rm.c revision 59863 
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
35static 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
42static char sccsid[] = "@(#)rm.c	8.5 (Berkeley) 4/18/94";
43#else
44static const char rcsid[] =
45  "$FreeBSD: head/bin/rm/rm.c 59863 2000-05-01 18:34:36Z asmodai $";
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
63char	*getflags __P((u_long, char *));
64
65int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
66uid_t uid;
67
68int	check __P((char *, char *, struct stat *));
69void	checkdot __P((char **));
70void	rm_file __P((char **));
71void	rm_overwrite __P((char *, struct stat *));
72void	rm_tree __P((char **));
73void	usage __P((void));
74
75/*
76 * rm --
77 *	This rm is different from historic rm's, but is expected to match
78 *	POSIX 1003.2 behavior.  The most visible difference is that -f
79 *	has two specific effects now, ignore non-existent files and force
80 * 	file removal.
81 */
82int
83main(argc, argv)
84	int argc;
85	char *argv[];
86{
87	int ch, rflag;
88	char *p;
89
90	/*
91	 * Test for the special case where the utility is called as
92	 * "unlink", for which the functionality provided is greatly
93	 * simplified.
94	 */
95	if ((p = rindex(argv[0], '/')) == NULL)
96		p = argv[0];
97	else
98		++p;
99	if (strcmp(p, "unlink") == 0) {
100		if (argc == 2) {
101			rm_file(&argv[1]);
102			exit(eval);
103		} else
104			usage();
105	}
106
107	Pflag = rflag = 0;
108	while ((ch = getopt(argc, argv, "dfiPRrvW")) != -1)
109		switch(ch) {
110		case 'd':
111			dflag = 1;
112			break;
113		case 'f':
114			fflag = 1;
115			iflag = 0;
116			break;
117		case 'i':
118			fflag = 0;
119			iflag = 1;
120			break;
121		case 'P':
122			Pflag = 1;
123			break;
124		case 'R':
125		case 'r':			/* Compatibility. */
126			rflag = 1;
127			break;
128		case 'v':
129			vflag = 1;
130			break;
131		case 'W':
132			Wflag = 1;
133			break;
134		default:
135			usage();
136		}
137	argc -= optind;
138	argv += optind;
139
140	if (argc < 1) {
141		if (fflag)
142			return 0;
143		usage();
144	}
145
146	checkdot(argv);
147	uid = geteuid();
148
149	if (*argv) {
150		stdin_ok = isatty(STDIN_FILENO);
151
152		if (rflag)
153			rm_tree(argv);
154		else
155			rm_file(argv);
156	}
157
158	exit (eval);
159}
160
161void
162rm_tree(argv)
163	char **argv;
164{
165	FTS *fts;
166	FTSENT *p;
167	int needstat;
168	int flags;
169	int rval;
170
171	/*
172	 * Remove a file hierarchy.  If forcing removal (-f), or interactive
173	 * (-i) or can't ask anyway (stdin_ok), don't stat the file.
174	 */
175	needstat = !uid || (!fflag && !iflag && stdin_ok);
176
177	/*
178	 * If the -i option is specified, the user can skip on the pre-order
179	 * visit.  The fts_number field flags skipped directories.
180	 */
181#define	SKIPPED	1
182
183	flags = FTS_PHYSICAL;
184	if (!needstat)
185		flags |= FTS_NOSTAT;
186	if (Wflag)
187		flags |= FTS_WHITEOUT;
188	if (!(fts = fts_open(argv, flags, (int (*)())NULL)))
189		err(1, NULL);
190	while ((p = fts_read(fts)) != NULL) {
191		switch (p->fts_info) {
192		case FTS_DNR:
193			if (!fflag || p->fts_errno != ENOENT) {
194				warnx("%s: %s",
195				    p->fts_path, strerror(p->fts_errno));
196				eval = 1;
197			}
198			continue;
199		case FTS_ERR:
200			errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
201		case FTS_NS:
202			/*
203			 * FTS_NS: assume that if can't stat the file, it
204			 * can't be unlinked.
