xref: /freebsd/bin/cp/cp.c (revision 045c8f526484cb3b97f5fd693987f4376fa43c5f)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1988, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * David Hitz of Auspex Systems Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #if 0
36 #ifndef lint
37 static char const copyright[] =
38 "@(#) Copyright (c) 1988, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 
42 #ifndef lint
43 static char sccsid[] = "@(#)cp.c	8.2 (Berkeley) 4/1/94";
44 #endif /* not lint */
45 #endif
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 /*
50  * Cp copies source files to target files.
51  *
52  * The global PATH_T structure "to" always contains the path to the
53  * current target file.  Since fts(3) does not change directories,
54  * this path can be either absolute or dot-relative.
55  *
56  * The basic algorithm is to initialize "to" and use fts(3) to traverse
57  * the file hierarchy rooted in the argument list.  A trivial case is the
58  * case of 'cp file1 file2'.  The more interesting case is the case of
59  * 'cp file1 file2 ... fileN dir' where the hierarchy is traversed and the
60  * path (relative to the root of the traversal) is appended to dir (stored
61  * in "to") to form the final target path.
62  */
63 
64 #include <sys/types.h>
65 #include <sys/stat.h>
66 
67 #include <assert.h>
68 #include <err.h>
69 #include <errno.h>
70 #include <fts.h>
71 #include <limits.h>
72 #include <signal.h>
73 #include <stdio.h>
74 #include <stdlib.h>
75 #include <string.h>
76 #include <unistd.h>
77 
78 #include "extern.h"
79 
80 #define	STRIP_TRAILING_SLASH(p) {					\
81 	while ((p).p_end > (p).p_path + 1 && (p).p_end[-1] == '/')	\
82 	*--(p).p_end = 0;						\
83 }
84 
85 static char emptystring[] = "";
86 
87 PATH_T to = { to.p_path, emptystring, "" };
88 
89 int fflag, iflag, lflag, nflag, pflag, sflag, vflag;
90 static int Hflag, Lflag, Rflag, rflag;
91 volatile sig_atomic_t info;
92 
93 enum op { FILE_TO_FILE, FILE_TO_DIR, DIR_TO_DNE };
94 
95 static int copy(char *[], enum op, int, struct stat *);
96 static void siginfo(int __unused);
97 
98 int
99 main(int argc, char *argv[])
100 {
101 	struct stat to_stat, tmp_stat;
102 	enum op type;
103 	int Pflag, ch, fts_options, r, have_trailing_slash;
104 	char *target;
105 
106 	fts_options = FTS_NOCHDIR | FTS_PHYSICAL;
107 	Pflag = 0;
108 	while ((ch = getopt(argc, argv, "HLPRafilnprsvx")) != -1)
109 		switch (ch) {
110 		case 'H':
111 			Hflag = 1;
112 			Lflag = Pflag = 0;
113 			break;
114 		case 'L':
115 			Lflag = 1;
116 			Hflag = Pflag = 0;
117 			break;
118 		case 'P':
119 			Pflag = 1;
120 			Hflag = Lflag = 0;
121 			break;
122 		case 'R':
123 			Rflag = 1;
124 			break;
125 		case 'a':
126 			pflag = 1;
127 			Rflag = 1;
128 			Pflag = 1;
129 			Hflag = Lflag = 0;
130 			break;
131 		case 'f':
132 			fflag = 1;
133 			iflag = nflag = 0;
134 			break;
135 		case 'i':
136 			iflag = 1;
137 			fflag = nflag = 0;
138 			break;
139 		case 'l':
140 			lflag = 1;
141 			break;
142 		case 'n':
143 			nflag = 1;
144 			fflag = iflag = 0;
145 			break;
146 		case 'p':
147 			pflag = 1;
148 			break;
149 		case 'r':
150 			rflag = Lflag = 1;
151 			Hflag = Pflag = 0;
152 			break;
153 		case 's':
154 			sflag = 1;
155 			break;
156 		case 'v':
157 			vflag = 1;
