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 #if 0
37 #ifndef lint
38 static char const copyright[] =
39 "@(#) Copyright (c) 1991, 1993, 1994\n\
40 The Regents of the University of California. All rights reserved.\n";
41 #endif /* not lint */
42
43 #ifndef lint
44 static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94";
45 #endif /* not lint */
46 #endif
47 #include <sys/cdefs.h>
48 __FBSDID("$FreeBSD: stable/12/bin/dd/dd.c 362830 2020-07-01 09:28:00Z rscheff $");
49
50 #include <sys/param.h>
51 #include <sys/stat.h>
52 #include <sys/capsicum.h>
53 #include <sys/conf.h>
54 #include <sys/disklabel.h>
55 #include <sys/filio.h>
56 #include <sys/mtio.h>
57 #include <sys/time.h>
58
59 #include <assert.h>
60 #include <capsicum_helpers.h>
61 #include <ctype.h>
62 #include <err.h>
63 #include <errno.h>
64 #include <fcntl.h>
65 #include <inttypes.h>
66 #include <locale.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #include <time.h>
71 #include <unistd.h>
72
73 #include "dd.h"
74 #include "extern.h"
75
76 static void dd_close(void);
77 static void dd_in(void);
78 static void getfdtype(IO *);
79 static void setup(void);
80
81 IO in, out; /* input/output state */
82 STAT st; /* statistics */
83 void (*cfunc)(void); /* conversion function */
84 uintmax_t cpy_cnt; /* # of blocks to copy */
85 static off_t pending = 0; /* pending seek if sparse */
86 uint64_t ddflags = 0; /* conversion options */
87 size_t cbsz; /* conversion block size */
88 uintmax_t files_cnt = 1; /* # of files to copy */
89 const u_char *ctab; /* conversion table */
90 char fill_char; /* Character to fill with if defined */
91 size_t speed = 0; /* maximum speed, in bytes per second */
92 volatile sig_atomic_t need_summary;
93 volatile sig_atomic_t need_progress;
94
95 int
main(int argc __unused,char * argv[])96 main(int argc __unused, char *argv[])
97 {
98 struct itimerval itv = { { 1, 0 }, { 1, 0 } }; /* SIGALARM every second, if needed */
99
100 (void)setlocale(LC_CTYPE, "");
101 jcl(argv);
102 setup();
103
104 caph_cache_catpages();
105 if (caph_enter() < 0)
106 err(1, "unable to enter capability mode");
107
108 (void)signal(SIGINFO, siginfo_handler);
109 if (ddflags & C_PROGRESS) {
110 (void)signal(SIGALRM, sigalarm_handler);
111 setitimer(ITIMER_REAL, &itv, NULL);
112 }
113 (void)signal(SIGINT, terminate);
114
115 atexit(summary);
116
117 while (files_cnt--)
118 dd_in();
119
120 dd_close();
121 /*
122 * Some devices such as cfi(4) may perform significant amounts
123 * of work when a write descriptor is closed. Close the out
124 * descriptor explicitly so that the summary handler (called
125 * from an atexit() hook) includes this work.
