xref: /freebsd/bin/cp/cp.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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 /*
36  * Cp copies source files to target files.
37  *
38  * The global PATH_T structure "to" always contains the path to the
39  * current target file.  Since fts(3) does not change directories,
40  * this path can be either absolute or dot-relative.
41  *
42  * The basic algorithm is to initialize "to" and use fts(3) to traverse
43  * the file hierarchy rooted in the argument list.  A trivial case is the
44  * case of 'cp file1 file2'.  The more interesting case is the case of
45  * 'cp file1 file2 ... fileN dir' where the hierarchy is traversed and the
46  * path (relative to the root of the traversal) is appended to dir (stored
47  * in "to") to form the final target path.
48  */
49 
50 #include <sys/types.h>
51 #include <sys/stat.h>
52 
53 #include <assert.h>
54 #include <err.h>
55 #include <errno.h>
56 #include <fts.h>
57 #include <limits.h>
58 #include <signal.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <unistd.h>
63 
64 #include "extern.h"
65 
66 #define	STRIP_TRAILING_SLASH(p) {					\
67 	while ((p).p_end > (p).p_path + 1 && (p).p_end[-1] == '/')	\
68 	*--(p).p_end = 0;						\
69 }
70 
71 static char emptystring[] = "";
72 
73 PATH_T to = { to.p_path, emptystring, "" };
74 
75 int Nflag, fflag, iflag, lflag, nflag, pflag, sflag, vflag;
76 static int Hflag, Lflag, Rflag, rflag;
77 volatile sig_atomic_t info;
78 
79 enum op { FILE_TO_FILE, FILE_TO_DIR, DIR_TO_DNE };
80 
81 static int copy(char *[], enum op, int, struct stat *);
82 static void siginfo(int __unused);
83 
84 int
85 main(int argc, char *argv[])
86 {
87 	struct stat to_stat, tmp_stat;
88 	enum op type;
89 	int Pflag, ch, fts_options, r, have_trailing_slash;
90 	char *target;
91 
92 	fts_options = FTS_NOCHDIR | FTS_PHYSICAL;
93 	Pflag = 0;
94 	while ((ch = getopt(argc, argv, "HLNPRafilnprsvx")) != -1)
95 		switch (ch) {
96 		case 'H':
97 			Hflag = 1;
98 			Lflag = Pflag = 0;
99 			break;
100 		case 'L':
101 			Lflag = 1;
102 			Hflag = Pflag = 0;
103 			break;
104 		case 'N':
105 			Nflag = 1;
106 			break;
107 		case 'P':
108 			Pflag = 1;
109 			Hflag = Lflag = 0;
110 			break;
111 		case 'R':
112 			Rflag = 1;
113 			break;
114 		case 'a':
115 			pflag = 1;
116 			Rflag = 1;
117 			Pflag = 1;
118 			Hflag = Lflag = 0;
119 			break;
120 		case 'f':
121 			fflag = 1;
122 			iflag = nflag = 0;
123 			break;
124 		case 'i':
125 			iflag = 1;
126 			fflag = nflag = 0;
127 			break;
128 		case 'l':
129 			lflag = 1;
130 			break;
131 		case 'n':
132 			nflag = 1;
133 			fflag = iflag = 0;
134 			break;
135 		case 'p':
136 			pflag = 1;
137 			break;
138 		case 'r':
139 			rflag = Lflag = 1;
140 			Hflag = Pflag = 0;
141 			break;
142 		case 's':
143 			sflag = 1;
144 			break;
145 		case 'v':
146 			vflag = 1;
147 			break;
148 		case 'x':
149 			fts_options |= FTS_XDEV;
150 			break;
151 		default:
152 			usage();
153 			break;
154 		}
155 	argc -= optind;
156 	argv += optind;
157 
158 	if (argc < 2)
159 		usage();
160 
