dd.c revision 11747 
1/*-
2 * Copyright (c) 1991, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Keith Muller of the University of California, San Diego and Lance
7 * Visser of Convex Computer Corporation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 *	This product includes software developed by the University of
20 *	California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 *    may be used to endorse or promote products derived from this software
23 *    without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 *	$Id: dd.c,v 1.4 1995/01/17 23:04:29 ache Exp $
38 */
39
40#ifndef lint
41static char copyright[] =
42"@(#) Copyright (c) 1991, 1993, 1994\n\
43	The Regents of the University of California.  All rights reserved.\n";
44#endif /* not lint */
45
46#ifndef lint
47static char sccsid[] = "@(#)dd.c	8.5 (Berkeley) 4/2/94";
48#endif /* not lint */
49
50#include <sys/param.h>
51#include <sys/stat.h>
52#include <sys/ioctl.h>
53#include <sys/mtio.h>
54
55#include <ctype.h>
56#include <err.h>
57#include <errno.h>
58#include <fcntl.h>
59#include <signal.h>
60#include <stdio.h>
61#include <stdlib.h>
62#include <string.h>
63#include <unistd.h>
64#include <locale.h>
65
66#include "dd.h"
67#include "extern.h"
68
69static void dd_close __P((void));
70static void dd_in __P((void));
71static void getfdtype __P((IO *));
72static void setup __P((void));
73
74IO	in, out;		/* input/output state */
75STAT	st;			/* statistics */
76void	(*cfunc) __P((void));	/* conversion function */
77u_long	cpy_cnt;		/* # of blocks to copy */
78u_int	ddflags;		/* conversion options */
79u_int	cbsz;			/* conversion block size */
80u_int	files_cnt = 1;		/* # of files to copy */
81u_char	*ctab;			/* conversion table */
82
83int
84main(argc, argv)
85	int argc;
86	char *argv[];
87{
88	(void) setlocale(LC_CTYPE, "");
89	jcl(argv);
90	setup();
91
92	(void)signal(SIGINFO, summaryx);
93	(void)signal(SIGINT, terminate);
94
95	atexit(summary);
96
97	while (files_cnt--)
98		dd_in();
99
100	dd_close();
101	exit(0);
102}
103
104static void
105setup()
106{
107	u_int cnt;
108
109	if (in.name == NULL) {
110		in.name = "stdin";
111		in.fd = STDIN_FILENO;
112	} else {
113		in.fd = open(in.name, O_RDONLY, 0);
114		if (in.fd < 0)
115			err(1, "%s", in.name);
116	}
117
118	getfdtype(&in);
119
120	if (files_cnt > 1 && !(in.flags & ISTAPE))
121		errx(1, "files is not supported for non-tape devices");
122
123	if (out.name == NULL) {
124		/* No way to check for read access here. */
125		out.fd = STDOUT_FILENO;
126		out.name = "stdout";
127	} else {
128#define	OFLAGS \
129    (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC))
130		out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE);
131		/*
132		 * May not have read access, so try again with write only.
133		 * Without read we may have a problem if output also does
134		 * not support seeks.
135		 */
136		if (out.fd < 0) {
137			out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE);
138			out.flags |= NOREAD;
139		}
140		if (out.fd < 0)
141			err(1, "%s", out.name);
142	}
143
144	getfdtype(&out);
145
146	/*
147	 * Allocate space for the input and output buffers.  If not doing
148	 * record oriented I/O, only need a single buffer.
149	 */
150	if (!(ddflags & (C_BLOCK|C_UNBLOCK))) {
151		if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL)
152			err(1, NULL);
153		out.db = in.db;
154	} else if ((in.db =
155	    malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL ||
156	    (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL)
157		err(1, NULL);
158	in.dbp = in.db;
159	out.dbp = out.db;
160
161	/* Position the input/output streams. */
162	if (in.offset)
163		pos_in();
164	if (out.offset)
165		pos_out();
166
167	/*
168	 * Truncate the output file; ignore errors because it fails on some
169	 * kinds of output files, tapes, for example.
