xref: /openbsd/bin/chmod/chmod.c (revision a0f924b8)
1 /*	$OpenBSD: chmod.c,v 1.43 2018/09/16 02:44:06 millert Exp $	*/
2 /*	$NetBSD: chmod.c,v 1.12 1995/03/21 09:02:09 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1989, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/types.h>
34 #include <sys/stat.h>
35 
36 #include <err.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <fts.h>
40 #include <grp.h>
41 #include <limits.h>
42 #include <pwd.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 int ischflags, ischown, ischgrp, ischmod;
49 extern char *__progname;
50 
51 gid_t a_gid(const char *);
52 uid_t a_uid(const char *, int);
53 static void __dead usage(void);
54 
55 int
main(int argc,char * argv[])56 main(int argc, char *argv[])
57 {
58 	FTS *ftsp;
59 	FTSENT *p;
60 	void *set;
61 	unsigned long val;
62 	int oct;
63 	mode_t omode;
64 	int Hflag, Lflag, Rflag, ch, fflag, fts_options, hflag, rval, atflags;
65 	uid_t uid;
66 	gid_t gid;
67 	u_int32_t fclear, fset;
68 	char *ep, *mode, *cp, *flags;
69 
70 	if (strlen(__progname) > 2) {
71 		ischown = __progname[2] == 'o';
72 		ischgrp = __progname[2] == 'g';
73 		ischmod = __progname[2] == 'm';
74 		ischflags = __progname[2] == 'f';
75 	}
76 
77 	uid = (uid_t)-1;
78 	gid = (gid_t)-1;
79 	Hflag = Lflag = Rflag = fflag = hflag = 0;
80 	while ((ch = getopt(argc, argv, "HLPRXfghorstuwx")) != -1)
81 		switch (ch) {
82 		case 'H':
83 			Hflag = 1;
84 			Lflag = 0;
85 			break;
86 		case 'L':
87 			Lflag = 1;
88 			Hflag = 0;
89 			break;
90 		case 'P':
91 			Hflag = Lflag = 0;
92 			break;
93 		case 'R':
94 			Rflag = 1;
95 			break;
96 		case 'f':		/* no longer documented. */
97 			fflag = 1;
98 			break;
99 		case 'h':
100 			hflag = 1;
101 			break;
102 		/*
103 		 * If this is a symbolic mode argument rather than
104 		 * an option, we are done with option processing.
105 		 */
106 		case 'g': case 'o': case 'r': case 's':
107 		case 't': case 'u': case 'w': case 'X': case 'x':
108 			if (!ischmod)
109 				usage();
110 			/*
111 			 * If getopt() moved past the argument, back up.
112 			 * If the argument contains option letters before
113 			 * mode letters, setmode() will catch them.
114 			 */
115 			if (optind > 1) {
116 				cp = argv[optind - 1];
117 				if (cp[strlen(cp) - 1] == ch)
118 					--optind;
119 			}
120 			goto done;
121 		default:
122 			usage();
123 		}
124 done:
125 	argv += optind;
126 	argc -= optind;
127 
128 	if (argc < 2)
129 		usage();
130 
131 	/*
132 	 * We alter the symlink itself if doing -h or -RP, or
133 	 * if doing -RH and the symlink wasn't a command line arg.
134 	 */
135 	atflags = AT_SYMLINK_NOFOLLOW;
136 
137 	fts_options = FTS_PHYSICAL;
138 	if (Rflag) {
139 		if (hflag)
140 			errx(1,
141 		"the -R and -h options may not be specified together.");
142 		if (Hflag)
143 			fts_options |= FTS_COMFOLLOW;
144 		if (Lflag) {
145 			fts_options &= ~FTS_PHYSICAL;
146 			fts_options |= FTS_LOGICAL;
147 			atflags = 0;
148 		}
149 	} else if (!hflag) {
150 		fts_options |= FTS_COMFOLLOW;
151 		atflags = 0;
152 	}
153 
154 	if (ischflags) {
155 		if (pledge("stdio rpath fattr", NULL) == -1)
156 			err(1, "pledge");
157 
158 		flags = *argv;
159 		if (*flags >= '0' && *flags <= '7') {
160 			errno = 0;
161 			val = strtoul(flags, &ep, 8);
162 			if (val > UINT_MAX)
163 				errno = ERANGE;
164 			if (errno)
165 				err(1, "invalid flags: %s", flags);
166 			if (*ep)
167 				errx(1, "invalid flags: %s", flags);
168 			fset = val;
169 			oct = 1;
170 		} else {
171 			if (strtofflags(&flags, &fset, &fclear))
172 				errx(1, "invalid flag: %s", flags);
173 			fclear = ~fclear;
174 			oct = 0;
175 		}
176 	} else if (ischmod) {
177 		mode = *argv;
178 		if (*mode >= '0' && *mode <= '7') {
179 			errno = 0;
180 			val = strtoul(mode, &ep, 8);
181 			if (val > INT_MAX)
182 				errno = ERANGE;
183 			if (errno)
184 				err(1, "invalid file mode: %s", mode);
185 			if (*ep)
186 				errx(1, "invalid file mode: %s", mode);
187 			omode = val;
188 			oct = 1;
189 		} else {
190 			if ((set = setmode(mode)) == NULL)
191 				errx(1, "invalid file mode: %s", mode);
192 			oct = 0;
193 		}
194 	} else if (ischown) {
195 		/* Both UID and GID are given. */
196 		if ((cp = strchr(*argv, ':')) != NULL) {
197 			*cp++ = '\0';
198 			gid = a_gid(cp);
199 		}
200 		/*
201 		 * UID and GID are separated by a dot and UID exists.
