xref: /freebsd/bin/rm/rm.c (revision 65b71c48d226f3ef3eb1c4452dccc678a7d2ac96)
1 /*-
2  * Copyright (c) 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if 0
31 #ifndef lint
32 static const char copyright[] =
33 "@(#) Copyright (c) 1990, 1993, 1994\n\
34 	The Regents of the University of California.  All rights reserved.\n";
35 #endif /* not lint */
36 
37 #ifndef lint
38 static char sccsid[] = "@(#)rm.c	8.5 (Berkeley) 4/18/94";
39 #endif /* not lint */
40 #endif
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/stat.h>
45 #include <sys/param.h>
46 #include <sys/mount.h>
47 
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <fts.h>
52 #include <grp.h>
53 #include <locale.h>
54 #include <pwd.h>
55 #include <stdint.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <sysexits.h>
60 #include <unistd.h>
61 
62 static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
63 static int rflag, Iflag, xflag;
64 static uid_t uid;
65 static volatile sig_atomic_t info;
66 
67 static int	check(const char *, const char *, struct stat *);
68 static int	check2(char **);
69 static void	checkdot(char **);
70 static void	checkslash(char **);
71 static void	rm_file(char **);
72 static int	rm_overwrite(const char *, struct stat *);
73 static void	rm_tree(char **);
74 static void siginfo(int __unused);
75 static void	usage(void);
76 
77 /*
78  * rm --
79  *	This rm is different from historic rm's, but is expected to match
80  *	POSIX 1003.2 behavior.	The most visible difference is that -f
81  *	has two specific effects now, ignore non-existent files and force
82  *	file removal.
83  */
84 int
85 main(int argc, char *argv[])
86 {
87 	int ch;
88 	char *p;
89 
90 	(void)setlocale(LC_ALL, "");
91 
92 	/*
93 	 * Test for the special case where the utility is called as
94 	 * "unlink", for which the functionality provided is greatly
95 	 * simplified.
96 	 */
97 	if ((p = strrchr(argv[0], '/')) == NULL)
98 		p = argv[0];
99 	else
100 		++p;
101 	if (strcmp(p, "unlink") == 0) {
102 		while (getopt(argc, argv, "") != -1)
103 			usage();
104 		argc -= optind;
105 		argv += optind;
106 		if (argc != 1)
107 			usage();
108 		rm_file(&argv[0]);
109 		exit(eval);
110 	}
111 
112 	Pflag = rflag = xflag = 0;
113 	while ((ch = getopt(argc, argv, "dfiIPRrvWx")) != -1)
114 		switch(ch) {
115 		case 'd':
116 			dflag = 1;
117 			break;
118 		case 'f':
119 			fflag = 1;
120 			iflag = 0;
121 			break;
122 		case 'i':
123 			fflag = 0;
124 			iflag = 1;
125 			break;
126 		case 'I':
127 			Iflag = 1;
128 			break;
129 		case 'P':
130 			Pflag = 1;
131 			break;
132 		case 'R':
133 		case 'r':			/* Compatibility. */
134 			rflag = 1;
135 			break;
136 		case 'v':
137 			vflag = 1;
138 			break;
139 		case 'W':
140 			Wflag = 1;
141 			break;
142 		case 'x':
143 			xflag = 1;
144 			break;
145 		default:
146 			usage();
147 		}
148 	argc -= optind;
149 	argv += optind;
150 
151 	if (argc < 1) {
152 		if (fflag)
153 			return (0);
154 		usage();
155 	}
156 
157 	checkdot(argv);
158 	if (getenv("POSIXLY_CORRECT") == NULL)
159 		checkslash(argv);
160 	uid = geteuid();
161 
162 	(void)signal(SIGINFO, siginfo);
163 	if (*argv) {
164 		stdin_ok = isatty(STDIN_FILENO);
165 
166 		if (Iflag) {
167 			if (check2(argv) == 0)
168 				exit (1);
169 		}
170 		if (rflag)
171 			rm_tree(argv);
172 		else
173 			rm_file(argv);
174 	}
175 
176 	exit (eval);
177 }
178 
179 static void
180 rm_tree(char **argv)
181 {
182 	FTS *fts;
183 	FTSENT *p;
184 	int needstat;
185 	int flags;
186 	int rval;
187 
188 	/*
189 	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
190 	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
191 	 */
192 	needstat = !uid || (!fflag && !iflag && stdin_ok);
193 
194 	/*
195 	 * If the -i option is specified, the user can skip on the pre-order
196 	 * visit.  The fts_number field flags skipped directories.
