xref: /freebsd/bin/cp/utils.c (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)utils.c	8.3 (Berkeley) 4/1/94";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/types.h>
41 #include <sys/acl.h>
42 #include <sys/param.h>
43 #include <sys/stat.h>
44 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
45 #include <sys/mman.h>
46 #endif
47 
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <fts.h>
52 #include <limits.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <sysexits.h>
56 #include <unistd.h>
57 
58 #include "extern.h"
59 
60 #define	cp_pct(x, y)	((y == 0) ? 0 : (int)(100.0 * (x) / (y)))
61 
62 /*
63  * Memory strategy threshold, in pages: if physmem is larger then this, use a
64  * large buffer.
65  */
66 #define PHYSPAGES_THRESHOLD (32*1024)
67 
68 /* Maximum buffer size in bytes - do not allow it to grow larger than this. */
69 #define BUFSIZE_MAX (2*1024*1024)
70 
71 /*
72  * Small (default) buffer size in bytes. It's inefficient for this to be
73  * smaller than MAXPHYS.
74  */
75 #define BUFSIZE_SMALL (MAXPHYS)
76 
77 int
78 copy_file(const FTSENT *entp, int dne)
79 {
80 	static char *buf = NULL;
81 	static size_t bufsize;
82 	struct stat *fs;
83 	ssize_t wcount;
84 	size_t wresid;
85 	off_t wtotal;
86 	int ch, checkch, from_fd, rcount, rval, to_fd;
87 	char *bufp;
88 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
89 	char *p;
90 #endif
91 
92 	from_fd = to_fd = -1;
93 	if (!lflag && !sflag &&
94 	    (from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
95 		warn("%s", entp->fts_path);
96 		return (1);
97 	}
98 
99 	fs = entp->fts_statp;
100 
101 	/*
102 	 * If the file exists and we're interactive, verify with the user.
103 	 * If the file DNE, set the mode to be the from file, minus setuid
104 	 * bits, modified by the umask; arguably wrong, but it makes copying
105 	 * executables work right and it's been that way forever.  (The
106 	 * other choice is 666 or'ed with the execute bits on the from file
107 	 * modified by the umask.)
108 	 */
109 	if (!dne) {
110 #define YESNO "(y/n [n]) "
111 		if (nflag) {
112 			if (vflag)
113 				printf("%s not overwritten\n", to.p_path);
114 			rval = 1;
115 			goto done;
116 		} else if (iflag) {
117 			(void)fprintf(stderr, "overwrite %s? %s",
118 			    to.p_path, YESNO);
119 			checkch = ch = getchar();
120 			while (ch != '\n' && ch != EOF)
121 				ch = getchar();
122 			if (checkch != 'y' && checkch != 'Y') {
123 				(void)fprintf(stderr, "not overwritten\n");
124 				rval = 1;
125 				goto done;
126 			}
127 		}
128 
129 		if (fflag) {
130 			/*
131 			 * Remove existing destination file name create a new
132 			 * file.
133 			 */
134 			(void)unlink(to.p_path);
135 			if (!lflag && !sflag) {
136 				to_fd = open(to.p_path,
137 				    O_WRONLY | O_TRUNC | O_CREAT,
138 				    fs->st_mode & ~(S_ISUID | S_ISGID));
139 			}
140 		} else if (!lflag && !sflag) {
141 			/* Overwrite existing destination file name. */
142 			to_fd = open(to.p_path, O_WRONLY | O_TRUNC, 0);
143 		}
144 	} else if (!lflag && !sflag) {
145 		to_fd = open(to.p_path, O_WRONLY | O_TRUNC | O_CREAT,
146 		    fs->st_mode & ~(S_ISUID | S_ISGID));
147 	}
148 
149 	if (!lflag && !sflag && to_fd == -1) {
150 		warn("%s", to.p_path);
151 		rval = 1;
152 		goto done;
153 	}
154 
155 	rval = 0;
156 
157 	if (!lflag && !sflag) {
158 		/*
159 		 * Mmap and write if less than 8M (the limit is so we don't
160 		 * totally trash memory on big files.  This is really a minor
161 		 * hack, but it wins some CPU back.
162 		 * Some filesystems, such as smbnetfs, don't support mmap,
163 		 * so this is a best-effort attempt.
