xref: /freebsd/bin/rm/rm.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1990, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)rm.c	8.5 (Berkeley) 4/18/94";
43 #else
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif
47 #endif /* not lint */
48 
49 #include <sys/stat.h>
50 #include <sys/param.h>
51 #include <sys/mount.h>
52 
53 #include <err.h>
54 #include <errno.h>
55 #include <fcntl.h>
56 #include <fts.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <sysexits.h>
61 #include <unistd.h>
62 
63 int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
64 uid_t uid;
65 
66 int	check __P((char *, char *, struct stat *));
67 void	checkdot __P((char **));
68 void	rm_file __P((char **));
69 void	rm_overwrite __P((char *, struct stat *));
70 void	rm_tree __P((char **));
71 void	usage __P((void));
72 
73 /*
74  * rm --
75  *	This rm is different from historic rm's, but is expected to match
76  *	POSIX 1003.2 behavior.  The most visible difference is that -f
77  *	has two specific effects now, ignore non-existent files and force
78  * 	file removal.
79  */
80 int
81 main(argc, argv)
82 	int argc;
83 	char *argv[];
84 {
85 	int ch, rflag;
86 	char *p;
87 
88 	/*
89 	 * Test for the special case where the utility is called as
90 	 * "unlink", for which the functionality provided is greatly
91 	 * simplified.
92 	 */
93 	if ((p = rindex(argv[0], '/')) == NULL)
94 		p = argv[0];
95 	else
96 		++p;
97 	if (strcmp(p, "unlink") == 0) {
98 		if (argc == 2) {
99 			rm_file(&argv[1]);
100 			exit(eval);
101 		} else
102 			usage();
103 	}
104 
105 	Pflag = rflag = 0;
106 	while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
107 		switch(ch) {
108 		case 'd':
109 			dflag = 1;
110 			break;
111 		case 'f':
112 			fflag = 1;
113 			iflag = 0;
114 			break;
115 		case 'i':
116 			fflag = 0;
117 			iflag = 1;
118 			break;
119 		case 'P':
120 			Pflag = 1;
121 			break;
122 		case 'R':
123 		case 'r':			/* Compatibility. */
124 			rflag = 1;
125 			break;
126 		case 'v':
127 			vflag = 1;
128 			break;
129 		case 'W':
130 			Wflag = 1;
131 			break;
132 		default:
133 			usage();
134 		}
135 	argc -= optind;
136 	argv += optind;
137 
138 	if (argc < 1) {
139 		if (fflag)
140 			return 0;
141 		usage();
142 	}
143 
144 	checkdot(argv);
145 	uid = geteuid();
146 
147 	if (*argv) {
148 		stdin_ok = isatty(STDIN_FILENO);
149 
150 		if (rflag)
151 			rm_tree(argv);
152 		else
153 			rm_file(argv);
154 	}
155 
156 	exit (eval);
157 }
158 
159 void
160 rm_tree(argv)
161 	char **argv;
162 {
163 	FTS *fts;
164 	FTSENT *p;
165 	int needstat;
166 	int flags;
167 	int rval;
168 
169 	/*
170 	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
171 	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
172 	 */
173 	needstat = !uid || (!fflag && !iflag && stdin_ok);
174 
175 	/*
176 	 * If the -i option is specified, the user can skip on the pre-order
177 	 * visit.  The fts_number field flags skipped directories.
178 	 */
179 #define	SKIPPED	1
180 
181 	flags = FTS_PHYSICAL;
182 	if (!needstat)
183 		flags |= FTS_NOSTAT;
184 	if (Wflag)
185 		flags |= FTS_WHITEOUT;
186 	if (!(fts = fts_open(argv, flags, (int (*)())NULL)))
187 		err(1, NULL);
188 	while ((p = fts_read(fts)) != NULL) {
189 		switch (p->fts_info) {
190 		case FTS_DNR:
191 			if (!fflag || p->fts_errno != ENOENT) {
192 				warnx("%s: %s",
193 				    p->fts_path, strerror(p->fts_errno));
194 				eval = 1;
195 			}
196 			continue;
197 		case FTS_ERR:
198 			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
199 		case FTS_NS:
200 			/*
201 			 * FTS_NS: assume that if can't stat the file, it
202 			 * can't be unlinked.
