busybox/coreutils/dd.c

/* vi: set sw=4 ts=4: */
/*
 * Mini dd implementation for busybox
 *
 *
 * Copyright (C) 2000,2001  Matt Kraai
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include <signal.h>  /* For FEATURE_DD_SIGNAL_HANDLING */
#include "libbb.h"

/* This is a NOEXEC applet. Be very careful! */


enum {
	ifd = STDIN_FILENO,
	ofd = STDOUT_FILENO,
};

static const struct suffix_mult dd_suffixes[] = {
	{ "c", 1 },
	{ "w", 2 },
	{ "b", 512 },
	{ "kD", 1000 },
	{ "k", 1024 },
	{ "K", 1024 },	/* compat with coreutils dd */
	{ "MD", 1000000 },
	{ "M", 1048576 },
	{ "GD", 1000000000 },
	{ "G", 1073741824 },
	{ }
};

struct globals {
	off_t out_full, out_part, in_full, in_part;
};
#define G (*(struct globals*)&bb_common_bufsiz1)
/* We have to zero it out because of NOEXEC */
#define INIT_G() memset(&G, 0, sizeof(G))


static void dd_output_status(int UNUSED_PARAM cur_signal)
{
	/* Deliberately using %u, not %d */
	fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
			"%"OFF_FMT"u+%"OFF_FMT"u records out\n",
			G.in_full, G.in_part,
			G.out_full, G.out_part);
}

static ssize_t full_write_or_warn(const void *buf, size_t len,
	const char *const filename)
{
	ssize_t n = full_write(ofd, buf, len);
	if (n < 0)
		bb_perror_msg("writing '%s'", filename);
	return n;
}

static bool write_and_stats(const void *buf, size_t len, size_t obs,
	const char *filename)
{
	ssize_t n = full_write_or_warn(buf, len, filename);
	if (n < 0)
		return 1;
	if ((size_t)n == obs)
		G.out_full++;
	else if (n) /* > 0 */
		G.out_part++;
	return 0;
}

#if ENABLE_LFS
#define XATOU_SFX xatoull_sfx
#else
#define XATOU_SFX xatoul_sfx
#endif

int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int dd_main(int argc UNUSED_PARAM, char **argv)
{
	enum {
		/* Must be in the same order as OP_conv_XXX! */
		/* (see "flags |= (1 << what)" below) */
		FLAG_NOTRUNC = 1 << 0,
		FLAG_SYNC    = 1 << 1,
		FLAG_NOERROR = 1 << 2,
		FLAG_FSYNC   = 1 << 3,
		/* end of conv flags */
		FLAG_TWOBUFS = 1 << 4,
		FLAG_COUNT   = 1 << 5,
	};
	static const char keywords[] ALIGN1 =
		"bs\0""count\0""seek\0""skip\0""if\0""of\0"
#if ENABLE_FEATURE_DD_IBS_OBS
		"ibs\0""obs\0""conv\0"
#endif
		;
#if ENABLE_FEATURE_DD_IBS_OBS
	static const char conv_words[] ALIGN1 =
		"notrunc\0""sync\0""noerror\0""fsync\0";
#endif
	enum {
		OP_bs = 0,
		OP_count,
		OP_seek,
		OP_skip,
		OP_if,
		OP_of,
#if ENABLE_FEATURE_DD_IBS_OBS
		OP_ibs,
		OP_obs,
		OP_conv,
		/* Must be in the same order as FLAG_XXX! */
		OP_conv_notrunc = 0,
		OP_conv_sync,
		OP_conv_noerror,
		OP_conv_fsync,
	/* Unimplemented conv=XXX: */
	//nocreat       do not create the output file
	//excl          fail if the output file already exists
	//fdatasync     physically write output file data before finishing
	//swab          swap every pair of input bytes
	//lcase         change upper case to lower case
	//ucase         change lower case to upper case
	//block         pad newline-terminated records with spaces to cbs-size
	//unblock       replace trailing spaces in cbs-size records with newline
	//ascii         from EBCDIC to ASCII
	//ebcdic        from ASCII to EBCDIC
	//ibm           from ASCII to alternate EBCDIC
#endif
	};
	int exitcode = EXIT_FAILURE;
	size_t ibs = 512, obs = 512;
	ssize_t n, w;
	char *ibuf, *obuf;
	/* And these are all zeroed at once! */
	struct {
		int flags;
		size_t oc;
		off_t count;
		off_t seek, skip;
		const char *infile, *outfile;
	} Z;
#define flags   (Z.flags  )
#define oc      (Z.oc     )
#define count   (Z.count  )
#define seek    (Z.seek   )
#define skip    (Z.skip   )
#define infile  (Z.infile )
#define outfile (Z.outfile)

	memset(&Z, 0, sizeof(Z));
	INIT_G();
	//fflush(NULL); - is this needed because of NOEXEC?

