xref: /freebsd/usr.bin/xinstall/xinstall.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*
2  * Copyright (c) 1987, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1987, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #if 0
37 #ifndef lint
38 static char sccsid[] = "@(#)xinstall.c	8.1 (Berkeley) 7/21/93";
39 #endif /* not lint */
40 #endif
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/mman.h>
47 #include <sys/mount.h>
48 #include <sys/stat.h>
49 #include <sys/time.h>
50 #include <sys/wait.h>
51 
52 #include <err.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <grp.h>
56 #include <paths.h>
57 #include <pwd.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <sysexits.h>
62 #include <unistd.h>
63 
64 /* Bootstrap aid - this doesn't exist in most older releases */
65 #ifndef MAP_FAILED
66 #define MAP_FAILED ((void *)-1)	/* from <sys/mman.h> */
67 #endif
68 
69 #define MAX_CMP_SIZE	(16 * 1024 * 1024)
70 
71 #define	DIRECTORY	0x01		/* Tell install it's a directory. */
72 #define	SETFLAGS	0x02		/* Tell install to set flags. */
73 #define	NOCHANGEBITS	(UF_IMMUTABLE | UF_APPEND | SF_IMMUTABLE | SF_APPEND)
74 #define	BACKUP_SUFFIX	".old"
75 
76 static struct passwd *pp;
77 static struct group *gp;
78 static gid_t gid;
79 static uid_t uid;
80 static int dobackup, docompare, dodir, dopreserve, dostrip, nommap, safecopy,
81     verbose;
82 static mode_t mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
83 static const char *suffix = BACKUP_SUFFIX;
84 
85 static int	compare(int, const char *, size_t, int, const char *, size_t);
86 static void	copy(int, const char *, int, const char *, off_t);
87 static int	create_newfile(const char *, int, struct stat *);
88 static int	create_tempfile(const char *, char *, size_t);
89 static void	install(const char *, const char *, u_long, u_int);
90 static void	install_dir(char *);
91 static u_long	numeric_id(const char *, const char *);
92 static void	strip(const char *);
93 static int	trymmap(int);
94 static void	usage(void);
95 
96 int
97 main(int argc, char *argv[])
98 {
99 	struct stat from_sb, to_sb;
100 	mode_t *set;
101 	u_long fset;
102 	int ch, no_target;
103 	u_int iflags;
104 	char *flags;
105 	const char *group, *owner, *to_name;
106 
107 	iflags = 0;
108 	group = owner = NULL;
109 	while ((ch = getopt(argc, argv, "B:bCcdf:g:Mm:o:pSsv")) != -1)
110 		switch((char)ch) {
111 		case 'B':
112 			suffix = optarg;
113 			/* FALLTHROUGH */
114 		case 'b':
115 			dobackup = 1;
116 			break;
117 		case 'C':
118 			docompare = 1;
119 			break;
120 		case 'c':
121 			/* For backwards compatibility. */
122 			break;
123 		case 'd':
124 			dodir = 1;
125 			break;
126 		case 'f':
127 			flags = optarg;
128 			if (strtofflags(&flags, &fset, NULL))
129 				errx(EX_USAGE, "%s: invalid flag", flags);
130 			iflags |= SETFLAGS;
131 			break;
132 		case 'g':
133 			group = optarg;
134 			break;
135 		case 'M':