205			 */
206			if (!needstat)
207				break;
208			if (!fflag || p->fts_errno != ENOENT) {
209				warnx("%s: %s",
210				    p->fts_path, strerror(p->fts_errno));
211				eval = 1;
212			}
213			continue;
214		case FTS_D:
215			/* Pre-order: give user chance to skip. */
216			if (!fflag && !check(p->fts_path, p->fts_accpath,
217			    p->fts_statp)) {
218				(void)fts_set(fts, p, FTS_SKIP);
219				p->fts_number = SKIPPED;
220			}
221			else if (!uid &&
222				 (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
223				 !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
224				 chflags(p->fts_accpath,
225					 p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
226				goto err;
227			continue;
228		case FTS_DP:
229			/* Post-order: see if user skipped. */
230			if (p->fts_number == SKIPPED)
231				continue;
232			break;
233		default:
234			if (!fflag &&
235			    !check(p->fts_path, p->fts_accpath, p->fts_statp))
236				continue;
237		}
238
239		rval = 0;
240		if (!uid &&
241		    (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
242		    !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
243			rval = chflags(p->fts_accpath,
244				       p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
245		if (rval == 0) {
246			/*
247			 * If we can't read or search the directory, may still be
248			 * able to remove it.  Don't print out the un{read,search}able
249			 * message unless the remove fails.
250			 */
251			switch (p->fts_info) {
252			case FTS_DP:
253			case FTS_DNR:
254				rval = rmdir(p->fts_accpath);
255				if (rval == 0 || (fflag && errno == ENOENT)) {
256					if (rval == 0 && vflag)
257						(void)printf("%s\n",
258						    p->fts_accpath);
259					continue;
260				}
261				break;
262
263			case FTS_W:
264				rval = undelete(p->fts_accpath);
265				if (rval == 0 && (fflag && errno == ENOENT)) {
266					if (vflag)
267						(void)printf("%s\n",
268						    p->fts_accpath);
269					continue;
270				}
271				break;
272
273			default:
274				if (Pflag)
275					rm_overwrite(p->fts_accpath, NULL);
276				rval = unlink(p->fts_accpath);
277				if (rval == 0 || (fflag && errno == ENOENT)) {
278					if (rval == 0 && vflag)
279						(void)printf("%s\n",
280						    p->fts_accpath);
281					continue;
282				}
283			}
284		}
285err:
286		warn("%s", p->fts_path);
287		eval = 1;
288	}
289	if (errno)
290		err(1, "fts_read");
291}
292
293void
294rm_file(argv)
295	char **argv;
296{
297	struct stat sb;
298	int rval;
299	char *f;
300
301	/*
302	 * Remove a file.  POSIX 1003.2 states that, by default, attempting
303	 * to remove a directory is an error, so must always stat the file.
304	 */
305	while ((f = *argv++) != NULL) {
306		/* Assume if can't stat the file, can't unlink it. */
307		if (lstat(f, &sb)) {
308			if (Wflag) {
309				sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
310			} else {
311				if (!fflag || errno != ENOENT) {
312					warn("%s", f);
313					eval = 1;
314				}
315				continue;
316			}
317		} else if (Wflag) {
318			warnx("%s: %s", f, strerror(EEXIST));
319			eval = 1;
320			continue;
321		}
322
323		if (S_ISDIR(sb.st_mode) && !dflag) {
324			warnx("%s: is a directory", f);
325			eval = 1;
326			continue;
327		}
328		if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
329			continue;
330		rval = 0;
331		if (!uid &&
332		    (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
333		    !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
334			rval = chflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
335		if (rval == 0) {
336			if (S_ISWHT(sb.st_mode))
337				rval = undelete(f);
338			else if (S_ISDIR(sb.st_mode))
339				rval = rmdir(f);
340			else {
341				if (Pflag)
342					rm_overwrite(f, &sb);
343				rval = unlink(f);
344			}
345		}
346		if (rval && (!fflag || errno != ENOENT)) {
347			warn("%s", f);
348			eval = 1;
349		}
350		if (vflag && rval == 0)
351			(void)printf("%s\n", f);
352	}
353}
354
355/*
356 * rm_overwrite --
357 *	Overwrite the file 3 times with varying bit patterns.