197 	 */
198 #define	SKIPPED	1
199 
200 	flags = FTS_PHYSICAL;
201 	if (!needstat)
202 		flags |= FTS_NOSTAT;
203 	if (Wflag)
204 		flags |= FTS_WHITEOUT;
205 	if (xflag)
206 		flags |= FTS_XDEV;
207 	if (!(fts = fts_open(argv, flags, NULL))) {
208 		if (fflag && errno == ENOENT)
209 			return;
210 		err(1, "fts_open");
211 	}
212 	while ((p = fts_read(fts)) != NULL) {
213 		switch (p->fts_info) {
214 		case FTS_DNR:
215 			if (!fflag || p->fts_errno != ENOENT) {
216 				warnx("%s: %s",
217 				    p->fts_path, strerror(p->fts_errno));
218 				eval = 1;
219 			}
220 			continue;
221 		case FTS_ERR:
222 			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
223 		case FTS_NS:
224 			/*
225 			 * Assume that since fts_read() couldn't stat the
226 			 * file, it can't be unlinked.
227 			 */
228 			if (!needstat)
229 				break;
230 			if (!fflag || p->fts_errno != ENOENT) {
231 				warnx("%s: %s",
232 				    p->fts_path, strerror(p->fts_errno));
233 				eval = 1;
234 			}
235 			continue;
236 		case FTS_D:
237 			/* Pre-order: give user chance to skip. */
238 			if (!fflag && !check(p->fts_path, p->fts_accpath,
239 			    p->fts_statp)) {
240 				(void)fts_set(fts, p, FTS_SKIP);
241 				p->fts_number = SKIPPED;
242 			}
243 			else if (!uid &&
244 				 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
245 				 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
246 				 lchflags(p->fts_accpath,
247 					 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
248 				goto err;
249 			continue;
250 		case FTS_DP:
251 			/* Post-order: see if user skipped. */
252 			if (p->fts_number == SKIPPED)
253 				continue;
254 			break;
255 		default:
256 			if (!fflag &&
257 			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
258 				continue;
259 		}
260 
261 		rval = 0;
262 		if (!uid &&
263 		    (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
264 		    !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
265 			rval = lchflags(p->fts_accpath,
266 				       p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
267 		if (rval == 0) {
268 			/*
269 			 * If we can't read or search the directory, may still be
270 			 * able to remove it.  Don't print out the un{read,search}able
271 			 * message unless the remove fails.
272 			 */
273 			switch (p->fts_info) {
274 			case FTS_DP:
275 			case FTS_DNR:
276 				rval = rmdir(p->fts_accpath);
277 				if (rval == 0 || (fflag && errno == ENOENT)) {
278 					if (rval == 0 && vflag)
279 						(void)printf("%s\n",
280 						    p->fts_path);
281 					if (rval == 0 && info) {
282 						info = 0;
283 						(void)printf("%s\n",
284 						    p->fts_path);
285 					}
286 					continue;
287 				}
288 				break;
289 
290 			case FTS_W:
291 				rval = undelete(p->fts_accpath);
292 				if (rval == 0 && (fflag && errno == ENOENT)) {
293 					if (vflag)
294 						(void)printf("%s\n",
295 						    p->fts_path);
296 					if (info) {
297 						info = 0;
298 						(void)printf("%s\n",
299 						    p->fts_path);
300 					}
301 					continue;
302 				}
303 				break;
304 
305 			case FTS_NS:
306 				/*
307 				 * Assume that since fts_read() couldn't stat
308 				 * the file, it can't be unlinked.
309 				 */
310 				if (fflag)
311 					continue;
312 				/* FALLTHROUGH */
313 
314 			case FTS_F:
315 			case FTS_NSOK:
316 				if (Pflag)
317 					if (!rm_overwrite(p->fts_accpath, p->fts_info ==
318 					    FTS_NSOK ? NULL : p->fts_statp))
319 						continue;
320 				/* FALLTHROUGH */
321 
322 			default:
323 				rval = unlink(p->fts_accpath);
324 				if (rval == 0 || (fflag && errno == ENOENT)) {
325 					if (rval == 0 && vflag)
326 						(void)printf("%s\n",
327 						    p->fts_path);
328 					if (rval == 0 && info) {
329 						info = 0;
330 						(void)printf("%s\n",
331 						    p->fts_path);
332 					}
333 					continue;
334 				}
335 			}
336 		}
337 err:
338 		warn("%s", p->fts_path);
339 		eval = 1;
340 	}
341 	if (!fflag && errno)
342 		err(1, "fts_read");
343 	fts_close(fts);
344 }
345 
346 static void
347 rm_file(char **argv)
348 {
349 	struct stat sb;
350 	int rval;
351 	char *f;
352 
353 	/*
354 	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
355 	 * to remove a directory is an error, so must always stat the file.
