xref: /freebsd/usr.sbin/chown/chown.c (revision 264104f26834fdb27974e0c5fdedf8f2f5a90383)
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  * 3. 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 <signal.h>
56 #include <stdint.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 static void	a_gid(const char *);
63 static void	a_uid(const char *);
64 static void	chownerr(const char *);
65 static uid_t	id(const char *, const char *);
66 static void	usage(void);
67 static void	print_info(const FTSENT *, int);
68 
69 static uid_t uid;
70 static gid_t gid;
71 static int ischown;
72 static const char *gname;
73 static volatile sig_atomic_t siginfo;
74 
75 static void
76 siginfo_handler(int sig __unused)
77 {
78 
79 	siginfo = 1;
80 }
81 
82 int
83 main(int argc, char **argv)
84 {
85 	FTS *ftsp;
86 	FTSENT *p;
87 	int Hflag, Lflag, Rflag, fflag, hflag, vflag, xflag;
88 	int ch, fts_options, rval;
89 	char *cp;
90 
91 	ischown = (strcmp(basename(argv[0]), "chown") == 0);
92 
93 	Hflag = Lflag = Rflag = fflag = hflag = vflag = xflag = 0;
94 	while ((ch = getopt(argc, argv, "HLPRfhvx")) != -1)
95 		switch (ch) {
96 		case 'H':
97 			Hflag = 1;
98 			Lflag = 0;
99 			break;
100 		case 'L':
101 			Lflag = 1;
102 			Hflag = 0;
103 			break;
104 		case 'P':
105 			Hflag = Lflag = 0;
106 			break;
107 		case 'R':
108 			Rflag = 1;
109 			break;
110 		case 'f':
111 			fflag = 1;
112 			break;
113 		case 'h':
114 			hflag = 1;
115 			break;
116 		case 'v':
117 			vflag++;
118 			break;
119 		case 'x':
120 			xflag = 1;
121 			break;
122 		case '?':
123 		default:
124 			usage();
125 		}
126 	argv += optind;
127 	argc -= optind;
128 
129 	if (argc < 2)
130 		usage();
131 
132 	(void)signal(SIGINFO, siginfo_handler);
133 
134 	if (Rflag) {
135 		if (hflag && (Hflag || Lflag))
136 			errx(1, "the -R%c and -h options may not be "
137 			    "specified together", Hflag ? 'H' : 'L');
138 		if (Lflag) {
139 			fts_options = FTS_LOGICAL;
140 		} else {
141 			fts_options = FTS_PHYSICAL;
142 
143 			if (Hflag) {
144 				fts_options |= FTS_COMFOLLOW;
145 			}
146 		}
147 	} else if (hflag) {
148 		fts_options = FTS_PHYSICAL;
149 	} else {
150 		fts_options = FTS_LOGICAL;
151 	}
152 
153 	if (xflag)
154 		fts_options |= FTS_XDEV;
155 
156 	uid = (uid_t)-1;
157 	gid = (gid_t)-1;
158 	if (ischown) {
159 		if ((cp = strchr(*argv, ':')) != NULL) {
160 			*cp++ = '\0';
161 			a_gid(cp);
162 		}
163 #ifdef SUPPORT_DOT
164 		else if ((cp = strchr(*argv, '.')) != NULL) {
165 			warnx("separation of user and group with a period is deprecated");
166 			*cp++ = '\0';
167 			a_gid(cp);
168 		}
169 #endif
170 		a_uid(*argv);
171 	} else
172 		a_gid(*argv);
173 
174 	if ((ftsp = fts_open(++argv, fts_options, NULL)) == NULL)
175 		err(1, NULL);
176 
177 	for (rval = 0; (p = fts_read(ftsp)) != NULL;) {
178 		int atflag;
179 
180 		if ((fts_options & FTS_LOGICAL) ||
181 		    ((fts_options & FTS_COMFOLLOW) &&
182 		    p->fts_level == FTS_ROOTLEVEL))
183 			atflag = 0;
184 		else
185 			atflag = AT_SYMLINK_NOFOLLOW;
186 
187 		switch (p->fts_info) {
188 		case FTS_D:			/* Change it at FTS_DP. */
189 			if (!Rflag)
190 				fts_set(ftsp, p, FTS_SKIP);
191 			continue;
192 		case FTS_DNR:			/* Warn, chown. */
193 			warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
194 			rval = 1;
195 			break;
196 		case FTS_ERR:			/* Warn, continue. */
197 		case FTS_NS:
198 			warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
