1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Keith Muller of the University of California, San Diego and Lance
9 * Visser of Convex Computer Corporation.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/param.h>
37#include <sys/stat.h>
38#include <sys/capsicum.h>
39#include <sys/conf.h>
40#include <sys/disklabel.h>
41#include <sys/filio.h>
42#include <sys/mtio.h>
43#include <sys/time.h>
44
45#include <assert.h>
46#include <capsicum_helpers.h>
47#include <ctype.h>
48#include <err.h>
49#include <errno.h>
50#include <fcntl.h>
51#include <inttypes.h>
52#include <locale.h>
53#include <signal.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <time.h>
58#include <unistd.h>
59
60#include "dd.h"
61#include "extern.h"
62
63static void dd_close(void);
64static void dd_in(void);
65static void getfdtype(IO *);
66static void setup(void);
67
68IO	in, out;		/* input/output state */
69STAT	st;			/* statistics */
70void	(*cfunc)(void);		/* conversion function */
71uintmax_t cpy_cnt;		/* # of blocks to copy */
72static off_t	pending = 0;	/* pending seek if sparse */
73uint64_t	ddflags = 0;	/* conversion options */
74size_t	cbsz;			/* conversion block size */
75uintmax_t files_cnt = 1;	/* # of files to copy */
76const	u_char *ctab;		/* conversion table */
77char	fill_char;		/* Character to fill with if defined */
78size_t	speed = 0;		/* maximum speed, in bytes per second */
79volatile sig_atomic_t need_summary;
80volatile sig_atomic_t need_progress;
81volatile sig_atomic_t kill_signal;
82
83int
84main(int argc __unused, char *argv[])
85{
86	struct itimerval itv = { { 1, 0 }, { 1, 0 } }; /* SIGALARM every second, if needed */
87
88	prepare_io();
89
90	(void)setlocale(LC_CTYPE, "");
91	jcl(argv);
92	setup();
93
94	caph_cache_catpages();
95	if (caph_enter() < 0)
96		err(1, "unable to enter capability mode");
97
98	(void)signal(SIGINFO, siginfo_handler);
99	if (ddflags & C_PROGRESS) {
100		(void)signal(SIGALRM, sigalarm_handler);
101		setitimer(ITIMER_REAL, &itv, NULL);
102	}
103
104	atexit(summary);
105
106	while (files_cnt--)
107		dd_in();
108
109	dd_close();
110	/*
111	 * Some devices such as cfi(4) may perform significant amounts
112	 * of work when a write descriptor is closed.  Close the out
113	 * descriptor explicitly so that the summary handler (called
114	 * from an atexit() hook) includes this work.
115	 */
116	if (close(out.fd) == -1 && errno != EINTR)
117		err(1, "close");
118	exit(0);
119}
120
121static int
122parity(u_char c)
123{
124	int i;
125
126	i = c ^ (c >> 1) ^ (c >> 2) ^ (c >> 3) ^
127	    (c >> 4) ^ (c >> 5) ^ (c >> 6) ^ (c >> 7);
128	return (i & 1);
129}
130
131static void
132setup(void)
133{
134	u_int cnt;
135	int iflags, oflags;
136	cap_rights_t rights;
137	unsigned long cmds[] = { FIODTYPE, MTIOCTOP };
138
139	if (in.name == NULL) {
140		in.name = "stdin";
141		in.fd = STDIN_FILENO;
142	} else {
143		iflags = 0;
144		if (ddflags & C_IDIRECT)
145			iflags |= O_DIRECT;
146		before_io();
147		in.fd = open(in.name, O_RDONLY | iflags, 0);
148		after_io();
149		if (in.fd == -1)
150			err(1, "%s", in.name);
151	}
152
153	getfdtype(&in);