#if ENABLE_FEATURE_DD_SIGNAL_HANDLING
	signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status);
#endif

	for (n = 1; argv[n]; n++) {
		int what;
		char *val;
		char *arg = argv[n];

#if ENABLE_DESKTOP
		/* "dd --". NB: coreutils 6.9 will complain if they see
		 * more than one of them. We wouldn't. */
		if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0')
			continue;
#endif
		val = strchr(arg, '=');
		if (val == NULL)
			bb_show_usage();
		*val = '\0';
		what = index_in_strings(keywords, arg);
		if (what < 0)
			bb_show_usage();
		/* *val = '='; - to preserve ps listing? */
		val++;
#if ENABLE_FEATURE_DD_IBS_OBS
		if (what == OP_ibs) {
			/* Must fit into positive ssize_t */
			ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
			/*continue;*/
		}
		if (what == OP_obs) {
			obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
			/*continue;*/
		}
		if (what == OP_conv) {
			while (1) {
				/* find ',', replace them with NUL so we can use val for
				 * index_in_strings() without copying.
				 * We rely on val being non-null, else strchr would fault.
				 */
				arg = strchr(val, ',');
				if (arg)
					*arg = '\0';
				what = index_in_strings(conv_words, val);
				if (what < 0)
					bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv");
				flags |= (1 << what);
				if (!arg) /* no ',' left, so this was the last specifier */
					break;
				/* *arg = ','; - to preserve ps listing? */
				val = arg + 1; /* skip this keyword and ',' */
			}
			continue; /* we trashed 'what', can't fall through */
		}
#endif
		if (what == OP_bs) {
			ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
			/*continue;*/
		}
		/* These can be large: */
		if (what == OP_count) {
			flags |= FLAG_COUNT;
			count = XATOU_SFX(val, dd_suffixes);
			/*continue;*/
		}
		if (what == OP_seek) {
			seek = XATOU_SFX(val, dd_suffixes);
			/*continue;*/
		}
		if (what == OP_skip) {
			skip = XATOU_SFX(val, dd_suffixes);
			/*continue;*/
		}
		if (what == OP_if) {
			infile = val;
			/*continue;*/
		}
		if (what == OP_of) {
			outfile = val;
			/*continue;*/
		}
	} /* end of "for (argv[n])" */

//XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
	ibuf = obuf = xmalloc(ibs);
	if (ibs != obs) {
		flags |= FLAG_TWOBUFS;
		obuf = xmalloc(obs);
	}
	if (infile != NULL)
		xmove_fd(xopen(infile, O_RDONLY), ifd);
	else {
		infile = bb_msg_standard_input;
	}
	if (outfile != NULL) {
		int oflag = O_WRONLY | O_CREAT;

		if (!seek && !(flags & FLAG_NOTRUNC))
			oflag |= O_TRUNC;

		xmove_fd(xopen(outfile, oflag), ofd);

		if (seek && !(flags & FLAG_NOTRUNC)) {
			if (ftruncate(ofd, seek * obs) < 0) {
				struct stat st;

				if (fstat(ofd, &st) < 0 || S_ISREG(st.st_mode) ||
						S_ISDIR(st.st_mode))
					goto die_outfile;
			}
		}
	} else {
		outfile = bb_msg_standard_output;
	}
	if (skip) {
		if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
			while (skip-- > 0) {
				n = safe_read(ifd, ibuf, ibs);
				if (n < 0)
					goto die_infile;
				if (n == 0)
					break;
			}
		}
	}
	if (seek) {
		if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
			goto die_outfile;
	}

	while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
		if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */
			memset(ibuf, 0, ibs);
		n = safe_read(ifd, ibuf, ibs);
		if (n == 0)
			break;
		if (n < 0) {
			if (!(flags & FLAG_NOERROR))
				goto die_infile;
			n = ibs;
			bb_simple_perror_msg(infile);
		}
		if ((size_t)n == ibs)
			G.in_full++;
		else {
			G.in_part++;
			if (flags & FLAG_SYNC) {
				memset(ibuf + n, '\0', ibs - n);
				n = ibs;
			}
		}
		if (flags & FLAG_TWOBUFS) {
			char *tmp = ibuf;
			while (n) {
				size_t d = obs - oc;