199 			rval = 1;
200 			continue;
201 		default:
202 			break;
203 		}
204 		if (siginfo) {
205 			print_info(p, 2);
206 			siginfo = 0;
207 		}
208 		if ((uid == (uid_t)-1 || uid == p->fts_statp->st_uid) &&
209 		    (gid == (gid_t)-1 || gid == p->fts_statp->st_gid))
210 			continue;
211 		if (fchownat(AT_FDCWD, p->fts_accpath, uid, gid, atflag)
212 		    == -1 && !fflag) {
213 			chownerr(p->fts_path);
214 			rval = 1;
215 		} else if (vflag)
216 			print_info(p, vflag);
217 	}
218 	if (errno)
219 		err(1, "fts_read");
220 	exit(rval);
221 }
222 
223 static void
224 a_gid(const char *s)
225 {
226 	struct group *gr;
227 
228 	if (*s == '\0')			/* Argument was "uid[:.]". */
229 		return;
230 	gname = s;
231 	gid = ((gr = getgrnam(s)) != NULL) ? gr->gr_gid : id(s, "group");
232 }
233 
234 static void
235 a_uid(const char *s)
236 {
237 	struct passwd *pw;
238 
239 	if (*s == '\0')			/* Argument was "[:.]gid". */
240 		return;
241 	uid = ((pw = getpwnam(s)) != NULL) ? pw->pw_uid : id(s, "user");
242 }
243 
244 static uid_t
245 id(const char *name, const char *type)
246 {
247 	uid_t val;
248 	char *ep;
249 
250 	/*
251 	 * XXX
252 	 * We know that uid_t's and gid_t's are unsigned longs.
253 	 */
254 	errno = 0;
255 	val = strtoul(name, &ep, 10);
256 	if (errno || *ep != '\0')
257 		errx(1, "%s: illegal %s name", name, type);
258 	return (val);
259 }
260 
261 static void
262 chownerr(const char *file)
263 {
264 	static uid_t euid = -1;
265 	static int ngroups = -1;
266 	static long ngroups_max;
267 	gid_t *groups;
268 
269 	/* Check for chown without being root. */
270 	if (errno != EPERM || (uid != (uid_t)-1 &&
271 	    euid == (uid_t)-1 && (euid = geteuid()) != 0)) {
272 		warn("%s", file);
273 		return;
274 	}
275 
276 	/* Check group membership; kernel just returns EPERM. */
277 	if (gid != (gid_t)-1 && ngroups == -1 &&
278 	    euid == (uid_t)-1 && (euid = geteuid()) != 0) {
279 		ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1;
280 		if ((groups = malloc(sizeof(gid_t) * ngroups_max)) == NULL)
281 			err(1, "malloc");
282 		ngroups = getgroups(ngroups_max, groups);
283 		while (--ngroups >= 0 && gid != groups[ngroups]);
284 		free(groups);
285 		if (ngroups < 0) {
286 			warnx("you are not a member of group %s", gname);
287 			return;
288 		}
289 	}
290 	warn("%s", file);
291 }
292 
293 static void
294 usage(void)
295 {
296 
297 	if (ischown)
298 		(void)fprintf(stderr, "%s\n%s\n",
299 		    "usage: chown [-fhvx] [-R [-H | -L | -P]] owner[:group]"
300 		    " file ...",
301 		    "       chown [-fhvx] [-R [-H | -L | -P]] :group file ...");
302 	else
303 		(void)fprintf(stderr, "%s\n",
304 		    "usage: chgrp [-fhvx] [-R [-H | -L | -P]] group file ...");
305 	exit(1);
306 }
307 
308 static void
309 print_info(const FTSENT *p, int vflag)
310 {
311 
312 	printf("%s", p->fts_path);
313 	if (vflag > 1) {
314 		if (ischown) {
315 			printf(": %ju:%ju -> %ju:%ju",
316 			    (uintmax_t)p->fts_statp->st_uid,
317 			    (uintmax_t)p->fts_statp->st_gid,
318 			    (uid == (uid_t)-1) ?
319 			    (uintmax_t)p->fts_statp->st_uid : (uintmax_t)uid,
320 			    (gid == (gid_t)-1) ?
321 			    (uintmax_t)p->fts_statp->st_gid : (uintmax_t)gid);
322 		} else {
323 			printf(": %ju -> %ju", (uintmax_t)p->fts_statp->st_gid,
324 			    (gid == (gid_t)-1) ?
325 			    (uintmax_t)p->fts_statp->st_gid : (uintmax_t)gid);
326 		}
327 	}
328 	printf("\n");
329 }
330