154
155	cap_rights_init(&rights, CAP_READ, CAP_SEEK);
156	if (caph_rights_limit(in.fd, &rights) == -1)
157		err(1, "unable to limit capability rights");
158
159	if (files_cnt > 1 && !(in.flags & ISTAPE))
160		errx(1, "files is not supported for non-tape devices");
161
162	cap_rights_set(&rights, CAP_FTRUNCATE, CAP_IOCTL, CAP_WRITE);
163	if (ddflags & (C_FDATASYNC | C_FSYNC))
164		cap_rights_set(&rights, CAP_FSYNC);
165	if (out.name == NULL) {
166		/* No way to check for read access here. */
167		out.fd = STDOUT_FILENO;
168		out.name = "stdout";
169		if (ddflags & C_OFSYNC) {
170			oflags = fcntl(out.fd, F_GETFL);
171			if (oflags == -1)
172				err(1, "unable to get fd flags for stdout");
173			oflags |= O_FSYNC;
174			if (fcntl(out.fd, F_SETFL, oflags) == -1)
175				err(1, "unable to set fd flags for stdout");
176		}
177	} else {
178		oflags = O_CREAT;
179		if (!(ddflags & (C_SEEK | C_NOTRUNC)))
180			oflags |= O_TRUNC;
181		if (ddflags & C_OFSYNC)
182			oflags |= O_FSYNC;
183		if (ddflags & C_ODIRECT)
184			oflags |= O_DIRECT;
185		before_io();
186		out.fd = open(out.name, O_RDWR | oflags, DEFFILEMODE);
187		after_io();
188		/*
189		 * May not have read access, so try again with write only.
190		 * Without read we may have a problem if output also does
191		 * not support seeks.
192		 */
193		if (out.fd == -1) {
194			before_io();
195			out.fd = open(out.name, O_WRONLY | oflags, DEFFILEMODE);
196			after_io();
197			out.flags |= NOREAD;
198			cap_rights_clear(&rights, CAP_READ);
199		}
200		if (out.fd == -1)
201			err(1, "%s", out.name);
202	}
203
204	getfdtype(&out);
205
206	if (caph_rights_limit(out.fd, &rights) == -1)
207		err(1, "unable to limit capability rights");
208	if (caph_ioctls_limit(out.fd, cmds, nitems(cmds)) == -1)
209		err(1, "unable to limit capability rights");
210
211	if (in.fd != STDIN_FILENO && out.fd != STDIN_FILENO) {
212		if (caph_limit_stdin() == -1)
213			err(1, "unable to limit capability rights");
214	}
215
216	if (in.fd != STDOUT_FILENO && out.fd != STDOUT_FILENO) {
217		if (caph_limit_stdout() == -1)
218			err(1, "unable to limit capability rights");
219	}
220
221	if (in.fd != STDERR_FILENO && out.fd != STDERR_FILENO) {
222		if (caph_limit_stderr() == -1)
223			err(1, "unable to limit capability rights");
224	}
225
226	/*
227	 * Allocate space for the input and output buffers.  If not doing
228	 * record oriented I/O, only need a single buffer.
229	 */
230	if (!(ddflags & (C_BLOCK | C_UNBLOCK))) {
231		if ((in.db = malloc((size_t)out.dbsz + in.dbsz - 1)) == NULL)
232			err(1, "input buffer");
233		out.db = in.db;
234	} else if ((in.db = malloc(MAX((size_t)in.dbsz, cbsz) + cbsz)) == NULL ||
235	    (out.db = malloc(out.dbsz + cbsz)) == NULL)
236		err(1, "output buffer");
237
238	/* dbp is the first free position in each buffer. */
239	in.dbp = in.db;
240	out.dbp = out.db;
241
242	/* Position the input/output streams. */
243	if (in.offset)
244		pos_in();
245	if (out.offset)
246		pos_out();
247
248	/*
249	 * Truncate the output file.  If it fails on a type of output file
250	 * that it should _not_ fail on, error out.