				if (d > (size_t)n)
					d = n;
				memcpy(obuf + oc, tmp, d);
				n -= d;
				tmp += d;
				oc += d;
				if (oc == obs) {
					if (write_and_stats(obuf, obs, obs, outfile))
						goto out_status;
					oc = 0;
				}
			}
		} else if (write_and_stats(ibuf, n, obs, outfile))
			goto out_status;

		if (flags & FLAG_FSYNC) {
			if (fsync(ofd) < 0)
				goto die_outfile;
		}
	}

	if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
		w = full_write_or_warn(obuf, oc, outfile);
		if (w < 0) goto out_status;
		if (w > 0) G.out_part++;
	}
	if (close(ifd) < 0) {
 die_infile:
		bb_simple_perror_msg_and_die(infile);
	}

	if (close(ofd) < 0) {
 die_outfile:
		bb_simple_perror_msg_and_die(outfile);
	}

	exitcode = EXIT_SUCCESS;
 out_status:
	dd_output_status(0);

	return exitcode;
}
1	niro	532	/* 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 <signal.h> /* For FEATURE_DD_SIGNAL_HANDLING */
12	niro	816	#include "libbb.h"
13	niro	532
14	niro	816	/* This is a NOEXEC applet. Be very careful! */
15
16
17			enum {
18			ifd = STDIN_FILENO,
19			ofd = STDOUT_FILENO,
20			};
21
22	niro	532	static const struct suffix_mult dd_suffixes[] = {
23			{ "c", 1 },
24			{ "w", 2 },
25			{ "b", 512 },
26			{ "kD", 1000 },
27			{ "k", 1024 },
28	niro	816	{ "K", 1024 }, /* compat with coreutils dd */
29	niro	532	{ "MD", 1000000 },
30			{ "M", 1048576 },
31			{ "GD", 1000000000 },
32			{ "G", 1073741824 },
33	niro	816	{ }
34	niro	532	};
35
36	niro	816	struct globals {
37			off_t out_full, out_part, in_full, in_part;
38			};
39			#define G ((struct globals)&bb_common_bufsiz1)
40			/* We have to zero it out because of NOEXEC */
41			#define INIT_G() memset(&G, 0, sizeof(G))
42	niro	532
43	niro	816
44			static void dd_output_status(int UNUSED_PARAM cur_signal)
45	niro	532	{
46	niro	816	/* Deliberately using %u, not %d */
47			fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
48			"%"OFF_FMT"u+%"OFF_FMT"u records out\n",
49			G.in_full, G.in_part,
50			G.out_full, G.out_part);
51	niro	532	}
52
53	niro	816	static ssize_t full_write_or_warn(const void *buf, size_t len,
54			const char *const filename)
55	niro	532	{
56	niro	816	ssize_t n = full_write(ofd, buf, len);
57	niro	532	if (n < 0)
58			bb_perror_msg("writing '%s'", filename);
59			return n;
60			}
61
62	niro	816	static bool write_and_stats(const void *buf, size_t len, size_t obs,
63			const char *filename)
64			{
65			ssize_t n = full_write_or_warn(buf, len, filename);
66			if (n < 0)
67			return 1;
68			if ((size_t)n == obs)
69			G.out_full++;
70			else if (n) /* > 0 */
71			G.out_part++;
72			return 0;
73			}
74
75	niro	532	#if ENABLE_LFS
76			#define XATOU_SFX xatoull_sfx
77			#else
78			#define XATOU_SFX xatoul_sfx
79			#endif
80
81	niro	816	int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
82			int dd_main(int argc UNUSED_PARAM, char **argv)
83	niro	532	{
84			enum {
85	niro	816	/* Must be in the same order as OP_conv_XXX! */
86			/* (see "flags \|= (1 << what)" below) */
87			FLAG_NOTRUNC = 1 << 0,
88			FLAG_SYNC = 1 << 1,
89			FLAG_NOERROR = 1 << 2,
90			FLAG_FSYNC = 1 << 3,
91			/* end of conv flags */
92			FLAG_TWOBUFS = 1 << 4,
93			FLAG_COUNT = 1 << 5,
94	niro	532	};
95	niro	816	static const char keywords[] ALIGN1 =
96			"bs\0""count\0""seek\0""skip\0""if\0""of\0"
97			#if ENABLE_FEATURE_DD_IBS_OBS
98			"ibs\0""obs\0""conv\0"
99			#endif
100			;
101			#if ENABLE_FEATURE_DD_IBS_OBS
102			static const char conv_words[] ALIGN1 =
103			"notrunc\0""sync\0""noerror\0""fsync\0";
104			#endif
105			enum {
106			OP_bs = 0,
107			OP_count,