136 			nommap = 1;
137 			break;
138 		case 'm':
139 			if (!(set = setmode(optarg)))
140 				errx(EX_USAGE, "invalid file mode: %s",
141 				     optarg);
142 			mode = getmode(set, 0);
143 			free(set);
144 			break;
145 		case 'o':
146 			owner = optarg;
147 			break;
148 		case 'p':
149 			docompare = dopreserve = 1;
150 			break;
151 		case 'S':
152 			safecopy = 1;
153 			break;
154 		case 's':
155 			dostrip = 1;
156 			break;
157 		case 'v':
158 			verbose = 1;
159 			break;
160 		case '?':
161 		default:
162 			usage();
163 		}
164 	argc -= optind;
165 	argv += optind;
166 
167 	/* some options make no sense when creating directories */
168 	if (dostrip && dodir) {
169 		warnx("-d and -s may not be specified together");
170 		usage();
171 	}
172 
173 	if (getenv("DONTSTRIP") != NULL) {
174 		warnx("DONTSTRIP set - will not strip installed binaries");
175 		dostrip = 0;
176 	}
177 
178 	/* must have at least two arguments, except when creating directories */
179 	if (argc == 0 || (argc == 1 && !dodir))
180 		usage();
181 
182 	/* need to make a temp copy so we can compare stripped version */
183 	if (docompare && dostrip)
184 		safecopy = 1;
185 
186 	/* get group and owner id's */
187 	if (group != NULL) {
188 		if ((gp = getgrnam(group)) != NULL)
189 			gid = gp->gr_gid;
190 		else
191 			gid = (gid_t)numeric_id(group, "group");
192 	} else
193 		gid = (gid_t)-1;
194 
195 	if (owner != NULL) {
196 		if ((pp = getpwnam(owner)) != NULL)
197 			uid = pp->pw_uid;
198 		else
199 			uid = (uid_t)numeric_id(owner, "user");
200 	} else
201 		uid = (uid_t)-1;
202 
203 	if (dodir) {
204 		for (; *argv != NULL; ++argv)
205 			install_dir(*argv);
206 		exit(EX_OK);
207 		/* NOTREACHED */
208 	}
209 
210 	no_target = stat(to_name = argv[argc - 1], &to_sb);
211 	if (!no_target && S_ISDIR(to_sb.st_mode)) {
212 		for (; *argv != to_name; ++argv)
213 			install(*argv, to_name, fset, iflags | DIRECTORY);
214 		exit(EX_OK);
215 		/* NOTREACHED */
216 	}
217 
218 	/* can't do file1 file2 directory/file */
219 	if (argc != 2) {
220 		if (no_target)
221 			warnx("target directory `%s' does not exist",
222 			    argv[argc - 1]);
223 		else
224 			warnx("target `%s' is not a directory",
225 			    argv[argc - 1]);
226 		usage();
227 	}
228 
229 	if (!no_target) {
230 		if (stat(*argv, &from_sb))
231 			err(EX_OSERR, "%s", *argv);
232 		if (!S_ISREG(to_sb.st_mode)) {
233 			errno = EFTYPE;
234 			err(EX_OSERR, "%s", to_name);
235 		}
236 		if (to_sb.st_dev == from_sb.st_dev &&
237 		    to_sb.st_ino == from_sb.st_ino)
238 			errx(EX_USAGE,
239 			    "%s and %s are the same file", *argv, to_name);
240 	}
241 	install(*argv, to_name, fset, iflags);
242 	exit(EX_OK);
243 	/* NOTREACHED */
244 }
245 
246 static u_long
247 numeric_id(const char *name, const char *type)
248 {
249 	u_long val;
250 	char *ep;
251 
252 	/*
253 	 * XXX
254 	 * We know that uid_t's and gid_t's are unsigned longs.