358 *
359 * XXX
360 * This is a cheap way to *really* delete files.  Note that only regular
361 * files are deleted, directories (and therefore names) will remain.
362 * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
363 * System V file system).  In a logging file system, you'll have to have
364 * kernel support.
365 */
366void
367rm_overwrite(file, sbp)
368	char *file;
369	struct stat *sbp;
370{
371	struct stat sb;
372	struct statfs fsb;
373	off_t len;
374	int bsize, fd, wlen;
375	char *buf = NULL;
376
377	fd = -1;
378	if (sbp == NULL) {
379		if (lstat(file, &sb))
380			goto err;
381		sbp = &sb;
382	}
383	if (!S_ISREG(sbp->st_mode))
384		return;
385	if ((fd = open(file, O_WRONLY, 0)) == -1)
386		goto err;
387	if (fstatfs(fd, &fsb) == -1)
388		goto err;
389	bsize = MAX(fsb.f_iosize, 1024);
390	if ((buf = malloc(bsize)) == NULL)
391		err(1, "malloc");
392
393#define	PASS(byte) {							\
394	memset(buf, byte, bsize);					\
395	for (len = sbp->st_size; len > 0; len -= wlen) {		\
396		wlen = len < bsize ? len : bsize;			\
397		if (write(fd, buf, wlen) != wlen)			\
398			goto err;					\
399	}								\
400}
401	PASS(0xff);
402	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
403		goto err;
404	PASS(0x00);
405	if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
406		goto err;
407	PASS(0xff);
408	if (!fsync(fd) && !close(fd)) {
409		free(buf);
410		return;
411	}
412
413err:	eval = 1;
414	if (buf)
415		free(buf);
416	warn("%s", file);
417}
418
419
420int
421check(path, name, sp)
422	char *path, *name;
423	struct stat *sp;
424{
425	int ch, first;
426	char modep[15], flagsp[128];
427
428	/* Check -i first. */
429	if (iflag)
430		(void)fprintf(stderr, "remove %s? ", path);
431	else {
432		/*
433		 * If it's not a symbolic link and it's unwritable and we're
434		 * talking to a terminal, ask.  Symbolic links are excluded
435		 * because their permissions are meaningless.  Check stdin_ok
436		 * first because we may not have stat'ed the file.
437		 */
438		if (!stdin_ok || S_ISLNK(sp->st_mode) ||
439		    (!access(name, W_OK) &&
440		    !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
441		    (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
442			return (1);
443		strmode(sp->st_mode, modep);
444		strcpy(flagsp, getflags(sp->st_flags, NULL));
445		if (*flagsp)
446			strcat(flagsp, " ");
447		(void)fprintf(stderr, "override %s%s%s/%s %sfor %s? ",
448		    modep + 1, modep[9] == ' ' ? "" : " ",
449		    user_from_uid(sp->st_uid, 0),
450		    group_from_gid(sp->st_gid, 0),
451		    *flagsp ? flagsp : "",
452		    path);
453	}
454	(void)fflush(stderr);
455
456	first = ch = getchar();
457	while (ch != '\n' && ch != EOF)
458		ch = getchar();
459	return (first == 'y' || first == 'Y');
460}
461
462#define ISDOT(a)	((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
463void
464checkdot(argv)
465	char **argv;
466{
467	char *p, **save, **t;
468	int complained;
469
470	complained = 0;
471	for (t = argv; *t;) {
472		if ((p = strrchr(*t, '/')) != NULL)
473			++p;
474		else
475			p = *t;
476		if (ISDOT(p)) {
477			if (!complained++)
478				warnx("\".\" and \"..\" may not be removed");
479			eval = 1;
480			for (save = t; (t[0] = t[1]) != NULL; ++t)
481				continue;
482			t = save;
483		} else
484			++t;
485	}
486}
487
488void
489usage()
490{
491
492	(void)fprintf(stderr, "%s\n%s\n",
493	    "usage: rm [-f | -i] [-dPRrvW] file ...",
494	    "       unlink file");
495	exit(EX_USAGE);
496}
497