108			OP_seek,
109			OP_skip,
110			OP_if,
111			OP_of,
112			#if ENABLE_FEATURE_DD_IBS_OBS
113			OP_ibs,
114			OP_obs,
115			OP_conv,
116			/* Must be in the same order as FLAG_XXX! */
117			OP_conv_notrunc = 0,
118			OP_conv_sync,
119			OP_conv_noerror,
120			OP_conv_fsync,
121			/* Unimplemented conv=XXX: */
122			//nocreat do not create the output file
123			//excl fail if the output file already exists
124			//fdatasync physically write output file data before finishing
125			//swab swap every pair of input bytes
126			//lcase change upper case to lower case
127			//ucase change lower case to upper case
128			//block pad newline-terminated records with spaces to cbs-size
129			//unblock replace trailing spaces in cbs-size records with newline
130			//ascii from EBCDIC to ASCII
131			//ebcdic from ASCII to EBCDIC
132			//ibm from ASCII to alternate EBCDIC
133			#endif
134			};
135			int exitcode = EXIT_FAILURE;
136			size_t ibs = 512, obs = 512;
137	niro	532	ssize_t n, w;
138			char ibuf, obuf;
139	niro	816	/* And these are all zeroed at once! */
140			struct {
141			int flags;
142			size_t oc;
143			off_t count;
144			off_t seek, skip;
145			const char infile, outfile;
146			} Z;
147			#define flags (Z.flags )
148			#define oc (Z.oc )
149			#define count (Z.count )
150			#define seek (Z.seek )
151			#define skip (Z.skip )
152			#define infile (Z.infile )
153			#define outfile (Z.outfile)
154	niro	532
155	niro	816	memset(&Z, 0, sizeof(Z));
156			INIT_G();
157			//fflush(NULL); - is this needed because of NOEXEC?
158	niro	532
159	niro	816	#if ENABLE_FEATURE_DD_SIGNAL_HANDLING
160			signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status);
161			#endif
162	niro	532
163	niro	816	for (n = 1; argv[n]; n++) {
164			int what;
165			char *val;
166	niro	532	char *arg = argv[n];
167
168	niro	816	#if ENABLE_DESKTOP
169			/* "dd --". NB: coreutils 6.9 will complain if they see
170			* more than one of them. We wouldn't. */
171			if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0')
172			continue;
173			#endif
174			val = strchr(arg, '=');
175			if (val == NULL)
176			bb_show_usage();
177			*val = '\0';
178			what = index_in_strings(keywords, arg);
179			if (what < 0)
180			bb_show_usage();
181			/* val = '='; - to preserve ps listing? /
182			val++;
183			#if ENABLE_FEATURE_DD_IBS_OBS
184			if (what == OP_ibs) {
185			/* Must fit into positive ssize_t */
186			ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
187			/continue;/
188			}
189			if (what == OP_obs) {
190			obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
191			/continue;/
192			}
193			if (what == OP_conv) {
194	niro	532	while (1) {
195	niro	816	/* find ',', replace them with NUL so we can use val for
196			* index_in_strings() without copying.
197			* We rely on val being non-null, else strchr would fault.
198			*/
199			arg = strchr(val, ',');
200			if (arg)
201			*arg = '\0';
202			what = index_in_strings(conv_words, val);
203			if (what < 0)
204			bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv");
205			flags \|= (1 << what);
206			if (!arg) /* no ',' left, so this was the last specifier */
207			break;
208			/* arg = ','; - to preserve ps listing? /
209			val = arg + 1; /* skip this keyword and ',' */
210	niro	532	}
211	niro	816	continue; /* we trashed 'what', can't fall through */
212			}
213			#endif
214			if (what == OP_bs) {
215			ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
216			/continue;/
217			}
218			/* These can be large: */
219			if (what == OP_count) {
220			flags \|= FLAG_COUNT;