126 */
127 if (close(out.fd) == -1 && errno != EINTR)
128 err(1, "close");
129 exit(0);
130 }
131
132 static int
parity(u_char c)133 parity(u_char c)
134 {
135 int i;
136
137 i = c ^ (c >> 1) ^ (c >> 2) ^ (c >> 3) ^
138 (c >> 4) ^ (c >> 5) ^ (c >> 6) ^ (c >> 7);
139 return (i & 1);
140 }
141
142 static void
setup(void)143 setup(void)
144 {
145 u_int cnt;
146 int iflags, oflags;
147 cap_rights_t rights;
148 unsigned long cmds[] = { FIODTYPE, MTIOCTOP };
149
150 if (in.name == NULL) {
151 in.name = "stdin";
152 in.fd = STDIN_FILENO;
153 } else {
154 iflags = 0;
155 if (ddflags & C_IDIRECT)
156 iflags |= O_DIRECT;
157 in.fd = open(in.name, O_RDONLY | iflags, 0);
158 if (in.fd == -1)
159 err(1, "%s", in.name);
160 }
161
162 getfdtype(&in);
163
164 cap_rights_init(&rights, CAP_READ, CAP_SEEK);
165 if (caph_rights_limit(in.fd, &rights) == -1)
166 err(1, "unable to limit capability rights");
167
168 if (files_cnt > 1 && !(in.flags & ISTAPE))
169 errx(1, "files is not supported for non-tape devices");
170
171 cap_rights_set(&rights, CAP_FTRUNCATE, CAP_IOCTL, CAP_WRITE);
172 if (ddflags & (C_FDATASYNC | C_FSYNC))
173 cap_rights_set(&rights, CAP_FSYNC);
174 if (out.name == NULL) {
175 /* No way to check for read access here. */
176 out.fd = STDOUT_FILENO;
177 out.name = "stdout";
178 if (ddflags & C_OFSYNC) {
179 oflags = fcntl(out.fd, F_GETFL);
180 if (oflags == -1)
181 err(1, "unable to get fd flags for stdout");
182 oflags |= O_FSYNC;
183 if (fcntl(out.fd, F_SETFL, oflags) == -1)
184 err(1, "unable to set fd flags for stdout");
185 }
186 } else {
187 oflags = O_CREAT;
188 if (!(ddflags & (C_SEEK | C_NOTRUNC)))
189 oflags |= O_TRUNC;
190 if (ddflags & C_OFSYNC)
191 oflags |= O_FSYNC;
192 if (ddflags & C_ODIRECT)
193 oflags |= O_DIRECT;
194 out.fd = open(out.name, O_RDWR | oflags, DEFFILEMODE);
195 /*
196 * May not have read access, so try again with write only.
197 * Without read we may have a problem if output also does
198 * not support seeks.
199 */
200 if (out.fd == -1) {
201 out.fd = open(out.name, O_WRONLY | oflags, DEFFILEMODE);
202 out.flags |= NOREAD;
203 cap_rights_clear(&rights, CAP_READ);
204 }
205 if (out.fd == -1)
206 err(1, "%s", out.name);
207 }
208
209 getfdtype(&out);
210
211 if (caph_rights_limit(out.fd, &rights) == -1)
212 err(1, "unable to limit capability rights");
213 if (caph_ioctls_limit(out.fd, cmds, nitems(cmds)) == -1)
214 err(1, "unable to limit capability rights");
215
216 if (in.fd != STDIN_FILENO && out.fd != STDIN_FILENO) {
217 if (caph_limit_stdin() == -1)
218 err(1, "unable to limit capability rights");
219 }
220
221 if (in.fd != STDOUT_FILENO && out.fd != STDOUT_FILENO) {
222 if (caph_limit_stdout() == -1)
223 err(1, "unable to limit capability rights");
224 }
225
226 if (in.fd != STDERR_FILENO && out.fd != STDERR_FILENO) {
227 if (caph_limit_stderr() == -1)
228 err(1, "unable to limit capability rights");
229 }
230
231 /*
232 * Allocate space for the input and output buffers. If not doing
233 * record oriented I/O, only need a single buffer.
234 */
235 if (!(ddflags & (C_BLOCK | C_UNBLOCK))) {
236 if ((in.db = malloc((size_t)out.dbsz + in.dbsz - 1)) == NULL)
237 err(1, "input buffer");
238 out.db = in.db;
239 } else if ((in.db = malloc(MAX((size_t)in.dbsz, cbsz) + cbsz)) == NULL ||
240 (out.db = malloc(out.dbsz + cbsz)) == NULL)
241 err(1, "output buffer");
242
243 /* dbp is the first free position in each buffer. */
244 in.dbp = in.db;
245 out.dbp = out.db;
246
247 /* Position the input/output streams. */
248 if (in.offset)
249 pos_in();
250 if (out.offset)
251 pos_out();
252
253 /*
254 * Truncate the output file. If it fails on a type of output file
255 * that it should _not_ fail on, error out.