356 	 */
357 	while ((f = *argv++) != NULL) {
358 		/* Assume if can't stat the file, can't unlink it. */
359 		if (lstat(f, &sb)) {
360 			if (Wflag) {
361 				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
362 			} else {
363 				if (!fflag || errno != ENOENT) {
364 					warn("%s", f);
365 					eval = 1;
366 				}
367 				continue;
368 			}
369 		} else if (Wflag) {
370 			warnx("%s: %s", f, strerror(EEXIST));
371 			eval = 1;
372 			continue;
373 		}
374 
375 		if (S_ISDIR(sb.st_mode) && !dflag) {
376 			warnx("%s: is a directory", f);
377 			eval = 1;
378 			continue;
379 		}
380 		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
381 			continue;
382 		rval = 0;
383 		if (!uid && !S_ISWHT(sb.st_mode) &&
384 		    (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
385 		    !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
386 			rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
387 		if (rval == 0) {
388 			if (S_ISWHT(sb.st_mode))
389 				rval = undelete(f);
390 			else if (S_ISDIR(sb.st_mode))
391 				rval = rmdir(f);
392 			else {
393 				if (Pflag)
394 					if (!rm_overwrite(f, &sb))
395 						continue;
396 				rval = unlink(f);
397 			}
398 		}
399 		if (rval && (!fflag || errno != ENOENT)) {
400 			warn("%s", f);
401 			eval = 1;
402 		}
403 		if (vflag && rval == 0)
404 			(void)printf("%s\n", f);
405 		if (info && rval == 0) {
406 			info = 0;
407 			(void)printf("%s\n", f);
408 		}
409 	}
410 }
411 
412 /*
413  * rm_overwrite --
414  *	Overwrite the file 3 times with varying bit patterns.
415  *
416  * XXX
417  * This is a cheap way to *really* delete files.  Note that only regular
418  * files are deleted, directories (and therefore names) will remain.
419  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
420  * System V file system).  In a logging or COW file system, you'll have to
421  * have kernel support.
422  */
423 static int
424 rm_overwrite(const char *file, struct stat *sbp)
425 {
426 	struct stat sb, sb2;
427 	struct statfs fsb;
428 	off_t len;
429 	int bsize, fd, wlen;
430 	char *buf = NULL;
431 
432 	fd = -1;
433 	if (sbp == NULL) {
434 		if (lstat(file, &sb))
435 			goto err;
436 		sbp = &sb;
437 	}
438 	if (!S_ISREG(sbp->st_mode))
439 		return (1);
440 	if (sbp->st_nlink > 1 && !fflag) {
441 		warnx("%s (inode %ju): not overwritten due to multiple links",
442 		    file, (uintmax_t)sbp->st_ino);
443 		return (0);
444 	}
445 	if ((fd = open(file, O_WRONLY|O_NONBLOCK|O_NOFOLLOW, 0)) == -1)
446 		goto err;
447 	if (fstat(fd, &sb2))
448 		goto err;
449 	if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino ||
450 	    !S_ISREG(sb2.st_mode)) {
451 		errno = EPERM;
452 		goto err;
453 	}
454 	if (fstatfs(fd, &fsb) == -1)
455 		goto err;
456 	bsize = MAX(fsb.f_iosize, 1024);
457 	if ((buf = malloc(bsize)) == NULL)
458 		err(1, "%s: malloc", file);
459 
460 #define	PASS(byte) {							\
461 	memset(buf, byte, bsize);					\
462 	for (len = sbp->st_size; len > 0; len -= wlen) {		\
463 		wlen = len < bsize ? len : bsize;			\
464 		if (write(fd, buf, wlen) != wlen)			\
465 			goto err;					\
466 	}								\
467 }
468 	PASS(0xff);
469 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
470 		goto err;
471 	PASS(0x00);
472 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
473 		goto err;
474 	PASS(0xff);
475 	if (!fsync(fd) && !close(fd)) {
476 		free(buf);
477 		return (1);
478 	}
479 
480 err:	eval = 1;
481 	if (buf)
482 		free(buf);
483 	if (fd != -1)
484 		close(fd);
485 	warn("%s", file);
486 	return (0);
487 }
488 
489 
490 static int
491 check(const char *path, const char *name, struct stat *sp)
492 {
493 	int ch, first;
494 	char modep[15], *flagsp;
495 
496 	/* Check -i first. */
497 	if (iflag)
498 		(void)fprintf(stderr, "remove %s? ", path);
499 	else {
500 		/*
501 		 * If it's not a symbolic link and it's unwritable and we're
502 		 * talking to a terminal, ask.  Symbolic links are excluded
503 		 * because their permissions are meaningless.  Check stdin_ok
504 		 * first because we may not have stat'ed the file.