255 	 */
256 	errno = 0;
257 	val = strtoul(name, &ep, 10);
258 	if (errno)
259 		err(EX_NOUSER, "%s", name);
260 	if (*ep != '\0')
261 		errx(EX_NOUSER, "unknown %s %s", type, name);
262 	return (val);
263 }
264 
265 /*
266  * install --
267  *	build a path name and install the file
268  */
269 static void
270 install(const char *from_name, const char *to_name, u_long fset, u_int flags)
271 {
272 	struct stat from_sb, temp_sb, to_sb;
273 	struct timeval tvb[2];
274 	int devnull, files_match, from_fd, serrno, target;
275 	int tempcopy, temp_fd, to_fd;
276 	char backup[MAXPATHLEN], *p, pathbuf[MAXPATHLEN], tempfile[MAXPATHLEN];
277 
278 	files_match = 0;
279 	from_fd = -1;
280 	to_fd = -1;
281 
282 	/* If try to install NULL file to a directory, fails. */
283 	if (flags & DIRECTORY || strcmp(from_name, _PATH_DEVNULL)) {
284 		if (stat(from_name, &from_sb))
285 			err(EX_OSERR, "%s", from_name);
286 		if (!S_ISREG(from_sb.st_mode)) {
287 			errno = EFTYPE;
288 			err(EX_OSERR, "%s", from_name);
289 		}
290 		/* Build the target path. */
291 		if (flags & DIRECTORY) {
292 			(void)snprintf(pathbuf, sizeof(pathbuf), "%s/%s",
293 			    to_name,
294 			    (p = strrchr(from_name, '/')) ? ++p : from_name);
295 			to_name = pathbuf;
296 		}
297 		devnull = 0;
298 	} else {
299 		devnull = 1;
300 	}
301 
302 	target = stat(to_name, &to_sb) == 0;
303 
304 	/* Only install to regular files. */
305 	if (target && !S_ISREG(to_sb.st_mode)) {
306 		errno = EFTYPE;
307 		warn("%s", to_name);
308 		return;
309 	}
310 
311 	/* Only copy safe if the target exists. */
312 	tempcopy = safecopy && target;
313 
314 	if (!devnull && (from_fd = open(from_name, O_RDONLY, 0)) < 0)
315 		err(EX_OSERR, "%s", from_name);
316 
317 	/* If we don't strip, we can compare first. */
318 	if (docompare && !dostrip && target) {
319 		if ((to_fd = open(to_name, O_RDONLY, 0)) < 0)
320 			err(EX_OSERR, "%s", to_name);
321 		if (devnull)
322 			files_match = to_sb.st_size == 0;
323 		else
324 			files_match = !(compare(from_fd, from_name,
325 			    (size_t)from_sb.st_size, to_fd,
326 			    to_name, (size_t)to_sb.st_size));
327 
328 		/* Close "to" file unless we match. */
329 		if (!files_match)
330 			(void)close(to_fd);
331 	}
332 
333 	if (!files_match) {
334 		if (tempcopy) {
335 			to_fd = create_tempfile(to_name, tempfile,
336 			    sizeof(tempfile));
337 			if (to_fd < 0)
338 				err(EX_OSERR, "%s", tempfile);
339 		} else {
340 			if ((to_fd = create_newfile(to_name, target,
341 			    &to_sb)) < 0)
342 				err(EX_OSERR, "%s", to_name);
343 			if (verbose)
344 				(void)printf("install: %s -> %s\n",
345 				    from_name, to_name);
346 		}
347 		if (!devnull)
348 			copy(from_fd, from_name, to_fd,
349 			     tempcopy ? tempfile : to_name, from_sb.st_size);
350 	}
351 
352 	if (dostrip) {
353 		strip(tempcopy ? tempfile : to_name);
354 
355 		/*
356 		 * Re-open our fd on the target, in case we used a strip
357 		 * that does not work in-place -- like GNU binutils strip.
358 		 */
359 		close(to_fd);
360 		to_fd = open(tempcopy ? tempfile : to_name, O_RDONLY, 0);
361 		if (to_fd < 0)
362 			err(EX_OSERR, "stripping %s", to_name);
363 	}
364 
365 	/*
366 	 * Compare the stripped temp file with the target.
367 	 */
368 	if (docompare && dostrip && target) {
369 		temp_fd = to_fd;
370 
371 		/* Re-open to_fd using the real target name. */
372 		if ((to_fd = open(to_name, O_RDONLY, 0)) < 0)
373 			err(EX_OSERR, "%s", to_name);
374 
375 		if (fstat(temp_fd, &temp_sb)) {
376 			serrno = errno;
377 			(void)unlink(tempfile);
378 			errno = serrno;
379 			err(EX_OSERR, "%s", tempfile);
380 		}
381 
382 		if (compare(temp_fd, tempfile, (size_t)temp_sb.st_size, to_fd,
383 			    to_name, (size_t)to_sb.st_size) == 0) {
384 			/*
385 			 * If target has more than one link we need to
386 			 * replace it in order to snap the extra links.
