Contents of /tags/mkinitrd-6_3_1/busybox/coreutils/dd.c
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Thu Aug 19 12:44:27 2010 UTC (14 years, 1 month ago) by niro
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File size: 9398 byte(s)
Thu Aug 19 12:44:27 2010 UTC (14 years, 1 month ago) by niro
File MIME type: text/plain
File size: 9398 byte(s)
tagged 'mkinitrd-6_3_1'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini dd implementation for busybox |
4 | * |
5 | * |
6 | * Copyright (C) 2000,2001 Matt Kraai |
7 | * |
8 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
9 | */ |
10 | |
11 | #include "libbb.h" |
12 | |
13 | /* This is a NOEXEC applet. Be very careful! */ |
14 | |
15 | |
16 | enum { |
17 | ifd = STDIN_FILENO, |
18 | ofd = STDOUT_FILENO, |
19 | }; |
20 | |
21 | static const struct suffix_mult dd_suffixes[] = { |
22 | { "c", 1 }, |
23 | { "w", 2 }, |
24 | { "b", 512 }, |
25 | { "kD", 1000 }, |
26 | { "k", 1024 }, |
27 | { "K", 1024 }, /* compat with coreutils dd */ |
28 | { "MD", 1000000 }, |
29 | { "M", 1048576 }, |
30 | { "GD", 1000000000 }, |
31 | { "G", 1073741824 }, |
32 | { "", 0 } |
33 | }; |
34 | |
35 | struct globals { |
36 | off_t out_full, out_part, in_full, in_part; |
37 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE |
38 | unsigned long long total_bytes; |
39 | unsigned long long begin_time_us; |
40 | #endif |
41 | } FIX_ALIASING; |
42 | #define G (*(struct globals*)&bb_common_bufsiz1) |
43 | #define INIT_G() do { \ |
44 | /* we have to zero it out because of NOEXEC */ \ |
45 | memset(&G, 0, sizeof(G)); \ |
46 | } while (0) |
47 | |
48 | |
49 | static void dd_output_status(int UNUSED_PARAM cur_signal) |
50 | { |
51 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE |
52 | double seconds; |
53 | unsigned long long bytes_sec; |
54 | unsigned long long now_us = monotonic_us(); /* before fprintf */ |
55 | #endif |
56 | |
57 | /* Deliberately using %u, not %d */ |
58 | fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n" |
59 | "%"OFF_FMT"u+%"OFF_FMT"u records out\n", |
60 | G.in_full, G.in_part, |
61 | G.out_full, G.out_part); |
62 | |
63 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE |
64 | fprintf(stderr, "%llu bytes (%sB) copied, ", |
65 | G.total_bytes, |
66 | /* show fractional digit, use suffixes */ |
67 | make_human_readable_str(G.total_bytes, 1, 0) |
68 | ); |
69 | /* Corner cases: |
70 | * ./busybox dd </dev/null >/dev/null |
71 | * ./busybox dd bs=1M count=2000 </dev/zero >/dev/null |
72 | * (echo DONE) | ./busybox dd >/dev/null |
73 | * (sleep 1; echo DONE) | ./busybox dd >/dev/null |
74 | */ |
75 | seconds = (now_us - G.begin_time_us) / 1000000.0; |
76 | bytes_sec = G.total_bytes / seconds; |
77 | fprintf(stderr, "%f seconds, %sB/s\n", |
78 | seconds, |
79 | /* show fractional digit, use suffixes */ |
80 | make_human_readable_str(bytes_sec, 1, 0) |
81 | ); |
82 | #endif |
83 | } |
84 | |
85 | static ssize_t full_write_or_warn(const void *buf, size_t len, |
86 | const char *const filename) |
87 | { |
88 | ssize_t n = full_write(ofd, buf, len); |
89 | if (n < 0) |
90 | bb_perror_msg("writing '%s'", filename); |
91 | return n; |
92 | } |
93 | |
94 | static bool write_and_stats(const void *buf, size_t len, size_t obs, |
95 | const char *filename) |
96 | { |
97 | ssize_t n = full_write_or_warn(buf, len, filename); |
98 | if (n < 0) |
99 | return 1; |
100 | if ((size_t)n == obs) |
101 | G.out_full++; |
102 | else if (n) /* > 0 */ |
103 | G.out_part++; |
104 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE |
105 | G.total_bytes += n; |
106 | #endif |
107 | return 0; |
108 | } |
109 | |
110 | #if ENABLE_LFS |
111 | # define XATOU_SFX xatoull_sfx |
112 | #else |
113 | # define XATOU_SFX xatoul_sfx |
114 | #endif |
115 | |
116 | int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
117 | int dd_main(int argc UNUSED_PARAM, char **argv) |
118 | { |
119 | enum { |
120 | /* Must be in the same order as OP_conv_XXX! */ |
121 | /* (see "flags |= (1 << what)" below) */ |
122 | FLAG_NOTRUNC = 1 << 0, |
