xref: /freebsd/bin/cp/cp.c (revision a0409676120c1e558d0ade943019934e0f15118d)
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 <err.h>
68 #include <errno.h>
69 #include <fts.h>
70 #include <limits.h>
71 #include <signal.h>
72 #include <stdio.h>
73 #include <stdlib.h>
74 #include <string.h>
75 #include <unistd.h>
76 
77 #include "extern.h"
78 
79 #define	STRIP_TRAILING_SLASH(p) {					\
80 	while ((p).p_end > (p).p_path + 1 && (p).p_end[-1] == '/')	\
81 	*--(p).p_end = 0;						\
82 }
83 
84 static char emptystring[] = "";
85 
86 PATH_T to = { to.p_path, emptystring, "" };
87 
88 int fflag, iflag, lflag, nflag, pflag, sflag, vflag;
89 static int Rflag, rflag;
90 volatile sig_atomic_t info;
91 
92 enum op { FILE_TO_FILE, FILE_TO_DIR, DIR_TO_DNE };
93 
94 static int copy(char *[], enum op, int);
95 static void siginfo(int __unused);
96 
97 int
98 main(int argc, char *argv[])
99 {
100 	struct stat to_stat, tmp_stat;
101 	enum op type;
102 	int Hflag, Lflag, ch, fts_options, r, have_trailing_slash;
103 	char *target;
104 
105 	fts_options = FTS_NOCHDIR | FTS_PHYSICAL;
106 	Hflag = Lflag = 0;
107 	while ((ch = getopt(argc, argv, "HLPRafilnprsvx")) != -1)
108 		switch (ch) {
109 		case 'H':
110 			Hflag = 1;
111 			Lflag = 0;
112 			break;
113 		case 'L':
114 			Lflag = 1;
115 			Hflag = 0;
116 			break;
117 		case 'P':
118 			Hflag = Lflag = 0;
119 			break;
120 		case 'R':
121 			Rflag = 1;
122 			break;
123 		case 'a':
124 			pflag = 1;
125 			Rflag = 1;
126 			Hflag = Lflag = 0;
127 			break;
128 		case 'f':
129 			fflag = 1;
130 			iflag = nflag = 0;
131 			break;
132 		case 'i':
133 			iflag = 1;
134 			fflag = nflag = 0;
135 			break;
136 		case 'l':
137 			lflag = 1;
138 			break;
139 		case 'n':
140 			nflag = 1;
141 			fflag = iflag = 0;
142 			break;
143 		case 'p':
144 			pflag = 1;
145 			break;
146 		case 'r':
147 			rflag = Lflag = 1;
148 			Hflag = 0;
149 			break;
150 		case 's':
151 			sflag = 1;
152 			break;
153 		case 'v':
154 			vflag = 1;
155 			break;
156 		case 'x':
157 			fts_options |= FTS_XDEV;
158 			break;
159 		default:
160 			usage();
161 			break;
162 		}
163 	argc -= optind;
164 	argv += optind;
165 
166 	if (argc < 2)
167 		usage();
168 
169 	if (Rflag && rflag)
170 		errx(1, "the -R and -r options may not be specified together");
171 	if (lflag && sflag)
172 		errx(1, "the -l and -s options may not be specified together");
173 	if (rflag)
174 		Rflag = 1;
175 	if (Rflag) {
176 		if (Hflag)
177 			fts_options |= FTS_COMFOLLOW;
178 		if (Lflag) {
179 			fts_options &= ~FTS_PHYSICAL;
180 			fts_options |= FTS_LOGICAL;
181 		}
182 	} else {
183 		fts_options &= ~FTS_PHYSICAL;
184 		fts_options |= FTS_LOGICAL | FTS_COMFOLLOW;
185 	}
186 	(void)signal(SIGINFO, siginfo);
187 
188 	/* Save the target base in "to". */
189 	target = argv[--argc];
190 	if (strlcpy(to.p_path, target, sizeof(to.p_path)) >= sizeof(to.p_path))
191 		errx(1, "%s: name too long", target);
192 	to.p_end = to.p_path + strlen(to.p_path);
193 	if (to.p_path == to.p_end) {
194 		*to.p_end++ = '.';
195 		*to.p_end = 0;
196 	}
197 	have_trailing_slash = (to.p_end[-1] == '/');
198 	if (have_trailing_slash)
199 		STRIP_TRAILING_SLASH(to);
200 	to.target_end = to.p_end;
201 
202 	/* Set end of argument list for fts(3). */
203 	argv[argc] = NULL;
204 
205 	/*
206 	 * Cp has two distinct cases:
207 	 *
208 	 * cp [-R] source target
209 	 * cp [-R] source1 ... sourceN directory
210 	 *
211 	 * In both cases, source can be either a file or a directory.