387 			 * Need to preserve target file times, though.
388 			 */
389 			if (to_sb.st_nlink != 1) {
390 				tvb[0].tv_sec = to_sb.st_atime;
391 				tvb[0].tv_usec = 0;
392 				tvb[1].tv_sec = to_sb.st_mtime;
393 				tvb[1].tv_usec = 0;
394 				(void)utimes(tempfile, tvb);
395 			} else {
396 				files_match = 1;
397 				(void)unlink(tempfile);
398 			}
399 			(void) close(temp_fd);
400 		}
401 	}
402 
403 	/*
404 	 * Move the new file into place if doing a safe copy
405 	 * and the files are different (or just not compared).
406 	 */
407 	if (tempcopy && !files_match) {
408 		/* Try to turn off the immutable bits. */
409 		if (to_sb.st_flags & NOCHANGEBITS)
410 			(void)chflags(to_name, to_sb.st_flags & ~NOCHANGEBITS);
411 		if (dobackup) {
412 			if ((size_t)snprintf(backup, MAXPATHLEN, "%s%s", to_name,
413 			    suffix) != strlen(to_name) + strlen(suffix)) {
414 				unlink(tempfile);
415 				errx(EX_OSERR, "%s: backup filename too long",
416 				    to_name);
417 			}
418 			if (verbose)
419 				(void)printf("install: %s -> %s\n", to_name, backup);
420 			if (rename(to_name, backup) < 0) {
421 				serrno = errno;
422 				unlink(tempfile);
423 				errno = serrno;
424 				err(EX_OSERR, "rename: %s to %s", to_name,
425 				     backup);
426 			}
427 		}
428 		if (verbose)
429 			(void)printf("install: %s -> %s\n", from_name, to_name);
430 		if (rename(tempfile, to_name) < 0) {
431 			serrno = errno;
432 			unlink(tempfile);
433 			errno = serrno;
434 			err(EX_OSERR, "rename: %s to %s",
435 			    tempfile, to_name);
436 		}
437 
438 		/* Re-open to_fd so we aren't hosed by the rename(2). */
439 		(void) close(to_fd);
440 		if ((to_fd = open(to_name, O_RDONLY, 0)) < 0)
441 			err(EX_OSERR, "%s", to_name);
442 	}
443 
444 	/*
445 	 * Preserve the timestamp of the source file if necessary.
446 	 */
447 	if (dopreserve && !files_match && !devnull) {
448 		tvb[0].tv_sec = from_sb.st_atime;
449 		tvb[0].tv_usec = 0;
450 		tvb[1].tv_sec = from_sb.st_mtime;
451 		tvb[1].tv_usec = 0;
452 		(void)utimes(to_name, tvb);
453 	}
454 
455 	if (fstat(to_fd, &to_sb) == -1) {
456 		serrno = errno;
457 		(void)unlink(to_name);
458 		errno = serrno;
459 		err(EX_OSERR, "%s", to_name);
460 	}
461 
462 	/*
463 	 * Set owner, group, mode for target; do the chown first,
464 	 * chown may lose the setuid bits.