158 			break;
159 		case 'x':
160 			fts_options |= FTS_XDEV;
161 			break;
162 		default:
163 			usage();
164 			break;
165 		}
166 	argc -= optind;
167 	argv += optind;
168 
169 	if (argc < 2)
170 		usage();
171 
172 	if (Rflag && rflag)
173 		errx(1, "the -R and -r options may not be specified together");
174 	if (lflag && sflag)
175 		errx(1, "the -l and -s options may not be specified together");
176 	if (rflag)
177 		Rflag = 1;
178 	if (Rflag) {
179 		if (Hflag)
180 			fts_options |= FTS_COMFOLLOW;
181 		if (Lflag) {
182 			fts_options &= ~FTS_PHYSICAL;
183 			fts_options |= FTS_LOGICAL;
184 		}
185 	} else if (!Pflag) {
186 		fts_options &= ~FTS_PHYSICAL;
187 		fts_options |= FTS_LOGICAL | FTS_COMFOLLOW;
188 	}
189 	(void)signal(SIGINFO, siginfo);
190 
191 	/* Save the target base in "to". */
192 	target = argv[--argc];
193 	if (strlcpy(to.p_path, target, sizeof(to.p_path)) >= sizeof(to.p_path))
194 		errx(1, "%s: name too long", target);
195 	to.p_end = to.p_path + strlen(to.p_path);
196 	if (to.p_path == to.p_end) {
197 		*to.p_end++ = '.';
198 		*to.p_end = 0;
199 	}
200 	have_trailing_slash = (to.p_end[-1] == '/');
201 	if (have_trailing_slash)
202 		STRIP_TRAILING_SLASH(to);
203 	to.target_end = to.p_end;
204 
205 	/* Set end of argument list for fts(3). */
206 	argv[argc] = NULL;
207 
208 	/*
209 	 * Cp has two distinct cases:
210 	 *
211 	 * cp [-R] source target
212 	 * cp [-R] source1 ... sourceN directory
213 	 *
214 	 * In both cases, source can be either a file or a directory.
215 	 *
216 	 * In (1), the target becomes a copy of the source. That is, if the
217 	 * source is a file, the target will be a file, and likewise for
218 	 * directories.
219 	 *
220 	 * In (2), the real target is not directory, but "directory/source".
221 	 */
222 	r = stat(to.p_path, &to_stat);
223 	if (r == -1 && errno != ENOENT)
224 		err(1, "%s", to.p_path);
225 	if (r == -1 || !S_ISDIR(to_stat.st_mode)) {
226 		/*
227 		 * Case (1).  Target is not a directory.
228 		 */
229 		if (argc > 1)
230 			errx(1, "%s is not a directory", to.p_path);
231 
232 		/*
233 		 * Need to detect the case:
234 		 *	cp -R dir foo
235 		 * Where dir is a directory and foo does not exist, where
236 		 * we want pathname concatenations turned on but not for
237 		 * the initial mkdir().
238 		 */
239 		if (r == -1) {
240 			if (Rflag && (Lflag || Hflag))
241 				stat(*argv, &tmp_stat);
242 			else
243 				lstat(*argv, &tmp_stat);
244 
245 			if (S_ISDIR(tmp_stat.st_mode) && Rflag)
246 				type = DIR_TO_DNE;
247 			else
248 				type = FILE_TO_FILE;
249 		} else
250 			type = FILE_TO_FILE;
251 
252 		if (have_trailing_slash && type == FILE_TO_FILE) {
253 			if (r == -1) {
254 				errx(1, "directory %s does not exist",
255 				    to.p_path);
256 			} else
257 				errx(1, "%s is not a directory", to.p_path);
258 		}
259 	} else
260 		/*
261 		 * Case (2).  Target is a directory.
262 		 */
263 		type = FILE_TO_DIR;
264 
265 	/*
266 	 * For DIR_TO_DNE, we could provide copy() with the to_stat we've
267 	 * already allocated on the stack here that isn't being used for
268 	 * anything.  Not doing so, though, simplifies later logic a little bit
269 	 * as we need to skip checking root_stat on the first iteration and
270 	 * ensure that we set it with the first mkdir().
