xref: /netbsd-src/bin/cp/utils.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /* $NetBSD: utils.c,v 1.47 2019/09/23 18:01:09 christos 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 1.47 2019/09/23 18:01:09 christos 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 #include <sys/extattr.h>
46 
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <fts.h>
51 #include <stdbool.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include "extern.h"
58 
59 #define	MMAP_MAX_SIZE	(8 * 1048576)
60 #define	MMAP_MAX_WRITE	(64 * 1024)
61 
62 int
63 set_utimes(const char *file, struct stat *fs)
64 {
65     struct timespec ts[2];
66 
67     ts[0] = fs->st_atimespec;
68     ts[1] = fs->st_mtimespec;
69 
70     if (lutimens(file, ts)) {
71 	warn("lutimens: %s", file);
72 	return (1);
73     }
74     return (0);
75 }
76 
77 struct finfo {
78 	const char *from;
79 	const char *to;
80 	off_t size;
81 };
82 
83 static void
84 progress(const struct finfo *fi, off_t written)
85 {
86 	int pcent = (int)((100.0 * written) / fi->size);
87 
88 	pinfo = 0;
89 	(void)fprintf(stderr, "%s => %s %llu/%llu bytes %d%% written\n",
90 	    fi->from, fi->to, (unsigned long long)written,
91 	    (unsigned long long)fi->size, pcent);
92 }
93 
94 int
95 copy_file(FTSENT *entp, int dne)
96 {
97 	static char buf[MAXBSIZE];
98 	struct stat to_stat, *fs;
99 	int ch, checkch, from_fd, rcount, rval, to_fd, tolnk, wcount;
100 	char *p;
101 	off_t ptotal = 0;
102 
103 	/* if hard linking then simply link and return */
104 	if (lflag) {
105 		(void)unlink(to.p_path);
106 		if (link(entp->fts_path, to.p_path)) {
107 			warn("%s", to.p_path);
108 			return (1);
109 		}
110 		return (0);
111 	}
112 
113 	if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
114 		warn("%s", entp->fts_path);
115 		return (1);
116 	}
117 
118 	to_fd = -1;
119 	fs = entp->fts_statp;
120 	tolnk = ((Rflag && !(Lflag || Hflag)) || Pflag);
121 
122 	/*
123 	 * If the file exists and we're interactive, verify with the user.
124 	 * If the file DNE, set the mode to be the from file, minus setuid
125 	 * bits, modified by the umask; arguably wrong, but it makes copying
126 	 * executables work right and it's been that way forever.  (The
127 	 * other choice is 666 or'ed with the execute bits on the from file
128 	 * modified by the umask.)
129 	 */
130 	if (!dne) {
131 		struct stat sb;
132 		int sval;
133 
134 		if (iflag) {
135 			(void)fprintf(stderr, "overwrite %s? ", to.p_path);
136 			checkch = ch = getchar();
137 			while (ch != '\n' && ch != EOF)
138 				ch = getchar();
139 			if (checkch != 'y' && checkch != 'Y') {
140 				(void)close(from_fd);
141 				return (0);
142 			}
143 		}
144 
145 		sval = tolnk ?
146 			lstat(to.p_path, &sb) : stat(to.p_path, &sb);
147 		if (sval == -1) {
148 			warn("stat: %s", to.p_path);
149 			(void)close(from_fd);
150 			return (1);
151 		}
152 
153 		if (!(tolnk && S_ISLNK(sb.st_mode)))
154 			to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
155 	} else
156 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
157 		    fs->st_mode & ~(S_ISUID | S_ISGID));
158 
159 	if (to_fd == -1 && (fflag || tolnk)) {
160 		/*
161 		 * attempt to remove existing destination file name and
162 		 * create a new file
163 		 */
164 		(void)unlink(to.p_path);
165 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
166 			     fs->st_mode & ~(S_ISUID | S_ISGID));
167 	}
168 
169 	if (to_fd == -1) {
170 		warn("%s", to.p_path);
171 		(void)close(from_fd);
172 		return (1);
173 	}
174 
175 	rval = 0;
176 
177 	/*
178 	 * There's no reason to do anything other than close the file
179 	 * now if it's regular and empty, so let's not bother.