170	 */
171	if (ddflags & (C_OF | C_SEEK | C_NOTRUNC) == (C_OF | C_SEEK))
172		(void)ftruncate(out.fd, (off_t)out.offset * out.dbsz);
173
174	/*
175	 * If converting case at the same time as another conversion, build a
176	 * table that does both at once.  If just converting case, use the
177	 * built-in tables.
178	 */
179	if (ddflags & (C_LCASE|C_UCASE))
180		if (ddflags & C_ASCII)
181			if (ddflags & C_LCASE) {
182				for (cnt = 0; cnt <= 0377; ++cnt)
183					if (isupper(ctab[cnt]))
184						ctab[cnt] = tolower(ctab[cnt]);
185			} else {
186				for (cnt = 0; cnt <= 0377; ++cnt)
187					if (islower(ctab[cnt]))
188						ctab[cnt] = toupper(ctab[cnt]);
189			}
190		else if (ddflags & C_EBCDIC)
191			if (ddflags & C_LCASE) {
192				for (cnt = 0; cnt <= 0377; ++cnt)
193					if (isupper(cnt))
194						ctab[cnt] = ctab[tolower(cnt)];
195			} else {
196				for (cnt = 0; cnt <= 0377; ++cnt)
197					if (islower(cnt))
198						ctab[cnt] = ctab[toupper(cnt)];
199			}
200		else {
201			ctab = ddflags & C_LCASE ? u2l : l2u;
202			if (ddflags & C_LCASE) {
203				for (cnt = 0; cnt <= 0377; ++cnt)
204					if (isupper(cnt))
205						ctab[cnt] = tolower(cnt);
206					else
207						ctab[cnt] = cnt;
208			} else {
209				for (cnt = 0; cnt <= 0377; ++cnt)
210					if (islower(cnt))
211						ctab[cnt] = toupper(cnt);
212					else
213						ctab[cnt] = cnt;
214			}
215		}
216	(void)time(&st.start);			/* Statistics timestamp. */
217}
218
219static void
220getfdtype(io)
221	IO *io;
222{
223	struct mtget mt;
224	struct stat sb;
225
226	if (fstat(io->fd, &sb))
227		err(1, "%s", io->name);
228	if (S_ISCHR(sb.st_mode))
229		io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE;
230	else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
231		io->flags |= ISPIPE;		/* XXX fixed in 4.4BSD */
232}
233
234static void
235dd_in()
236{
237	int flags, n;
238
239	for (flags = ddflags;;) {
240		if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt)
241			return;
242
243		/*
244		 * Zero the buffer first if trying to recover from errors so
245		 * lose the minimum amount of data.  If doing block operations
246		 * use spaces.
247		 */
248		if ((flags & (C_NOERROR|C_SYNC)) == (C_NOERROR|C_SYNC))
249			if (flags & (C_BLOCK|C_UNBLOCK))
250				memset(in.dbp, ' ', in.dbsz);
251			else
252				memset(in.dbp, 0, in.dbsz);
253
254		n = read(in.fd, in.dbp, in.dbsz);
255		if (n == 0) {
256			in.dbrcnt = 0;
257			return;
258		}
259
260		/* Read error. */
261		if (n < 0) {
262			/*
263			 * If noerror not specified, die.  POSIX requires that
264			 * the warning message be followed by an I/O display.
265			 */
266			if (!(flags & C_NOERROR))
267				err(1, "%s", in.name);
268			warn("%s", in.name);
269			summary();
270
271			/*
272			 * If it's not a tape drive or a pipe, seek past the
273			 * error.  If your OS doesn't do the right thing for
274			 * raw disks this section should be modified to re-read
275			 * in sector size chunks.
