xref: /netbsd-src/bin/cp/utils.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /* $NetBSD: utils.c,v 1.46 2018/07/17 13:04:58 darcy 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 1.46 2018/07/17 13:04:58 darcy 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 empty, so let's not bother.
180 	 */
181 	if (fs->st_size > 0) {
182 		struct finfo fi;
183 
184 		fi.from = entp->fts_path;
185 		fi.to = to.p_path;
186 		fi.size = fs->st_size;
187 
188 		/*
189 		 * Mmap and write if less than 8M (the limit is so
190 		 * we don't totally trash memory on big files).
191 		 * This is really a minor hack, but it wins some CPU back.
192 		 */
193 		bool use_read;
194 
195 		use_read = true;
196 		if (fs->st_size <= MMAP_MAX_SIZE) {
197 			size_t fsize = (size_t)fs->st_size;
198 			p = mmap(NULL, fsize, PROT_READ, MAP_FILE|MAP_SHARED,
199 			    from_fd, (off_t)0);
200 			if (p != MAP_FAILED) {
201 				size_t remainder;
202 
203 				use_read = false;
204 
205 				(void) madvise(p, (size_t)fs->st_size,
206 				     MADV_SEQUENTIAL);
207 
208 				/*
209 				 * Write out the data in small chunks to
210 				 * avoid locking the output file for a
211 				 * long time if the reading the data from
212 				 * the source is slow.
213 				 */
214 				remainder = fsize;
215 				do {
216 					ssize_t chunk;
217 
218 					chunk = (remainder > MMAP_MAX_WRITE) ?
219 					    MMAP_MAX_WRITE : remainder;
220 					if (write(to_fd, &p[fsize - remainder],
221 					    chunk) != chunk) {
222 						warn("%s", to.p_path);
223 						rval = 1;
224 						break;
225 					}
226 					remainder -= chunk;
227 					ptotal += chunk;
228 					if (pinfo)
229 						progress(&fi, ptotal);
230 				} while (remainder > 0);
231 
232 				if (munmap(p, fsize) < 0) {
233 					warn("%s", entp->fts_path);
234 					rval = 1;
235 				}
236 			}
237 		}
238 
239 		if (use_read) {
240 			while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
241 				wcount = write(to_fd, buf, (size_t)rcount);
242 				if (rcount != wcount || wcount == -1) {
243 					warn("%s", to.p_path);
244 					rval = 1;
245 					break;
246 				}
247 				ptotal += wcount;
248 				if (pinfo)
249 					progress(&fi, ptotal);
250 			}
251 			if (rcount < 0) {
252 				warn("%s", entp->fts_path);
253 				rval = 1;
254 			}
255 		}
256 	}
257 
258 	if (pflag && (fcpxattr(from_fd, to_fd) != 0))
259 		warn("%s: error copying extended attributes", to.p_path);
260 
261 	(void)close(from_fd);
262 
263 	if (rval == 1) {
264 		(void)close(to_fd);
265 		return (1);
266 	}
267 
268 	if (pflag && setfile(fs, to_fd))
269 		rval = 1;
270 	/*
271 	 * If the source was setuid or setgid, lose the bits unless the
272 	 * copy is owned by the same user and group.
