xref: /freebsd/usr.sbin/chown/chown.c (revision b9c36cc755002809a7d7c7109e3425fdfca036d2)
1 /*
2  * Copyright (c) 1988, 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) 1988, 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[] = "@(#)chown.c	8.8 (Berkeley) 4/4/94";
39 #endif /* not lint */
40 #endif
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/stat.h>
47 
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <fts.h>
52 #include <grp.h>
53 #include <libgen.h>
54 #include <pwd.h>
55 #include <stdint.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 
61 static void	a_gid(const char *);
62 static void	a_uid(const char *);
63 static void	chownerr(const char *);
64 static uid_t	id(const char *, const char *);
65 static void	usage(void);
66 
67 static uid_t uid;
68 static gid_t gid;
69 static int ischown;
70 static const char *gname;
71 
72 int
73 main(int argc, char **argv)
74 {
75 	FTS *ftsp;
76 	FTSENT *p;
77 	int Hflag, Lflag, Rflag, fflag, hflag, vflag, xflag;
78 	int ch, fts_options, rval;
79 	char *cp;
80 
81 	ischown = (strcmp(basename(argv[0]), "chown") == 0);
82 
83 	Hflag = Lflag = Rflag = fflag = hflag = vflag = xflag = 0;
84 	while ((ch = getopt(argc, argv, "HLPRfhvx")) != -1)
85 		switch (ch) {
86 		case 'H':
87 			Hflag = 1;
88 			Lflag = 0;
89 			break;
90 		case 'L':
91 			Lflag = 1;
92 			Hflag = 0;
93 			break;
94 		case 'P':
95 			Hflag = Lflag = 0;
96 			break;
97 		case 'R':
98 			Rflag = 1;
99 			break;
100 		case 'f':
101 			fflag = 1;
102 			break;
103 		case 'h':
104 			hflag = 1;
105 			break;
106 		case 'v':
107 			vflag++;
108 			break;
109 		case 'x':
110 			xflag = 1;
111 			break;
112 		case '?':
113 		default:
114 			usage();
115 		}
116 	argv += optind;
117 	argc -= optind;
118 
119 	if (argc < 2)
120 		usage();
121 
122 	if (Rflag) {
123 		if (hflag && (Hflag || Lflag))
124 			errx(1, "the -R%c and -h options may not be "
125 			    "specified together", Hflag ? 'H' : 'L');
126 		if (Lflag) {
127 			fts_options = FTS_LOGICAL;
128 		} else {
129 			fts_options = FTS_PHYSICAL;
130 
131 			if (Hflag) {
132 				fts_options |= FTS_COMFOLLOW;
133 			}
134 		}
135 	} else if (hflag) {
136 		fts_options = FTS_PHYSICAL;
137 	} else {
138 		fts_options = FTS_LOGICAL;
139 	}
140 
141 	if (xflag)
142 		fts_options |= FTS_XDEV;
143 
144 	uid = (uid_t)-1;
145 	gid = (gid_t)-1;
146 	if (ischown) {
147 		if ((cp = strchr(*argv, ':')) != NULL) {
148 			*cp++ = '\0';
149 			a_gid(cp);
150 		}
151 #ifdef SUPPORT_DOT
152 		else if ((cp = strchr(*argv, '.')) != NULL) {
153 			warnx("separation of user and group with a period is deprecated");
154 			*cp++ = '\0';
155 			a_gid(cp);
156 		}
157 #endif
158 		a_uid(*argv);
159 	} else
160 		a_gid(*argv);
161 
162 	if ((ftsp = fts_open(++argv, fts_options, NULL)) == NULL)
163 		err(1, NULL);
164 
165 	for (rval = 0; (p = fts_read(ftsp)) != NULL;) {
166 		int atflag;
167 
168 		if ((fts_options & FTS_LOGICAL) ||
169 		    ((fts_options & FTS_COMFOLLOW) &&
170 		    p->fts_level == FTS_ROOTLEVEL))
171 			atflag = 0;
172 		else
173 			atflag = AT_SYMLINK_NOFOLLOW;
174 
175 		switch (p->fts_info) {
176 		case FTS_D:			/* Change it at FTS_DP. */
177 			if (!Rflag)
178 				fts_set(ftsp, p, FTS_SKIP);
179 			continue;
180 		case FTS_DNR:			/* Warn, chown. */
181 			warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
182 			rval = 1;
183 			break;
184 		case FTS_ERR:			/* Warn, continue. */
185 		case FTS_NS:
186 			warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
187 			rval = 1;
188 			continue;
189 		default:
190 			break;
191 		}
192 		if ((uid == (uid_t)-1 || uid == p->fts_statp->st_uid) &&
193 		    (gid == (gid_t)-1 || gid == p->fts_statp->st_gid))
194 			continue;
195 		if (fchownat(AT_FDCWD, p->fts_accpath, uid, gid, atflag)
196 		    == -1 && !fflag) {
197 			chownerr(p->fts_path);
198 			rval = 1;
199 		} else if (vflag) {
200 			printf("%s", p->fts_path);
201 			if (vflag > 1) {
202 				if (ischown) {
203 					printf(": %ju:%ju -> %ju:%ju",
204 					    (uintmax_t)
205 					    p->fts_statp->st_uid,
206 					    (uintmax_t)
207 					    p->fts_statp->st_gid,
208 					    (uid == (uid_t)-1) ?
