[last], buf2[last], 0xff, trailing);
  94 }
  95
  96 bool buf_cmp_mask(const void *_buf1, const void *_buf2,
  97                 const void *_mask, unsigned size)
  98 {
  99         if (!_buf1 || !_buf2)
 100                 return _buf1 != _buf2 || _buf1 != _mask;
 101
 102         const uint8_t *buf1 = _buf1, *buf2 = _buf2, *mask = _mask;
 103         unsigned last = size / 8;
 104         for (unsigned i = 0; i < last; i++)
 105         {
 106                 if (buf_cmp_masked(buf1[i], buf2[i], mask[i]))
 107                         return true;
 108         }
 109         unsigned trailing = size % 8;
 110         if (!trailing)
 111                 return false;
 112         return buf_cmp_trailing(buf1[last], buf2[last], mask[last], trailing);
 113 }
 114
 115
 116 void* buf_set_ones(void *_buf, unsigned size)
 117 {
 118         uint8_t *buf = _buf;
 119         if (!buf)
 120                 return NULL;
 121
 122         memset(buf, 0xff, size / 8);
 123
 124         unsigned trailing_bits = size % 8;
 125         if (trailing_bits)
 126                 buf[size / 8] = (1 << trailing_bits) - 1;
 127
 128         return buf;
 129 }
 130
 131 void* buf_set_buf(const void *_src, unsigned src_start,
 132                 void *_dst, unsigned dst_start, unsigned len)
 133 {
 134         const uint8_t *src = _src;
 135         uint8_t *dst = _dst;
 136
 137         unsigned src_idx = src_start, dst_idx = dst_start;
 138         for (unsigned i = 0; i < len; i++)
 139         {
 140                 if (((src[src_idx / 8] >> (src_idx % 8)) & 1) == 1)
 141                         dst[dst_idx / 8] |= 1 << (dst_idx % 8);
 142                 else
 143                         dst[dst_idx / 8] &= ~(1 << (dst_idx % 8));
 144                 dst_idx++;
 145                 src_idx++;
 146         }
 147
 148         return dst;
 149 }
 150
 151 uint32_t flip_u32(uint32_t value, unsigned int num)
 152 {
 153         uint32_t c = (bit_reverse_table256[value & 0xff] << 24) |
 154                 (bit_reverse_table256[(value >> 8) & 0xff] << 16) |
 155                 (bit_reverse_table256[(value >> 16) & 0xff] << 8) |
 156                 (bit_reverse_table256[(value >> 24) & 0xff]);
 157
 158         if (num < 32)
 159                 c = c >> (32 - num);
 160
 161         return c;
 162 }
 163
 164 static int ceil_f_to_u32(float x)
 165 {
 166         if (x < 0)      /* return zero for negative numbers */
 167                 return 0;
 168
 169         uint32_t y = x; /* cut off fraction */
 170
 171         if ((x - y) > 0.0) /* if there was a fractional part, increase by one */
 172                 y++;
 173
 174         return y;
 175 }
 176
 177 char* buf_to_str(const void *_buf, unsigned buf_len, unsigned radix)
 178 {
 179         float factor;
 180         switch (radix) {
 181         case 16:
 182                 factor = 2.0;   /* log(256) / log(16) = 2.0 */
 183                 break;
 184         case 10:
 185                 factor = 2.40824;   /* log(256) / log(10) = 2.40824 */
 186                 break;
 187         case 8:
 188                 factor = 2.66667;       /* log(256) / log(8) = 2.66667 */
 189                 break;
 190         default:
 191                 return NULL;
 192         }
 193
 194         unsigned str_len = ceil_f_to_u32(DIV_ROUND_UP(buf_len, 8) * factor);
 195         char *str = calloc(str_len + 1, 1);
 196
 197         const uint8_t *buf = _buf;
 198         int b256_len = DIV_ROUND_UP(buf_len, 8);
 199         for (int i = b256_len - 1; i >= 0; i--)
 200         {
 201                 uint32_t tmp = buf[i];
 202                 if (((unsigned)i == (buf_len / 8)) && (buf_len % 8))
 203                         tmp &= (0xff >> (8 - (buf_len % 8)));
 204
 205                 /* base-256 digits */
 206                 for (unsigned j = str_len; j > 0; j--)
 207                 {
 208                         tmp += (uint32_t)str[j-1] * 256;