161 	if (Rflag && rflag)
162 		errx(1, "the -R and -r options may not be specified together");
163 	if (lflag && sflag)
164 		errx(1, "the -l and -s options may not be specified together");
165 	if (rflag)
166 		Rflag = 1;
167 	if (Rflag) {
168 		if (Hflag)
169 			fts_options |= FTS_COMFOLLOW;
170 		if (Lflag) {
171 			fts_options &= ~FTS_PHYSICAL;
172 			fts_options |= FTS_LOGICAL;
173 		}
174 	} else if (!Pflag) {
175 		fts_options &= ~FTS_PHYSICAL;
176 		fts_options |= FTS_LOGICAL | FTS_COMFOLLOW;
177 	}
178 	(void)signal(SIGINFO, siginfo);
179 
180 	/* Save the target base in "to". */
181 	target = argv[--argc];
182 	if (strlcpy(to.p_path, target, sizeof(to.p_path)) >= sizeof(to.p_path))
183 		errx(1, "%s: name too long", target);
184 	to.p_end = to.p_path + strlen(to.p_path);
185 	if (to.p_path == to.p_end) {
186 		*to.p_end++ = '.';
187 		*to.p_end = 0;
188 	}
189 	have_trailing_slash = (to.p_end[-1] == '/');
190 	if (have_trailing_slash)
191 		STRIP_TRAILING_SLASH(to);
192 	to.target_end = to.p_end;
193 
194 	/* Set end of argument list for fts(3). */
195 	argv[argc] = NULL;
196 
197 	/*
198 	 * Cp has two distinct cases:
199 	 *
200 	 * cp [-R] source target
201 	 * cp [-R] source1 ... sourceN directory
202 	 *
203 	 * In both cases, source can be either a file or a directory.
204 	 *
205 	 * In (1), the target becomes a copy of the source. That is, if the
206 	 * source is a file, the target will be a file, and likewise for
207 	 * directories.
208 	 *
209 	 * In (2), the real target is not directory, but "directory/source".
210 	 */
211 	r = stat(to.p_path, &to_stat);
212 	if (r == -1 && errno != ENOENT)
213 		err(1, "%s", to.p_path);
214 	if (r == -1 || !S_ISDIR(to_stat.st_mode)) {
215 		/*
216 		 * Case (1).  Target is not a directory.
217 		 */
218 		if (argc > 1)
219 			errx(1, "%s is not a directory", to.p_path);
220 
221 		/*
222 		 * Need to detect the case:
223 		 *	cp -R dir foo
224 		 * Where dir is a directory and foo does not exist, where
225 		 * we want pathname concatenations turned on but not for
226 		 * the initial mkdir().
227 		 */
228 		if (r == -1) {
229 			if (Rflag && (Lflag || Hflag))
230 				stat(*argv, &tmp_stat);
231 			else
232 				lstat(*argv, &tmp_stat);
233 
234 			if (S_ISDIR(tmp_stat.st_mode) && Rflag)
235 				type = DIR_TO_DNE;
236 			else
237 				type = FILE_TO_FILE;
238 		} else
239 			type = FILE_TO_FILE;
240 
241 		if (have_trailing_slash && type == FILE_TO_FILE) {
242 			if (r == -1) {
243 				errx(1, "directory %s does not exist",
244 				    to.p_path);
245 			} else
246 				errx(1, "%s is not a directory", to.p_path);
247 		}
248 	} else
249 		/*
250 		 * Case (2).  Target is a directory.
251 		 */
252 		type = FILE_TO_DIR;
253 
254 	/*
255 	 * For DIR_TO_DNE, we could provide copy() with the to_stat we've
256 	 * already allocated on the stack here that isn't being used for
257 	 * anything.  Not doing so, though, simplifies later logic a little bit
258 	 * as we need to skip checking root_stat on the first iteration and
259 	 * ensure that we set it with the first mkdir().
