source: MondoRescue/branches/3.3/mindi-busybox/coreutils/dd.c@ 3621

Last change on this file since 3621 was 3621, checked in by Bruno Cornec, 7 years ago

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.

File size: 14.7 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//config:config DD
12//config: bool "dd"
13//config: default y
14//config: help
15//config: dd copies a file (from standard input to standard output,
16//config: by default) using specific input and output blocksizes,
17//config: while optionally performing conversions on it.
18//config:
19//config:config FEATURE_DD_SIGNAL_HANDLING
20//config: bool "Enable signal handling for status reporting"
21//config: default y
22//config: depends on DD
23//config: help
24//config: Sending a SIGUSR1 signal to a running `dd' process makes it
25//config: print to standard error the number of records read and written
26//config: so far, then to resume copying.
27//config:
28//config: $ dd if=/dev/zero of=/dev/null &
29//config: $ pid=$!; kill -USR1 $pid; sleep 1; kill $pid
30//config: 10899206+0 records in
31//config: 10899206+0 records out
32//config:
33//config:config FEATURE_DD_THIRD_STATUS_LINE
34//config: bool "Enable the third status line upon signal"
35//config: default y
36//config: depends on DD && FEATURE_DD_SIGNAL_HANDLING
37//config: help
38//config: Displays a coreutils-like third status line with transferred bytes,
39//config: elapsed time and speed.
40//config:
41//config:config FEATURE_DD_IBS_OBS
42//config: bool "Enable ibs, obs and conv options"
43//config: default y
44//config: depends on DD
45//config: help
46//config: Enables support for writing a certain number of bytes in and out,
47//config: at a time, and performing conversions on the data stream.
48//config:
49//config:config FEATURE_DD_STATUS
50//config: bool "Enable status display options"
51//config: default y
52//config: depends on DD
53//config: help
54//config: Enables support for status=noxfer/none option.
55
56//usage:#define dd_trivial_usage
57//usage: "[if=FILE] [of=FILE] " IF_FEATURE_DD_IBS_OBS("[ibs=N] [obs=N] ") "[bs=N] [count=N] [skip=N]\n"
58//usage: " [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync] [iflag=skip_bytes]")
59//usage:#define dd_full_usage "\n\n"
60//usage: "Copy a file with converting and formatting\n"
61//usage: "\n if=FILE Read from FILE instead of stdin"
62//usage: "\n of=FILE Write to FILE instead of stdout"
63//usage: "\n bs=N Read and write N bytes at a time"
64//usage: IF_FEATURE_DD_IBS_OBS(
65//usage: "\n ibs=N Read N bytes at a time"
66//usage: )
67//usage: IF_FEATURE_DD_IBS_OBS(
68//usage: "\n obs=N Write N bytes at a time"
69//usage: )
70//usage: "\n count=N Copy only N input blocks"
71//usage: "\n skip=N Skip N input blocks"
72//usage: "\n seek=N Skip N output blocks"
73//usage: IF_FEATURE_DD_IBS_OBS(
74//usage: "\n conv=notrunc Don't truncate output file"
75//usage: "\n conv=noerror Continue after read errors"
76//usage: "\n conv=sync Pad blocks with zeros"
77//usage: "\n conv=fsync Physically write data out before finishing"
78//usage: "\n conv=swab Swap every pair of bytes"
79//usage: "\n iflag=skip_bytes skip=N is in bytes"
80//usage: )
81//usage: IF_FEATURE_DD_STATUS(
82//usage: "\n status=noxfer Suppress rate output"
83//usage: "\n status=none Suppress all output"
84//usage: )
85//usage: "\n"
86//usage: "\nN may be suffixed by c (1), w (2), b (512), kB (1000), k (1024), MB, M, GB, G"
87//usage:
88//usage:#define dd_example_usage
89//usage: "$ dd if=/dev/zero of=/dev/ram1 bs=1M count=4\n"
90//usage: "4+0 records in\n"
91//usage: "4+0 records out\n"
92
93#include "libbb.h"
94#include "common_bufsiz.h"
95
96/* This is a NOEXEC applet. Be very careful! */
97
98
99enum {
100 ifd = STDIN_FILENO,
101 ofd = STDOUT_FILENO,
