xref: /openbsd/bin/cp/cp.c (revision d415bd75)
1 /*	$OpenBSD: cp.c,v 1.53 2019/06/28 13:34:58 deraadt Exp $	*/
2 /*	$NetBSD: cp.c,v 1.14 1995/09/07 06:14:51 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * David Hitz of Auspex Systems Inc.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 /*
37  * Cp copies source files to target files.
38  *
39  * The global PATH_T structure "to" always contains the path to the
40  * current target file.  Since fts(3) does not change directories,
41  * this path can be either absolute or dot-relative.
42  *
43  * The basic algorithm is to initialize "to" and use fts(3) to traverse
44  * the file hierarchy rooted in the argument list.  A trivial case is the
45  * case of 'cp file1 file2'.  The more interesting case is the case of
46  * 'cp file1 file2 ... fileN dir' where the hierarchy is traversed and the
47  * path (relative to the root of the traversal) is appended to dir (stored
48  * in "to") to form the final target path.
49  */
50 
51 #include <sys/types.h>
52 #include <sys/stat.h>
53 #include <sys/mman.h>
54 #include <sys/time.h>
55 
56 #include <dirent.h>
57 #include <err.h>
58 #include <errno.h>
59 #include <fcntl.h>
60 #include <fts.h>
61 #include <limits.h>
62 #include <stdio.h>
63 #include <stdlib.h>
64 #include <string.h>
65 #include <unistd.h>
66 
67 #include "extern.h"
68 
69 #define	fts_dne(_x)	(_x->fts_pointer != NULL)
70 
71 PATH_T to = { to.p_path, "" };
72 
73 uid_t myuid;
74 int Rflag, fflag, iflag, pflag, rflag, vflag;
75 mode_t myumask;
76 
77 enum op { FILE_TO_FILE, FILE_TO_DIR, DIR_TO_DNE };
78 
79 int copy(char *[], enum op, int);
80 char *find_last_component(char *);
81 
82 int
83 main(int argc, char *argv[])
84 {
85 	struct stat to_stat, tmp_stat;
86 	enum op type;
87 	int Hflag, Lflag, Pflag, ch, fts_options, r;
88 	char *target;
89 
90 	Hflag = Lflag = Pflag = Rflag = 0;
91 	while ((ch = getopt(argc, argv, "HLPRafiprv")) != -1)
92 		switch (ch) {
93 		case 'H':
94 			Hflag = 1;
95 			Lflag = Pflag = 0;
96 			break;
97 		case 'L':
98 			Lflag = 1;
99 			Hflag = Pflag = 0;
100 			break;
101 		case 'P':
102 			Pflag = 1;
103 			Hflag = Lflag = 0;
104 			break;
105 		case 'R':
106 			Rflag = 1;
107 			break;
108 		case 'a':
109 			Rflag = 1;
110 			pflag = 1;
111 			Pflag = 1;
112 			Hflag = Lflag = 0;
113 			break;
114 		case 'f':
115 			fflag = 1;
116 			iflag = 0;
117 			break;
118 		case 'i':
119 			iflag = 1;
120 			fflag = 0;
121 			break;
122 		case 'p':
123 			pflag = 1;
124 			break;
125 		case 'r':
126 			rflag = 1;
127 			break;
128 		case 'v':
129 			vflag = 1;
130 			break;
131 		default:
132 			usage();
133 			break;
134 		}
135 	argc -= optind;
136 	argv += optind;
137 
138 	/*
139 	 * Unfortunately, -R will use mkfifo & mknod;
140 	 * -p will use fchown, fchmod, lchown, fchflags..