276			 */
277			if (!(in.flags & (ISPIPE|ISTAPE)) &&
278			    lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
279				warn("%s", in.name);
280
281			/* If sync not specified, omit block and continue. */
282			if (!(ddflags & C_SYNC))
283				continue;
284
285			/* Read errors count as full blocks. */
286			in.dbcnt += in.dbrcnt = in.dbsz;
287			++st.in_full;
288
289		/* Handle full input blocks. */
290		} else if (n == in.dbsz) {
291			in.dbcnt += in.dbrcnt = n;
292			++st.in_full;
293
294		/* Handle partial input blocks. */
295		} else {
296			/* If sync, use the entire block. */
297			if (ddflags & C_SYNC)
298				in.dbcnt += in.dbrcnt = in.dbsz;
299			else
300				in.dbcnt += in.dbrcnt = n;
301			++st.in_part;
302		}
303
304		/*
305		 * POSIX states that if bs is set and no other conversions
306		 * than noerror, notrunc or sync are specified, the block
307		 * is output without buffering as it is read.
308		 */
309		if (ddflags & C_BS) {
310			out.dbcnt = in.dbcnt;
311			dd_out(1);
312			in.dbcnt = 0;
313			continue;
314		}
315
316		if (ddflags & C_SWAB) {
317			if ((n = in.dbcnt) & 1) {
318				++st.swab;
319				--n;
320			}
321			swab(in.dbp, in.dbp, n);
322		}
323
324		in.dbp += in.dbrcnt;
325		(*cfunc)();
326	}
327}
328
329/*
330 * Cleanup any remaining I/O and flush output.  If necesssary, output file
331 * is truncated.
332 */
333static void
334dd_close()
335{
336	if (cfunc == def)
337		def_close();
338	else if (cfunc == block)
339		block_close();
340	else if (cfunc == unblock)
341		unblock_close();
342	if (ddflags & C_OSYNC && out.dbcnt < out.dbsz) {
343		memset(out.dbp, 0, out.dbsz - out.dbcnt);
344		out.dbcnt = out.dbsz;
345	}
346	if (out.dbcnt)
347		dd_out(1);
348}
349
350void
351dd_out(force)
352	int force;
353{
354	static int warned;
355	int cnt, n, nw;
356	u_char *outp;
357
358	/*
359	 * Write one or more blocks out.  The common case is writing a full
360	 * output block in a single write; increment the full block stats.
361	 * Otherwise, we're into partial block writes.  If a partial write,
362	 * and it's a character device, just warn.  If a tape device, quit.
363	 *
364	 * The partial writes represent two cases.  1: Where the input block
365	 * was less than expected so the output block was less than expected.
366	 * 2: Where the input block was the right size but we were forced to
367	 * write the block in multiple chunks.  The original versions of dd(1)
368	 * never wrote a block in more than a single write, so the latter case
369	 * never happened.
370	 *
371	 * One special case is if we're forced to do the write -- in that case
372	 * we play games with the buffer size, and it's usually a partial write.
373	 */
374	outp = out.db;
375	for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
376		for (cnt = n;; cnt -= nw) {
377			nw = write(out.fd, outp, cnt);
378			if (nw <= 0) {
379				if (nw == 0)
380					errx(1, "%s: end of device", out.name);
381				if (errno != EINTR)
382					err(1, "%s", out.name);
383				nw = 0;
384			}
385			outp += nw;
386			st.bytes += nw;
387			if (nw == n) {
388				if (n != out.dbsz)
389					++st.out_part;
390				else
391					++st.out_full;
392				break;
393			}
394			++st.out_part;
395			if (nw == cnt)
396				break;
397			if (out.flags & ISCHR && !warned) {
398				warned = 1;
399				warnx("%s: short write on character device",
400				    out.name);
401			}
402			if (out.flags & ISTAPE)
403				errx(1, "%s: short write on tape device", out.name);
404		}
405		if ((out.dbcnt -= n) < out.dbsz)
406			break;
407	}
408
409	/* Reassemble the output block. */
410	if (out.dbcnt)
411		memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
412	out.dbp = out.db + out.dbcnt;
413}
414