xref: /dragonfly/bin/cp/utils.c (revision 25a2db75)
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  * 4. 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 #include <sys/param.h>
31 #include <sys/stat.h>
32 #include <sys/time.h>
33 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
34 #include <sys/mman.h>
35 #endif
36 
37 #include <err.h>
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <fts.h>
41 #include <limits.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <sysexits.h>
45 #include <unistd.h>
46 
47 #include "extern.h"
48 
49 #define	cp_pct(x, y)	((y == 0) ? 0 : (int)(100.0 * (x) / (y)))
50 
51 
52 int
53 copy_file(const FTSENT *entp, int dne)
54 {
55 	static char buf[MAXBSIZE];
56 	struct stat *fs;
57 	ssize_t wcount, rcount;
58 	size_t wresid;
59 	off_t wtotal;
60 	int ch, checkch, from_fd = 0, rval, to_fd = 0;
61 	char *bufp;
62 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
63 	char *p;
64 #endif
65 
66 	if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
67 		warn("%s", entp->fts_path);
68 		return (1);
69 	}
70 
71 	fs = entp->fts_statp;
72 
73 	/*
74 	 * If the file exists and we're interactive, verify with the user.
75 	 * If the file DNE, set the mode to be the from file, minus setuid
76 	 * bits, modified by the umask; arguably wrong, but it makes copying
77 	 * executables work right and it's been that way forever.  (The
78 	 * other choice is 666 or'ed with the execute bits on the from file
79 	 * modified by the umask.)
80 	 */
81 	if (!dne) {
82 #define YESNO "(y/n [n]) "
83 		if (nflag) {
84 			if (vflag)
85 				printf("%s not overwritten\n", to.p_path);
86 			close(from_fd);
87 			return (0);
88 		} else if (iflag) {
89 			fprintf(stderr, "overwrite %s? %s",
90 					to.p_path, YESNO);
91 			checkch = ch = getchar();
92 			while (ch != '\n' && ch != EOF)
93 				ch = getchar();
94 			if (checkch != 'y' && checkch != 'Y') {
95 				close(from_fd);
96 				fprintf(stderr, "not overwritten\n");
97 				return (1);
98 			}
99 		}
100 
101 		if (fflag) {
102 		    /* remove existing destination file name,
103 		     * create a new file  */
104 		    unlink(to.p_path);
105 		    if (!lflag)
106 			to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
107 			    fs->st_mode & ~(S_ISUID | S_ISGID));
108 		} else {
109 		    if (!lflag)
110 			/* overwrite existing destination file name */
111 			    to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
112 		}
113 	} else {
114 		if (!lflag)
115 			to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
116 			    fs->st_mode & ~(S_ISUID | S_ISGID));
117 	}
118 
119 	if (to_fd == -1) {
120 		warn("%s", to.p_path);
121 		close(from_fd);
122 		return (1);
123 	}
124 
125 	rval = 0;
126 
127 	if (!lflag) {
128 	/*
129 		 * Mmap and write if less than 8M (the limit is so we don't totally
130 		 * trash memory on big files.  This is really a minor hack, but it
131 		 * wins some CPU back.
132 		 * Some filesystems, such as smbnetfs, don't support mmap,
133 		 * so this is a best-effort attempt.
134 	 */
135 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
136 		if (S_ISREG(fs->st_mode) && fs->st_size > 0 &&
137 		    fs->st_size <= 8 * 1024 * 1024 &&
138 		    (p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
139 		    MAP_SHARED, from_fd, (off_t)0)) != MAP_FAILED) {
140 			wtotal = 0;
141 			for (bufp = p, wresid = fs->st_size; ;
142 			    bufp += wcount, wresid -= (size_t)wcount) {
143 				wcount = write(to_fd, bufp, wresid);
144 				if (wcount <= 0)
145 					break;
146 				wtotal += wcount;
147 				if (info) {
148 					info = 0;
149 					fprintf(stderr,
150 					    "%s -> %s %3d%%\n",
151 					    entp->fts_path, to.p_path,
152 					    cp_pct(wtotal, fs->st_size));
153 				}
154 				if (wcount >= (ssize_t)wresid)
155 					break;
156 			}
157 			if (wcount != (ssize_t)wresid) {
158 				warn("%s", to.p_path);
159 				rval = 1;
160 			}
161 			/* Some systems don't unmap on close(2). */
162 			if (munmap(p, fs->st_size) < 0) {
163 				warn("%s", entp->fts_path);
164 				rval = 1;
165 			}
166 		} else
167 #endif
168 		{
169 			wtotal = 0;
170 			while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
171 				for (bufp = buf, wresid = rcount; ;
172 				    bufp += wcount, wresid -= wcount) {
173 					wcount = write(to_fd, bufp, wresid);
174 					if (wcount <= 0)
175 						break;
176 					wtotal += wcount;
177 					if (info) {
178 						info = 0;
179 						fprintf(stderr,
180 						    "%s -> %s %3d%%\n",
181 						    entp->fts_path, to.p_path,
182 						    cp_pct(wtotal, fs->st_size));
183 					}
184 					if (wcount >= (ssize_t)wresid)
185 						break;
186 				}
187 				if (wcount != (ssize_t)wresid) {
188 					warn("%s", to.p_path);
189 					rval = 1;
190 					break;
191 				}
192 			}
193 			if (rcount < 0) {
194 				warn("%s", entp->fts_path);
195 				rval = 1;
196 			}
197 		}
198 	} else {
199 		if (link(entp->fts_path, to.p_path)) {
200 			warn("%s", to.p_path);
201 			rval = 1;
202 		}
203 	}
204 
205 	/*
206 	 * Don't remove the target even after an error.  The target might
207 	 * not be a regular file, or its attributes might be important,
208 	 * or its contents might be irreplaceable.  It would only be safe
209 	 * to remove it if we created it and its length is 0.
