source: MondoRescue/branches/3.0/mindi-busybox/coreutils/dd.c@ 2899

Last change on this file since 2899 was 2725, checked in by Bruno Cornec, 13 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
File size: 9.2 KB
Line 
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 source tree.
9 */
10
11#include "libbb.h"
12
13/* This is a NOEXEC applet. Be very careful! */
14
15
16enum {
17 ifd = STDIN_FILENO,
18 ofd = STDOUT_FILENO,
19};
20
21static 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
35struct 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
49static 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
85static 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
94static 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
116int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
117int 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}
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