xref: /freebsd/bin/cp/utils.c (revision 0de89efe5c443f213c7ea28773ef2dc6cf3af2ed)
1 /*-
2  * Copyright (c) 1991, 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  *	$Id: utils.c,v 1.13 1997/02/22 14:01:34 peter Exp $
34  */
35 
36 #ifndef lint
37 static char const sccsid[] = "@(#)utils.c	8.3 (Berkeley) 4/1/94";
38 #endif /* not lint */
39 
40 #include <sys/param.h>
41 #include <sys/stat.h>
42 #include <sys/mman.h>
43 #include <sys/time.h>
44 
45 #include <err.h>
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <fts.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
53 
54 #include "extern.h"
55 
56 int
57 copy_file(entp, dne)
58 	FTSENT *entp;
59 	int dne;
60 {
61 	static char buf[MAXBSIZE];
62 	struct stat to_stat, *fs;
63 	int ch, checkch, from_fd, rcount, rval, to_fd, wcount;
64 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
65 	char *p;
66 #endif
67 
68 	if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
69 		warn("%s", entp->fts_path);
70 		return (1);
71 	}
72 
73 	fs = entp->fts_statp;
74 
75 	/*
76 	 * If the file exists and we're interactive, verify with the user.
77 	 * If the file DNE, set the mode to be the from file, minus setuid
78 	 * bits, modified by the umask; arguably wrong, but it makes copying
79 	 * executables work right and it's been that way forever.  (The
80 	 * other choice is 666 or'ed with the execute bits on the from file
81 	 * modified by the umask.)
82 	 */
83 	if (!dne) {
84 #define YESNO "(y/n [n]) "
85 		if (iflag) {
86 			(void)fprintf(stderr, "overwrite %s? %s",
87 					to.p_path, YESNO);
88 			checkch = ch = getchar();
89 			while (ch != '\n' && ch != EOF)
90 				ch = getchar();
91 			if (checkch != 'y' && checkch != 'Y') {
92 				(void)close(from_fd);
93 				(void)fprintf(stderr, "not overwritten\n");
94 				return (0);
95 			}
96 		}
97 
98 		if (fflag) {
99 		    /* remove existing destination file name,
100 		     * create a new file  */
101 		    (void)unlink(to.p_path);
102 		    to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
103 				 fs->st_mode & ~(S_ISUID | S_ISGID));
104 		} else
105 		    /* overwrite existing destination file name */
106 		    to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
107 	} else
108 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
109 		    fs->st_mode & ~(S_ISUID | S_ISGID));
110 
111 	if (to_fd == -1) {
112 		warn("%s", to.p_path);
113 		(void)close(from_fd);
114 		return (1);;
115 	}
116 
117 	rval = 0;
118 
119 	/*
120 	 * Mmap and write if less than 8M (the limit is so we don't totally
121 	 * trash memory on big files.  This is really a minor hack, but it
122 	 * wins some CPU back.
123 	 */
124 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
125 	if (fs->st_size <= 8 * 1048576) {
126 		if ((p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
127 		    MAP_SHARED, from_fd, (off_t)0)) == MAP_FAILED) {
128 			warn("%s", entp->fts_path);
129 			rval = 1;
130 		} else {
131 			if (write(to_fd, p, fs->st_size) != fs->st_size) {
132 				warn("%s", to.p_path);
133 				rval = 1;
134 			}
135 			/* Some systems don't unmap on close(2). */
136 			if (munmap(p, fs->st_size) < 0) {
137 				warn("%s", entp->fts_path);
138 				rval = 1;
139 			}
140 		}
141 	} else
142 #endif
143 	{
144 		while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
145 			wcount = write(to_fd, buf, rcount);
146 			if (rcount != wcount || wcount == -1) {
147 				warn("%s", to.p_path);
148 				rval = 1;
149 				break;
150 			}
151 		}
152 		if (rcount < 0) {
153 			warn("%s", entp->fts_path);
154 			rval = 1;
155 		}
156 	}
157 
158 	/*
159 	 * Don't remove the target even after an error.  The target might
160 	 * not be a regular file, or its attributes might be important,
161 	 * or its contents might be irreplacable.  It would only be safe
162 	 * to remove it if we created it and its length is 0.
