summaryrefslogtreecommitdiff
path: root/src/cksum.c
blob: b1a8f0c5fc79a66abc2619d60f96a3feca0bb2b6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
/* cksum -- calculate and print POSIX checksums and sizes of files
   Copyright (C) 1992-2017 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Q. Frank Xia, qx@math.columbia.edu.
   Cosmetic changes and reorganization by David MacKenzie, djm@gnu.ai.mit.edu.

  Usage: cksum [file...]

  The code segment between "#ifdef CRCTAB" and "#else" is the code
  which calculates the "crctab". It is included for those who want
  verify the correctness of the "crctab". To recreate the "crctab",
  do something like the following:

      cc -DCRCTAB -o crctab cksum.c
      crctab > crctab.h

  This software is compatible with neither the System V nor the BSD
  'sum' program.  It is supposed to conform to POSIX, except perhaps
  for foreign language support.  Any inconsistency with the standard
  (other than foreign language support) is a bug.  */

#include <config.h>

/* The official name of this program (e.g., no 'g' prefix).  */
#define PROGRAM_NAME "cksum"

#define AUTHORS proper_name ("Q. Frank Xia")

#include <stdio.h>
#include <sys/types.h>
#include <stdint.h>
#include "system.h"
#include "fadvise.h"
#include "xbinary-io.h"

#ifdef CRCTAB

# define BIT(x)	((uint_fast32_t) 1 << (x))
# define SBIT	BIT (31)

/* The generating polynomial is

          32   26   23   22   16   12   11   10   8   7   5   4   2   1
    G(X)=X  + X  + X  + X  + X  + X  + X  + X  + X + X + X + X + X + X + 1

  The i bit in GEN is set if X^i is a summand of G(X) except X^32.  */

# define GEN	(BIT (26) | BIT (23) | BIT (22) | BIT (16) | BIT (12) \
                 | BIT (11) | BIT (10) | BIT (8) | BIT (7) | BIT (5) \
                 | BIT (4) | BIT (2) | BIT (1) | BIT (0))

static uint_fast32_t r[8];

static void
fill_r (void)
{
  int i;

  r[0] = GEN;
  for (i = 1; i < 8; i++)
    r[i] = (r[i - 1] << 1) ^ ((r[i - 1] & SBIT) ? GEN : 0);
}

static uint_fast32_t
crc_remainder (int m)
{
  uint_fast32_t rem = 0;
  int i;

  for (i = 0; i < 8; i++)
    if (BIT (i) & m)
      rem ^= r[i];

  return rem & 0xFFFFFFFF;	/* Make it run on 64-bit machine.  */
}

int
main (void)
{
  int i;

  fill_r ();
  printf ("static uint_fast32_t const crctab[256] =\n{\n  0x00000000");
  for (i = 0; i < 51; i++)
    {
      printf (",\n  0x%08x, 0x%08x, 0x%08x, 0x%08x, 0x%08x",
              crc_remainder (i * 5 + 1), crc_remainder (i * 5 + 2),
              crc_remainder (i * 5 + 3), crc_remainder (i * 5 + 4),
              crc_remainder (i * 5 + 5));
    }
  printf ("\n};\n");
  return EXIT_SUCCESS;
}

#else /* !CRCTAB */

# include <getopt.h>
# include "long-options.h"
# include "die.h"
# include "error.h"

/* Number of bytes to read at once.  */
# define BUFLEN (1 << 16)

static uint_fast32_t const crctab[256] =
{
  0x00000000,
  0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
  0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
  0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
  0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
  0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
  0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
  0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
  0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
  0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
  0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
  0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
  0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
  0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
  0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
  0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
  0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
  0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
  0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
  0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
  0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
  0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
  0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
  0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
  0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
  0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
  0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
  0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
  0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
  0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
  0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
  0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
  0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
  0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
  0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
  0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
  0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
  0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
  0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
  0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
  0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
  0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
  0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
  0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
  0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
  0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
  0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
  0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
  0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
  0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
  0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
  0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
};

/* Nonzero if any of the files read were the standard input. */
static bool have_read_stdin;

/* Calculate and print the checksum and length in bytes
   of file FILE, or of the standard input if FILE is "-".
   If PRINT_NAME is true, print FILE next to the checksum and size.
   Return true if successful.  */

static bool
cksum (const char *file, bool print_name)
{
  unsigned char buf[BUFLEN];
  uint_fast32_t crc = 0;
  uintmax_t length = 0;
  size_t bytes_read;
  FILE *fp;
  char length_buf[INT_BUFSIZE_BOUND (uintmax_t)];
  char const *hp;

  if (STREQ (file, "-"))
    {
      fp = stdin;
      have_read_stdin = true;
      xset_binary_mode (STDIN_FILENO, O_BINARY);
    }
  else
    {
      fp = fopen (file, (O_BINARY ? "rb" : "r"));
      if (fp == NULL)
        {
          error (0, errno, "%s", quotef (file));
          return false;
        }
    }

  fadvise (fp, FADVISE_SEQUENTIAL);

  while ((bytes_read = fread (buf, 1, BUFLEN, fp)) > 0)
    {
      unsigned char *cp = buf;

      if (length + bytes_read < length)
        die (EXIT_FAILURE, 0, _("%s: file too long"), quotef (file));
      length += bytes_read;
      while (bytes_read--)
        crc = (crc << 8) ^ crctab[((crc >> 24) ^ *cp++) & 0xFF];
      if (feof (fp))
        break;
    }

  if (ferror (fp))
    {
      error (0, errno, "%s", quotef (file));
      if (!STREQ (file, "-"))
        fclose (fp);
      return false;
    }

  if (!STREQ (file, "-") && fclose (fp) == EOF)
    {
      error (0, errno, "%s", quotef (file));
      return false;
    }

  hp = umaxtostr (length, length_buf);

  for (; length; length >>= 8)
    crc = (crc << 8) ^ crctab[((crc >> 24) ^ length) & 0xFF];

  crc = ~crc & 0xFFFFFFFF;

  if (print_name)
    printf ("%u %s %s\n", (unsigned int) crc, hp, file);
  else
    printf ("%u %s\n", (unsigned int) crc, hp);

  if (ferror (stdout))
    die (EXIT_FAILURE, errno, "-: %s", _("write error"));

  return true;
}

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    emit_try_help ();
  else
    {
      printf (_("\
Usage: %s [FILE]...\n\
  or:  %s [OPTION]\n\
"),
              program_name, program_name);
      fputs (_("\
Print CRC checksum and byte counts of each FILE.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      emit_ancillary_info (PROGRAM_NAME);
    }
  exit (status);
}

int
main (int argc, char **argv)
{
  int i;
  bool ok;

  initialize_main (&argc, &argv);
  set_program_name (argv[0]);
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  /* Line buffer stdout to ensure lines are written atomically and immediately
     so that processes running in parallel do not intersperse their output.  */
  setvbuf (stdout, NULL, _IOLBF, 0);

  parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE, Version,
                      usage, AUTHORS, (char const *) NULL);
  if (getopt_long (argc, argv, "", NULL, NULL) != -1)
    usage (EXIT_FAILURE);

  have_read_stdin = false;

  if (optind == argc)
    ok = cksum ("-", false);
  else
    {
      ok = true;
      for (i = optind; i < argc; i++)
        ok &= cksum (argv[i], true);
    }

  if (have_read_stdin && fclose (stdin) == EOF)
    die (EXIT_FAILURE, errno, "-");
  return ok ? EXIT_SUCCESS : EXIT_FAILURE;
}

#endif /* !CRCTAB */