256 */
257 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK) &&
258 out.flags & ISTRUNC)
259 if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
260 err(1, "truncating %s", out.name);
261
262 if (ddflags & (C_LCASE | C_UCASE | C_ASCII | C_EBCDIC | C_PARITY)) {
263 if (ctab != NULL) {
264 for (cnt = 0; cnt <= 0377; ++cnt)
265 casetab[cnt] = ctab[cnt];
266 } else {
267 for (cnt = 0; cnt <= 0377; ++cnt)
268 casetab[cnt] = cnt;
269 }
270 if ((ddflags & C_PARITY) && !(ddflags & C_ASCII)) {
271 /*
272 * If the input is not EBCDIC, and we do parity
273 * processing, strip input parity.
274 */
275 for (cnt = 200; cnt <= 0377; ++cnt)
276 casetab[cnt] = casetab[cnt & 0x7f];
277 }
278 if (ddflags & C_LCASE) {
279 for (cnt = 0; cnt <= 0377; ++cnt)
280 casetab[cnt] = tolower(casetab[cnt]);
281 } else if (ddflags & C_UCASE) {
282 for (cnt = 0; cnt <= 0377; ++cnt)
283 casetab[cnt] = toupper(casetab[cnt]);
284 }
285 if ((ddflags & C_PARITY)) {
286 /*
287 * This should strictly speaking be a no-op, but I
288 * wonder what funny LANG settings could get us.
289 */
290 for (cnt = 0; cnt <= 0377; ++cnt)
291 casetab[cnt] = casetab[cnt] & 0x7f;
292 }
293 if ((ddflags & C_PARSET)) {
294 for (cnt = 0; cnt <= 0377; ++cnt)
295 casetab[cnt] = casetab[cnt] | 0x80;
296 }
297 if ((ddflags & C_PAREVEN)) {
298 for (cnt = 0; cnt <= 0377; ++cnt)
299 if (parity(casetab[cnt]))
300 casetab[cnt] = casetab[cnt] | 0x80;
301 }
302 if ((ddflags & C_PARODD)) {
303 for (cnt = 0; cnt <= 0377; ++cnt)
304 if (!parity(casetab[cnt]))
305 casetab[cnt] = casetab[cnt] | 0x80;
306 }
307
308 ctab = casetab;
309 }
310
311 if (clock_gettime(CLOCK_MONOTONIC, &st.start))
312 err(1, "clock_gettime");
313 }
314
315 static void
getfdtype(IO * io)316 getfdtype(IO *io)
317 {
318 struct stat sb;
319 int type;
320
321 if (fstat(io->fd, &sb) == -1)
322 err(1, "%s", io->name);
323 if (S_ISREG(sb.st_mode))
324 io->flags |= ISTRUNC;
325 if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
326 if (ioctl(io->fd, FIODTYPE, &type) == -1) {
327 err(1, "%s", io->name);
328 } else {
329 if (type & D_TAPE)
330 io->flags |= ISTAPE;
331 else if (type & (D_DISK | D_MEM))
332 io->flags |= ISSEEK;
333 if (S_ISCHR(sb.st_mode) && (type & D_TAPE) == 0)
334 io->flags |= ISCHR;
335 }
336 return;
337 }
338 errno = 0;
339 if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
340 io->flags |= ISPIPE;
341 else
342 io->flags |= ISSEEK;
343 }
344
345 /*
346 * Limit the speed by adding a delay before every block read.
347 * The delay (t_usleep) is equal to the time computed from block
348 * size and the specified speed limit (t_target) minus the time
349 * spent on actual read and write operations (t_io).