123 | FLAG_SYNC = 1 << 1, |
124 | FLAG_NOERROR = 1 << 2, |
125 | FLAG_FSYNC = 1 << 3, |
126 | /* end of conv flags */ |
127 | FLAG_TWOBUFS = 1 << 4, |
128 | FLAG_COUNT = 1 << 5, |
129 | }; |
130 | static const char keywords[] ALIGN1 = |
131 | "bs\0""count\0""seek\0""skip\0""if\0""of\0" |
132 | #if ENABLE_FEATURE_DD_IBS_OBS |
133 | "ibs\0""obs\0""conv\0" |
134 | #endif |
135 | ; |
136 | #if ENABLE_FEATURE_DD_IBS_OBS |
137 | static const char conv_words[] ALIGN1 = |
138 | "notrunc\0""sync\0""noerror\0""fsync\0"; |
139 | #endif |
140 | enum { |
141 | OP_bs = 0, |
142 | OP_count, |
143 | OP_seek, |
144 | OP_skip, |
145 | OP_if, |
146 | OP_of, |
147 | #if ENABLE_FEATURE_DD_IBS_OBS |
148 | OP_ibs, |
149 | OP_obs, |
150 | OP_conv, |
151 | /* Must be in the same order as FLAG_XXX! */ |
152 | OP_conv_notrunc = 0, |
153 | OP_conv_sync, |
154 | OP_conv_noerror, |
155 | OP_conv_fsync, |
156 | /* Unimplemented conv=XXX: */ |
157 | //nocreat do not create the output file |
158 | //excl fail if the output file already exists |
159 | //fdatasync physically write output file data before finishing |
160 | //swab swap every pair of input bytes |
161 | //lcase change upper case to lower case |
162 | //ucase change lower case to upper case |
163 | //block pad newline-terminated records with spaces to cbs-size |
164 | //unblock replace trailing spaces in cbs-size records with newline |
165 | //ascii from EBCDIC to ASCII |
166 | //ebcdic from ASCII to EBCDIC |
167 | //ibm from ASCII to alternate EBCDIC |
168 | #endif |
169 | }; |
170 | int exitcode = EXIT_FAILURE; |
171 | size_t ibs = 512, obs = 512; |
172 | ssize_t n, w; |
173 | char *ibuf, *obuf; |
174 | /* And these are all zeroed at once! */ |
175 | struct { |
176 | int flags; |
177 | size_t oc; |
178 | off_t count; |
179 | off_t seek, skip; |
180 | const char *infile, *outfile; |
181 | } Z; |
182 | #define flags (Z.flags ) |
183 | #define oc (Z.oc ) |
184 | #define count (Z.count ) |
185 | #define seek (Z.seek ) |
186 | #define skip (Z.skip ) |
187 | #define infile (Z.infile ) |
188 | #define outfile (Z.outfile) |
189 | |
190 | memset(&Z, 0, sizeof(Z)); |
191 | INIT_G(); |
192 | //fflush_all(); - is this needed because of NOEXEC? |
193 | |
194 | for (n = 1; argv[n]; n++) { |
195 | int what; |
196 | char *val; |
197 | char *arg = argv[n]; |
198 | |
199 | #if ENABLE_DESKTOP |
200 | /* "dd --". NB: coreutils 6.9 will complain if they see |
201 | * more than one of them. We wouldn't. */ |
202 | if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0') |
203 | continue; |
204 | #endif |
205 | val = strchr(arg, '='); |
206 | if (val == NULL) |
207 | bb_show_usage(); |
208 | *val = '\0'; |
209 | what = index_in_strings(keywords, arg); |
210 | if (what < 0) |
211 | bb_show_usage(); |
212 | /* *val = '='; - to preserve ps listing? */ |
213 | val++; |
214 | #if ENABLE_FEATURE_DD_IBS_OBS |
215 | if (what == OP_ibs) { |
216 | /* Must fit into positive ssize_t */ |
217 | ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes); |
218 | /*continue;*/ |
219 | } |
220 | if (what == OP_obs) { |
221 | obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes); |
222 | /*continue;*/ |
223 | } |
224 | if (what == OP_conv) { |
225 | while (1) { |
226 | /* find ',', replace them with NUL so we can use val for |
227 | * index_in_strings() without copying. |
228 | * We rely on val being non-null, else strchr would fault. |
229 | */ |
230 | arg = strchr(val, ','); |
231 | if (arg) |
232 | *arg = '\0'; |
233 | what = index_in_strings(conv_words, val); |
234 | if (what < 0) |
235 | bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv"); |
236 | flags |= (1 << what); |
237 | if (!arg) /* no ',' left, so this was the last specifier */ |
238 | break; |
239 | /* *arg = ','; - to preserve ps listing? */ |
240 | val = arg + 1; /* skip this keyword and ',' */ |
241 | } |
242 | continue; /* we trashed 'what', can't fall through */ |
243 | } |
244 | #endif |
245 | if (what == OP_bs) { |
246 | ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes); |