163 	 */
164 
165 	if (pflag && setfile(fs, to_fd))
166 		rval = 1;
167 	/*
168 	 * If the source was setuid or setgid, lose the bits unless the
169 	 * copy is owned by the same user and group.
170 	 */
171 #define	RETAINBITS \
172 	(S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
173 	else if (fs->st_mode & (S_ISUID | S_ISGID) && fs->st_uid == myuid)
174 		if (fstat(to_fd, &to_stat)) {
175 			warn("%s", to.p_path);
176 			rval = 1;
177 		} else if (fs->st_gid == to_stat.st_gid &&
178 		    fchmod(to_fd, fs->st_mode & RETAINBITS & ~myumask)) {
179 			warn("%s", to.p_path);
180 			rval = 1;
181 		}
182 	(void)close(from_fd);
183 	if (close(to_fd)) {
184 		warn("%s", to.p_path);
185 		rval = 1;
186 	}
187 	return (rval);
188 }
189 
190 int
191 copy_link(p, exists)
192 	FTSENT *p;
193 	int exists;
194 {
195 	int len;
196 	char link[MAXPATHLEN];
197 
198 	if ((len = readlink(p->fts_path, link, sizeof(link))) == -1) {
199 		warn("readlink: %s", p->fts_path);
200 		return (1);
201 	}
202 	link[len] = '\0';
203 	if (exists && unlink(to.p_path)) {
204 		warn("unlink: %s", to.p_path);
205 		return (1);
206 	}
207 	if (symlink(link, to.p_path)) {
208 		warn("symlink: %s", link);
209 		return (1);
210 	}
211 	return (0);
212 }
213 
214 int
215 copy_fifo(from_stat, exists)
216 	struct stat *from_stat;
217 	int exists;
218 {
219 	if (exists && unlink(to.p_path)) {
220 		warn("unlink: %s", to.p_path);
221 		return (1);
222 	}
223 	if (mkfifo(to.p_path, from_stat->st_mode)) {
224 		warn("mkfifo: %s", to.p_path);
225 		return (1);
226 	}
227 	return (pflag ? setfile(from_stat, 0) : 0);
228 }
229 
230 int
231 copy_special(from_stat, exists)
232 	struct stat *from_stat;
233 	int exists;
234 {
235 	if (exists && unlink(to.p_path)) {
236 		warn("unlink: %s", to.p_path);
237 		return (1);
238 	}
239 	if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
240 		warn("mknod: %s", to.p_path);
241 		return (1);
242 	}
243 	return (pflag ? setfile(from_stat, 0) : 0);
244 }
245 
246 
247 int
248 setfile(fs, fd)
249 	register struct stat *fs;
250 	int fd;
251 {
252 	static struct timeval tv[2];
253 	int rval;
254 
255 	rval = 0;
256 	fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
257 		       S_IRWXU | S_IRWXG | S_IRWXO;
258 
259 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
260 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
261 	if (utimes(to.p_path, tv)) {
262 		warn("utimes: %s", to.p_path);
263 		rval = 1;
264 	}
265 	/*
266 	 * Changing the ownership probably won't succeed, unless we're root
267 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
268 	 * the mode; current BSD behavior is to remove all setuid bits on
269 	 * chown.  If chown fails, lose setuid/setgid bits.
270 	 */
271 	if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
272 	    chown(to.p_path, fs->st_uid, fs->st_gid)) {
273 		if (errno != EPERM) {
274 			warn("chown: %s", to.p_path);
275 			rval = 1;
276 		}
277 		fs->st_mode &= ~(S_ISUID | S_ISGID);
278 	}
279 	if (fd ? fchmod(fd, fs->st_mode) : chmod(to.p_path, fs->st_mode)) {
280 		warn("chown: %s", to.p_path);
281 		rval = 1;
282 	}
283 
284 	if (fd ?
285 	    fchflags(fd, fs->st_flags) : chflags(to.p_path, fs->st_flags)) {
286 		warn("chflags: %s", to.p_path);
287 		rval = 1;
288 	}
289 	return (rval);
290 }
291 
292 void
293 usage()
294 {
295 	(void)fprintf(stderr, "%s\n%s\n",
296 "usage: cp [-R [-H | -L | -P]] [-f | -i] [-p] src target",
297 "       cp [-R [-H | -L | -P]] [-f | -i] [-p] src1 ... srcN directory");
298 	exit(1);
299 }
300