271 	 */
272 	exit (copy(argv, type, fts_options, (type == DIR_TO_DNE ? NULL :
273 	    &to_stat)));
274 }
275 
276 /* Does the right thing based on -R + -H/-L/-P */
277 static int
278 copy_stat(const char *path, struct stat *sb)
279 {
280 
281 	/*
282 	 * For -R -H/-P, we need to lstat() instead; copy() cares about the link
283 	 * itself rather than the target if we're not following links during the
284 	 * traversal.
285 	 */
286 	if (!Rflag || Lflag)
287 		return (stat(path, sb));
288 	return (lstat(path, sb));
289 }
290 
291 
292 static int
293 copy(char *argv[], enum op type, int fts_options, struct stat *root_stat)
294 {
295 	struct stat created_root_stat, to_stat;
296 	FTS *ftsp;
297 	FTSENT *curr;
298 	int base = 0, dne, badcp, rval;
299 	size_t nlen;
300 	char *p, *recurse_path, *target_mid;
301 	mode_t mask, mode;
302 
303 	/*
304 	 * Keep an inverted copy of the umask, for use in correcting
305 	 * permissions on created directories when not using -p.
306 	 */
307 	mask = ~umask(0777);
308 	umask(~mask);
309 
310 	recurse_path = NULL;
311 	if ((ftsp = fts_open(argv, fts_options, NULL)) == NULL)
312 		err(1, "fts_open");
313 	for (badcp = rval = 0; errno = 0, (curr = fts_read(ftsp)) != NULL;
314             badcp = 0) {
315 		switch (curr->fts_info) {
316 		case FTS_NS:
317 		case FTS_DNR:
318 		case FTS_ERR:
319 			warnx("%s: %s",
320 			    curr->fts_path, strerror(curr->fts_errno));
321 			badcp = rval = 1;
322 			continue;
323 		case FTS_DC:			/* Warn, continue. */
324 			warnx("%s: directory causes a cycle", curr->fts_path);
325 			badcp = rval = 1;
326 			continue;
327 		default:
328 			;
329 		}
330 
331 		if (curr->fts_info == FTS_D && type != FILE_TO_FILE &&
332 		    root_stat != NULL &&
333 		    root_stat->st_dev == curr->fts_statp->st_dev &&
334 		    root_stat->st_ino == curr->fts_statp->st_ino) {
335 			assert(recurse_path == NULL);
336 			if (curr->fts_level > FTS_ROOTLEVEL) {
337 				/*
338 				 * If the recursion isn't at the immediate
339 				 * level, we can just not traverse into this
340 				 * directory.
341 				 */
342 				fts_set(ftsp, curr, FTS_SKIP);
343 				continue;
344 			} else {
345 				const char *slash;
346 
347 				/*
348 				 * Grab the last path component and double it,
349 				 * to make life easier later and ensure that
350 				 * we work even with fts_level == 0 is a couple
351 				 * of components deep in fts_path.  No path
352 				 * separators are fine and expected in the
353 				 * common case, though.
354 				 */
355 				slash = strrchr(curr->fts_path, '/');
356 				if (slash != NULL)
357 					slash++;
358 				else
359 					slash = curr->fts_path;
360 				if (asprintf(&recurse_path, "%s/%s",
361 				    curr->fts_path, slash) == -1)
362 					err(1, "asprintf");
363 			}
364 		}
365 
366 		if (recurse_path != NULL &&
367 		    strcmp(curr->fts_path, recurse_path) == 0) {
368 			fts_set(ftsp, curr, FTS_SKIP);
369 			continue;
370 		}
371 
372 		/*
373 		 * If we are in case (2) or (3) above, we need to append the
374 		 * source name to the target name.