505 		 */
506 		if (!stdin_ok || S_ISLNK(sp->st_mode) ||
507 		    (!access(name, W_OK) &&
508 		    !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
509 		    (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
510 			return (1);
511 		strmode(sp->st_mode, modep);
512 		if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
513 			err(1, "fflagstostr");
514 		if (Pflag)
515 			errx(1,
516 			    "%s: -P was specified, but file is not writable",
517 			    path);
518 		(void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
519 		    modep + 1, modep[9] == ' ' ? "" : " ",
520 		    user_from_uid(sp->st_uid, 0),
521 		    group_from_gid(sp->st_gid, 0),
522 		    *flagsp ? flagsp : "", *flagsp ? " " : "",
523 		    path);
524 		free(flagsp);
525 	}
526 	(void)fflush(stderr);
527 
528 	first = ch = getchar();
529 	while (ch != '\n' && ch != EOF)
530 		ch = getchar();
531 	return (first == 'y' || first == 'Y');
532 }
533 
534 #define ISSLASH(a)	((a)[0] == '/' && (a)[1] == '\0')
535 static void
536 checkslash(char **argv)
537 {
538 	char **t, **u;
539 	int complained;
540 
541 	complained = 0;
542 	for (t = argv; *t;) {
543 		if (ISSLASH(*t)) {
544 			if (!complained++)
545 				warnx("\"/\" may not be removed");
546 			eval = 1;
547 			for (u = t; u[0] != NULL; ++u)
548 				u[0] = u[1];
549 		} else {
550 			++t;
551 		}
552 	}
553 }
554 
555 static int
556 check2(char **argv)
557 {
558 	struct stat st;
559 	int first;
560 	int ch;
561 	int fcount = 0;
562 	int dcount = 0;
563 	int i;
564 	const char *dname = NULL;
565 
566 	for (i = 0; argv[i]; ++i) {
567 		if (lstat(argv[i], &st) == 0) {
568 			if (S_ISDIR(st.st_mode)) {
569 				++dcount;
570 				dname = argv[i];    /* only used if 1 dir */
571 			} else {
572 				++fcount;
573 			}
574 		}
575 	}
576 	first = 0;
577 	while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
578 		if (dcount && rflag) {
579 			fprintf(stderr, "recursively remove");
580 			if (dcount == 1)
581 				fprintf(stderr, " %s", dname);
582 			else
583 				fprintf(stderr, " %d dirs", dcount);
584 			if (fcount == 1)
585 				fprintf(stderr, " and 1 file");
586 			else if (fcount > 1)
587 				fprintf(stderr, " and %d files", fcount);
588 		} else if (dcount + fcount > 3) {
589 			fprintf(stderr, "remove %d files", dcount + fcount);
590 		} else {
591 			return(1);
592 		}
593 		fprintf(stderr, "? ");
594 		fflush(stderr);
595 
596 		first = ch = getchar();
597 		while (ch != '\n' && ch != EOF)
598 			ch = getchar();
599 		if (ch == EOF)
600 			break;
601 	}
602 	return (first == 'y' || first == 'Y');
603 }
604 
605 #define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
606 static void
607 checkdot(char **argv)
608 {
609 	char *p, **save, **t;
610 	int complained;
611 
612 	complained = 0;
613 	for (t = argv; *t;) {
614 		if ((p = strrchr(*t, '/')) != NULL)
615 			++p;
616 		else
617 			p = *t;
618 		if (ISDOT(p)) {
619 			if (!complained++)
620 				warnx("\".\" and \"..\" may not be removed");
621 			eval = 1;
622 			for (save = t; (t[0] = t[1]) != NULL; ++t)
623 				continue;
624 			t = save;
625 		} else
626 			++t;
627 	}
628 }
629 
630 static void
631 usage(void)
632 {
633 
634 	(void)fprintf(stderr, "%s\n%s\n",
635 	    "usage: rm [-f | -i] [-dIPRrvWx] file ...",
636 	    "       unlink file");
637 	exit(EX_USAGE);
638 }
639 
640 static void
641 siginfo(int sig __unused)
642 {
643 
644 	info = 1;
645 }
646