141 	 */
142 	if (Rflag == 0 && pflag == 0)
143 		if (pledge("stdio rpath wpath cpath fattr", NULL) == -1)
144 			err(1, "pledge");
145 
146 	if (argc < 2)
147 		usage();
148 
149 	fts_options = FTS_NOCHDIR | FTS_PHYSICAL;
150 	if (rflag) {
151 		if (Rflag)
152 			errx(1,
153 		    "the -R and -r options may not be specified together.");
154 		if (Hflag || Lflag || Pflag)
155 			errx(1,
156 	"the -H, -L, and -P options may not be specified with the -r option.");
157 		fts_options &= ~FTS_PHYSICAL;
158 		fts_options |= FTS_LOGICAL;
159 	}
160 	if (Rflag) {
161 		if (Hflag)
162 			fts_options |= FTS_COMFOLLOW;
163 		if (Lflag) {
164 			fts_options &= ~FTS_PHYSICAL;
165 			fts_options |= FTS_LOGICAL;
166 		}
167 	} else {
168 		fts_options &= ~FTS_PHYSICAL;
169 		fts_options |= FTS_LOGICAL;
170 	}
171 
172 	myuid = getuid();
173 
174 	/* Copy the umask for explicit mode setting. */
175 	myumask = umask(0);
176 	(void)umask(myumask);
177 
178 	/* Save the target base in "to". */
179 	target = argv[--argc];
180 	if (strlcpy(to.p_path, target, sizeof to.p_path) >= sizeof(to.p_path))
181 		errx(1, "%s: name too long", target);
182 	to.p_end = to.p_path + strlen(to.p_path);
183 	if (to.p_path == to.p_end) {
184 		*to.p_end++ = '.';
185 		*to.p_end = '\0';
186 	}
187 	to.target_end = to.p_end;
188 
189 	/* Set end of argument list for fts(3). */
190 	argv[argc] = NULL;
191 
192 	/*
193 	 * Cp has two distinct cases:
194 	 *
195 	 * cp [-R] source target
196 	 * cp [-R] source1 ... sourceN directory
197 	 *
198 	 * In both cases, source can be either a file or a directory.
199 	 *
200 	 * In (1), the target becomes a copy of the source. That is, if the
201 	 * source is a file, the target will be a file, and likewise for
202 	 * directories.
203 	 *
204 	 * In (2), the real target is not directory, but "directory/source".
205 	 */
206 	r = stat(to.p_path, &to_stat);
207 	if (r == -1 && errno != ENOENT)
208 		err(1, "%s", to.p_path);
209 	if (r == -1 || !S_ISDIR(to_stat.st_mode)) {
210 		/*
211 		 * Case (1).  Target is not a directory.
212 		 */
213 		if (argc > 1)
214 			usage();
215 		/*
216 		 * Need to detect the case:
217 		 *	cp -R dir foo
218 		 * Where dir is a directory and foo does not exist, where
219 		 * we want pathname concatenations turned on but not for
220 		 * the initial mkdir().
221 		 */
222 		if (r == -1) {
223 			if (rflag || (Rflag && (Lflag || Hflag)))
224 				stat(*argv, &tmp_stat);
225 			else
226 				lstat(*argv, &tmp_stat);
227 
228 			if (S_ISDIR(tmp_stat.st_mode) && (Rflag || rflag))
229 				type = DIR_TO_DNE;
230 			else
231 				type = FILE_TO_FILE;
232 		} else
233 			type = FILE_TO_FILE;
234 	} else {
235 		/*
236 		 * Case (2).  Target is a directory.
237 		 */
238 		type = FILE_TO_DIR;
239 	}
240 
241 	return (copy(argv, type, fts_options));
242 }
243 
244 char *
245 find_last_component(char *path)
246 {
247 	char *p;
248 
249 	if ((p = strrchr(path, '/')) == NULL)
250 		p = path;
251 	else {
252 		/* Special case foo/ */
253 		if (!*(p+1)) {
254 			while ((p >= path) && *p == '/')
255 				p--;
256 
257 			while ((p >= path) && *p != '/')
258 				p--;
259 		}
260 
261 		p++;
262 	}
263 
264 	return (p);
265 }
266 
267 int
268 copy(char *argv[], enum op type, int fts_options)
269 {
270 	struct stat to_stat;
271 	FTS *ftsp;
272 	FTSENT *curr;
273 	int base, cval, nlen, rval;
274 	char *p, *target_mid;
275 	base = 0;
276 
277 	if ((ftsp = fts_open(argv, fts_options, NULL)) == NULL)
278 		err(1, NULL);
279 	for (rval = 0; (curr = fts_read(ftsp)) != NULL;) {
280 		switch (curr->fts_info) {
281 		case FTS_NS:
282 		case FTS_DNR:
283 		case FTS_ERR:
284 			warnx("%s: %s",
285 			    curr->fts_path, strerror(curr->fts_errno));
286 			rval = 1;
287 			continue;
288 		case FTS_DC:
289 			warnx("%s: directory causes a cycle", curr->fts_path);
290 			rval = 1;
291 			continue;
292 		}
293 
294 		/*
295 		 * If we are in case (2) or (3) above, we need to append the
296 		 * source name to the target name.