375 		 */
376 		if (type != FILE_TO_FILE) {
377 			/*
378 			 * Need to remember the roots of traversals to create
379 			 * correct pathnames.  If there's a directory being
380 			 * copied to a non-existent directory, e.g.
381 			 *	cp -R a/dir noexist
382 			 * the resulting path name should be noexist/foo, not
383 			 * noexist/dir/foo (where foo is a file in dir), which
384 			 * is the case where the target exists.
385 			 *
386 			 * Also, check for "..".  This is for correct path
387 			 * concatenation for paths ending in "..", e.g.
388 			 *	cp -R .. /tmp
389 			 * Paths ending in ".." are changed to ".".  This is
390 			 * tricky, but seems the easiest way to fix the problem.
391 			 *
392 			 * XXX
393 			 * Since the first level MUST be FTS_ROOTLEVEL, base
394 			 * is always initialized.
395 			 */
396 			if (curr->fts_level == FTS_ROOTLEVEL) {
397 				if (type != DIR_TO_DNE) {
398 					p = strrchr(curr->fts_path, '/');
399 					base = (p == NULL) ? 0 :
400 					    (int)(p - curr->fts_path + 1);
401 
402 					if (!strcmp(&curr->fts_path[base],
403 					    ".."))
404 						base += 1;
405 				} else
406 					base = curr->fts_pathlen;
407 			}
408 
409 			p = &curr->fts_path[base];
410 			nlen = curr->fts_pathlen - base;
411 			target_mid = to.target_end;
412 			if (*p != '/' && target_mid[-1] != '/')
413 				*target_mid++ = '/';
414 			*target_mid = 0;
415 			if (target_mid - to.p_path + nlen >= PATH_MAX) {
416 				warnx("%s%s: name too long (not copied)",
417 				    to.p_path, p);
418 				badcp = rval = 1;
419 				continue;
420 			}
421 			(void)strncat(target_mid, p, nlen);
422 			to.p_end = target_mid + nlen;
423 			*to.p_end = 0;
424 			STRIP_TRAILING_SLASH(to);
425 		}
426 
427 		if (curr->fts_info == FTS_DP) {
428 			/*
429 			 * We are nearly finished with this directory.  If we
430 			 * didn't actually copy it, or otherwise don't need to
431 			 * change its attributes, then we are done.
432 			 */
433 			if (!curr->fts_number)
434 				continue;
435 			/*
436 			 * If -p is in effect, set all the attributes.
437 			 * Otherwise, set the correct permissions, limited
438 			 * by the umask.  Optimise by avoiding a chmod()
439 			 * if possible (which is usually the case if we
440 			 * made the directory).  Note that mkdir() does not
441 			 * honour setuid, setgid and sticky bits, but we
442 			 * normally want to preserve them on directories.
443 			 */
444 			if (pflag) {
445 				if (setfile(curr->fts_statp, -1))
446 					rval = 1;
447 				if (preserve_dir_acls(curr->fts_statp,
448 				    curr->fts_accpath, to.p_path) != 0)
449 					rval = 1;
450 			} else {
451 				mode = curr->fts_statp->st_mode;
452 				if ((mode & (S_ISUID | S_ISGID | S_ISTXT)) ||
453 				    ((mode | S_IRWXU) & mask) != (mode & mask))
454 					if (chmod(to.p_path, mode & mask) !=
455 					    0) {
456 						warn("chmod: %s", to.p_path);
457 						rval = 1;
458 					}
459 			}
460 			continue;
461 		}
462 
463 		/* Not an error but need to remember it happened. */
464 		if (copy_stat(to.p_path, &to_stat) == -1)
465 			dne = 1;
466 		else {
467 			if (to_stat.st_dev == curr->fts_statp->st_dev &&
468 			    to_stat.st_ino == curr->fts_statp->st_ino) {
469 				warnx("%s and %s are identical (not copied).",
470 				    to.p_path, curr->fts_path);
471 				badcp = rval = 1;