251	 */
252	if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK) &&
253	    out.flags & ISTRUNC)
254		if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
255			err(1, "truncating %s", out.name);
256
257	if (ddflags & (C_LCASE  | C_UCASE | C_ASCII | C_EBCDIC | C_PARITY)) {
258		if (ctab != NULL) {
259			for (cnt = 0; cnt <= 0377; ++cnt)
260				casetab[cnt] = ctab[cnt];
261		} else {
262			for (cnt = 0; cnt <= 0377; ++cnt)
263				casetab[cnt] = cnt;
264		}
265		if ((ddflags & C_PARITY) && !(ddflags & C_ASCII)) {
266			/*
267			 * If the input is not EBCDIC, and we do parity
268			 * processing, strip input parity.
269			 */
270			for (cnt = 200; cnt <= 0377; ++cnt)
271				casetab[cnt] = casetab[cnt & 0x7f];
272		}
273		if (ddflags & C_LCASE) {
274			for (cnt = 0; cnt <= 0377; ++cnt)
275				casetab[cnt] = tolower(casetab[cnt]);
276		} else if (ddflags & C_UCASE) {
277			for (cnt = 0; cnt <= 0377; ++cnt)
278				casetab[cnt] = toupper(casetab[cnt]);
279		}
280		if ((ddflags & C_PARITY)) {
281			/*
282			 * This should strictly speaking be a no-op, but I
283			 * wonder what funny LANG settings could get us.
284			 */
285			for (cnt = 0; cnt <= 0377; ++cnt)
286				casetab[cnt] = casetab[cnt] & 0x7f;
287		}
288		if ((ddflags & C_PARSET)) {
289			for (cnt = 0; cnt <= 0377; ++cnt)
290				casetab[cnt] = casetab[cnt] | 0x80;
291		}
292		if ((ddflags & C_PAREVEN)) {
293			for (cnt = 0; cnt <= 0377; ++cnt)
294				if (parity(casetab[cnt]))
295					casetab[cnt] = casetab[cnt] | 0x80;
296		}
297		if ((ddflags & C_PARODD)) {
298			for (cnt = 0; cnt <= 0377; ++cnt)
299				if (!parity(casetab[cnt]))
300					casetab[cnt] = casetab[cnt] | 0x80;
301		}
302
303		ctab = casetab;
304	}
305
306	if (clock_gettime(CLOCK_MONOTONIC, &st.start))
307		err(1, "clock_gettime");
308}
309
310static void
311getfdtype(IO *io)
312{
313	struct stat sb;
314	int type;
315
316	if (fstat(io->fd, &sb) == -1)
317		err(1, "%s", io->name);
318	if (S_ISREG(sb.st_mode))
319		io->flags |= ISTRUNC;
320	if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
321		if (ioctl(io->fd, FIODTYPE, &type) == -1) {
322			err(1, "%s", io->name);
323		} else {
324			if (type & D_TAPE)
325				io->flags |= ISTAPE;
326			else if (type & (D_DISK | D_MEM))
327				io->flags |= ISSEEK;
328			if (S_ISCHR(sb.st_mode) && (type & D_TAPE) == 0)
329				io->flags |= ISCHR;
330		}
331		return;
332	}
333	errno = 0;
334	if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
335		io->flags |= ISPIPE;
336	else
337		io->flags |= ISSEEK;
338}
339
340/*
341 * Limit the speed by adding a delay before every block read.
342 * The delay (t_usleep) is equal to the time computed from block
343 * size and the specified speed limit (t_target) minus the time
344 * spent on actual read and write operations (t_io).
345 */
346static void
347speed_limit(void)
348{
349	static double t_prev, t_usleep;
350	double t_now, t_io, t_target;
351
352	t_now = secs_elapsed();
353	t_io = t_now - t_prev - t_usleep;
354	t_target = (double)in.dbsz / (double)speed;
355	t_usleep = t_target - t_io;
356	if (t_usleep > 0)
357		usleep(t_usleep * 1000000);
358	else
359		t_usleep = 0;
360	t_prev = t_now;
361}
362
363static void
364swapbytes(void *v, size_t len)
365{
366	unsigned char *p = v;
367	unsigned char t;
368
369	while (len > 1) {
370		t = p[0];
371		p[0] = p[1];
372		p[1] = t;
373		p += 2;
374		len -= 2;
375	}
376}
377
378static void
379dd_in(void)
380{
381	ssize_t n;
382
383	for (;;) {
384		switch (cpy_cnt) {
385		case -1:			/* count=0 was specified */
386			return;
387		case 0:
388			break;
389		default:
390			if (st.in_full + st.in_part >= (uintmax_t)cpy_cnt)
391				return;
392			break;
393		}
394
395		if (speed > 0)
396			speed_limit();
397
398		/*
399		 * Zero the buffer first if sync; if doing block operations,
400		 * use spaces.