209 					    (uintmax_t)
210 					    p->fts_statp->st_uid :
211 					    (uintmax_t)uid,
212 					    (gid == (gid_t)-1) ?
213 					    (uintmax_t)
214 					    p->fts_statp->st_gid :
215 					    (uintmax_t)gid);
216 				} else {
217 					printf(": %ju -> %ju",
218 					    (uintmax_t)
219 					    p->fts_statp->st_gid,
220 					    (gid == (gid_t)-1) ?
221 					    (uintmax_t)
222 					    p->fts_statp->st_gid :
223 					    (uintmax_t)gid);
224 				}
225 			}
226 			printf("\n");
227 		}
228 	}
229 	if (errno)
230 		err(1, "fts_read");
231 	exit(rval);
232 }
233 
234 static void
235 a_gid(const char *s)
236 {
237 	struct group *gr;
238 
239 	if (*s == '\0')			/* Argument was "uid[:.]". */
240 		return;
241 	gname = s;
242 	gid = ((gr = getgrnam(s)) != NULL) ? gr->gr_gid : id(s, "group");
243 }
244 
245 static void
246 a_uid(const char *s)
247 {
248 	struct passwd *pw;
249 
250 	if (*s == '\0')			/* Argument was "[:.]gid". */
251 		return;
252 	uid = ((pw = getpwnam(s)) != NULL) ? pw->pw_uid : id(s, "user");
253 }
254 
255 static uid_t
256 id(const char *name, const char *type)
257 {
258 	uid_t val;
259 	char *ep;
260 
261 	/*
262 	 * XXX
263 	 * We know that uid_t's and gid_t's are unsigned longs.
264 	 */
265 	errno = 0;
266 	val = strtoul(name, &ep, 10);
267 	if (errno || *ep != '\0')
268 		errx(1, "%s: illegal %s name", name, type);
269 	return (val);
270 }
271 
272 static void
273 chownerr(const char *file)
274 {
275 	static uid_t euid = -1;
276 	static int ngroups = -1;
277 	static long ngroups_max;
278 	gid_t *groups;
279 
280 	/* Check for chown without being root. */
281 	if (errno != EPERM || (uid != (uid_t)-1 &&
282 	    euid == (uid_t)-1 && (euid = geteuid()) != 0)) {
283 		warn("%s", file);
284 		return;
285 	}
286 
287 	/* Check group membership; kernel just returns EPERM. */
288 	if (gid != (gid_t)-1 && ngroups == -1 &&
289 	    euid == (uid_t)-1 && (euid = geteuid()) != 0) {
290 		ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1;
291 		if ((groups = malloc(sizeof(gid_t) * ngroups_max)) == NULL)
292 			err(1, "malloc");
293 		ngroups = getgroups(ngroups_max, groups);
294 		while (--ngroups >= 0 && gid != groups[ngroups]);
295 		free(groups);
296 		if (ngroups < 0) {
297 			warnx("you are not a member of group %s", gname);
298 			return;
299 		}
300 	}
301 	warn("%s", file);
302 }
303 
304 static void
305 usage(void)
306 {
307 
308 	if (ischown)
309 		(void)fprintf(stderr, "%s\n%s\n",
310 		    "usage: chown [-fhvx] [-R [-H | -L | -P]] owner[:group]"
311 		    " file ...",
312 		    "       chown [-fhvx] [-R [-H | -L | -P]] :group file ...");
313 	else
314 		(void)fprintf(stderr, "%s\n",
315 		    "usage: chgrp [-fhvx] [-R [-H | -L | -P]] group file ...");
316 	exit(1);
317 }
318