273 	 */
274 #define	RETAINBITS \
275 	(S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
276 	if (!pflag && dne
277 	    && fs->st_mode & (S_ISUID | S_ISGID) && fs->st_uid == myuid) {
278 		if (fstat(to_fd, &to_stat)) {
279 			warn("%s", to.p_path);
280 			rval = 1;
281 		} else if (fs->st_gid == to_stat.st_gid &&
282 		    fchmod(to_fd, fs->st_mode & RETAINBITS & ~myumask)) {
283 			warn("%s", to.p_path);
284 			rval = 1;
285 		}
286 	}
287 	if (close(to_fd)) {
288 		warn("%s", to.p_path);
289 		rval = 1;
290 	}
291 	/* set the mod/access times now after close of the fd */
292 	if (pflag && set_utimes(to.p_path, fs)) {
293 	    rval = 1;
294 	}
295 	return (rval);
296 }
297 
298 int
299 copy_link(FTSENT *p, int exists)
300 {
301 	int len;
302 	char target[MAXPATHLEN];
303 
304 	if ((len = readlink(p->fts_path, target, sizeof(target)-1)) == -1) {
305 		warn("readlink: %s", p->fts_path);
306 		return (1);
307 	}
308 	target[len] = '\0';
309 	if (exists && unlink(to.p_path)) {
310 		warn("unlink: %s", to.p_path);
311 		return (1);
312 	}
313 	if (symlink(target, to.p_path)) {
314 		warn("symlink: %s", target);
315 		return (1);
316 	}
317 	return (pflag ? setfile(p->fts_statp, 0) : 0);
318 }
319 
320 int
321 copy_fifo(struct stat *from_stat, int exists)
322 {
323 	if (exists && unlink(to.p_path)) {
324 		warn("unlink: %s", to.p_path);
325 		return (1);
326 	}
327 	if (mkfifo(to.p_path, from_stat->st_mode)) {
328 		warn("mkfifo: %s", to.p_path);
329 		return (1);
330 	}
331 	return (pflag ? setfile(from_stat, 0) : 0);
332 }
333 
334 int
335 copy_special(struct stat *from_stat, int exists)
336 {
337 	if (exists && unlink(to.p_path)) {
338 		warn("unlink: %s", to.p_path);
339 		return (1);
340 	}
341 	if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
342 		warn("mknod: %s", to.p_path);
343 		return (1);
344 	}
345 	return (pflag ? setfile(from_stat, 0) : 0);
346 }
347 
348 
349 /*
350  * Function: setfile
351  *
352  * Purpose:
353  *   Set the owner/group/permissions for the "to" file to the information
354  *   in the stat structure.  If fd is zero, also call set_utimes() to set
355  *   the mod/access times.  If fd is non-zero, the caller must do a utimes
356  *   itself after close(fd).
357  */
358 int
359 setfile(struct stat *fs, int fd)
360 {
361 	int rval, islink;
362 
363 	rval = 0;
364 	islink = S_ISLNK(fs->st_mode);
365 	fs->st_mode &= S_ISUID | S_ISGID | S_IRWXU | S_IRWXG | S_IRWXO;
366 
367 	/*
368 	 * Changing the ownership probably won't succeed, unless we're root
369 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
370 	 * the mode; current BSD behavior is to remove all setuid bits on
371 	 * chown.  If chown fails, lose setuid/setgid bits.
372 	 */
373 	if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
374 	    lchown(to.p_path, fs->st_uid, fs->st_gid)) {
375 		if (errno != EPERM) {
376 			warn("chown: %s", to.p_path);
377 			rval = 1;
378 		}
379 		fs->st_mode &= ~(S_ISUID | S_ISGID);
380 	}
381 	if (fd ? fchmod(fd, fs->st_mode) : lchmod(to.p_path, fs->st_mode)) {
382 		warn("chmod: %s", to.p_path);
383 		rval = 1;
384 	}
385 
386 	if (!islink && !Nflag) {
387 		unsigned long fflags = fs->st_flags;
388 		/*
389 		 * XXX
390 		 * NFS doesn't support chflags; ignore errors unless
391 		 * there's reason to believe we're losing bits.
392 		 * (Note, this still won't be right if the server
393 		 * supports flags and we were trying to *remove* flags
394 		 * on a file that we copied, i.e., that we didn't create.)
395 		 */
396 		errno = 0;
397 		if ((fd ? fchflags(fd, fflags) :
398 		    chflags(to.p_path, fflags)) == -1)
399 			if (errno != EOPNOTSUPP || fs->st_flags != 0) {
400 				warn("chflags: %s", to.p_path);
401 				rval = 1;
402 			}
403 	}
404 	/* if fd is non-zero, caller must call set_utimes() after close() */
405 	if (fd == 0 && set_utimes(to.p_path, fs))
406 	    rval = 1;
407 	return (rval);
408 }
409 
410 void
411 usage(void)
412 {
413 	(void)fprintf(stderr,
414 	    "usage: %s [-R [-H | -L | -P]] [-f | -i] [-alNpv] src target\n"
415 	    "       %s [-R [-H | -L | -P]] [-f | -i] [-alNpv] src1 ... srcN directory\n",
416 	    getprogname(), getprogname());
417 	exit(1);
418 	/* NOTREACHED */
419 }
420