401		 */
402		if (ddflags & C_SYNC) {
403			if (ddflags & C_FILL)
404				memset(in.dbp, fill_char, in.dbsz);
405			else if (ddflags & (C_BLOCK | C_UNBLOCK))
406				memset(in.dbp, ' ', in.dbsz);
407			else
408				memset(in.dbp, 0, in.dbsz);
409		}
410
411		in.dbrcnt = 0;
412fill:
413		before_io();
414		n = read(in.fd, in.dbp + in.dbrcnt, in.dbsz - in.dbrcnt);
415		after_io();
416
417		/* EOF */
418		if (n == 0 && in.dbrcnt == 0)
419			return;
420
421		/* Read error */
422		if (n == -1) {
423			/*
424			 * If noerror not specified, die.  POSIX requires that
425			 * the warning message be followed by an I/O display.
426			 */
427			if (!(ddflags & C_NOERROR))
428				err(1, "%s", in.name);
429			warn("%s", in.name);
430			summary();
431
432			/*
433			 * If it's a seekable file descriptor, seek past the
434			 * error.  If your OS doesn't do the right thing for
435			 * raw disks this section should be modified to re-read
436			 * in sector size chunks.
437			 */
438			if (in.flags & ISSEEK &&
439			    lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
440				warn("%s", in.name);
441
442			/* If sync not specified, omit block and continue. */
443			if (!(ddflags & C_SYNC))
444				continue;
445		}
446
447		/* If conv=sync, use the entire block. */
448		if (ddflags & C_SYNC)
449			n = in.dbsz;
450
451		/* Count the bytes read for this block. */
452		in.dbrcnt += n;
453
454		/* Count the number of full and partial blocks. */
455		if (in.dbrcnt == in.dbsz)
456			++st.in_full;
457		else if (ddflags & C_IFULLBLOCK && n != 0)
458			goto fill; /* these don't count */
459		else
460			++st.in_part;
461
462		/* Count the total bytes read for this file. */
463		in.dbcnt += in.dbrcnt;
464
465		/*
466		 * POSIX states that if bs is set and no other conversions
467		 * than noerror, notrunc or sync are specified, the block
468		 * is output without buffering as it is read.
469		 */
470		if ((ddflags & ~(C_NOERROR | C_NOTRUNC | C_SYNC)) == C_BS) {
471			out.dbcnt = in.dbcnt;
472			dd_out(1);
473			in.dbcnt = 0;
474			continue;
475		}
476
477		if (ddflags & C_SWAB) {
478			if ((n = in.dbrcnt) & 1) {
479				++st.swab;
480				--n;
481			}
482			swapbytes(in.dbp, (size_t)n);
483		}
484
485		/* Advance to the next block. */
486		in.dbp += in.dbrcnt;
487		(*cfunc)();
488		if (need_summary)
489			summary();
490		if (need_progress)
491			progress();
492	}
493}
494
495/*
496 * Clean up any remaining I/O and flush output.  If necessary, the output file
497 * is truncated.
498 */
499static void
500dd_close(void)
501{
502	if (cfunc == def)
503		def_close();
504	else if (cfunc == block)
505		block_close();
506	else if (cfunc == unblock)
507		unblock_close();
508	if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) {
509		if (ddflags & C_FILL)
510			memset(out.dbp, fill_char, out.dbsz - out.dbcnt);
511		else if (ddflags & (C_BLOCK | C_UNBLOCK))
512			memset(out.dbp, ' ', out.dbsz - out.dbcnt);
513		else
514			memset(out.dbp, 0, out.dbsz - out.dbcnt);
515		out.dbcnt = out.dbsz;
516	}
517	if (out.dbcnt || pending)
518		dd_out(1);
519
520	/*
521	 * If the file ends with a hole, ftruncate it to extend its size
522	 * up to the end of the hole (without having to write any data).
