46ea855ec11ebe0b2606eff61a7d8ddda0ece289
2 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 as published
6 * by the Free Software Foundation.
14 #include <unistd.h> /* for unlink() */
16 #include <getopt.h> /* for getopt() */
21 #if (__BYTE_ORDER == __LITTLE_ENDIAN)
22 # define HOST_TO_LE16(x) (x)
23 # define HOST_TO_LE32(x) (x)
24 # define LE16_TO_HOST(x) (x)
25 # define LE32_TO_HOST(x) (x)
27 # define HOST_TO_LE16(x) bswap_16(x)
28 # define HOST_TO_LE32(x) bswap_32(x)
29 # define LE16_TO_HOST(x) bswap_16(x)
30 # define LE32_TO_HOST(x) bswap_32(x)
33 uint32_t crc32buf(char *buf
, size_t len
);
39 static char *progname
;
45 #define ERR(fmt, ...) do { \
47 fprintf(stderr, "[%s] *** error: " fmt "\n", \
48 progname, ## __VA_ARGS__ ); \
51 #define ERRS(fmt, ...) do { \
54 fprintf(stderr, "[%s] *** error: " fmt ": %s\n", \
55 progname, ## __VA_ARGS__, strerror(save)); \
58 void usage(int status
)
60 FILE *stream
= (status
!= EXIT_SUCCESS
) ? stderr
: stdout
;
62 fprintf(stream
, "Usage: %s [OPTIONS...]\n", progname
);
66 " -i <file> read input from the file <file>\n"
67 " -o <file> write output to the file <file>\n"
68 " -h show this screen\n"
74 int main(int argc
, char *argv
[])
76 int res
= EXIT_FAILURE
;
84 FILE *outfile
, *infile
;
86 progname
= basename(argv
[0]);
91 c
= getopt(argc
, argv
, "i:o:h");
111 if (ifname
== NULL
) {
112 ERR("no input file specified");
116 if (ofname
== NULL
) {
117 ERR("no output file specified");
121 err
= stat(ifname
, &st
);
123 ERRS("stat failed on %s", ifname
);
128 buf
= malloc(buflen
);
130 ERR("no memory for buffer\n");
134 infile
= fopen(ifname
, "r");
135 if (infile
== NULL
) {
136 ERRS("could not open \"%s\" for reading", ifname
);
141 fread(buf
, buflen
, 1, infile
);
143 ERRS("unable to read from file %s", ifname
);
147 crc
= crc32buf(buf
, buflen
);
148 hdr
= (uint32_t *)buf
;
149 *hdr
= HOST_TO_LE32(crc
);
151 outfile
= fopen(ofname
, "w");
152 if (outfile
== NULL
) {
153 ERRS("could not open \"%s\" for writing", ofname
);
158 fwrite(buf
, buflen
, 1, outfile
);
160 ERRS("unable to write to file %s", ofname
);
170 if (res
!= EXIT_SUCCESS
) {
184 /**********************************************************************/
185 /* The following was grabbed and tweaked from the old snippets collection
186 * of public domain C code. */
188 /**********************************************************************\
189 |* Demonstration program to compute the 32-bit CRC used as the frame *|
190 |* check sequence in ADCCP (ANSI X3.66, also known as FIPS PUB 71 *|
191 |* and FED-STD-1003, the U.S. versions of CCITT's X.25 link-level *|
192 |* protocol). The 32-bit FCS was added via the Federal Register, *|
193 |* 1 June 1982, p.23798. I presume but don't know for certain that *|
194 |* this polynomial is or will be included in CCITT V.41, which *|
195 |* defines the 16-bit CRC (often called CRC-CCITT) polynomial. FIPS *|
196 |* PUB 78 says that the 32-bit FCS reduces otherwise undetected *|
197 |* errors by a factor of 10^-5 over 16-bit FCS. *|
198 \**********************************************************************/
200 /* Copyright (C) 1986 Gary S. Brown. You may use this program, or
201 code or tables extracted from it, as desired without restriction.*/
203 /* First, the polynomial itself and its table of feedback terms. The */
205 /* X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 */
206 /* Note that we take it "backwards" and put the highest-order term in */
207 /* the lowest-order bit. The X^32 term is "implied"; the LSB is the */
208 /* X^31 term, etc. The X^0 term (usually shown as "+1") results in */
209 /* the MSB being 1. */
211 /* Note that the usual hardware shift register implementation, which */
212 /* is what we're using (we're merely optimizing it by doing eight-bit */
213 /* chunks at a time) shifts bits into the lowest-order term. In our */
214 /* implementation, that means shifting towards the right. Why do we */
215 /* do it this way? Because the calculated CRC must be transmitted in */
216 /* order from highest-order term to lowest-order term. UARTs transmit */
217 /* characters in order from LSB to MSB. By storing the CRC this way, */
218 /* we hand it to the UART in the order low-byte to high-byte; the UART */
219 /* sends each low-bit to hight-bit; and the result is transmission bit */
220 /* by bit from highest- to lowest-order term without requiring any bit */
221 /* shuffling on our part. Reception works similarly. */
223 /* The feedback terms table consists of 256, 32-bit entries. Notes: */
225 /* 1. The table can be generated at runtime if desired; code to do so */
226 /* is shown later. It might not be obvious, but the feedback */
227 /* terms simply represent the results of eight shift/xor opera- */
228 /* tions for all combinations of data and CRC register values. */
230 /* 2. The CRC accumulation logic is the same for all CRC polynomials, */
231 /* be they sixteen or thirty-two bits wide. You simply choose the */
232 /* appropriate table. Alternatively, because the table can be */
233 /* generated at runtime, you can start by generating the table for */
234 /* the polynomial in question and use exactly the same "updcrc", */
235 /* if your application needn't simultaneously handle two CRC */
236 /* polynomials. (Note, however, that XMODEM is strange.) */
238 /* 3. For 16-bit CRCs, the table entries need be only 16 bits wide; */
239 /* of course, 32-bit entries work OK if the high 16 bits are zero. */
241 /* 4. The values must be right-shifted by eight bits by the "updcrc" */
242 /* logic; the shift must be unsigned (bring in zeroes). On some */
243 /* hardware you could probably optimize the shift in assembler by */
244 /* using byte-swap instructions. */
246 static const uint32_t crc_32_tab
[] = { /* CRC polynomial 0xedb88320 */
247 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
248 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
249 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
250 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
251 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
252 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
253 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
254 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
255 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
256 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
257 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
258 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
259 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
260 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
261 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
262 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
263 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
264 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
265 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
266 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
267 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
268 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
269 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
270 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
271 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
272 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
273 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
274 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
275 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
276 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
277 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
278 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
279 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
280 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
281 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
282 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
283 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
284 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
285 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
286 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
287 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
288 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
289 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
292 #define UPDC32(octet,crc) (crc_32_tab[((crc) ^ (octet)) & 0xff] ^ ((crc) >> 8))
294 uint32_t crc32buf(char *buf
, size_t len
)
300 for ( ; len
; --len
, ++buf
)
302 crc
= UPDC32(*buf
, crc
);
305 return crc
^ 0xFFFFFFFF;