202 		 * required for backwards compatibility pre-dating POSIX.2
203 		 * likely to stay here forever
204 		 */
205 		else if ((cp = strchr(*argv, '.')) != NULL &&
206 		    (uid = a_uid(*argv, 1)) == (uid_t)-1) {
207 			*cp++ = '\0';
208 			gid = a_gid(cp);
209 		}
210 		if (uid == (uid_t)-1)
211 			uid = a_uid(*argv, 0);
212 	} else
213 		gid = a_gid(*argv);
214 
215 	if ((ftsp = fts_open(++argv, fts_options, 0)) == NULL)
216 		err(1, NULL);
217 	for (rval = 0; (p = fts_read(ftsp)) != NULL;) {
218 		switch (p->fts_info) {
219 		case FTS_D:
220 			if (!Rflag)
221 				fts_set(ftsp, p, FTS_SKIP);
222 			if (ischmod)
223 				break;
224 			else
225 				continue;
226 		case FTS_DNR:			/* Warn, chmod, continue. */
227 			warnc(p->fts_errno, "%s", p->fts_path);
228 			rval = 1;
229 			break;
230 		case FTS_DP:			/* Already changed at FTS_D. */
231 			if (ischmod)
232 				continue;
233 			else
234 				break;
235 		case FTS_ERR:			/* Warn, continue. */
236 		case FTS_NS:
237 			warnc(p->fts_errno, "%s", p->fts_path);
238 			rval = 1;
239 			continue;
240 		case FTS_SL:			/* Ignore. */
241 		case FTS_SLNONE:
242 			/*
243 			 * The only symlinks that end up here are ones that
244 			 * don't point to anything or that loop and ones
245 			 * that we found doing a physical walk.
246 			 */
247 			if (!hflag && (fts_options & FTS_LOGICAL))
248 				continue;
249 			break;
250 		default:
251 			break;
252 		}
253 
254 		/*
255 		 * For -RH, the decision of how to handle symlinks depends
256 		 * on the level: follow it iff it's a command line arg.
257 		 */
258 		if (fts_options & FTS_COMFOLLOW) {
259 			atflags = p->fts_level == FTS_ROOTLEVEL ? 0 :
260 			    AT_SYMLINK_NOFOLLOW;
261 		}
262 
263 		if (ischmod) {
264 			if (!fchmodat(AT_FDCWD, p->fts_accpath, oct ? omode :
265 			    getmode(set, p->fts_statp->st_mode), atflags)
266 			    || fflag)
267 				continue;
268 		} else if (!ischflags) {
269 			if (!fchownat(AT_FDCWD, p->fts_accpath, uid, gid,
270 			    atflags) || fflag)
271 				continue;
272 		} else {
273 			if (!chflagsat(AT_FDCWD, p->fts_accpath, oct ? fset :
274 			    (p->fts_statp->st_flags | fset) & fclear, atflags))
275 				continue;
276 		}
277 
278 		/* error case */
279 		warn("%s", p->fts_path);
280 		rval = 1;
281 	}
282 	if (errno)
283 		err(1, "fts_read");
284 	fts_close(ftsp);
285 	return (rval);
286 }
287 
288 /*
289  * Given a UID or user name in a string, return the UID.  If an empty string
290  * was given, returns -1.  If silent is 0, exits on invalid user names/UIDs;
291  * otherwise, returns -1.
292  */
293 uid_t
a_uid(const char * s,int silent)294 a_uid(const char *s, int silent)
295 {
296 	const char *errstr;
297 	uid_t uid;
298 
299 	if (*s == '\0')			/* Argument was "[:.]gid". */
300 		return ((uid_t)-1);
301 
302 	/* User name was given. */
303 	if (uid_from_user(s, &uid) != -1)
304 		return (uid);
305 
306 	/* UID was given. */
307 	uid = (uid_t)strtonum(s, 0, UID_MAX, &errstr);
308 	if (errstr) {
309 		if (silent)
310 			return ((uid_t)-1);
311 		else
312 			errx(1, "user is %s: %s", errstr, s);
313 	}
314 
315 	return (uid);
316 }
317 
318 /*
319  * Given a GID or group name in a string, return the GID.  If an empty string
320  * was given, returns -1.  Exits on invalid user names/UIDs.
321  */
322 gid_t
a_gid(const char * s)323 a_gid(const char *s)
324 {
325 	const char *errstr;
326 	gid_t gid;
327 
328 	if (*s == '\0')			/* Argument was "uid[:.]". */
329 		return ((gid_t)-1);
330 
331 	/* Group name was given. */
332 	if (gid_from_group(s, &gid) != -1)
333 		return (gid);
334 
335 	/* GID was given. */
336 	gid = (gid_t)strtonum(s, 0, GID_MAX, &errstr);
337 	if (errstr)
338 		errx(1, "group is %s: %s", errstr, s);
339 
340 	return (gid);
341 }
342 
343 static void __dead
usage(void)344 usage(void)
345 {
346 	fprintf(stderr,
347 	    "usage: %s [-h] [-R [-H | -L | -P]] %s file ...\n",
348 	    __progname, ischmod ? "mode" : ischflags ? "flags" :
349 	    ischown ? "owner[:group]" : "group");
350 	if (ischown)
351 		fprintf(stderr,
352 		    "       %s [-h] [-R [-H | -L | -P]] :group file ...\n",
353 		    __progname);
354 	exit(1);
355 }
356