350 */
351 static void
speed_limit(void)352 speed_limit(void)
353 {
354 static double t_prev, t_usleep;
355 double t_now, t_io, t_target;
356
357 t_now = secs_elapsed();
358 t_io = t_now - t_prev - t_usleep;
359 t_target = (double)in.dbsz / (double)speed;
360 t_usleep = t_target - t_io;
361 if (t_usleep > 0)
362 usleep(t_usleep * 1000000);
363 else
364 t_usleep = 0;
365 t_prev = t_now;
366 }
367
368 static void
swapbytes(void * v,size_t len)369 swapbytes(void *v, size_t len)
370 {
371 unsigned char *p = v;
372 unsigned char t;
373
374 while (len > 1) {
375 t = p[0];
376 p[0] = p[1];
377 p[1] = t;
378 p += 2;
379 len -= 2;
380 }
381 }
382
383 static void
dd_in(void)384 dd_in(void)
385 {
386 ssize_t n;
387
388 for (;;) {
389 switch (cpy_cnt) {
390 case -1: /* count=0 was specified */
391 return;
392 case 0:
393 break;
394 default:
395 if (st.in_full + st.in_part >= (uintmax_t)cpy_cnt)
396 return;
397 break;
398 }
399
400 if (speed > 0)
401 speed_limit();
402
403 /*
404 * Zero the buffer first if sync; if doing block operations,
405 * use spaces.
406 */
407 if (ddflags & C_SYNC) {
408 if (ddflags & C_FILL)
409 memset(in.dbp, fill_char, in.dbsz);
410 else if (ddflags & (C_BLOCK | C_UNBLOCK))
411 memset(in.dbp, ' ', in.dbsz);
412 else
413 memset(in.dbp, 0, in.dbsz);
414 }
415
416 in.dbrcnt = 0;
417 fill:
418 n = read(in.fd, in.dbp + in.dbrcnt, in.dbsz - in.dbrcnt);
419
420 /* EOF */
421 if (n == 0 && in.dbrcnt == 0)
422 return;
423
424 /* Read error */
425 if (n == -1) {
426 /*
427 * If noerror not specified, die. POSIX requires that
428 * the warning message be followed by an I/O display.
429 */
430 if (!(ddflags & C_NOERROR))
431 err(1, "%s", in.name);
432 warn("%s", in.name);
433 summary();
434
435 /*
436 * If it's a seekable file descriptor, seek past the
437 * error. If your OS doesn't do the right thing for
438 * raw disks this section should be modified to re-read
439 * in sector size chunks.
440 */
441 if (in.flags & ISSEEK &&
442 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
443 warn("%s", in.name);
444
445 /* If sync not specified, omit block and continue. */
446 if (!(ddflags & C_SYNC))
447 continue;
448 }
449
450 /* If conv=sync, use the entire block. */
451 if (ddflags & C_SYNC)
452 n = in.dbsz;
453
454 /* Count the bytes read for this block. */
455 in.dbrcnt += n;
456
457 /* Count the number of full and partial blocks. */
458 if (in.dbrcnt == in.dbsz)
459 ++st.in_full;
460 else if (ddflags & C_IFULLBLOCK && n != 0)
461 goto fill; /* these don't count */
462 else
463 ++st.in_part;
464
465 /* Count the total bytes read for this file. */
466 in.dbcnt += in.dbrcnt;
467
468 /*
469 * POSIX states that if bs is set and no other conversions
470 * than noerror, notrunc or sync are specified, the block
471 * is output without buffering as it is read.
472 */
473 if ((ddflags & ~(C_NOERROR | C_NOTRUNC | C_SYNC)) == C_BS) {
474 out.dbcnt = in.dbcnt;
475 dd_out(1);
476 in.dbcnt = 0;
477 continue;
478 }
479
480 if (ddflags & C_SWAB) {
481 if ((n = in.dbrcnt) & 1) {
482 ++st.swab;
483 --n;
484 }
485 swapbytes(in.dbp, (size_t)n);
486 }
487
488 /* Advance to the next block. */
489 in.dbp += in.dbrcnt;
490 (*cfunc)();
491 if (need_summary)
492 summary();
493 if (need_progress)
494 progress();
495 }
496 }
497
498 /*
499 * Clean up any remaining I/O and flush output. If necessary, the output file
500 * is truncated.
