xref: /freebsd/bin/cp/utils.c (revision 952d112864d8008aa87278a30a539d888a8493cd)
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  *	$Id$
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 		if (iflag) {
85 			(void)fprintf(stderr, "overwrite %s? ", to.p_path);
86 			checkch = ch = getchar();
87 			while (ch != '\n' && ch != EOF)
88 				ch = getchar();
89 			if (checkch != 'y' && checkch != 'Y') {
90 				(void)close(from_fd);
91 				return (0);
92 			}
93 		}
94 
95 		if (fflag) {
96 		    /* remove existing destination file name,
97 		     * create a new file  */
98 		    (void)unlink(to.p_path);
99 		    to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
100 				 fs->st_mode & ~(S_ISUID | S_ISGID));
101 		} else
102 		    /* overwrite existing destination file name */
103 		    to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
104 	} else
105 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
106 		    fs->st_mode & ~(S_ISUID | S_ISGID));
107 
108 	if (to_fd == -1) {
109 		warn("%s", to.p_path);
110 		(void)close(from_fd);
111 		return (1);;
112 	}
113 
114 	rval = 0;
115 
116 	/*
117 	 * Mmap and write if less than 8M (the limit is so we don't totally
118 	 * trash memory on big files.  This is really a minor hack, but it
119 	 * wins some CPU back.
120 	 */
121 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
122 	if (fs->st_size <= 8 * 1048576) {
123 		if ((p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
124 		    MAP_SHARED, from_fd, (off_t)0)) == MAP_FAILED) {
125 			warn("%s", entp->fts_path);
126 			rval = 1;
127 		} else {
128 			if (write(to_fd, p, fs->st_size) != fs->st_size) {
129 				warn("%s", to.p_path);
130 				rval = 1;
131 			}
132 			/* Some systems don't unmap on close(2). */
133 			if (munmap(p, fs->st_size) < 0) {
134 				warn("%s", entp->fts_path);
135 				rval = 1;
136 			}
137 		}
138 	} else
139 #endif
140 	{
141 		while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
142 			wcount = write(to_fd, buf, rcount);
143 			if (rcount != wcount || wcount == -1) {
144 				warn("%s", to.p_path);
145 				rval = 1;
146 				break;
147 			}
148 		}
149 		if (rcount < 0) {
150 			warn("%s", entp->fts_path);
151 			rval = 1;
152 		}
153 	}
154 
155 	/*
156 	 * Don't remove the target even after an error.  The target might
157 	 * not be a regular file, or its attributes might be important,
158 	 * or its contents might be irreplacable.  It would only be safe
159 	 * to remove it if we created it and its length is 0.
160 	 */
161 
162 	if (pflag && setfile(fs, to_fd))
163 		rval = 1;
164 	/*
165 	 * If the source was setuid or setgid, lose the bits unless the
166 	 * copy is owned by the same user and group.
167 	 */
168 #define	RETAINBITS \
169 	(S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
170 	else if (fs->st_mode & (S_ISUID | S_ISGID) && fs->st_uid == myuid)
171 		if (fstat(to_fd, &to_stat)) {
172 			warn("%s", to.p_path);
173 			rval = 1;
174 		} else if (fs->st_gid == to_stat.st_gid &&
175 		    fchmod(to_fd, fs->st_mode & RETAINBITS & ~myumask)) {
176 			warn("%s", to.p_path);
177 			rval = 1;
178 		}
179 	(void)close(from_fd);
180 	if (close(to_fd)) {
181 		warn("%s", to.p_path);
182 		rval = 1;
183 	}
184 	return (rval);
185 }
186 
187 int
188 copy_link(p, exists)
189 	FTSENT *p;
190 	int exists;
191 {
192 	int len;
193 	char link[MAXPATHLEN];
194 
195 	if ((len = readlink(p->fts_path, link, sizeof(link))) == -1) {
196 		warn("readlink: %s", p->fts_path);
197 		return (1);
198 	}
199 	link[len] = '\0';
200 	if (exists && unlink(to.p_path)) {
201 		warn("unlink: %s", to.p_path);
202 		return (1);
203 	}
204 	if (symlink(link, to.p_path)) {
205 		warn("symlink: %s", link);
206 		return (1);
207 	}
208 	return (0);
209 }
210 
211 int
212 copy_fifo(from_stat, exists)
213 	struct stat *from_stat;
214 	int exists;
215 {
216 	if (exists && unlink(to.p_path)) {
217 		warn("unlink: %s", to.p_path);
218 		return (1);
219 	}
220 	if (mkfifo(to.p_path, from_stat->st_mode)) {
221 		warn("mkfifo: %s", to.p_path);
222 		return (1);
223 	}
224 	return (pflag ? setfile(from_stat, 0) : 0);
225 }
226 
227 int
228 copy_special(from_stat, exists)
229 	struct stat *from_stat;
230 	int exists;
231 {
232 	if (exists && unlink(to.p_path)) {
233 		warn("unlink: %s", to.p_path);
234 		return (1);
235 	}
236 	if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
237 		warn("mknod: %s", to.p_path);
238 		return (1);
239 	}
240 	return (pflag ? setfile(from_stat, 0) : 0);
241 }
242 
243 
244 int
245 setfile(fs, fd)
246 	register struct stat *fs;
247 	int fd;
248 {
249 	static struct timeval tv[2];
250 	int rval;
251 
252 	rval = 0;
253 	fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
254 		       S_IRWXU | S_IRWXG | S_IRWXO;
255 
256 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
257 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
258 	if (utimes(to.p_path, tv)) {
259 		warn("utimes: %s", to.p_path);
260 		rval = 1;
261 	}
262 	/*
263 	 * Changing the ownership probably won't succeed, unless we're root
264 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
265 	 * the mode; current BSD behavior is to remove all setuid bits on
266 	 * chown.  If chown fails, lose setuid/setgid bits.
267 	 */
268 	if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
269 	    chown(to.p_path, fs->st_uid, fs->st_gid)) {
270 		if (errno != EPERM) {
271 			warn("chown: %s", to.p_path);
272 			rval = 1;
273 		}
274 		fs->st_mode &= ~(S_ISUID | S_ISGID);
275 	}
276 	if (fd ? fchmod(fd, fs->st_mode) : chmod(to.p_path, fs->st_mode)) {
277 		warn("chown: %s", to.p_path);
278 		rval = 1;
279 	}
280 
281 	if (fd ?
282 	    fchflags(fd, fs->st_flags) : chflags(to.p_path, fs->st_flags)) {
283 		warn("chflags: %s", to.p_path);
284 		rval = 1;
285 	}
286 	return (rval);
287 }
288 
289 void
290 usage()
291 {
292 	(void)fprintf(stderr, "%s\n%s\n",
293 "usage: cp [-R [-H | -L | -P]] [-f | -i] [-p] src target",
294 "       cp [-R [-H | -L | -P]] [-f | -i] [-p] src1 ... srcN directory");
295 	exit(1);
296 }
297