164 		 */
165 #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
166 		if (S_ISREG(fs->st_mode) && fs->st_size > 0 &&
167 		    fs->st_size <= 8 * 1024 * 1024 &&
168 		    (p = mmap(NULL, (size_t)fs->st_size, PROT_READ,
169 		    MAP_SHARED, from_fd, (off_t)0)) != MAP_FAILED) {
170 			wtotal = 0;
171 			for (bufp = p, wresid = fs->st_size; ;
172 			    bufp += wcount, wresid -= (size_t)wcount) {
173 				wcount = write(to_fd, bufp, wresid);
174 				if (wcount <= 0)
175 					break;
176 				wtotal += wcount;
177 				if (info) {
178 					info = 0;
179 					(void)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 			}
191 			/* Some systems don't unmap on close(2). */
192 			if (munmap(p, fs->st_size) < 0) {
193 				warn("%s", entp->fts_path);
194 				rval = 1;
195 			}
196 		} else
197 #endif
198 		{
199 			if (buf == NULL) {
200 				/*
201 				 * Note that buf and bufsize are static. If
202 				 * malloc() fails, it will fail at the start
203 				 * and not copy only some files.
204 				 */
205 				if (sysconf(_SC_PHYS_PAGES) >
206 				    PHYSPAGES_THRESHOLD)
207 					bufsize = MIN(BUFSIZE_MAX, MAXPHYS * 8);
208 				else
209 					bufsize = BUFSIZE_SMALL;
210 				buf = malloc(bufsize);
211 				if (buf == NULL)
212 					err(1, "Not enough memory");
213 			}
214 			wtotal = 0;
215 			while ((rcount = read(from_fd, buf, bufsize)) > 0) {
216 				for (bufp = buf, wresid = rcount; ;
217 				    bufp += wcount, wresid -= wcount) {
218 					wcount = write(to_fd, bufp, wresid);
219 					if (wcount <= 0)
220 						break;
221 					wtotal += wcount;
222 					if (info) {
223 						info = 0;
224 						(void)fprintf(stderr,
225 						    "%s -> %s %3d%%\n",
226 						    entp->fts_path, to.p_path,
227 						    cp_pct(wtotal, fs->st_size));
228 					}
229 					if (wcount >= (ssize_t)wresid)
230 						break;
231 				}
232 				if (wcount != (ssize_t)wresid) {
233 					warn("%s", to.p_path);
234 					rval = 1;
235 					break;
236 				}
237 			}
238 			if (rcount < 0) {
239 				warn("%s", entp->fts_path);
240 				rval = 1;
241 			}
242 		}
243 	} else if (lflag) {
244 		if (link(entp->fts_path, to.p_path)) {
245 			warn("%s", to.p_path);
246 			rval = 1;
247 		}
248 	} else if (sflag) {
249 		if (symlink(entp->fts_path, to.p_path)) {
250 			warn("%s", to.p_path);
251 			rval = 1;
252 		}
253 	}
254 
255 	/*
256 	 * Don't remove the target even after an error.  The target might
257 	 * not be a regular file, or its attributes might be important,
258 	 * or its contents might be irreplaceable.  It would only be safe
259 	 * to remove it if we created it and its length is 0.
260 	 */
261 
262 	if (!lflag && !sflag) {
263 		if (pflag && setfile(fs, to_fd))
264 			rval = 1;
265 		if (pflag && preserve_fd_acls(from_fd, to_fd) != 0)
266 			rval = 1;
267 		if (close(to_fd)) {
268 			warn("%s", to.p_path);
269 			rval = 1;
270 		}
271 	}
272 
273 done:
274 	if (from_fd != -1)
275 		(void)close(from_fd);
276 	return (rval);
277 }
278 
279 int
280 copy_link(const FTSENT *p, int exists)
281 {
282 	int len;
283 	char llink[PATH_MAX];
284 
285 	if (exists && nflag) {
286 		if (vflag)
287 			printf("%s not overwritten\n", to.p_path);
288 		return (1);
289 	}