210 	 */
211 
212 	if (!lflag) {
213 		if (pflag && setfile(fs, to_fd))
214 			rval = 1;
215 		if (close(to_fd)) {
216 			warn("%s", to.p_path);
217 			rval = 1;
218 		}
219 	}
220 
221 	close(from_fd);
222 
223 	return (rval);
224 }
225 
226 int
227 copy_link(const FTSENT *p, int exists)
228 {
229 	int len;
230 	char llink[PATH_MAX];
231 
232 	if ((len = readlink(p->fts_path, llink, sizeof(llink) - 1)) == -1) {
233 		warn("readlink: %s", p->fts_path);
234 		return (1);
235 	}
236 	llink[len] = '\0';
237 	if (exists && unlink(to.p_path)) {
238 		warn("unlink: %s", to.p_path);
239 		return (1);
240 	}
241 	if (symlink(llink, to.p_path)) {
242 		warn("symlink: %s", llink);
243 		return (1);
244 	}
245 	return (pflag ? setfile(p->fts_statp, -1) : 0);
246 }
247 
248 int
249 copy_fifo(struct stat *from_stat, int exists)
250 {
251 	if (exists && unlink(to.p_path)) {
252 		warn("unlink: %s", to.p_path);
253 		return (1);
254 	}
255 	if (mkfifo(to.p_path, from_stat->st_mode)) {
256 		warn("mkfifo: %s", to.p_path);
257 		return (1);
258 	}
259 	return (pflag ? setfile(from_stat, -1) : 0);
260 }
261 
262 int
263 copy_special(struct stat *from_stat, int exists)
264 {
265 	if (exists && unlink(to.p_path)) {
266 		warn("unlink: %s", to.p_path);
267 		return (1);
268 	}
269 	if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
270 		warn("mknod: %s", to.p_path);
271 		return (1);
272 	}
273 	return (pflag ? setfile(from_stat, -1) : 0);
274 }
275 
276 int
277 setfile(struct stat *fs, int fd)
278 {
279 	static struct timeval tv[2];
280 	struct stat ts;
281 	int rval, gotstat, islink, fdval;
282 
283 	rval = 0;
284 	fdval = fd != -1;
285 	islink = !fdval && S_ISLNK(fs->st_mode);
286 	fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
287 		       S_IRWXU | S_IRWXG | S_IRWXO;
288 
289 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
290 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
291 	if (islink ? lutimes(to.p_path, tv) : utimes(to.p_path, tv)) {
292 		warn("%sutimes: %s", islink ? "l" : "", to.p_path);
293 		rval = 1;
294 	}
295 	if (fdval ? fstat(fd, &ts) :
296 	    (islink ? lstat(to.p_path, &ts) : stat(to.p_path, &ts)))
297 		gotstat = 0;
298 	else {
299 		gotstat = 1;
300 		ts.st_mode &= S_ISUID | S_ISGID | S_ISVTX |
301 			      S_IRWXU | S_IRWXG | S_IRWXO;
302 	}
303 	/*
304 	 * Changing the ownership probably won't succeed, unless we're root
305 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
306 	 * the mode; current BSD behavior is to remove all setuid bits on
307 	 * chown.  If chown fails, lose setuid/setgid bits.
308 	 */
309 	if (!gotstat || fs->st_uid != ts.st_uid || fs->st_gid != ts.st_gid)
310 		if (fdval ? fchown(fd, fs->st_uid, fs->st_gid) :
311 		    (islink ? lchown(to.p_path, fs->st_uid, fs->st_gid) :
312 		    chown(to.p_path, fs->st_uid, fs->st_gid))) {
313 			if (errno != EPERM) {
314 				warn("chown: %s", to.p_path);
315 				rval = 1;
316 			}
317 			fs->st_mode &= ~(S_ISUID | S_ISGID);
318 		}
319 
320 	if (!gotstat || fs->st_mode != ts.st_mode)
321 		if (fdval ? fchmod(fd, fs->st_mode) :
322 		    (islink ? lchmod(to.p_path, fs->st_mode) :
323 		    chmod(to.p_path, fs->st_mode))) {
324 			warn("chmod: %s", to.p_path);
325 			rval = 1;
326 		}
327 
328 	if (!gotstat || fs->st_flags != ts.st_flags)
329 		if (fdval ?
330 		    fchflags(fd, fs->st_flags) :
331 		    (islink ? lchflags(to.p_path, fs->st_flags) :
332 		    chflags(to.p_path, fs->st_flags))) {
333 			warn("chflags: %s", to.p_path);
334 			rval = 1;
335 		}
336 
337 	return (rval);
338 }
339 
340 void
341 usage(void)
342 {
343 
344 	fprintf(stderr, "%s\n%s\n",
345 "usage: cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file target_file",
346 "       cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpvx] source_file ... "
347 "target_directory");
348 	exit(EX_USAGE);
349 }
350