102};
103
104struct globals {
105 off_t out_full, out_part, in_full, in_part;
106#if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
107 unsigned long long total_bytes;
108 unsigned long long begin_time_us;
109#endif
110 int flags;
111} FIX_ALIASING;
112#define G (*(struct globals*)bb_common_bufsiz1)
113#define INIT_G() do { \
114 setup_common_bufsiz(); \
115 /* we have to zero it out because of NOEXEC */ \
116 memset(&G, 0, sizeof(G)); \
117} while (0)
118
119enum {
120 /* Must be in the same order as OP_conv_XXX! */
121 /* (see "flags |= (1 << what)" below) */
122 FLAG_NOTRUNC = (1 << 0) * ENABLE_FEATURE_DD_IBS_OBS,
123 FLAG_SYNC = (1 << 1) * ENABLE_FEATURE_DD_IBS_OBS,
124 FLAG_NOERROR = (1 << 2) * ENABLE_FEATURE_DD_IBS_OBS,
125 FLAG_FSYNC = (1 << 3) * ENABLE_FEATURE_DD_IBS_OBS,
126 FLAG_SWAB = (1 << 4) * ENABLE_FEATURE_DD_IBS_OBS,
127 /* end of conv flags */
128 /* start of input flags */
129 FLAG_IFLAG_SHIFT = 5,
130 FLAG_SKIP_BYTES = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS,
131 /* end of input flags */
132 FLAG_TWOBUFS = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS,
133 FLAG_COUNT = 1 << 7,
134 FLAG_STATUS = 1 << 8,
135 FLAG_STATUS_NONE = 1 << 9,
136 FLAG_STATUS_NOXFER = 1 << 10,
137};
138
139static void dd_output_status(int UNUSED_PARAM cur_signal)
140{
141#if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
142 double seconds;
143 unsigned long long bytes_sec;
144 unsigned long long now_us = monotonic_us(); /* before fprintf */
145#endif
146
147 /* Deliberately using %u, not %d */
148 fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
149 "%"OFF_FMT"u+%"OFF_FMT"u records out\n",
150 G.in_full, G.in_part,
151 G.out_full, G.out_part);
152
153#if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
154# if ENABLE_FEATURE_DD_STATUS
155 if (G.flags & FLAG_STATUS_NOXFER) /* status=noxfer active? */
156 return;
157 //TODO: should status=none make dd stop reacting to USR1 entirely?
158 //So far we react to it (we print the stats),
159 //status=none only suppresses final, non-USR1 generated status message.
160# endif
161 fprintf(stderr, "%llu bytes (%sB) copied, ",
162 G.total_bytes,
163 /* show fractional digit, use suffixes */
164 make_human_readable_str(G.total_bytes, 1, 0)
165 );
166 /* Corner cases:
167 * ./busybox dd </dev/null >/dev/null
168 * ./busybox dd bs=1M count=2000 </dev/zero >/dev/null
169 * (echo DONE) | ./busybox dd >/dev/null
170 * (sleep 1; echo DONE) | ./busybox dd >/dev/null
171 */
172 seconds = (now_us - G.begin_time_us) / 1000000.0;
173 bytes_sec = G.total_bytes / seconds;
174 fprintf(stderr, "%f seconds, %sB/s\n",
175 seconds,
176 /* show fractional digit, use suffixes */
177 make_human_readable_str(bytes_sec, 1, 0)
178 );
179#endif
180}
181
182static ssize_t full_write_or_warn(const void *buf, size_t len,
183 const char *const filename)
184{
185 ssize_t n = full_write(ofd, buf, len);
186 if (n < 0)
187 bb_perror_msg("writing '%s'", filename);
188 return n;
189}
190
191static bool write_and_stats(const void *buf, size_t len, size_t obs,
192 const char *filename)
193{
194 ssize_t n = full_write_or_warn(buf, len, filename);
195 if (n < 0)
196 return 1;
197 if ((size_t)n == obs)
198 G.out_full++;
199 else if (n) /* > 0 */
200 G.out_part++;
201#if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
202 G.total_bytes += n;
203#endif
204 return 0;
205}
206
207#if ENABLE_LFS
208# define XATOU_SFX xatoull_sfx
209#else
210# define XATOU_SFX xatoul_sfx
211#endif
212
213#if ENABLE_FEATURE_DD_IBS_OBS
214static int parse_comma_flags(char *val, const char *words, const char *error_in)
215{
216 int flags = 0;
217 while (1) {
218 int n;
219 char *arg;
220 /* find ',', replace them with NUL so we can use val for
221 * index_in_strings() without copying.