247 | /*continue;*/ |
248 | } |
249 | /* These can be large: */ |
250 | if (what == OP_count) { |
251 | flags |= FLAG_COUNT; |
252 | count = XATOU_SFX(val, dd_suffixes); |
253 | /*continue;*/ |
254 | } |
255 | if (what == OP_seek) { |
256 | seek = XATOU_SFX(val, dd_suffixes); |
257 | /*continue;*/ |
258 | } |
259 | if (what == OP_skip) { |
260 | skip = XATOU_SFX(val, dd_suffixes); |
261 | /*continue;*/ |
262 | } |
263 | if (what == OP_if) { |
264 | infile = val; |
265 | /*continue;*/ |
266 | } |
267 | if (what == OP_of) { |
268 | outfile = val; |
269 | /*continue;*/ |
270 | } |
271 | } /* end of "for (argv[n])" */ |
272 | |
273 | //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever |
274 | ibuf = obuf = xmalloc(ibs); |
275 | if (ibs != obs) { |
276 | flags |= FLAG_TWOBUFS; |
277 | obuf = xmalloc(obs); |
278 | } |
279 | |
280 | #if ENABLE_FEATURE_DD_SIGNAL_HANDLING |
281 | signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status); |
282 | #endif |
283 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE |
284 | G.begin_time_us = monotonic_us(); |
285 | #endif |
286 | |
287 | if (infile != NULL) |
288 | xmove_fd(xopen(infile, O_RDONLY), ifd); |
289 | else { |
290 | infile = bb_msg_standard_input; |
291 | } |
292 | if (outfile != NULL) { |
293 | int oflag = O_WRONLY | O_CREAT; |
294 | |
295 | if (!seek && !(flags & FLAG_NOTRUNC)) |
296 | oflag |= O_TRUNC; |
297 | |
298 | xmove_fd(xopen(outfile, oflag), ofd); |
299 | |
300 | if (seek && !(flags & FLAG_NOTRUNC)) { |
301 | if (ftruncate(ofd, seek * obs) < 0) { |
302 | struct stat st; |
303 | |
304 | if (fstat(ofd, &st) < 0 |
305 | || S_ISREG(st.st_mode) |
306 | || S_ISDIR(st.st_mode) |
307 | ) { |
308 | goto die_outfile; |
309 | } |
310 | } |
311 | } |
312 | } else { |
313 | outfile = bb_msg_standard_output; |
314 | } |
315 | if (skip) { |
316 | if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) { |
317 | while (skip-- > 0) { |
318 | n = safe_read(ifd, ibuf, ibs); |
319 | if (n < 0) |
320 | goto die_infile; |
321 | if (n == 0) |
322 | break; |
323 | } |
324 | } |
325 | } |
326 | if (seek) { |
327 | if (lseek(ofd, seek * obs, SEEK_CUR) < 0) |
328 | goto die_outfile; |
329 | } |
330 | |
331 | while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) { |
332 | n = safe_read(ifd, ibuf, ibs); |
333 | if (n == 0) |
334 | break; |
335 | if (n < 0) { |
336 | /* "Bad block" */ |
337 | if (!(flags & FLAG_NOERROR)) |
338 | goto die_infile; |
339 | bb_simple_perror_msg(infile); |
340 | /* GNU dd with conv=noerror skips over bad blocks */ |
341 | xlseek(ifd, ibs, SEEK_CUR); |
342 | /* conv=noerror,sync writes NULs, |
343 | * conv=noerror just ignores input bad blocks */ |
344 | n = 0; |
345 | } |
346 | if ((size_t)n == ibs) |
347 | G.in_full++; |
348 | else { |
349 | G.in_part++; |
350 | if (flags & FLAG_SYNC) { |
351 | memset(ibuf + n, 0, ibs - n); |
352 | n = ibs; |
353 | } |
354 | } |
355 | if (flags & FLAG_TWOBUFS) { |
356 | char *tmp = ibuf; |
357 | while (n) { |
358 | size_t d = obs - oc; |
359 | |
360 | if (d > (size_t)n) |
361 | d = n; |
362 | memcpy(obuf + oc, tmp, d); |
363 | n -= d; |
364 | tmp += d; |
365 | oc += d; |
366 | if (oc == obs) { |
367 | if (write_and_stats(obuf, obs, obs, outfile)) |
368 | goto out_status; |
369 | oc = 0; |
370 | } |
371 | } |
372 | } else if (write_and_stats(ibuf, n, obs, outfile)) |
373 | goto out_status; |
374 | |
375 | if (flags & FLAG_FSYNC) { |
376 | if (fsync(ofd) < 0) |
377 | goto die_outfile; |
378 | } |
379 | } |
380 | |
381 | if (ENABLE_FEATURE_DD_IBS_OBS && oc) { |
382 | w = full_write_or_warn(obuf, oc, outfile); |
383 | if (w < 0) goto out_status; |
384 | if (w > 0) G.out_part++; |
385 | } |
386 | if (close(ifd) < 0) { |
387 | die_infile: |
388 | bb_simple_perror_msg_and_die(infile); |
389 | } |
390 | |
391 | if (close(ofd) < 0) { |
392 | die_outfile: |
393 | bb_simple_perror_msg_and_die(outfile); |
394 | } |
395 | |
396 | exitcode = EXIT_SUCCESS; |
397 | out_status: |
398 | dd_output_status(0); |
399 | |
400 | return exitcode; |
401 | } |