212 	 *
213 	 * In (1), the target becomes a copy of the source. That is, if the
214 	 * source is a file, the target will be a file, and likewise for
215 	 * directories.
216 	 *
217 	 * In (2), the real target is not directory, but "directory/source".
218 	 */
219 	r = stat(to.p_path, &to_stat);
220 	if (r == -1 && errno != ENOENT)
221 		err(1, "%s", to.p_path);
222 	if (r == -1 || !S_ISDIR(to_stat.st_mode)) {
223 		/*
224 		 * Case (1).  Target is not a directory.
225 		 */
226 		if (argc > 1)
227 			errx(1, "%s is not a directory", to.p_path);
228 
229 		/*
230 		 * Need to detect the case:
231 		 *	cp -R dir foo
232 		 * Where dir is a directory and foo does not exist, where
233 		 * we want pathname concatenations turned on but not for
234 		 * the initial mkdir().
235 		 */
236 		if (r == -1) {
237 			if (Rflag && (Lflag || Hflag))
238 				stat(*argv, &tmp_stat);
239 			else
240 				lstat(*argv, &tmp_stat);
241 
242 			if (S_ISDIR(tmp_stat.st_mode) && Rflag)
243 				type = DIR_TO_DNE;
244 			else
245 				type = FILE_TO_FILE;
246 		} else
247 			type = FILE_TO_FILE;
248 
249 		if (have_trailing_slash && type == FILE_TO_FILE) {
250 			if (r == -1) {
251 				errx(1, "directory %s does not exist",
252 				    to.p_path);
253 			} else
254 				errx(1, "%s is not a directory", to.p_path);
255 		}
256 	} else
257 		/*
258 		 * Case (2).  Target is a directory.
259 		 */
260 		type = FILE_TO_DIR;
261 
262 	exit (copy(argv, type, fts_options));
263 }
264 
265 static int
266 copy(char *argv[], enum op type, int fts_options)
267 {
268 	struct stat to_stat;
269 	FTS *ftsp;
270 	FTSENT *curr;
271 	int base = 0, dne, badcp, rval;
272 	size_t nlen;
273 	char *p, *target_mid;
274 	mode_t mask, mode;
275 
276 	/*
277 	 * Keep an inverted copy of the umask, for use in correcting
278 	 * permissions on created directories when not using -p.
279 	 */
280 	mask = ~umask(0777);
281 	umask(~mask);
282 
283 	if ((ftsp = fts_open(argv, fts_options, NULL)) == NULL)
284 		err(1, "fts_open");
285 	for (badcp = rval = 0; errno = 0, (curr = fts_read(ftsp)) != NULL;
286             badcp = 0) {
287 		switch (curr->fts_info) {
288 		case FTS_NS:
289 		case FTS_DNR:
290 		case FTS_ERR:
291 			warnx("%s: %s",
292 			    curr->fts_path, strerror(curr->fts_errno));
293 			badcp = rval = 1;
294 			continue;
295 		case FTS_DC:			/* Warn, continue. */
296 			warnx("%s: directory causes a cycle", curr->fts_path);
297 			badcp = rval = 1;
298 			continue;
299 		default:
300 			;
301 		}
302 
303 		/*
304 		 * If we are in case (2) or (3) above, we need to append the
305 		 * source name to the target name.