465 	 */
466 	if ((gid != (gid_t)-1 && gid != to_sb.st_gid) ||
467 	    (uid != (uid_t)-1 && uid != to_sb.st_uid) ||
468 	    (mode != (to_sb.st_mode & ALLPERMS))) {
469 		/* Try to turn off the immutable bits. */
470 		if (to_sb.st_flags & NOCHANGEBITS)
471 			(void)fchflags(to_fd, to_sb.st_flags & ~NOCHANGEBITS);
472 	}
473 
474 	if ((gid != (gid_t)-1 && gid != to_sb.st_gid) ||
475 	    (uid != (uid_t)-1 && uid != to_sb.st_uid))
476 		if (fchown(to_fd, uid, gid) == -1) {
477 			serrno = errno;
478 			(void)unlink(to_name);
479 			errno = serrno;
480 			err(EX_OSERR,"%s: chown/chgrp", to_name);
481 		}
482 
483 	if (mode != (to_sb.st_mode & ALLPERMS))
484 		if (fchmod(to_fd, mode)) {
485 			serrno = errno;
486 			(void)unlink(to_name);
487 			errno = serrno;
488 			err(EX_OSERR, "%s: chmod", to_name);
489 		}
490 
491 	/*
492 	 * If provided a set of flags, set them, otherwise, preserve the
493 	 * flags, except for the dump flag.
494 	 * NFS does not support flags.  Ignore EOPNOTSUPP flags if we're just
495 	 * trying to turn off UF_NODUMP.  If we're trying to set real flags,
496 	 * then warn if the fs doesn't support it, otherwise fail.
497 	 */
498 	if (!devnull && (flags & SETFLAGS ||
499 	    (from_sb.st_flags & ~UF_NODUMP) != to_sb.st_flags) &&
500 	    fchflags(to_fd,
501 	    flags & SETFLAGS ? fset : from_sb.st_flags & ~UF_NODUMP)) {
502 		if (flags & SETFLAGS) {
503 			if (errno == EOPNOTSUPP)
504 				warn("%s: chflags", to_name);
505 			else {
506 				serrno = errno;
507 				(void)unlink(to_name);
508 				errno = serrno;
509 				err(EX_OSERR, "%s: chflags", to_name);
510 			}
511 		}
512 	}
513 
514 	(void)close(to_fd);
515 	if (!devnull)
516 		(void)close(from_fd);
517 }
518 
519 /*
520  * compare --
521  *	compare two files; non-zero means files differ
522  */
523 static int
524 compare(int from_fd, const char *from_name __unused, size_t from_len,
525 	int to_fd, const char *to_name __unused, size_t to_len)
526 {
527 	char *p, *q;
528 	int rv;
529 	int done_compare;
530 
531 	rv = 0;
532 	if (from_len != to_len)
533 		return 1;
534 
535 	if (from_len <= MAX_CMP_SIZE) {
536 		done_compare = 0;
537 		if (trymmap(from_fd) && trymmap(to_fd)) {
538 			p = mmap(NULL, from_len, PROT_READ, MAP_SHARED, from_fd, (off_t)0);
539 			if (p == (char *)MAP_FAILED)
540 				goto out;
541 			q = mmap(NULL, from_len, PROT_READ, MAP_SHARED, to_fd, (off_t)0);
542 			if (q == (char *)MAP_FAILED) {
543 				munmap(p, from_len);
544 				goto out;
545 			}
546 
547 			rv = memcmp(p, q, from_len);
548 			munmap(p, from_len);
549 			munmap(q, from_len);
550 			done_compare = 1;
551 		}
552 	out:
553 		if (!done_compare) {
554 			char buf1[MAXBSIZE];
555 			char buf2[MAXBSIZE];
556 			int n1, n2;
557 
558 			rv = 0;
559 			lseek(from_fd, 0, SEEK_SET);
560 			lseek(to_fd, 0, SEEK_SET);
561 			while (rv == 0) {
562 				n1 = read(from_fd, buf1, sizeof(buf1));
563 				if (n1 == 0)
564 					break;		/* EOF */
565 				else if (n1 > 0) {
566 					n2 = read(to_fd, buf2, n1);
567 					if (n2 == n1)
568 						rv = memcmp(buf1, buf2, n1);
569 					else
570 						rv = 1;	/* out of sync */
571 				} else
572 					rv = 1;		/* read failure */
573 			}
574 			lseek(from_fd, 0, SEEK_SET);
575 			lseek(to_fd, 0, SEEK_SET);
576 		}
577 	} else
578 		rv = 1;	/* don't bother in this case */
579 
580 	return rv;
581 }
582 
583 /*
584  * create_tempfile --
585  *	create a temporary file based on path and open it
586  */
587 static int
588 create_tempfile(const char *path, char *temp, size_t tsize)
589 {
590 	char *p;
591 
592 	(void)strncpy(temp, path, tsize);
593 	temp[tsize - 1] = '\0';
594 	if ((p = strrchr(temp, '/')) != NULL)
595 		p++;
596 	else
597 		p = temp;
598 	(void)strncpy(p, "INS@XXXX", &temp[tsize - 1] - p);
599 	temp[tsize - 1] = '\0';
600 	return (mkstemp(temp));
601 }
602 
603 /*
604  * create_newfile --
605  *	create a new file, overwriting an existing one if necessary
606  */
607 static int
608 create_newfile(const char *path, int target, struct stat *sbp)
609 {
610 	char backup[MAXPATHLEN];
611 	int saved_errno = 0;
612 	int newfd;
613 
614 	if (target) {
615 		/*
616 		 * Unlink now... avoid ETXTBSY errors later.  Try to turn
617 		 * off the append/immutable bits -- if we fail, go ahead,
618 		 * it might work.