203 			 */
204 			if (!needstat)
205 				break;
206 			if (!fflag || p->fts_errno != ENOENT) {
207 				warnx("%s: %s",
208 				    p->fts_path, strerror(p->fts_errno));
209 				eval = 1;
210 			}
211 			continue;
212 		case FTS_D:
213 			/* Pre-order: give user chance to skip. */
214 			if (!fflag && !check(p->fts_path, p->fts_accpath,
215 			    p->fts_statp)) {
216 				(void)fts_set(fts, p, FTS_SKIP);
217 				p->fts_number = SKIPPED;
218 			}
219 			else if (!uid &&
220 				 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
221 				 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
222 				 chflags(p->fts_accpath,
223 					 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
224 				goto err;
225 			continue;
226 		case FTS_DP:
227 			/* Post-order: see if user skipped. */
228 			if (p->fts_number == SKIPPED)
229 				continue;
230 			break;
231 		default:
232 			if (!fflag &&
233 			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
234 				continue;
235 		}
236 
237 		rval = 0;
238 		if (!uid &&
239 		    (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
240 		    !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
241 			rval = chflags(p->fts_accpath,
242 				       p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
243 		if (rval == 0) {
244 			/*
245 			 * If we can't read or search the directory, may still be
246 			 * able to remove it.  Don't print out the un{read,search}able
247 			 * message unless the remove fails.
248 			 */
249 			switch (p->fts_info) {
250 			case FTS_DP:
251 			case FTS_DNR:
252 				rval = rmdir(p->fts_accpath);
253 				if (rval == 0 || (fflag && errno == ENOENT)) {
254 					if (rval == 0 && vflag)
255 						(void)printf("%s\n",
256 						    p->fts_accpath);
257 					continue;
258 				}
259 				break;
260 
261 			case FTS_W:
262 				rval = undelete(p->fts_accpath);
263 				if (rval == 0 && (fflag && errno == ENOENT)) {
264 					if (vflag)
265 						(void)printf("%s\n",
266 						    p->fts_accpath);
267 					continue;
268 				}
269 				break;
270 
271 			default:
272 				if (Pflag)
273 					rm_overwrite(p->fts_accpath, NULL);
274 				rval = unlink(p->fts_accpath);
275 				if (rval == 0 || (fflag && errno == ENOENT)) {
276 					if (rval == 0 && vflag)
277 						(void)printf("%s\n",
278 						    p->fts_accpath);
279 					continue;
280 				}
281 			}
282 		}
283 err:
284 		warn("%s", p->fts_path);
285 		eval = 1;
286 	}
287 	if (errno)
288 		err(1, "fts_read");
289 }
290 
291 void
292 rm_file(argv)
293 	char **argv;
294 {
295 	struct stat sb;
296 	int rval;
297 	char *f;
298 
299 	/*
300 	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
301 	 * to remove a directory is an error, so must always stat the file.
302 	 */
303 	while ((f = *argv++) != NULL) {
304 		/* Assume if can't stat the file, can't unlink it. */
305 		if (lstat(f, &sb)) {
306 			if (Wflag) {
307 				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
308 			} else {
309 				if (!fflag || errno != ENOENT) {
310 					warn("%s", f);
311 					eval = 1;
312 				}
313 				continue;
314 			}
315 		} else if (Wflag) {
316 			warnx("%s: %s", f, strerror(EEXIST));
317 			eval = 1;
318 			continue;
319 		}
320 
321 		if (S_ISDIR(sb.st_mode) && !dflag) {
322 			warnx("%s: is a directory", f);
323 			eval = 1;
324 			continue;
325 		}
326 		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
327 			continue;
328 		rval = 0;
329 		if (!uid &&
330 		    (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
331 		    !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
332 			rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
333 		if (rval == 0) {
334 			if (S_ISWHT(sb.st_mode))
335 				rval = undelete(f);
336 			else if (S_ISDIR(sb.st_mode))
337 				rval = rmdir(f);
338 			else {
339 				if (Pflag)
340 					rm_overwrite(f, &sb);
341 				rval = unlink(f);
342 			}
343 		}
344 		if (rval && (!fflag || errno != ENOENT)) {
345 			warn("%s", f);
346 			eval = 1;
347 		}
348 		if (vflag && rval == 0)
349 			(void)printf("%s\n", f);
350 	}
351 }
352 
353 /*
354  * rm_overwrite --
355  *	Overwrite the file 3 times with varying bit patterns.