297 		 */
298 		if (type != FILE_TO_FILE) {
299 			/*
300 			 * Need to remember the roots of traversals to create
301 			 * correct pathnames.  If there's a directory being
302 			 * copied to a non-existent directory, e.g.
303 			 *	cp -R a/dir noexist
304 			 * the resulting path name should be noexist/foo, not
305 			 * noexist/dir/foo (where foo is a file in dir), which
306 			 * is the case where the target exists.
307 			 *
308 			 * Also, check for "..".  This is for correct path
309 			 * concatenation for paths ending in "..", e.g.
310 			 *	cp -R .. /tmp
311 			 * Paths ending in ".." are changed to ".".  This is
312 			 * tricky, but seems the easiest way to fix the problem.
313 			 *
314 			 * XXX
315 			 * Since the first level MUST be FTS_ROOTLEVEL, base
316 			 * is always initialized.
317 			 */
318 			if (curr->fts_level == FTS_ROOTLEVEL) {
319 				if (type != DIR_TO_DNE) {
320 					p = find_last_component(curr->fts_path);
321 					base = p - curr->fts_path;
322 
323 					if (!strcmp(&curr->fts_path[base],
324 					    ".."))
325 						base += 1;
326 				} else
327 					base = curr->fts_pathlen;
328 			}
329 
330 			p = &curr->fts_path[base];
331 			nlen = curr->fts_pathlen - base;
332 			target_mid = to.target_end;
333 			if (*p != '/' && target_mid[-1] != '/')
334 				*target_mid++ = '/';
335 			*target_mid = '\0';
336 			if (target_mid - to.p_path + nlen >= PATH_MAX) {
337 				warnx("%s%s: name too long (not copied)",
338 				    to.p_path, p);
339 				rval = 1;
340 				continue;
341 			}
342 			(void)strncat(target_mid, p, nlen);
343 			to.p_end = target_mid + nlen;
344 			*to.p_end = '\0';
345 		}
346 
347 		/* Not an error but need to remember it happened */
348 		if (stat(to.p_path, &to_stat) == -1) {
349 			if (curr->fts_info == FTS_DP)
350 				continue;
351 			/*
352 			 * We use fts_pointer as a boolean to indicate that
353 			 * we created this directory ourselves.  We'll use
354 			 * this later on via the fts_dne macro to decide
355 			 * whether or not to set the directory mode during
356 			 * the post-order pass.
357 			 */
358 			curr->fts_pointer = (void *)1;
359 		} else {
360 			/*
361 			 * Set directory mode/user/times on the post-order
362 			 * pass.  We can't do this earlier because the mode
363 			 * may not allow us write permission.  Furthermore,
364 			 * if we set the times during the pre-order pass,
365 			 * they will get changed later when the directory
366 			 * is populated.
367 			 */
368 			if (curr->fts_info == FTS_DP) {
369 				if (!S_ISDIR(to_stat.st_mode))
370 					continue;
371 				/*
372 				 * If not -p and directory didn't exist, set
373 				 * it to be the same as the from directory,
374 				 * unmodified by the umask; arguably wrong,
375 				 * but it's been that way forever.