619 		 */
620 		if (sbp->st_flags & NOCHANGEBITS)
621 			(void)chflags(path, sbp->st_flags & ~NOCHANGEBITS);
622 
623 		if (dobackup) {
624 			if ((size_t)snprintf(backup, MAXPATHLEN, "%s%s",
625 			    path, suffix) != strlen(path) + strlen(suffix))
626 				errx(EX_OSERR, "%s: backup filename too long",
627 				    path);
628 			(void)snprintf(backup, MAXPATHLEN, "%s%s",
629 			    path, suffix);
630 			if (verbose)
631 				(void)printf("install: %s -> %s\n",
632 				    path, backup);
633 			if (rename(path, backup) < 0)
634 				err(EX_OSERR, "rename: %s to %s", path, backup);
635 		} else
636 			if (unlink(path) < 0)
637 				saved_errno = errno;
638 	}
639 
640 	newfd = open(path, O_CREAT | O_RDWR | O_TRUNC, S_IRUSR | S_IWUSR);
641 	if (newfd < 0 && saved_errno != 0)
642 		errno = saved_errno;
643 	return newfd;
644 }
645 
646 /*
647  * copy --
648  *	copy from one file to another
649  */
650 static void
651 copy(int from_fd, const char *from_name, int to_fd, const char *to_name,
652     off_t size)
653 {
654 	int nr, nw;
655 	int serrno;
656 	char *p, buf[MAXBSIZE];
657 	int done_copy;
658 
659 	/* Rewind file descriptors. */
660 	if (lseek(from_fd, (off_t)0, SEEK_SET) == (off_t)-1)
661 		err(EX_OSERR, "lseek: %s", from_name);
662 	if (lseek(to_fd, (off_t)0, SEEK_SET) == (off_t)-1)
663 		err(EX_OSERR, "lseek: %s", to_name);
664 
665 	/*
666 	 * Mmap and write if less than 8M (the limit is so we don't totally
667 	 * trash memory on big files.  This is really a minor hack, but it
668 	 * wins some CPU back.
