1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
11 #include <unistd.h> /* for unlink() */
13 #include <getopt.h> /* for getopt() */
18 #if (__BYTE_ORDER == __LITTLE_ENDIAN)
19 # define HOST_TO_LE16(x) (x)
20 # define HOST_TO_LE32(x) (x)
21 # define LE16_TO_HOST(x) (x)
22 # define LE32_TO_HOST(x) (x)
24 # define HOST_TO_LE16(x) bswap_16(x)
25 # define HOST_TO_LE32(x) bswap_32(x)
26 # define LE16_TO_HOST(x) bswap_16(x)
27 # define LE32_TO_HOST(x) bswap_32(x)
30 uint32_t crc32buf(char *buf
, size_t len
);
36 static char *progname
;
42 #define ERR(fmt, ...) do { \
44 fprintf(stderr, "[%s] *** error: " fmt "\n", \
45 progname, ## __VA_ARGS__ ); \
48 #define ERRS(fmt, ...) do { \
51 fprintf(stderr, "[%s] *** error: " fmt ": %s\n", \
52 progname, ## __VA_ARGS__, strerror(save)); \
55 void usage(int status
)
57 FILE *stream
= (status
!= EXIT_SUCCESS
) ? stderr
: stdout
;
59 fprintf(stream
, "Usage: %s [OPTIONS...]\n", progname
);
63 " -i <file> read input from the file <file>\n"
64 " -o <file> write output to the file <file>\n"
65 " -h show this screen\n"
71 int main(int argc
, char *argv
[])
73 int res
= EXIT_FAILURE
;
81 FILE *outfile
, *infile
;
83 progname
= basename(argv
[0]);
88 c
= getopt(argc
, argv
, "i:o:h");
108 if (ifname
== NULL
) {
109 ERR("no input file specified");
113 if (ofname
== NULL
) {
114 ERR("no output file specified");
118 err
= stat(ifname
, &st
);
120 ERRS("stat failed on %s", ifname
);
125 buf
= malloc(buflen
);
127 ERR("no memory for buffer\n");
131 infile
= fopen(ifname
, "r");
132 if (infile
== NULL
) {
133 ERRS("could not open \"%s\" for reading", ifname
);
138 fread(buf
, buflen
, 1, infile
);
140 ERRS("unable to read from file %s", ifname
);
144 crc
= crc32buf(buf
, buflen
);
145 hdr
= (uint32_t *)buf
;
146 *hdr
= HOST_TO_LE32(crc
);
148 outfile
= fopen(ofname
, "w");
149 if (outfile
== NULL
) {
150 ERRS("could not open \"%s\" for writing", ofname
);
155 fwrite(buf
, buflen
, 1, outfile
);
157 ERRS("unable to write to file %s", ofname
);
167 if (res
!= EXIT_SUCCESS
) {
181 /**********************************************************************/
182 /* The following was grabbed and tweaked from the old snippets collection
183 * of public domain C code. */
185 /**********************************************************************\
186 |* Demonstration program to compute the 32-bit CRC used as the frame *|
187 |* check sequence in ADCCP (ANSI X3.66, also known as FIPS PUB 71 *|
188 |* and FED-STD-1003, the U.S. versions of CCITT's X.25 link-level *|
189 |* protocol). The 32-bit FCS was added via the Federal Register, *|
190 |* 1 June 1982, p.23798. I presume but don't know for certain that *|
191 |* this polynomial is or will be included in CCITT V.41, which *|
192 |* defines the 16-bit CRC (often called CRC-CCITT) polynomial. FIPS *|
193 |* PUB 78 says that the 32-bit FCS reduces otherwise undetected *|
194 |* errors by a factor of 10^-5 over 16-bit FCS. *|
195 \**********************************************************************/
197 /* Copyright (C) 1986 Gary S. Brown. You may use this program, or
198 code or tables extracted from it, as desired without restriction.*/
200 /* First, the polynomial itself and its table of feedback terms. The */
202 /* 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 */
203 /* Note that we take it "backwards" and put the highest-order term in */
204 /* the lowest-order bit. The X^32 term is "implied"; the LSB is the */
205 /* X^31 term, etc. The X^0 term (usually shown as "+1") results in */
206 /* the MSB being 1. */
208 /* Note that the usual hardware shift register implementation, which */
209 /* is what we're using (we're merely optimizing it by doing eight-bit */
210 /* chunks at a time) shifts bits into the lowest-order term. In our */
211 /* implementation, that means shifting towards the right. Why do we */
212 /* do it this way? Because the calculated CRC must be transmitted in */
213 /* order from highest-order term to lowest-order term. UARTs transmit */
214 /* characters in order from LSB to MSB. By storing the CRC this way, */
215 /* we hand it to the UART in the order low-byte to high-byte; the UART */
216 /* sends each low-bit to hight-bit; and the result is transmission bit */
217 /* by bit from highest- to lowest-order term without requiring any bit */
218 /* shuffling on our part. Reception works similarly. */
220 /* The feedback terms table consists of 256, 32-bit entries. Notes: */
222 /* 1. The table can be generated at runtime if desired; code to do so */
223 /* is shown later. It might not be obvious, but the feedback */
224 /* terms simply represent the results of eight shift/xor opera- */
225 /* tions for all combinations of data and CRC register values. */
227 /* 2. The CRC accumulation logic is the same for all CRC polynomials, */
228 /* be they sixteen or thirty-two bits wide. You simply choose the */
229 /* appropriate table. Alternatively, because the table can be */
230 /* generated at runtime, you can start by generating the table for */
231 /* the polynomial in question and use exactly the same "updcrc", */
232 /* if your application needn't simultaneously handle two CRC */
233 /* polynomials. (Note, however, that XMODEM is strange.) */
235 /* 3. For 16-bit CRCs, the table entries need be only 16 bits wide; */
236 /* of course, 32-bit entries work OK if the high 16 bits are zero. */
238 /* 4. The values must be right-shifted by eight bits by the "updcrc" */
239 /* logic; the shift must be unsigned (bring in zeroes). On some */
240 /* hardware you could probably optimize the shift in assembler by */
241 /* using byte-swap instructions. */
243 static const uint32_t crc_32_tab
[] = { /* CRC polynomial 0xedb88320 */
244 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
245 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
246 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
247 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
248 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
249 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
250 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
251 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
252 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
253 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
254 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
255 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
256 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
257 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
258 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
259 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
260 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
261 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
262 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
263 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
264 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
265 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
266 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
267 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
268 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
269 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
270 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
271 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
272 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
273 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
274 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
275 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
276 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
277 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
278 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
279 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
280 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
281 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
282 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
283 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
284 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
285 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
286 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
289 #define UPDC32(octet,crc) (crc_32_tab[((crc) ^ (octet)) & 0xff] ^ ((crc) >> 8))
291 uint32_t crc32buf(char *buf
, size_t len
)
297 for ( ; len
; --len
, ++buf
)
299 crc
= UPDC32(*buf
, crc
);
302 return crc
^ 0xFFFFFFFF;