523	 */
524	if (out.seek_offset > 0 && (out.flags & ISTRUNC)) {
525		if (ftruncate(out.fd, out.seek_offset) == -1)
526			err(1, "truncating %s", out.name);
527	}
528
529	if (ddflags & C_FSYNC) {
530		if (fsync(out.fd) == -1)
531			err(1, "fsyncing %s", out.name);
532	} else if (ddflags & C_FDATASYNC) {
533		if (fdatasync(out.fd) == -1)
534			err(1, "fdatasyncing %s", out.name);
535	}
536}
537
538void
539dd_out(int force)
540{
541	u_char *outp;
542	size_t cnt, n;
543	ssize_t nw;
544	static int warned;
545	int sparse;
546
547	/*
548	 * Write one or more blocks out.  The common case is writing a full
549	 * output block in a single write; increment the full block stats.
550	 * Otherwise, we're into partial block writes.  If a partial write,
551	 * and it's a character device, just warn.  If a tape device, quit.
552	 *
553	 * The partial writes represent two cases.  1: Where the input block
554	 * was less than expected so the output block was less than expected.
555	 * 2: Where the input block was the right size but we were forced to
556	 * write the block in multiple chunks.  The original versions of dd(1)
557	 * never wrote a block in more than a single write, so the latter case
558	 * never happened.
559	 *
560	 * One special case is if we're forced to do the write -- in that case
561	 * we play games with the buffer size, and it's usually a partial write.
562	 */
563	outp = out.db;
564
565	/*
566	 * If force, first try to write all pending data, else try to write
567	 * just one block. Subsequently always write data one full block at
568	 * a time at most.
569	 */
570	for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
571		cnt = n;
572		do {
573			sparse = 0;
574			if (ddflags & C_SPARSE) {
575				/* Is buffer sparse? */
576				sparse = BISZERO(outp, cnt);
577			}
578			if (sparse && !force) {
579				pending += cnt;
580				nw = cnt;
581			} else {
582				if (pending != 0) {
583					/*
584					 * Seek past hole.  Note that we need to record the
585					 * reached offset, because we might have no more data
586					 * to write, in which case we'll need to call
587					 * ftruncate to extend the file size.
588					 */
589					out.seek_offset = lseek(out.fd, pending, SEEK_CUR);
590					if (out.seek_offset == -1)
591						err(2, "%s: seek error creating sparse file",
592						    out.name);
593					pending = 0;
594				}
595				if (cnt) {
596					before_io();
597					nw = write(out.fd, outp, cnt);
598					after_io();
599					out.seek_offset = 0;
600				} else {
601					return;
602				}
603			}
604
605			if (nw <= 0) {
606				if (nw == 0)
607					errx(1, "%s: end of device", out.name);
608				if (errno != EINTR)
609					err(1, "%s", out.name);
610				nw = 0;
611			}
612
613			outp += nw;
614			st.bytes += nw;
615
616			if ((size_t)nw == n && n == (size_t)out.dbsz)
617				++st.out_full;
618			else
619				++st.out_part;
620
621			if ((size_t) nw != cnt) {
622				if (out.flags & ISTAPE)
623					errx(1, "%s: short write on tape device",
624				    	out.name);
625				if (out.flags & ISCHR && !warned) {
626					warned = 1;
627					warnx("%s: short write on character device",
628				    	out.name);
629				}
630			}
631
632			cnt -= nw;
633		} while (cnt != 0);
634
635		if ((out.dbcnt -= n) < out.dbsz)
636			break;
637	}
638
639	/* Reassemble the output block. */
640	if (out.dbcnt)
641		(void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
642	out.dbp = out.db + out.dbcnt;
643}
644