xref: /netbsd-src/bin/cp/utils.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /* $NetBSD: utils.c,v 1.27 2004/01/04 16:04:18 jschauma Exp $ */
2 
3 /*-
4  * Copyright (c) 1991, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)utils.c	8.3 (Berkeley) 4/1/94";
36 #else
37 __RCSID("$NetBSD: utils.c,v 1.27 2004/01/04 16:04:18 jschauma Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/mman.h>
42 #include <sys/param.h>
43 #include <sys/stat.h>
44 #include <sys/time.h>
45 
46 #include <err.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <fts.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 #include "extern.h"
56 
57 int
58 set_utimes(const char *file, struct stat *fs)
59 {
60     static struct timeval tv[2];
61 
62     TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
63     TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
64 
65     if (lutimes(file, tv)) {
66 	warn("lutimes: %s", file);
67 	return (1);
68     }
69     return (0);
70 }
71 
72 int
73 copy_file(FTSENT *entp, int dne)
74 {
75 	static char buf[MAXBSIZE];
76 	struct stat to_stat, *fs;
77 	int ch, checkch, from_fd, rcount, rval, to_fd, wcount;
78 	char *p;
79 
80 	if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
81 		warn("%s", entp->fts_path);
82 		return (1);
83 	}
84 
85 	fs = entp->fts_statp;
86 
87 	/*
88 	 * If the file exists and we're interactive, verify with the user.
89 	 * If the file DNE, set the mode to be the from file, minus setuid
90 	 * bits, modified by the umask; arguably wrong, but it makes copying
91 	 * executables work right and it's been that way forever.  (The
92 	 * other choice is 666 or'ed with the execute bits on the from file
93 	 * modified by the umask.)
94 	 */
95 	if (!dne) {
96 		if (iflag) {
97 			(void)fprintf(stderr, "overwrite %s? ", to.p_path);
98 			checkch = ch = getchar();
99 			while (ch != '\n' && ch != EOF)
100 				ch = getchar();
101 			if (checkch != 'y' && checkch != 'Y') {
102 				(void)close(from_fd);
103 				return (0);
104 			}
105 		}
106 		/* overwrite existing destination file name */
107 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
108 	} else
109 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
110 		    fs->st_mode & ~(S_ISUID | S_ISGID));
111 
112 	if (to_fd == -1 && fflag) {
113 		/*
114 		 * attempt to remove existing destination file name and
115 		 * create a new file
116 		 */
117 		(void)unlink(to.p_path);
118 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
119 			     fs->st_mode & ~(S_ISUID | S_ISGID));
120 	}
121 
122 	if (to_fd == -1) {
123 		warn("%s", to.p_path);
124 		(void)close(from_fd);
125 		return (1);
126 	}
127 
128 	rval = 0;
129 
130 	/*
131 	 * There's no reason to do anything other than close the file
132 	 * now if it's empty, so let's not bother.
133 	 */
134 
135 	if (fs->st_size > 0) {
136 
137 		/*
138 		 * Mmap and write if less than 8M (the limit is so
139 		 * we don't totally trash memory on big files).
140 		 * This is really a minor hack, but it wins some CPU back.
141 		 */
142 
143 		if (fs->st_size <= 8 * 1048576) {
144 			p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
145 			    MAP_FILE|MAP_SHARED, from_fd, (off_t)0);
146 			if (p == MAP_FAILED) {
147 				goto mmap_failed;
148 			} else {
149 				(void) madvise(p, (size_t)fs->st_size,
150 				     MADV_SEQUENTIAL);
151 				if (write(to_fd, p, fs->st_size) !=
152 				    fs->st_size) {
153 					warn("%s", to.p_path);
154 					rval = 1;
155 				}
156 				if (munmap(p, fs->st_size) < 0) {
157 					warn("%s", entp->fts_path);
158 					rval = 1;
159 				}
160 			}
161 		} else {
162 mmap_failed:
163 			while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
164 				wcount = write(to_fd, buf, rcount);
165 				if (rcount != wcount || wcount == -1) {
166 					warn("%s", to.p_path);
167 					rval = 1;
168 					break;
169 				}
170 			}
171 			if (rcount < 0) {
172 				warn("%s", entp->fts_path);
173 				rval = 1;
174 			}
175 		}
176 	}
177 
178 	if (rval == 1) {
179 		(void)close(from_fd);
180 		(void)close(to_fd);
181 		return (1);
182 	}
183 
184 	if (pflag && setfile(fs, to_fd))
185 		rval = 1;
186 	/*
187 	 * If the source was setuid or setgid, lose the bits unless the
188 	 * copy is owned by the same user and group.