221			count = XATOU_SFX(val, dd_suffixes);
222			/continue;/
223			}
224			if (what == OP_seek) {
225			seek = XATOU_SFX(val, dd_suffixes);
226			/continue;/
227			}
228			if (what == OP_skip) {
229			skip = XATOU_SFX(val, dd_suffixes);
230			/continue;/
231			}
232			if (what == OP_if) {
233			infile = val;
234			/continue;/
235			}
236			if (what == OP_of) {
237			outfile = val;
238			/continue;/
239			}
240			} /* end of "for (argv[n])" */
241	niro	532
242	niro	816	//XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
243	niro	532	ibuf = obuf = xmalloc(ibs);
244			if (ibs != obs) {
245	niro	816	flags \|= FLAG_TWOBUFS;
246	niro	532	obuf = xmalloc(obs);
247			}
248			if (infile != NULL)
249	niro	816	xmove_fd(xopen(infile, O_RDONLY), ifd);
250	niro	532	else {
251			infile = bb_msg_standard_input;
252			}
253			if (outfile != NULL) {
254	niro	816	int oflag = O_WRONLY \| O_CREAT;
255	niro	532
256	niro	816	if (!seek && !(flags & FLAG_NOTRUNC))
257	niro	532	oflag \|= O_TRUNC;
258
259	niro	816	xmove_fd(xopen(outfile, oflag), ofd);
260	niro	532
261	niro	816	if (seek && !(flags & FLAG_NOTRUNC)) {
262	niro	532	if (ftruncate(ofd, seek * obs) < 0) {
263			struct stat st;
264
265			if (fstat(ofd, &st) < 0 \|\| S_ISREG(st.st_mode) \|\|
266			S_ISDIR(st.st_mode))
267			goto die_outfile;
268			}
269			}
270			} else {
271			outfile = bb_msg_standard_output;
272			}
273			if (skip) {
274			if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
275			while (skip-- > 0) {
276			n = safe_read(ifd, ibuf, ibs);
277			if (n < 0)
278	niro	816	goto die_infile;
279	niro	532	if (n == 0)
280			break;
281			}
282			}
283			}
284			if (seek) {
285			if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
286			goto die_outfile;
287			}
288
289	niro	816	while (!(flags & FLAG_COUNT) \|\| (G.in_full + G.in_part != count)) {
290			if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */
291			memset(ibuf, 0, ibs);
292	niro	532	n = safe_read(ifd, ibuf, ibs);
293			if (n == 0)
294			break;
295			if (n < 0) {
296	niro	816	if (!(flags & FLAG_NOERROR))
297			goto die_infile;
298			n = ibs;
299			bb_simple_perror_msg(infile);
300	niro	532	}
301			if ((size_t)n == ibs)
302	niro	816	G.in_full++;
303	niro	532	else {
304	niro	816	G.in_part++;
305			if (flags & FLAG_SYNC) {
306	niro	532	memset(ibuf + n, '\0', ibs - n);
307			n = ibs;
308			}
309			}
310	niro	816	if (flags & FLAG_TWOBUFS) {
311	niro	532	char *tmp = ibuf;
312			while (n) {
313			size_t d = obs - oc;
314
315	niro	816	if (d > (size_t)n)
316	niro	532	d = n;
317			memcpy(obuf + oc, tmp, d);
318			n -= d;
319			tmp += d;
320			oc += d;
321			if (oc == obs) {
322	niro	816	if (write_and_stats(obuf, obs, obs, outfile))
323			goto out_status;
324	niro	532	oc = 0;
325			}
326			}
327	niro	816	} else if (write_and_stats(ibuf, n, obs, outfile))
328			goto out_status;
329
330			if (flags & FLAG_FSYNC) {
331			if (fsync(ofd) < 0)
332			goto die_outfile;
333	niro	532	}
334			}
335
336			if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
337	niro	816	w = full_write_or_warn(obuf, oc, outfile);
338	niro	532	if (w < 0) goto out_status;
339	niro	816	if (w > 0) G.out_part++;
340	niro	532	}
341			if (close(ifd) < 0) {
342	niro	816	die_infile:
343			bb_simple_perror_msg_and_die(infile);
344	niro	532	}
345
346			if (close(ofd) < 0) {
347			die_outfile:
348	niro	816	bb_simple_perror_msg_and_die(outfile);
349	niro	532	}
350	niro	816
351			exitcode = EXIT_SUCCESS;
352	niro	532	out_status:
353			dd_output_status(0);
354
355	niro	816	return exitcode;
356	niro	532	}