180 	 */
181 	bool need_copy = !S_ISREG(fs->st_mode) || fs->st_size > 0;
182 
183 	struct finfo fi;
184 
185 	fi.from = entp->fts_path;
186 	fi.to = to.p_path;
187 	fi.size = fs->st_size;
188 
189 	/*
190 	 * Mmap and write if less than 8M (the limit is so
191 	 * we don't totally trash memory on big files).
192 	 * This is really a minor hack, but it wins some CPU back.
193 	 */
194 	if (S_ISREG(fs->st_mode) && fs->st_size && fs->st_size <= MMAP_MAX_SIZE) {
195 		size_t fsize = (size_t)fs->st_size;
196 		p = mmap(NULL, fsize, PROT_READ, MAP_FILE|MAP_SHARED,
197 		    from_fd, (off_t)0);
198 		if (p != MAP_FAILED) {
199 			size_t remainder;
200 
201 			need_copy = false;
202 
203 			(void) madvise(p, (size_t)fs->st_size, MADV_SEQUENTIAL);
204 
205 			/*
206 			 * Write out the data in small chunks to
207 			 * avoid locking the output file for a
208 			 * long time if the reading the data from
209 			 * the source is slow.
210 			 */
211 			remainder = fsize;
212 			do {
213 				ssize_t chunk;
214 
215 				chunk = (remainder > MMAP_MAX_WRITE) ?
216 				    MMAP_MAX_WRITE : remainder;
217 				if (write(to_fd, &p[fsize - remainder],
218 				    chunk) != chunk) {
219 					warn("%s", to.p_path);
220 					rval = 1;
221 					break;
222 				}
223 				remainder -= chunk;
224 				ptotal += chunk;
225 				if (pinfo)
226 					progress(&fi, ptotal);
227 			} while (remainder > 0);
228 
229 			if (munmap(p, fsize) < 0) {
230 				warn("%s", entp->fts_path);
231 				rval = 1;
232 			}
233 		}
234 	}
235 
236 	if (need_copy) {
237 		while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
238 			wcount = write(to_fd, buf, (size_t)rcount);
239 			if (rcount != wcount || wcount == -1) {
240 				warn("%s", to.p_path);
241 				rval = 1;
242 				break;
243 			}
244 			ptotal += wcount;
245 			if (pinfo)
246 				progress(&fi, ptotal);
247 		}
248 		if (rcount < 0) {
249 			warn("%s", entp->fts_path);
250 			rval = 1;
251 		}
252 	}
253 
254 	if (pflag && (fcpxattr(from_fd, to_fd) != 0))
255 		warn("%s: error copying extended attributes", to.p_path);
256 
257 	(void)close(from_fd);
258 
259 	if (rval == 1) {
260 		(void)close(to_fd);
261 		return (1);
262 	}
263 
264 	if (pflag && setfile(fs, to_fd))
265 		rval = 1;
266 	/*
267 	 * If the source was setuid or setgid, lose the bits unless the
268 	 * copy is owned by the same user and group.