189 	 */
190 #define	RETAINBITS \
191 	(S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
192 	else if (fs->st_mode & (S_ISUID | S_ISGID) && fs->st_uid == myuid) {
193 		if (fstat(to_fd, &to_stat)) {
194 			warn("%s", to.p_path);
195 			rval = 1;
196 		} else if (fs->st_gid == to_stat.st_gid &&
197 		    fchmod(to_fd, fs->st_mode & RETAINBITS & ~myumask)) {
198 			warn("%s", to.p_path);
199 			rval = 1;
200 		}
201 	}
202 	(void)close(from_fd);
203 	if (close(to_fd)) {
204 		warn("%s", to.p_path);
205 		rval = 1;
206 	}
207 	/* set the mod/access times now after close of the fd */
208 	if (pflag && set_utimes(to.p_path, fs)) {
209 	    rval = 1;
210 	}
211 	return (rval);
212 }
213 
214 int
215 copy_link(FTSENT *p, int exists)
216 {
217 	int len;
218 	char target[MAXPATHLEN];
219 
220 	if ((len = readlink(p->fts_path, target, sizeof(target)-1)) == -1) {
221 		warn("readlink: %s", p->fts_path);
222 		return (1);
223 	}
224 	target[len] = '\0';
225 	if (exists && unlink(to.p_path)) {
226 		warn("unlink: %s", to.p_path);
227 		return (1);
228 	}
229 	if (symlink(target, to.p_path)) {
230 		warn("symlink: %s", target);
231 		return (1);
232 	}
233 	return (pflag ? setfile(p->fts_statp, 0) : 0);
234 }
235 
236 int
237 copy_fifo(struct stat *from_stat, int exists)
238 {
239 	if (exists && unlink(to.p_path)) {
240 		warn("unlink: %s", to.p_path);
241 		return (1);
242 	}
243 	if (mkfifo(to.p_path, from_stat->st_mode)) {
244 		warn("mkfifo: %s", to.p_path);
245 		return (1);
246 	}
247 	return (pflag ? setfile(from_stat, 0) : 0);
248 }
249 
250 int
251 copy_special(struct stat *from_stat, int exists)
252 {
253 	if (exists && unlink(to.p_path)) {
254 		warn("unlink: %s", to.p_path);
255 		return (1);
256 	}
257 	if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
258 		warn("mknod: %s", to.p_path);
259 		return (1);
260 	}
261 	return (pflag ? setfile(from_stat, 0) : 0);
262 }
263 
264 
265 /*
266  * Function: setfile
267  *
268  * Purpose:
269  *   Set the owner/group/permissions for the "to" file to the information
270  *   in the stat structure.  If fd is zero, also call set_utimes() to set
271  *   the mod/access times.  If fd is non-zero, the caller must do a utimes
272  *   itself after close(fd).
273  */
274 int
275 setfile(struct stat *fs, int fd)
276 {
277 	int rval, islink;
278 
279 	rval = 0;
280 	islink = S_ISLNK(fs->st_mode);
281 	fs->st_mode &= S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;
282 
283 	/*
284 	 * Changing the ownership probably won't succeed, unless we're root
285 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
286 	 * the mode; current BSD behavior is to remove all setuid bits on
287 	 * chown.  If chown fails, lose setuid/setgid bits.
288 	 */
289 	if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
290 	    lchown(to.p_path, fs->st_uid, fs->st_gid)) {
291 		if (errno != EPERM) {
292 			warn("chown: %s", to.p_path);
293 			rval = 1;
294 		}
295 		fs->st_mode &= ~(S_ISUID | S_ISGID);
296 	}
297 	if (fd ? fchmod(fd, fs->st_mode) : lchmod(to.p_path, fs->st_mode)) {
298 		warn("chmod: %s", to.p_path);
299 		rval = 1;
300 	}
301 
302 	if (!islink) {
303 		/*
304 		 * XXX
305 		 * NFS doesn't support chflags; ignore errors unless
306 		 * there's reason to believe we're losing bits.
307 		 * (Note, this still won't be right if the server
308 		 * supports flags and we were trying to *remove* flags
309 		 * on a file that we copied, i.e., that we didn't create.)
310 		 */
311 		errno = 0;
312 		if (fd ? fchflags(fd, fs->st_flags) :
313 		    chflags(to.p_path, fs->st_flags))
314 			if (errno != EOPNOTSUPP || fs->st_flags != 0) {
315 				warn("chflags: %s", to.p_path);
316 				rval = 1;
317 			}
318 	}
319 	/* if fd is non-zero, caller must call set_utimes() after close() */
320 	if (fd == 0 && set_utimes(to.p_path, fs))
321 	    rval = 1;
322 	return (rval);
323 }
324 
325 void
326 usage(void)
327 {
328 	(void)fprintf(stderr,
329 	    "usage: %s [-R [-H | -L | -P]] [-f | -i] [-pv] src target\n"
330 	    "       %s [-R [-H | -L | -P]] [-f | -i] [-pv] src1 ... srcN directory\n",
331 	    getprogname(), getprogname());
332 	exit(1);
333 	/* NOTREACHED */
334 }
335