260 	 */
261 	exit (copy(argv, type, fts_options, (type == DIR_TO_DNE ? NULL :
262 	    &to_stat)));
263 }
264 
265 /* Does the right thing based on -R + -H/-L/-P */
266 static int
267 copy_stat(const char *path, struct stat *sb)
268 {
269 
270 	/*
271 	 * For -R -H/-P, we need to lstat() instead; copy() cares about the link
272 	 * itself rather than the target if we're not following links during the
273 	 * traversal.
274 	 */
275 	if (!Rflag || Lflag)
276 		return (stat(path, sb));
277 	return (lstat(path, sb));
278 }
279 
280 
281 static int
282 copy(char *argv[], enum op type, int fts_options, struct stat *root_stat)
283 {
284 	char rootname[NAME_MAX];
285 	struct stat created_root_stat, to_stat;
286 	FTS *ftsp;
287 	FTSENT *curr;
288 	int base = 0, dne, badcp, rval;
289 	size_t nlen;
290 	char *p, *recurse_path, *target_mid;
291 	mode_t mask, mode;
292 
293 	/*
294 	 * Keep an inverted copy of the umask, for use in correcting
295 	 * permissions on created directories when not using -p.
296 	 */
297 	mask = ~umask(0777);
298 	umask(~mask);
299 
300 	recurse_path = NULL;
301 	if ((ftsp = fts_open(argv, fts_options, NULL)) == NULL)
302 		err(1, "fts_open");
303 	for (badcp = rval = 0; (curr = fts_read(ftsp)) != NULL; badcp = 0) {
304 		switch (curr->fts_info) {
305 		case FTS_NS:
306 		case FTS_DNR:
307 		case FTS_ERR:
308 			warnx("%s: %s",
309 			    curr->fts_path, strerror(curr->fts_errno));
310 			badcp = rval = 1;
311 			continue;
312 		case FTS_DC:			/* Warn, continue. */
313 			warnx("%s: directory causes a cycle", curr->fts_path);
314 			badcp = rval = 1;
315 			continue;
316 		default:
317 			;
318 		}
319 
320 		/*
321 		 * Stash the root basename off for detecting recursion later.
322 		 *
323 		 * This will be essential if the root is a symlink and we're
324 		 * rolling with -L or -H.  The later bits will need this bit in
325 		 * particular.
326 		 */
327 		if (curr->fts_level == FTS_ROOTLEVEL) {
328 			strlcpy(rootname, curr->fts_name, sizeof(rootname));
329 		}
330 
331 		/*
332 		 * If we are in case (2) or (3) above, we need to append the
333 		 * source name to the target name.
334 		 */
335 		if (type != FILE_TO_FILE) {
336 			/*
337 			 * Need to remember the roots of traversals to create
338 			 * correct pathnames.  If there's a directory being
339 			 * copied to a non-existent directory, e.g.
340 			 *	cp -R a/dir noexist
341 			 * the resulting path name should be noexist/foo, not
342 			 * noexist/dir/foo (where foo is a file in dir), which
343 			 * is the case where the target exists.
344 			 *
345 			 * Also, check for "..".  This is for correct path
346 			 * concatenation for paths ending in "..", e.g.
347 			 *	cp -R .. /tmp
348 			 * Paths ending in ".." are changed to ".".  This is
349 			 * tricky, but seems the easiest way to fix the problem.
350 			 *
351 			 * XXX
352 			 * Since the first level MUST be FTS_ROOTLEVEL, base
353 			 * is always initialized.
354 			 */
355 			if (curr->fts_level == FTS_ROOTLEVEL) {
356 				if (type != DIR_TO_DNE) {
357 					p = strrchr(curr->fts_path, '/');
358 					base = (p == NULL) ? 0 :
359 					    (int)(p - curr->fts_path + 1);
360 
361 					if (!strcmp(&curr->fts_path[base],
362 					    ".."))