472 				if (S_ISDIR(curr->fts_statp->st_mode))
473 					(void)fts_set(ftsp, curr, FTS_SKIP);
474 				continue;
475 			}
476 			if (!S_ISDIR(curr->fts_statp->st_mode) &&
477 			    S_ISDIR(to_stat.st_mode)) {
478 				warnx("cannot overwrite directory %s with "
479 				    "non-directory %s",
480 				    to.p_path, curr->fts_path);
481 				badcp = rval = 1;
482 				continue;
483 			}
484 			dne = 0;
485 		}
486 
487 		switch (curr->fts_statp->st_mode & S_IFMT) {
488 		case S_IFLNK:
489 			/* Catch special case of a non-dangling symlink. */
490 			if ((fts_options & FTS_LOGICAL) ||
491 			    ((fts_options & FTS_COMFOLLOW) &&
492 			    curr->fts_level == 0)) {
493 				if (copy_file(curr, dne))
494 					badcp = rval = 1;
495 			} else {
496 				if (copy_link(curr, !dne))
497 					badcp = rval = 1;
498 			}
499 			break;
500 		case S_IFDIR:
501 			if (!Rflag) {
502 				warnx("%s is a directory (not copied).",
503 				    curr->fts_path);
504 				(void)fts_set(ftsp, curr, FTS_SKIP);
505 				badcp = rval = 1;
506 				break;
507 			}
508 			/*
509 			 * If the directory doesn't exist, create the new
510 			 * one with the from file mode plus owner RWX bits,
511 			 * modified by the umask.  Trade-off between being
512 			 * able to write the directory (if from directory is
513 			 * 555) and not causing a permissions race.  If the
514 			 * umask blocks owner writes, we fail.
515 			 */
516 			if (dne) {
517 				if (mkdir(to.p_path,
518 				    curr->fts_statp->st_mode | S_IRWXU) < 0)
519 					err(1, "%s", to.p_path);
520 				/*
521 				 * First DNE with a NULL root_stat is the root
522 				 * path, so set root_stat.  We can't really
523 				 * tell in all cases if the target path is
524 				 * within the src path, so we just stat() the
525 				 * first directory we created and use that.
526 				 */
527 				if (root_stat == NULL &&
528 				    stat(to.p_path, &created_root_stat) == -1) {
529 					err(1, "stat");
530 				} else if (root_stat == NULL) {
531 					root_stat = &created_root_stat;
532 				}
533 			} else if (!S_ISDIR(to_stat.st_mode)) {
534 				errno = ENOTDIR;
535 				err(1, "%s", to.p_path);
536 			}
537 			/*
538 			 * Arrange to correct directory attributes later
539 			 * (in the post-order phase) if this is a new
540 			 * directory, or if the -p flag is in effect.
541 			 */
542 			curr->fts_number = pflag || dne;
543 			break;
544 		case S_IFBLK:
545 		case S_IFCHR:
546 			if (Rflag && !sflag) {
547 				if (copy_special(curr->fts_statp, !dne))
548 					badcp = rval = 1;
549 			} else {
550 				if (copy_file(curr, dne))
551 					badcp = rval = 1;
552 			}
553 			break;
554 		case S_IFSOCK:
555 			warnx("%s is a socket (not copied).",
556 			    curr->fts_path);
557 			break;
558 		case S_IFIFO:
559 			if (Rflag && !sflag) {
560 				if (copy_fifo(curr->fts_statp, !dne))
561 					badcp = rval = 1;
562 			} else {
563 				if (copy_file(curr, dne))
564 					badcp = rval = 1;
565 			}
566 			break;
567 		default:
568 			if (copy_file(curr, dne))
569 				badcp = rval = 1;
570 			break;
571 		}
572 		if (vflag && !badcp)
573 			(void)printf("%s -> %s\n", curr->fts_path, to.p_path);
574 	}
575 	if (errno)
576 		err(1, "fts_read");
577 	fts_close(ftsp);
578 	free(recurse_path);
579 	return (rval);
580 }
581 
582 static void
583 siginfo(int sig __unused)
584 {
585 
586 	info = 1;
587 }
588