222 * We rely on val being non-null, else strchr would fault.
223 */
224 arg = strchr(val, ',');
225 if (arg)
226 *arg = '\0';
227 n = index_in_strings(words, val);
228 if (n < 0)
229 bb_error_msg_and_die(bb_msg_invalid_arg_to, val, error_in);
230 flags |= (1 << n);
231 if (!arg) /* no ',' left, so this was the last specifier */
232 break;
233 *arg = ','; /* to preserve ps listing */
234 val = arg + 1; /* skip this keyword and ',' */
235 }
236 return flags;
237}
238#endif
239
240int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
241int dd_main(int argc UNUSED_PARAM, char **argv)
242{
243 static const char keywords[] ALIGN1 =
244 "bs\0""count\0""seek\0""skip\0""if\0""of\0"IF_FEATURE_DD_STATUS("status\0")
245#if ENABLE_FEATURE_DD_IBS_OBS
246 "ibs\0""obs\0""conv\0""iflag\0"
247#endif
248 ;
249#if ENABLE_FEATURE_DD_IBS_OBS
250 static const char conv_words[] ALIGN1 =
251 "notrunc\0""sync\0""noerror\0""fsync\0""swab\0";
252 static const char iflag_words[] ALIGN1 =
253 "skip_bytes\0";
254#endif
255#if ENABLE_FEATURE_DD_STATUS
256 static const char status_words[] ALIGN1 =
257 "none\0""noxfer\0";
258#endif
259 enum {
260 OP_bs = 0,
261 OP_count,
262 OP_seek,
263 OP_skip,
264 OP_if,
265 OP_of,
266 IF_FEATURE_DD_STATUS(OP_status,)
267#if ENABLE_FEATURE_DD_IBS_OBS
268 OP_ibs,
269 OP_obs,
270 OP_conv,
271 OP_iflag,
272 /* Must be in the same order as FLAG_XXX! */
273 OP_conv_notrunc = 0,
274 OP_conv_sync,
275 OP_conv_noerror,
276 OP_conv_fsync,
277 OP_conv_swab,
278 /* Unimplemented conv=XXX: */
279 //nocreat do not create the output file
280 //excl fail if the output file already exists
281 //fdatasync physically write output file data before finishing
282 //lcase change upper case to lower case
283 //ucase change lower case to upper case
284 //block pad newline-terminated records with spaces to cbs-size
285 //unblock replace trailing spaces in cbs-size records with newline
286 //ascii from EBCDIC to ASCII
287 //ebcdic from ASCII to EBCDIC
288 //ibm from ASCII to alternate EBCDIC
289 /* Partially implemented: */
290 //swab swap every pair of input bytes: will abort on non-even reads
291 OP_iflag_skip_bytes,
292#endif
293 };
294 smallint exitcode = EXIT_FAILURE;
295 int i;
296 size_t ibs = 512;
297 char *ibuf;
298#if ENABLE_FEATURE_DD_IBS_OBS
299 size_t obs = 512;
300 char *obuf;
301#else
302# define obs ibs
303# define obuf ibuf
304#endif
305 /* These are all zeroed at once! */
306 struct {
307 size_t oc;
308 ssize_t prev_read_size; /* for detecting swab failure */
309 off_t count;
310 off_t seek, skip;
311 const char *infile, *outfile;
312 } Z;
313#define oc (Z.oc )
314#define prev_read_size (Z.prev_read_size)
315#define count (Z.count )
316#define seek (Z.seek )
317#define skip (Z.skip )
318#define infile (Z.infile )
319#define outfile (Z.outfile)
320
321 memset(&Z, 0, sizeof(Z));
322 INIT_G();
323 //fflush_all(); - is this needed because of NOEXEC?