376 				 */
377 				if (pflag && setfile(curr->fts_statp, -1))
378 					rval = 1;
379 				else if (fts_dne(curr))
380 					(void)chmod(to.p_path,
381 					    curr->fts_statp->st_mode);
382 				continue;
383 			}
384 			if (to_stat.st_dev == curr->fts_statp->st_dev &&
385 			    to_stat.st_ino == curr->fts_statp->st_ino) {
386 				warnx("%s and %s are identical (not copied).",
387 				    to.p_path, curr->fts_path);
388 				rval = 1;
389 				if (S_ISDIR(curr->fts_statp->st_mode))
390 					(void)fts_set(ftsp, curr, FTS_SKIP);
391 				continue;
392 			}
393 			if (!S_ISDIR(curr->fts_statp->st_mode) &&
394 			    S_ISDIR(to_stat.st_mode)) {
395 		warnx("cannot overwrite directory %s with non-directory %s",
396 				    to.p_path, curr->fts_path);
397 				rval = 1;
398 				continue;
399 			}
400 		}
401 
402 		switch (curr->fts_statp->st_mode & S_IFMT) {
403 		case S_IFLNK:
404 			if ((cval = copy_link(curr, !fts_dne(curr))) == 1)
405 				rval = 1;
406 			if (!cval && vflag)
407 				(void)fprintf(stdout, "%s -> %s\n",
408 				    curr->fts_path, to.p_path);
409 			break;
410 		case S_IFDIR:
411 			if (!Rflag && !rflag) {
412 				warnx("%s is a directory (not copied).",
413 				    curr->fts_path);
414 				(void)fts_set(ftsp, curr, FTS_SKIP);
415 				rval = 1;
416 				break;
417 			}
418 			/*
419 			 * If the directory doesn't exist, create the new
420 			 * one with the from file mode plus owner RWX bits,
421 			 * modified by the umask.  Trade-off between being
422 			 * able to write the directory (if from directory is
423 			 * 555) and not causing a permissions race.  If the
424 			 * umask blocks owner writes, we fail..
425 			 */
426 			if (fts_dne(curr)) {
427 				if (mkdir(to.p_path,
428 				    curr->fts_statp->st_mode | S_IRWXU) == -1)
429 					err(1, "%s", to.p_path);
430 				else if (vflag)
431 					(void)fprintf(stdout, "%s -> %s\n",
432 					    curr->fts_path, to.p_path);
433 			} else if (!S_ISDIR(to_stat.st_mode))
434 				errc(1, ENOTDIR, "%s", to.p_path);
435 			break;
436 		case S_IFBLK:
437 		case S_IFCHR:
438 			if (Rflag) {
439 				if ((cval = copy_special(curr->fts_statp,
440 				    !fts_dne(curr))) == 1)
441 					rval = 1;
442 			} else
443 				if ((cval = copy_file(curr, !fts_dne(curr))) == 1)
444 					rval = 1;
445 			if (!cval && vflag)
446 				(void)fprintf(stdout, "%s -> %s\n",
447 				    curr->fts_path, to.p_path);
448 			cval = 0;
449 			break;
450 		case S_IFIFO:
451 			if (Rflag) {
452 				if ((cval = copy_fifo(curr->fts_statp,
453 				    !fts_dne(curr))) == 1)
454 					rval = 1;
455 			} else
456 				if ((cval = copy_file(curr, !fts_dne(curr))) == 1)
457 					rval = 1;
458 			if (!cval && vflag)
459 				(void)fprintf(stdout, "%s -> %s\n",
460 				    curr->fts_path, to.p_path);
461 			cval = 0;
462 			break;
463 		case S_IFSOCK:
464 			warnc(EOPNOTSUPP, "%s", curr->fts_path);
465 			break;
466 		default:
467 			if ((cval = copy_file(curr, !fts_dne(curr))) == 1)
468 				rval = 1;
469 			if (!cval && vflag)
470 				(void)fprintf(stdout, "%s -> %s\n",
471 				    curr->fts_path, to.p_path);
472 			cval = 0;
473 			break;
474 		}
475 	}
476 	if (errno)
477 		err(1, "fts_read");
478 	(void)fts_close(ftsp);
479 	return (rval);
480 }
481