669 	 */
670 	done_copy = 0;
671 	if (size <= 8 * 1048576 && trymmap(from_fd) &&
672 	    (p = mmap(NULL, (size_t)size, PROT_READ, MAP_SHARED,
673 		    from_fd, (off_t)0)) != (char *)MAP_FAILED) {
674 		if ((nw = write(to_fd, p, size)) != size) {
675 			serrno = errno;
676 			(void)unlink(to_name);
677 			errno = nw > 0 ? EIO : serrno;
678 			err(EX_OSERR, "%s", to_name);
679 		}
680 		done_copy = 1;
681 	}
682 	if (!done_copy) {
683 		while ((nr = read(from_fd, buf, sizeof(buf))) > 0)
684 			if ((nw = write(to_fd, buf, nr)) != nr) {
685 				serrno = errno;
686 				(void)unlink(to_name);
687 				errno = nw > 0 ? EIO : serrno;
688 				err(EX_OSERR, "%s", to_name);
689 			}
690 		if (nr != 0) {
691 			serrno = errno;
692 			(void)unlink(to_name);
693 			errno = serrno;
694 			err(EX_OSERR, "%s", from_name);
695 		}
696 	}
697 }
698 
699 /*
700  * strip --
701  *	use strip(1) to strip the target file
702  */
703 static void
704 strip(const char *to_name)
705 {
706 	const char *stripbin;
707 	int serrno, status;
708 
709 	switch (fork()) {
710 	case -1:
711 		serrno = errno;
712 		(void)unlink(to_name);
713 		errno = serrno;
714 		err(EX_TEMPFAIL, "fork");
715 	case 0:
716 		stripbin = getenv("STRIPBIN");
717 		if (stripbin == NULL)
718 			stripbin = "strip";
719 		execlp(stripbin, stripbin, to_name, (char *)NULL);
720 		err(EX_OSERR, "exec(%s)", stripbin);
721 	default:
722 		if (wait(&status) == -1 || status) {
723 			serrno = errno;
724 			(void)unlink(to_name);
725 			errc(EX_SOFTWARE, serrno, "wait");
726 			/* NOTREACHED */
727 		}
728 	}
729 }
730 
731 /*
732  * install_dir --
733  *	build directory hierarchy
734  */
735 static void
736 install_dir(char *path)
737 {
738 	char *p;
739 	struct stat sb;
740 	int ch;
741 
742 	for (p = path;; ++p)
743 		if (!*p || (p != path && *p  == '/')) {
744 			ch = *p;
745 			*p = '\0';
746 			if (stat(path, &sb)) {
747 				if (errno != ENOENT || mkdir(path, 0755) < 0) {
748 					err(EX_OSERR, "mkdir %s", path);
749 					/* NOTREACHED */
750 				} else if (verbose)
751 					(void)printf("install: mkdir %s\n",
752 						     path);
753 			} else if (!S_ISDIR(sb.st_mode))
754 				errx(EX_OSERR, "%s exists but is not a directory", path);
755 			if (!(*p = ch))
756 				break;
757  		}
758 
759 	if ((gid != (gid_t)-1 || uid != (uid_t)-1) && chown(path, uid, gid))
760 		warn("chown %u:%u %s", uid, gid, path);
761 	if (chmod(path, mode))
762 		warn("chmod %o %s", mode, path);
763 }
764 
765 /*
766  * usage --
767  *	print a usage message and die
768  */
769 static void
770 usage(void)
771 {
772 	(void)fprintf(stderr,
773 "usage: install [-bCcMpSsv] [-B suffix] [-f flags] [-g group] [-m mode]\n"
774 "               [-o owner] file1 file2\n"
775 "       install [-bCcMpSsv] [-B suffix] [-f flags] [-g group] [-m mode]\n"
776 "               [-o owner] file1 ... fileN directory\n"
777 "       install -d [-v] [-g group] [-m mode] [-o owner] directory ...\n");
778 	exit(EX_USAGE);
779 	/* NOTREACHED */
780 }
781 
782 /*
783  * trymmap --
784  *	return true (1) if mmap should be tried, false (0) if not.
785  */
786 static int
787 trymmap(int fd)
788 {
789 /*
790  * The ifdef is for bootstrapping - f_fstypename doesn't exist in
791  * pre-Lite2-merge systems.
792  */
793 #ifdef MFSNAMELEN
794 	struct statfs stfs;
795 
796 	if (nommap || fstatfs(fd, &stfs) != 0)
797 		return (0);
798 	if (strcmp(stfs.f_fstypename, "ufs") == 0 ||
799 	    strcmp(stfs.f_fstypename, "cd9660") == 0)
800 		return (1);
801 #endif
802 	return (0);
803 }
804