306 		 */
307 		if (type != FILE_TO_FILE) {
308 			/*
309 			 * Need to remember the roots of traversals to create
310 			 * correct pathnames.  If there's a directory being
311 			 * copied to a non-existent directory, e.g.
312 			 *	cp -R a/dir noexist
313 			 * the resulting path name should be noexist/foo, not
314 			 * noexist/dir/foo (where foo is a file in dir), which
315 			 * is the case where the target exists.
316 			 *
317 			 * Also, check for "..".  This is for correct path
318 			 * concatenation for paths ending in "..", e.g.
319 			 *	cp -R .. /tmp
320 			 * Paths ending in ".." are changed to ".".  This is
321 			 * tricky, but seems the easiest way to fix the problem.
322 			 *
323 			 * XXX
324 			 * Since the first level MUST be FTS_ROOTLEVEL, base
325 			 * is always initialized.
326 			 */
327 			if (curr->fts_level == FTS_ROOTLEVEL) {
328 				if (type != DIR_TO_DNE) {
329 					p = strrchr(curr->fts_path, '/');
330 					base = (p == NULL) ? 0 :
331 					    (int)(p - curr->fts_path + 1);
332 
333 					if (!strcmp(&curr->fts_path[base],
334 					    ".."))
335 						base += 1;
336 				} else
337 					base = curr->fts_pathlen;
338 			}
339 
340 			p = &curr->fts_path[base];
341 			nlen = curr->fts_pathlen - base;
342 			target_mid = to.target_end;
343 			if (*p != '/' && target_mid[-1] != '/')
344 				*target_mid++ = '/';
345 			*target_mid = 0;
346 			if (target_mid - to.p_path + nlen >= PATH_MAX) {
347 				warnx("%s%s: name too long (not copied)",
348 				    to.p_path, p);
349 				badcp = rval = 1;
350 				continue;
351 			}
352 			(void)strncat(target_mid, p, nlen);
353 			to.p_end = target_mid + nlen;
354 			*to.p_end = 0;
355 			STRIP_TRAILING_SLASH(to);
356 		}
357 
358 		if (curr->fts_info == FTS_DP) {
359 			/*
360 			 * We are nearly finished with this directory.  If we
361 			 * didn't actually copy it, or otherwise don't need to
362 			 * change its attributes, then we are done.
363 			 */
364 			if (!curr->fts_number)
365 				continue;
366 			/*
367 			 * If -p is in effect, set all the attributes.
368 			 * Otherwise, set the correct permissions, limited
369 			 * by the umask.  Optimise by avoiding a chmod()
370 			 * if possible (which is usually the case if we
371 			 * made the directory).  Note that mkdir() does not
372 			 * honour setuid, setgid and sticky bits, but we
373 			 * normally want to preserve them on directories.