363 						base += 1;
364 				} else
365 					base = curr->fts_pathlen;
366 			}
367 
368 			p = &curr->fts_path[base];
369 			nlen = curr->fts_pathlen - base;
370 			target_mid = to.target_end;
371 			if (*p != '/' && target_mid[-1] != '/')
372 				*target_mid++ = '/';
373 			*target_mid = 0;
374 			if (target_mid - to.p_path + nlen >= PATH_MAX) {
375 				warnx("%s%s: name too long (not copied)",
376 				    to.p_path, p);
377 				badcp = rval = 1;
378 				continue;
379 			}
380 			(void)strncat(target_mid, p, nlen);
381 			to.p_end = target_mid + nlen;
382 			*to.p_end = 0;
383 			STRIP_TRAILING_SLASH(to);
384 
385 			/*
386 			 * We're on the verge of recursing on ourselves.  Either
387 			 * we need to stop right here (we knowingly just created
388 			 * it), or we will in an immediate descendant.  Record
389 			 * the path of the immediate descendant to make our
390 			 * lives a little less complicated looking.
391 			 */
392 			if (curr->fts_info == FTS_D && root_stat != NULL &&
393 			    root_stat->st_dev == curr->fts_statp->st_dev &&
394 			    root_stat->st_ino == curr->fts_statp->st_ino) {
395 				assert(recurse_path == NULL);
396 
397 				if (root_stat == &created_root_stat) {
398 					/*
399 					 * This directory didn't exist when we
400 					 * started, we created it as part of
401 					 * traversal.  Stop right here before we
402 					 * do something silly.
403 					 */
404 					fts_set(ftsp, curr, FTS_SKIP);
405 					continue;
406 				}
407 
408 
409 				if (asprintf(&recurse_path, "%s/%s", to.p_path,
410 				    rootname) == -1)
411 					err(1, "asprintf");
412 			}
413 
414 			if (recurse_path != NULL &&
415 			    strcmp(to.p_path, recurse_path) == 0) {
416 				fts_set(ftsp, curr, FTS_SKIP);
417 				continue;
418 			}
419 		}
420 
421 		if (curr->fts_info == FTS_DP) {
422 			/*
423 			 * We are nearly finished with this directory.  If we
424 			 * didn't actually copy it, or otherwise don't need to
425 			 * change its attributes, then we are done.
426 			 */
427 			if (!curr->fts_number)
428 				continue;
429 			/*
430 			 * If -p is in effect, set all the attributes.
431 			 * Otherwise, set the correct permissions, limited
432 			 * by the umask.  Optimise by avoiding a chmod()
433 			 * if possible (which is usually the case if we
434 			 * made the directory).  Note that mkdir() does not
435 			 * honour setuid, setgid and sticky bits, but we
436 			 * normally want to preserve them on directories.
437 			 */
438 			if (pflag) {
439 				if (setfile(curr->fts_statp, -1))
440 					rval = 1;
441 				if (preserve_dir_acls(curr->fts_statp,
442 				    curr->fts_accpath, to.p_path) != 0)
443 					rval = 1;
444 			} else {
445 				mode = curr->fts_statp->st_mode;
446 				if ((mode & (S_ISUID | S_ISGID | S_ISTXT)) ||
447 				    ((mode | S_IRWXU) & mask) != (mode & mask))
448 					if (chmod(to.p_path, mode & mask) !=
449 					    0) {
450 						warn("chmod: %s", to.p_path);
451 						rval = 1;
452 					}
453 			}
454 			continue;
455 		}
456 
457 		/* Not an error but need to remember it happened. */
458 		if (copy_stat(to.p_path, &to_stat) == -1)
459 			dne = 1;
460 		else {
461 			if (to_stat.st_dev == curr->fts_statp->st_dev &&
462 			    to_stat.st_ino == curr->fts_statp->st_ino) {
463 				warnx("%s and %s are identical (not copied).",
464 				    to.p_path, curr->fts_path);