324
325 for (i = 1; argv[i]; i++) {
326 int what;
327 char *val;
328 char *arg = argv[i];
329
330#if ENABLE_DESKTOP
331 /* "dd --". NB: coreutils 6.9 will complain if they see
332 * more than one of them. We wouldn't. */
333 if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0')
334 continue;
335#endif
336 val = strchr(arg, '=');
337 if (val == NULL)
338 bb_show_usage();
339 *val = '\0';
340 what = index_in_strings(keywords, arg);
341 if (what < 0)
342 bb_show_usage();
343 /* *val = '='; - to preserve ps listing? */
344 val++;
345#if ENABLE_FEATURE_DD_IBS_OBS
346 if (what == OP_ibs) {
347 /* Must fit into positive ssize_t */
348 ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
349 /*continue;*/
350 }
351 if (what == OP_obs) {
352 obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
353 /*continue;*/
354 }
355 if (what == OP_conv) {
356 G.flags |= parse_comma_flags(val, conv_words, "conv");
357 /*continue;*/
358 }
359 if (what == OP_iflag) {
360 G.flags |= parse_comma_flags(val, iflag_words, "iflag") << FLAG_IFLAG_SHIFT;
361 /*continue;*/
362 }
363#endif
364 if (what == OP_bs) {
365 ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
366 obs = ibs;
367 /*continue;*/
368 }
369 /* These can be large: */
370 if (what == OP_count) {
371 G.flags |= FLAG_COUNT;
372 count = XATOU_SFX(val, cwbkMG_suffixes);
373 /*continue;*/
374 }
375 if (what == OP_seek) {
376 seek = XATOU_SFX(val, cwbkMG_suffixes);
377 /*continue;*/
378 }
379 if (what == OP_skip) {
380 skip = XATOU_SFX(val, cwbkMG_suffixes);
381 /*continue;*/
382 }
383 if (what == OP_if) {
384 infile = val;
385 /*continue;*/
386 }
387 if (what == OP_of) {
388 outfile = val;
389 /*continue;*/
390 }
391#if ENABLE_FEATURE_DD_STATUS
392 if (what == OP_status) {
393 int n;
394 n = index_in_strings(status_words, val);
395 if (n < 0)
396 bb_error_msg_and_die(bb_msg_invalid_arg_to, val, "status");
397 G.flags |= FLAG_STATUS << n;
398 /*continue;*/
399 }
400#endif
401 } /* end of "for (argv[i])" */
402
403//XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
404 ibuf = xmalloc(ibs);
405 obuf = ibuf;
406#if ENABLE_FEATURE_DD_IBS_OBS
407 if (ibs != obs) {
408 G.flags |= FLAG_TWOBUFS;
409 obuf = xmalloc(obs);
410 }
411#endif
412
413#if ENABLE_FEATURE_DD_SIGNAL_HANDLING
414 signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status);
415#endif
416#if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
417 G.begin_time_us = monotonic_us();
418#endif
419
420 if (infile) {
421 xmove_fd(xopen(infile, O_RDONLY), ifd);
422 } else {
423 infile = bb_msg_standard_input;
424 }
425 if (outfile) {
426 int oflag = O_WRONLY | O_CREAT;
427
428 if (!seek && !(G.flags & FLAG_NOTRUNC))
429 oflag |= O_TRUNC;
430
431 xmove_fd(xopen(outfile, oflag), ofd);
432
433 if (seek && !(G.flags & FLAG_NOTRUNC)) {
434 if (ftruncate(ofd, seek * obs) < 0) {
435 struct stat st;
436
437 if (fstat(ofd, &st) < 0