374 			 */
375 			if (pflag) {
376 				if (setfile(curr->fts_statp, -1))
377 					rval = 1;
378 				if (preserve_dir_acls(curr->fts_statp,
379 				    curr->fts_accpath, to.p_path) != 0)
380 					rval = 1;
381 			} else {
382 				mode = curr->fts_statp->st_mode;
383 				if ((mode & (S_ISUID | S_ISGID | S_ISTXT)) ||
384 				    ((mode | S_IRWXU) & mask) != (mode & mask))
385 					if (chmod(to.p_path, mode & mask) !=
386 					    0) {
387 						warn("chmod: %s", to.p_path);
388 						rval = 1;
389 					}
390 			}
391 			continue;
392 		}
393 
394 		/* Not an error but need to remember it happened. */
395 		if (stat(to.p_path, &to_stat) == -1)
396 			dne = 1;
397 		else {
398 			if (to_stat.st_dev == curr->fts_statp->st_dev &&
399 			    to_stat.st_ino == curr->fts_statp->st_ino) {
400 				warnx("%s and %s are identical (not copied).",
401 				    to.p_path, curr->fts_path);
402 				badcp = rval = 1;
403 				if (S_ISDIR(curr->fts_statp->st_mode))
404 					(void)fts_set(ftsp, curr, FTS_SKIP);
405 				continue;
406 			}
407 			if (!S_ISDIR(curr->fts_statp->st_mode) &&
408 			    S_ISDIR(to_stat.st_mode)) {
409 				warnx("cannot overwrite directory %s with "
410 				    "non-directory %s",
411 				    to.p_path, curr->fts_path);
412 				badcp = rval = 1;
413 				continue;
414 			}
415 			dne = 0;
416 		}
417 
418 		switch (curr->fts_statp->st_mode & S_IFMT) {
419 		case S_IFLNK:
420 			/* Catch special case of a non-dangling symlink. */
421 			if ((fts_options & FTS_LOGICAL) ||
422 			    ((fts_options & FTS_COMFOLLOW) &&
423 			    curr->fts_level == 0)) {
424 				if (copy_file(curr, dne))
425 					badcp = rval = 1;
426 			} else {
427 				if (copy_link(curr, !dne))
428 					badcp = rval = 1;
429 			}
430 			break;
431 		case S_IFDIR:
432 			if (!Rflag) {
433 				warnx("%s is a directory (not copied).",
434 				    curr->fts_path);
435 				(void)fts_set(ftsp, curr, FTS_SKIP);
436 				badcp = rval = 1;
437 				break;
438 			}
439 			/*
440 			 * If the directory doesn't exist, create the new
441 			 * one with the from file mode plus owner RWX bits,
442 			 * modified by the umask.  Trade-off between being
443 			 * able to write the directory (if from directory is
444 			 * 555) and not causing a permissions race.  If the
445 			 * umask blocks owner writes, we fail.
446 			 */
447 			if (dne) {
448 				if (mkdir(to.p_path,
449 				    curr->fts_statp->st_mode | S_IRWXU) < 0)
450 					err(1, "%s", to.p_path);
451 			} else if (!S_ISDIR(to_stat.st_mode)) {
452 				errno = ENOTDIR;
453 				err(1, "%s", to.p_path);
454 			}
455 			/*
456 			 * Arrange to correct directory attributes later
457 			 * (in the post-order phase) if this is a new
458 			 * directory, or if the -p flag is in effect.
459 			 */
460 			curr->fts_number = pflag || dne;
461 			break;
462 		case S_IFBLK:
463 		case S_IFCHR:
464 			if (Rflag && !sflag) {
465 				if (copy_special(curr->fts_statp, !dne))
466 					badcp = rval = 1;
467 			} else {
468 				if (copy_file(curr, dne))
469 					badcp = rval = 1;
470 			}
471 			break;
472 		case S_IFSOCK:
473 			warnx("%s is a socket (not copied).",
474 			    curr->fts_path);
475 			break;
476 		case S_IFIFO:
477 			if (Rflag && !sflag) {
478 				if (copy_fifo(curr->fts_statp, !dne))
479 					badcp = rval = 1;
480 			} else {
481 				if (copy_file(curr, dne))
482 					badcp = rval = 1;
483 			}
484 			break;
485 		default:
486 			if (copy_file(curr, dne))
487 				badcp = rval = 1;
488 			break;
489 		}
490 		if (vflag && !badcp)
491 			(void)printf("%s -> %s\n", curr->fts_path, to.p_path);
492 	}
493 	if (errno)
494 		err(1, "fts_read");
495 	fts_close(ftsp);
496 	return (rval);
497 }
498 
499 static void
500 siginfo(int sig __unused)
501 {
502 
503 	info = 1;
504 }
505