356  *
357  * XXX
358  * This is a cheap way to *really* delete files.  Note that only regular
359  * files are deleted, directories (and therefore names) will remain.
360  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
361  * System V file system).  In a logging file system, you'll have to have
362  * kernel support.
363  */
364 void
365 rm_overwrite(file, sbp)
366 	char *file;
367 	struct stat *sbp;
368 {
369 	struct stat sb;
370 	struct statfs fsb;
371 	off_t len;
372 	int bsize, fd, wlen;
373 	char *buf = NULL;
374 
375 	fd = -1;
376 	if (sbp == NULL) {
377 		if (lstat(file, &sb))
378 			goto err;
379 		sbp = &sb;
380 	}
381 	if (!S_ISREG(sbp->st_mode))
382 		return;
383 	if ((fd = open(file, O_WRONLY, 0)) == -1)
384 		goto err;
385 	if (fstatfs(fd, &fsb) == -1)
386 		goto err;
387 	bsize = MAX(fsb.f_iosize, 1024);
388 	if ((buf = malloc(bsize)) == NULL)
389 		err(1, "malloc");
390 
391 #define	PASS(byte) {							\
392 	memset(buf, byte, bsize);					\
393 	for (len = sbp->st_size; len > 0; len -= wlen) {		\
394 		wlen = len < bsize ? len : bsize;			\
395 		if (write(fd, buf, wlen) != wlen)			\
396 			goto err;					\
397 	}								\
398 }
399 	PASS(0xff);
400 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
401 		goto err;
402 	PASS(0x00);
403 	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
404 		goto err;
405 	PASS(0xff);
406 	if (!fsync(fd) && !close(fd)) {
407 		free(buf);
408 		return;
409 	}
410 
411 err:	eval = 1;
412 	if (buf)
413 		free(buf);
414 	warn("%s", file);
415 }
416 
417 
418 int
419 check(path, name, sp)
420 	char *path, *name;
421 	struct stat *sp;
422 {
423 	int ch, first;
424 	char modep[15], *flagsp;
425 
426 	/* Check -i first. */
427 	if (iflag)
428 		(void)fprintf(stderr, "remove %s? ", path);
429 	else {
430 		/*
431 		 * If it's not a symbolic link and it's unwritable and we're
432 		 * talking to a terminal, ask.  Symbolic links are excluded
433 		 * because their permissions are meaningless.  Check stdin_ok
434 		 * first because we may not have stat'ed the file.
435 		 */
436 		if (!stdin_ok || S_ISLNK(sp->st_mode) ||
437 		    (!access(name, W_OK) &&
438 		    !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
439 		    (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
440 			return (1);
441 		strmode(sp->st_mode, modep);
442 		if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
443 			err(1, NULL);
444 		(void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
445 		    modep + 1, modep[9] == ' ' ? "" : " ",
446 		    user_from_uid(sp->st_uid, 0),
447 		    group_from_gid(sp->st_gid, 0),
448 		    *flagsp ? flagsp : "", *flagsp ? " " : "",
449 		    path);
450 		free(flagsp);
451 	}
452 	(void)fflush(stderr);
453 
454 	first = ch = getchar();
455 	while (ch != '\n' && ch != EOF)
456 		ch = getchar();
457 	return (first == 'y' || first == 'Y');
458 }
459 
460 #define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
461 void
462 checkdot(argv)
463 	char **argv;
464 {
465 	char *p, **save, **t;
466 	int complained;
467 
468 	complained = 0;
469 	for (t = argv; *t;) {
470 		if ((p = strrchr(*t, '/')) != NULL)
471 			++p;
472 		else
473 			p = *t;
474 		if (ISDOT(p)) {
475 			if (!complained++)
476 				warnx("\".\" and \"..\" may not be removed");
477 			eval = 1;
478 			for (save = t; (t[0] = t[1]) != NULL; ++t)
479 				continue;
480 			t = save;
481 		} else
482 			++t;
483 	}
484 }
485 
486 void
487 usage()
488 {
489 
490 	(void)fprintf(stderr, "%s\n%s\n",
491 	    "usage: rm [-f | -i] [-dPRrvW] file ...",
492 	    "       unlink file");
493 	exit(EX_USAGE);
494 }
495