465 				badcp = rval = 1;
466 				if (S_ISDIR(curr->fts_statp->st_mode))
467 					(void)fts_set(ftsp, curr, FTS_SKIP);
468 				continue;
469 			}
470 			if (!S_ISDIR(curr->fts_statp->st_mode) &&
471 			    S_ISDIR(to_stat.st_mode)) {
472 				warnx("cannot overwrite directory %s with "
473 				    "non-directory %s",
474 				    to.p_path, curr->fts_path);
475 				badcp = rval = 1;
476 				continue;
477 			}
478 			dne = 0;
479 		}
480 
481 		switch (curr->fts_statp->st_mode & S_IFMT) {
482 		case S_IFLNK:
483 			/* Catch special case of a non-dangling symlink. */
484 			if ((fts_options & FTS_LOGICAL) ||
485 			    ((fts_options & FTS_COMFOLLOW) &&
486 			    curr->fts_level == 0)) {
487 				if (copy_file(curr, dne))
488 					badcp = rval = 1;
489 			} else {
490 				if (copy_link(curr, !dne))
491 					badcp = rval = 1;
492 			}
493 			break;
494 		case S_IFDIR:
495 			if (!Rflag) {
496 				warnx("%s is a directory (not copied).",
497 				    curr->fts_path);
498 				(void)fts_set(ftsp, curr, FTS_SKIP);
499 				badcp = rval = 1;
500 				break;
501 			}
502 			/*
503 			 * If the directory doesn't exist, create the new
504 			 * one with the from file mode plus owner RWX bits,
505 			 * modified by the umask.  Trade-off between being
506 			 * able to write the directory (if from directory is
507 			 * 555) and not causing a permissions race.  If the
508 			 * umask blocks owner writes, we fail.
509 			 */
510 			if (dne) {
511 				if (mkdir(to.p_path,
512 				    curr->fts_statp->st_mode | S_IRWXU) < 0)
513 					err(1, "%s", to.p_path);
514 				/*
515 				 * First DNE with a NULL root_stat is the root
516 				 * path, so set root_stat.  We can't really
517 				 * tell in all cases if the target path is
518 				 * within the src path, so we just stat() the
519 				 * first directory we created and use that.
520 				 */
521 				if (root_stat == NULL &&
522 				    stat(to.p_path, &created_root_stat) == -1) {
523 					err(1, "stat");
524 				} else if (root_stat == NULL) {
525 					root_stat = &created_root_stat;
526 				}
527 			} else if (!S_ISDIR(to_stat.st_mode)) {
528 				errno = ENOTDIR;
529 				err(1, "%s", to.p_path);
530 			}
531 			/*
532 			 * Arrange to correct directory attributes later
533 			 * (in the post-order phase) if this is a new
534 			 * directory, or if the -p flag is in effect.
535 			 */
536 			curr->fts_number = pflag || dne;
537 			break;
538 		case S_IFBLK:
539 		case S_IFCHR:
540 			if (Rflag && !sflag) {
541 				if (copy_special(curr->fts_statp, !dne))
542 					badcp = rval = 1;
543 			} else {
544 				if (copy_file(curr, dne))
545 					badcp = rval = 1;
546 			}
547 			break;
548 		case S_IFSOCK:
549 			warnx("%s is a socket (not copied).",
550 			    curr->fts_path);
551 			break;
552 		case S_IFIFO:
553 			if (Rflag && !sflag) {
554 				if (copy_fifo(curr->fts_statp, !dne))
555 					badcp = rval = 1;
556 			} else {
557 				if (copy_file(curr, dne))
558 					badcp = rval = 1;
559 			}
560 			break;
561 		default:
562 			if (copy_file(curr, dne))
563 				badcp = rval = 1;
564 			break;
565 		}
566 		if (vflag && !badcp)
567 			(void)printf("%s -> %s\n", curr->fts_path, to.p_path);
568 	}
569 	if (errno)
570 		err(1, "fts_read");
571 	fts_close(ftsp);
572 	free(recurse_path);
573 	return (rval);
574 }
575 
576 static void
577 siginfo(int sig __unused)
578 {
579 
580 	info = 1;
581 }
582