269 	 */
270 #define	RETAINBITS \
271 	(S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
272 	if (!pflag && dne
273 	    && fs->st_mode & (S_ISUID | S_ISGID) && fs->st_uid == myuid) {
274 		if (fstat(to_fd, &to_stat)) {
275 			warn("%s", to.p_path);
276 			rval = 1;
277 		} else if (fs->st_gid == to_stat.st_gid &&
278 		    fchmod(to_fd, fs->st_mode & RETAINBITS & ~myumask)) {
279 			warn("%s", to.p_path);
280 			rval = 1;
281 		}
282 	}
283 	if (close(to_fd)) {
284 		warn("%s", to.p_path);
285 		rval = 1;
286 	}
287 	/* set the mod/access times now after close of the fd */
288 	if (pflag && set_utimes(to.p_path, fs)) {
289 	    rval = 1;
290 	}
291 	return (rval);
292 }
293 
294 int
295 copy_link(FTSENT *p, int exists)
296 {
297 	int len;
298 	char target[MAXPATHLEN];
299 
300 	if ((len = readlink(p->fts_path, target, sizeof(target)-1)) == -1) {
301 		warn("readlink: %s", p->fts_path);
302 		return (1);
303 	}
304 	target[len] = '\0';
305 	if (exists && unlink(to.p_path)) {
306 		warn("unlink: %s", to.p_path);
307 		return (1);
308 	}
309 	if (symlink(target, to.p_path)) {
310 		warn("symlink: %s", target);
311 		return (1);
312 	}
313 	return (pflag ? setfile(p->fts_statp, 0) : 0);
314 }
315 
316 int
317 copy_fifo(struct stat *from_stat, int exists)
318 {
319 	if (exists && unlink(to.p_path)) {
320 		warn("unlink: %s", to.p_path);
321 		return (1);
322 	}
323 	if (mkfifo(to.p_path, from_stat->st_mode)) {
324 		warn("mkfifo: %s", to.p_path);
325 		return (1);
326 	}
327 	return (pflag ? setfile(from_stat, 0) : 0);
328 }
329 
330 int
331 copy_special(struct stat *from_stat, int exists)
332 {
333 	if (exists && unlink(to.p_path)) {
334 		warn("unlink: %s", to.p_path);
335 		return (1);
336 	}
337 	if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
338 		warn("mknod: %s", to.p_path);
339 		return (1);
340 	}
341 	return (pflag ? setfile(from_stat, 0) : 0);
342 }
343 
344 
345 /*
346  * Function: setfile
347  *
348  * Purpose:
349  *   Set the owner/group/permissions for the "to" file to the information
350  *   in the stat structure.  If fd is zero, also call set_utimes() to set
351  *   the mod/access times.  If fd is non-zero, the caller must do a utimes
352  *   itself after close(fd).
353  */
354 int
355 setfile(struct stat *fs, int fd)
356 {
357 	int rval, islink;
358 
359 	rval = 0;
360 	islink = S_ISLNK(fs->st_mode);
361 	fs->st_mode &= S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;
362 
363 	/*
364 	 * Changing the ownership probably won't succeed, unless we're root
365 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
366 	 * the mode; current BSD behavior is to remove all setuid bits on
367 	 * chown.  If chown fails, lose setuid/setgid bits.
368 	 */
369 	if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
370 	    lchown(to.p_path, fs->st_uid, fs->st_gid)) {
371 		if (errno != EPERM) {
372 			warn("chown: %s", to.p_path);
373 			rval = 1;
374 		}
375 		fs->st_mode &= ~(S_ISUID | S_ISGID);
376 	}
377 	if (fd ? fchmod(fd, fs->st_mode) : lchmod(to.p_path, fs->st_mode)) {
378 		warn("chmod: %s", to.p_path);
379 		rval = 1;
380 	}
381 
382 	if (!islink && !Nflag) {
383 		unsigned long fflags = fs->st_flags;
384 		/*
385 		 * XXX
386 		 * NFS doesn't support chflags; ignore errors unless
387 		 * there's reason to believe we're losing bits.
388 		 * (Note, this still won't be right if the server
389 		 * supports flags and we were trying to *remove* flags
390 		 * on a file that we copied, i.e., that we didn't create.)
391 		 */
392 		errno = 0;
393 		if ((fd ? fchflags(fd, fflags) :
394 		    chflags(to.p_path, fflags)) == -1)
395 			if (errno != EOPNOTSUPP || fs->st_flags != 0) {
396 				warn("chflags: %s", to.p_path);
397 				rval = 1;
398 			}
399 	}
400 	/* if fd is non-zero, caller must call set_utimes() after close() */
401 	if (fd == 0 && set_utimes(to.p_path, fs))
402 	    rval = 1;
403 	return (rval);
404 }
405 
406 void
407 usage(void)
408 {
409 	(void)fprintf(stderr,
410 	    "usage: %s [-R [-H | -L | -P]] [-f | -i] [-alNpv] src target\n"
411 	    "       %s [-R [-H | -L | -P]] [-f | -i] [-alNpv] src1 ... srcN directory\n",
412 	    getprogname(), getprogname());
413 	exit(1);
414 	/* NOTREACHED */
415 }
416