290 	if ((len = readlink(p->fts_path, llink, sizeof(llink) - 1)) == -1) {
291 		warn("readlink: %s", p->fts_path);
292 		return (1);
293 	}
294 	llink[len] = '\0';
295 	if (exists && unlink(to.p_path)) {
296 		warn("unlink: %s", to.p_path);
297 		return (1);
298 	}
299 	if (symlink(llink, to.p_path)) {
300 		warn("symlink: %s", llink);
301 		return (1);
302 	}
303 	return (pflag ? setfile(p->fts_statp, -1) : 0);
304 }
305 
306 int
307 copy_fifo(struct stat *from_stat, int exists)
308 {
309 
310 	if (exists && nflag) {
311 		if (vflag)
312 			printf("%s not overwritten\n", to.p_path);
313 		return (1);
314 	}
315 	if (exists && unlink(to.p_path)) {
316 		warn("unlink: %s", to.p_path);
317 		return (1);
318 	}
319 	if (mkfifo(to.p_path, from_stat->st_mode)) {
320 		warn("mkfifo: %s", to.p_path);
321 		return (1);
322 	}
323 	return (pflag ? setfile(from_stat, -1) : 0);
324 }
325 
326 int
327 copy_special(struct stat *from_stat, int exists)
328 {
329 
330 	if (exists && nflag) {
331 		if (vflag)
332 			printf("%s not overwritten\n", to.p_path);
333 		return (1);
334 	}
335 	if (exists && unlink(to.p_path)) {
336 		warn("unlink: %s", to.p_path);
337 		return (1);
338 	}
339 	if (mknod(to.p_path, from_stat->st_mode, from_stat->st_rdev)) {
340 		warn("mknod: %s", to.p_path);
341 		return (1);
342 	}
343 	return (pflag ? setfile(from_stat, -1) : 0);
344 }
345 
346 int
347 setfile(struct stat *fs, int fd)
348 {
349 	static struct timespec tspec[2];
350 	struct stat ts;
351 	int rval, gotstat, islink, fdval;
352 
353 	rval = 0;
354 	fdval = fd != -1;
355 	islink = !fdval && S_ISLNK(fs->st_mode);
356 	fs->st_mode &= S_ISUID | S_ISGID | S_ISVTX |
357 	    S_IRWXU | S_IRWXG | S_IRWXO;
358 
359 	tspec[0] = fs->st_atim;
360 	tspec[1] = fs->st_mtim;
361 	if (fdval ? futimens(fd, tspec) : utimensat(AT_FDCWD, to.p_path, tspec,
362 	    islink ? AT_SYMLINK_NOFOLLOW : 0)) {
363 		warn("utimensat: %s", to.p_path);
364 		rval = 1;
365 	}
366 	if (fdval ? fstat(fd, &ts) :
367 	    (islink ? lstat(to.p_path, &ts) : stat(to.p_path, &ts)))
368 		gotstat = 0;
369 	else {
370 		gotstat = 1;
371 		ts.st_mode &= S_ISUID | S_ISGID | S_ISVTX |
372 		    S_IRWXU | S_IRWXG | S_IRWXO;
373 	}
374 	/*
375 	 * Changing the ownership probably won't succeed, unless we're root
376 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
377 	 * the mode; current BSD behavior is to remove all setuid bits on
378 	 * chown.  If chown fails, lose setuid/setgid bits.
379 	 */
380 	if (!gotstat || fs->st_uid != ts.st_uid || fs->st_gid != ts.st_gid)
381 		if (fdval ? fchown(fd, fs->st_uid, fs->st_gid) :
382 		    (islink ? lchown(to.p_path, fs->st_uid, fs->st_gid) :
383 		    chown(to.p_path, fs->st_uid, fs->st_gid))) {
384 			if (errno != EPERM) {
385 				warn("chown: %s", to.p_path);
386 				rval = 1;
387 			}
388 			fs->st_mode &= ~(S_ISUID | S_ISGID);
389 		}
390 
391 	if (!gotstat || fs->st_mode != ts.st_mode)
392 		if (fdval ? fchmod(fd, fs->st_mode) :
393 		    (islink ? lchmod(to.p_path, fs->st_mode) :
394 		    chmod(to.p_path, fs->st_mode))) {
395 			warn("chmod: %s", to.p_path);
396 			rval = 1;
397 		}
398 
399 	if (!gotstat || fs->st_flags != ts.st_flags)
400 		if (fdval ?