 209                         str[j-1] = (uint8_t)(tmp % radix);
 210                         tmp /= radix;
 211                 }
 212         }
 213
 214         const char *DIGITS = "0123456789ABCDEF";
 215         for (unsigned j = 0; j < str_len; j++)
 216                 str[j] = DIGITS[(int)str[j]];
 217
 218         return str;
 219 }
 220
 221 /// identify radix, and skip radix-prefix (0, 0x or 0X)
 222 static void str_radix_guess(const char **_str, unsigned *_str_len,
 223                 unsigned *_radix)
 224 {
 225         unsigned radix = *_radix;
 226         if (0 != radix)
 227                 return;
 228         const char *str = *_str;
 229         unsigned str_len = *_str_len;
 230         if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 231         {
 232                 radix = 16;
 233                 str += 2;
 234                 str_len -= 2;
 235         }
 236         else if ((str[0] == '0') && (str_len != 1))
 237         {
 238                 radix = 8;
 239                 str += 1;
 240                 str_len -= 1;
 241         }
 242         else
 243         {
 244                 radix = 10;
 245         }
 246         *_str = str;
 247         *_str_len = str_len;
 248         *_radix = radix;
 249 }
 250
 251 int str_to_buf(const char *str, unsigned str_len,
 252                 void *_buf, unsigned buf_len, unsigned radix)
 253 {
 254         str_radix_guess(&str, &str_len, &radix);
 255
 256         float factor;
 257         if (radix == 16)
 258                 factor = 0.5; /* log(16) / log(256) = 0.5 */
 259         else if (radix == 10)
 260                 factor = 0.41524; /* log(10) / log(256) = 0.41524 */
 261         else if (radix == 8)
 262                 factor = 0.375; /* log(8) / log(256) = 0.375 */
 263         else
 264                 return 0;
 265
 266         /* copy to zero-terminated buffer */
 267         char *charbuf = malloc(str_len + 1);
 268         memcpy(charbuf, str, str_len);
 269         charbuf[str_len] = '\0';
 270
 271         /* number of digits in base-256 notation */
 272         unsigned b256_len = ceil_f_to_u32(str_len * factor);
 273         uint8_t *b256_buf = calloc(b256_len, 1);
 274
 275         /* go through zero terminated buffer */
 276         /* input digits (ASCII) */
 277         unsigned i;
 278         for (i = 0; charbuf[i]; i++)
 279         {
 280                 uint32_t tmp = charbuf[i];
 281                 if ((tmp >= '0') && (tmp <= '9'))
 282                         tmp = (tmp - '0');
 283                 else if ((tmp >= 'a') && (tmp <= 'f'))
 284                         tmp = (tmp - 'a' + 10);
 285                 else if ((tmp >= 'A') && (tmp <= 'F'))
 286                         tmp = (tmp - 'A' + 10);
 287                 else continue;  /* skip characters other than [0-9,a-f,A-F] */
 288
 289                 if (tmp >= radix)
 290                         continue;       /* skip digits invalid for the current radix */
 291
 292                 /* base-256 digits */
 293                 for (unsigned j = 0; j < b256_len; j++)
 294                 {
 295                         tmp += (uint32_t)b256_buf[j] * radix;
 296                         b256_buf[j] = (uint8_t)(tmp & 0xFF);
 297                         tmp >>= 8;
 298                 }
 299
 300         }
 301
 302         uint8_t *buf = _buf;
 303         for (unsigned j = 0; j < DIV_ROUND_UP(buf_len, 8); j++)
 304         {
 305                 if (j < b256_len)
 306                         buf[j] = b256_buf[j];
 307                 else
 308                         buf[j] = 0;
 309         }
 310
 311         /* mask out bits that don't belong to the buffer */
 312         if (buf_len % 8)
 313                 buf[(buf_len / 8)] &= 0xff >> (8 - (buf_len % 8));
 314
 315         free(b256_buf);
 316         free(charbuf);
 317
 318         return i;
 319 }