501 */
502 static void
dd_close(void)503 dd_close(void)
504 {
505 if (cfunc == def)
506 def_close();
507 else if (cfunc == block)
508 block_close();
509 else if (cfunc == unblock)
510 unblock_close();
511 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) {
512 if (ddflags & C_FILL)
513 memset(out.dbp, fill_char, out.dbsz - out.dbcnt);
514 else if (ddflags & (C_BLOCK | C_UNBLOCK))
515 memset(out.dbp, ' ', out.dbsz - out.dbcnt);
516 else
517 memset(out.dbp, 0, out.dbsz - out.dbcnt);
518 out.dbcnt = out.dbsz;
519 }
520 if (out.dbcnt || pending)
521 dd_out(1);
522
523 /*
524 * If the file ends with a hole, ftruncate it to extend its size
525 * up to the end of the hole (without having to write any data).
526 */
527 if (out.seek_offset > 0 && (out.flags & ISTRUNC)) {
528 if (ftruncate(out.fd, out.seek_offset) == -1)
529 err(1, "truncating %s", out.name);
530 }
531
532 if (ddflags & C_FSYNC) {
533 if (fsync(out.fd) == -1)
534 err(1, "fsyncing %s", out.name);
535 } else if (ddflags & C_FDATASYNC) {
536 if (fdatasync(out.fd) == -1)
537 err(1, "fdatasyncing %s", out.name);
538 }
539 }
540
541 void
dd_out(int force)542 dd_out(int force)
543 {
544 u_char *outp;
545 size_t cnt, n;
546 ssize_t nw;
547 static int warned;
548 int sparse;
549
550 /*
551 * Write one or more blocks out. The common case is writing a full
552 * output block in a single write; increment the full block stats.
553 * Otherwise, we're into partial block writes. If a partial write,
554 * and it's a character device, just warn. If a tape device, quit.
555 *
556 * The partial writes represent two cases. 1: Where the input block
557 * was less than expected so the output block was less than expected.
558 * 2: Where the input block was the right size but we were forced to
559 * write the block in multiple chunks. The original versions of dd(1)
560 * never wrote a block in more than a single write, so the latter case
561 * never happened.
562 *
563 * One special case is if we're forced to do the write -- in that case
564 * we play games with the buffer size, and it's usually a partial write.
565 */
566 outp = out.db;
567
568 /*
569 * If force, first try to write all pending data, else try to write
570 * just one block. Subsequently always write data one full block at
571 * a time at most.
572 */
573 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
574 cnt = n;
575 do {
576 sparse = 0;
577 if (ddflags & C_SPARSE) {
578 /* Is buffer sparse? */
579 sparse = BISZERO(outp, cnt);
580 }
581 if (sparse && !force) {
582 pending += cnt;
583 nw = cnt;
584 } else {
585 if (pending != 0) {
586 /*
587 * Seek past hole. Note that we need to record the
588 * reached offset, because we might have no more data
589 * to write, in which case we'll need to call
590 * ftruncate to extend the file size.
591 */
592 out.seek_offset = lseek(out.fd, pending, SEEK_CUR);
593 if (out.seek_offset == -1)
594 err(2, "%s: seek error creating sparse file",
595 out.name);
596 pending = 0;
597 }
598 if (cnt) {
599 nw = write(out.fd, outp, cnt);
600 out.seek_offset = 0;
601 } else {
602 return;
603 }
604 }
605
606 if (nw <= 0) {
607 if (nw == 0)
608 errx(1, "%s: end of device", out.name);
609 if (errno != EINTR)
610 err(1, "%s", out.name);
611 nw = 0;
612 }
613
614 outp += nw;
615 st.bytes += nw;
616
617 if ((size_t)nw == n && n == (size_t)out.dbsz)
618 ++st.out_full;
619 else
620 ++st.out_part;
621
622 if ((size_t) nw != cnt) {
623 if (out.flags & ISTAPE)
624 errx(1, "%s: short write on tape device",
625 out.name);
626 if (out.flags & ISCHR && !warned) {
627 warned = 1;
628 warnx("%s: short write on character device",
629 out.name);
630 }
631 }
632
633 cnt -= nw;
634 } while (cnt != 0);
635
636 if ((out.dbcnt -= n) < out.dbsz)
637 break;
638 }
639
640 /* Reassemble the output block. */
641 if (out.dbcnt)
642 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
643 out.dbp = out.db + out.dbcnt;
644 }
645