401 		    fchflags(fd, fs->st_flags) :
402 		    (islink ? lchflags(to.p_path, fs->st_flags) :
403 		    chflags(to.p_path, fs->st_flags))) {
404 			warn("chflags: %s", to.p_path);
405 			rval = 1;
406 		}
407 
408 	return (rval);
409 }
410 
411 int
412 preserve_fd_acls(int source_fd, int dest_fd)
413 {
414 	acl_t acl;
415 	acl_type_t acl_type;
416 	int acl_supported = 0, ret, trivial;
417 
418 	ret = fpathconf(source_fd, _PC_ACL_NFS4);
419 	if (ret > 0 ) {
420 		acl_supported = 1;
421 		acl_type = ACL_TYPE_NFS4;
422 	} else if (ret < 0 && errno != EINVAL) {
423 		warn("fpathconf(..., _PC_ACL_NFS4) failed for %s", to.p_path);
424 		return (1);
425 	}
426 	if (acl_supported == 0) {
427 		ret = fpathconf(source_fd, _PC_ACL_EXTENDED);
428 		if (ret > 0 ) {
429 			acl_supported = 1;
430 			acl_type = ACL_TYPE_ACCESS;
431 		} else if (ret < 0 && errno != EINVAL) {
432 			warn("fpathconf(..., _PC_ACL_EXTENDED) failed for %s",
433 			    to.p_path);
434 			return (1);
435 		}
436 	}
437 	if (acl_supported == 0)
438 		return (0);
439 
440 	acl = acl_get_fd_np(source_fd, acl_type);
441 	if (acl == NULL) {
442 		warn("failed to get acl entries while setting %s", to.p_path);
443 		return (1);
444 	}
445 	if (acl_is_trivial_np(acl, &trivial)) {
446 		warn("acl_is_trivial() failed for %s", to.p_path);
447 		acl_free(acl);
448 		return (1);
449 	}
450 	if (trivial) {
451 		acl_free(acl);
452 		return (0);
453 	}
454 	if (acl_set_fd_np(dest_fd, acl, acl_type) < 0) {
455 		warn("failed to set acl entries for %s", to.p_path);
456 		acl_free(acl);
457 		return (1);
458 	}
459 	acl_free(acl);
460 	return (0);
461 }
462 
463 int
464 preserve_dir_acls(struct stat *fs, char *source_dir, char *dest_dir)
465 {
466 	acl_t (*aclgetf)(const char *, acl_type_t);
467 	int (*aclsetf)(const char *, acl_type_t, acl_t);
468 	struct acl *aclp;
469 	acl_t acl;
470 	acl_type_t acl_type;
471 	int acl_supported = 0, ret, trivial;
472 
473 	ret = pathconf(source_dir, _PC_ACL_NFS4);
474 	if (ret > 0) {
475 		acl_supported = 1;
476 		acl_type = ACL_TYPE_NFS4;
477 	} else if (ret < 0 && errno != EINVAL) {
478 		warn("fpathconf(..., _PC_ACL_NFS4) failed for %s", source_dir);
479 		return (1);
480 	}
481 	if (acl_supported == 0) {
482 		ret = pathconf(source_dir, _PC_ACL_EXTENDED);
483 		if (ret > 0) {
484 			acl_supported = 1;
485 			acl_type = ACL_TYPE_ACCESS;
486 		} else if (ret < 0 && errno != EINVAL) {
487 			warn("fpathconf(..., _PC_ACL_EXTENDED) failed for %s",
488 			    source_dir);
489 			return (1);
490 		}
491 	}
492 	if (acl_supported == 0)
493 		return (0);
494 
495 	/*
496 	 * If the file is a link we will not follow it.
497 	 */
498 	if (S_ISLNK(fs->st_mode)) {
499 		aclgetf = acl_get_link_np;
500 		aclsetf = acl_set_link_np;
501 	} else {
502 		aclgetf = acl_get_file;
503 		aclsetf = acl_set_file;
504 	}
505 	if (acl_type == ACL_TYPE_ACCESS) {
506 		/*
507 		 * Even if there is no ACL_TYPE_DEFAULT entry here, a zero
508 		 * size ACL will be returned. So it is not safe to simply
509 		 * check the pointer to see if the default ACL is present.
510 		 */
511 		acl = aclgetf(source_dir, ACL_TYPE_DEFAULT);
512 		if (acl == NULL) {
513 			warn("failed to get default acl entries on %s",
514 			    source_dir);
515 			return (1);
516 		}
517 		aclp = &acl->ats_acl;
518 		if (aclp->acl_cnt != 0 && aclsetf(dest_dir,
519 		    ACL_TYPE_DEFAULT, acl) < 0) {
520 			warn("failed to set default acl entries on %s",
521 			    dest_dir);
522 			acl_free(acl);
523 			return (1);
524 		}
525 		acl_free(acl);
526 	}
527 	acl = aclgetf(source_dir, acl_type);
528 	if (acl == NULL) {
529 		warn("failed to get acl entries on %s", source_dir);
530 		return (1);
531 	}
532 	if (acl_is_trivial_np(acl, &trivial)) {
533 		warn("acl_is_trivial() failed on %s", source_dir);
534 		acl_free(acl);
535 		return (1);
536 	}
537 	if (trivial) {
538 		acl_free(acl);
539 		return (0);
540 	}
541 	if (aclsetf(dest_dir, acl_type, acl) < 0) {
542 		warn("failed to set acl entries on %s", dest_dir);
543 		acl_free(acl);
544 		return (1);
545 	}
546 	acl_free(acl);
547 	return (0);
548 }
549 
550 void
551 usage(void)
552 {
553 
554 	(void)fprintf(stderr, "%s\n%s\n",
555 	    "usage: cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpsvx] "
556 	    "source_file target_file",
557 	    "       cp [-R [-H | -L | -P]] [-f | -i | -n] [-alpsvx] "
558 	    "source_file ... "
559 	    "target_directory");
560 	exit(EX_USAGE);
561 }
562