438 || S_ISREG(st.st_mode)
439 || S_ISDIR(st.st_mode)
440 ) {
441 goto die_outfile;
442 }
443 }
444 }
445 } else {
446 outfile = bb_msg_standard_output;
447 }
448 if (skip) {
449 size_t blocksz = (G.flags & FLAG_SKIP_BYTES) ? 1 : ibs;
450 if (lseek(ifd, skip * blocksz, SEEK_CUR) < 0) {
451 do {
452 ssize_t n = safe_read(ifd, ibuf, blocksz);
453 if (n < 0)
454 goto die_infile;
455 if (n == 0)
456 break;
457 } while (--skip != 0);
458 }
459 }
460 if (seek) {
461 if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
462 goto die_outfile;
463 }
464
465 while (!(G.flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
466 ssize_t n;
467
468 n = safe_read(ifd, ibuf, ibs);
469 if (n == 0)
470 break;
471 if (n < 0) {
472 /* "Bad block" */
473 if (!(G.flags & FLAG_NOERROR))
474 goto die_infile;
475 bb_simple_perror_msg(infile);
476 /* GNU dd with conv=noerror skips over bad blocks */
477 xlseek(ifd, ibs, SEEK_CUR);
478 /* conv=noerror,sync writes NULs,
479 * conv=noerror just ignores input bad blocks */
480 n = 0;
481 }
482 if (G.flags & FLAG_SWAB) {
483 uint16_t *p16;
484 ssize_t n2;
485
486 /* Our code allows only last read to be odd-sized */
487 if (prev_read_size & 1)
488 bb_error_msg_and_die("can't swab %lu byte buffer",
489 (unsigned long)prev_read_size);
490 prev_read_size = n;
491
492 /* If n is odd, last byte is not swapped:
493 * echo -n "qwe" | dd conv=swab
494 * prints "wqe".
495 */
496 p16 = (void*) ibuf;
497 n2 = (n >> 1);
498 while (--n2 >= 0) {
499 *p16 = bswap_16(*p16);
500 p16++;
501 }
502 }
503 if ((size_t)n == ibs)
504 G.in_full++;
505 else {
506 G.in_part++;
507 if (G.flags & FLAG_SYNC) {
508 memset(ibuf + n, 0, ibs - n);
509 n = ibs;
510 }
511 }
512 if (G.flags & FLAG_TWOBUFS) {
513 char *tmp = ibuf;
514 while (n) {
515 size_t d = obs - oc;
516
517 if (d > (size_t)n)
518 d = n;
519 memcpy(obuf + oc, tmp, d);
520 n -= d;
521 tmp += d;
522 oc += d;
523 if (oc == obs) {
524 if (write_and_stats(obuf, obs, obs, outfile))
525 goto out_status;
526 oc = 0;
527 }
528 }
529 } else {
530 if (write_and_stats(ibuf, n, obs, outfile))
531 goto out_status;
532 }
533
534 if (G.flags & FLAG_FSYNC) {
535 if (fsync(ofd) < 0)
536 goto die_outfile;
537 }
538 }
539
540 if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
541 if (write_and_stats(obuf, oc, obs, outfile))
542 goto out_status;
543 }
544 if (close(ifd) < 0) {
545 die_infile:
546 bb_simple_perror_msg_and_die(infile);
547 }
548
549 if (close(ofd) < 0) {
550 die_outfile:
551 bb_simple_perror_msg_and_die(outfile);
552 }
553
554 exitcode = EXIT_SUCCESS;
555 out_status:
556 if (!ENABLE_FEATURE_DD_STATUS || !(G.flags & FLAG_STATUS_NONE))
557 dd_output_status(0);
558
559 if (ENABLE_FEATURE_CLEAN_UP) {
560 free(obuf);
561 if (G.flags & FLAG_TWOBUFS)
562 free(ibuf);
563 }
564
565 return exitcode;
566}
Note: See TracBrowser for help on using the repository browser.