xref: /netbsd-src/usr.sbin/sysinst/target.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: target.c,v 1.3 2015/10/18 09:21:55 martin Exp $	*/
2 
3 /*
4  * Copyright 1997 Jonathan Stone
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed for the NetBSD Project by
18  *      Jonathan Stone.
19  * 4. The name of Jonathan Stone may not be used to endorse
20  *    or promote products derived from this software without specific prior
21  *    written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY JONATHAN STONE ``AS IS''
24  * AND 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 PIERMONT INFORMATION SYSTEMS INC. BE
27  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
33  * THE POSSIBILITY OF SUCH DAMAGE.
34  *
35  */
36 
37 /* Copyright below applies to the realpath() code */
38 
39 /*
40  * Copyright (c) 1989, 1991, 1993, 1995
41  *      The Regents of the University of California.  All rights reserved.
42  *
43  * This code is derived from software contributed to Berkeley by
44  * Jan-Simon Pendry.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  * 1. Redistributions of source code must retain the above copyright
50  *    notice, this list of conditions and the following disclaimer.
51  * 2. Redistributions in binary form must reproduce the above copyright
52  *    notice, this list of conditions and the following disclaimer in the
53  *    documentation and/or other materials provided with the distribution.
54  * 3. Neither the name of the University nor the names of its contributors
55  *    may be used to endorse or promote products derived from this software
56  *    without specific prior written permission.
57  *
58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68  * SUCH DAMAGE.
69  */
70 
71 
72 #include <sys/cdefs.h>
73 #if defined(LIBC_SCCS) && !defined(lint)
74 __RCSID("$NetBSD: target.c,v 1.3 2015/10/18 09:21:55 martin Exp $");
75 #endif
76 
77 /*
78  * target.c -- path-prefixing routines to access the target installation
79  *  filesystems. Makes the install tools more independent of whether
80  *  we're installing into a separate filesystem hierarchy mounted under
81  * /targetroot, or into the currently active root mounted on /.
82  */
83 
84 #include <sys/param.h>			/* XXX vm_param.h always defines TRUE*/
85 #include <sys/types.h>
86 #include <sys/sysctl.h>
87 #include <sys/stat.h>			/* stat() */
88 #include <sys/mount.h>			/* statfs() */
89 
90 #include <fcntl.h>
91 #include <stdio.h>
92 #include <stdarg.h>
93 #include <unistd.h>
94 #include <curses.h>			/* defines TRUE, but checks  */
95 #include <errno.h>
96 
97 
98 #include "defs.h"
99 #include "md.h"
100 #include "msg_defs.h"
101 #include "menu_defs.h"
102 
103 /*
104  * local  prototypes
105  */
106 
107 static void make_prefixed_dir (const char *prefix, const char *path);
108 static int do_target_chdir (const char *dir, int flag);
109 int	target_test(unsigned int mode, const char *path);
110 int	target_test_dir (const char *path);	/* deprecated */
111 int	target_test_file (const char *path);	/* deprecated */
112 int	target_test_symlink (const char *path);	/* deprecated */
113 
114 void unwind_mounts(void);
115 
116 /* Record a mount for later unwinding of target mounts. */
117 struct unwind_mount {
118 	struct unwind_mount *um_prev;
119 	char um_mountpoint[4];		/* Allocated longer... */
120 };
121 
122 /* Unwind-mount stack */
123 struct unwind_mount *unwind_mountlist = NULL;
124 
125 /*
126  * Debugging options
127  */
128 /*#define DEBUG_ROOT*/		/* turn on what-is-root? debugging. */
129 /*#define DEBUG_UNWIND*/	/* turn on unwind-target-mount debugging. */
130 
131 /*
132  * debugging helper. curses...
133  */
134 #if defined(DEBUG)  ||	defined(DEBUG_ROOT)
135 void
136 backtowin(void)
137 {
138 
139 	fflush(stdout);	/* curses does not leave stdout linebuffered. */
140 	getchar();	/* wait for user to press return */
141 	wrefresh(stdscr);
142 }
143 #endif
144 
145 
146 /*
147  * Is the root partition we're running from the same as the root
148  * which the user has selected to install/upgrade?
149  * Uses global variable "pm->diskdev" to find the selected device for
150  * install/upgrade.
151  */
152 int
153 target_already_root(void)
154 {
155 
156 	if (pm == NULL)
157 		return TRUE;
158 
159 	if (strcmp(pm->diskdev, "") == 0)
160 		/* No root partition was ever selected.
161 		 * Assume that the currently mounted one should be used
162 		 */
163 		return 1;
164 
165 	return is_active_rootpart(pm->diskdev, pm->rootpart);
166 }
167 
168 
169 /*
170  * Is this device partition (e.g., "sd0a") mounted as root?
171  */
172 int
173 is_active_rootpart(const char *dev, int ptn)
174 {
175 	int mib[2];
176 	char rootdev[SSTRSIZE];
177 	int rootptn;
178 	size_t varlen;
179 
180 	mib[0] = CTL_KERN;
181 	mib[1] = KERN_ROOT_DEVICE;
182 	varlen = sizeof(rootdev);
183 	if (sysctl(mib, 2, rootdev, &varlen, NULL, 0) < 0)
184 		return 1;
185 
186 	if (strcmp(dev, rootdev) != 0)
187 		return 0;
188 
189 	mib[1] = KERN_ROOT_PARTITION;
190 	varlen = sizeof rootptn;
191 	if (sysctl(mib, 2, &rootptn, &varlen, NULL, 0) < 0)
192 		return 1;
193 
194 	return ptn == rootptn;
195 }
196 
197 /*
198  * Pathname  prefixing glue to support installation either
199  * from in-ramdisk miniroots or on-disk diskimages.
200  * If our root is on the target disk, the install target is mounted
201  * on /targetroot and we need to prefix installed pathnames with /targetroot.
202  * otherwise we are installing to the currently-active root and
203  * no prefix is needed.
204  */
205 const char *
206 target_prefix(void)
207 {
208 	/*
209 	 * XXX fetch sysctl variable for current root, and compare
210 	 * to the devicename of the install target disk.
211 	 */
212 	return(target_already_root() ? "" : targetroot_mnt);
213 }
214 
215 /*
216  * concatenate two pathnames.
217  * XXX returns either input args or result in a static buffer.
218  * The caller must copy if it wants to use the pathname past the
219  * next call to a target-prefixing  function, or to modify the inputs..
220  * Used only  internally so this is probably safe.
221  */
222 const char *
223 concat_paths(const char *prefix, const char *suffix)
224 {
225 	static char real_path[MAXPATHLEN];
226 
227 	/* absolute prefix and null suffix? */
228 	if (prefix[0] == '/' && suffix[0] == 0)
229 		return prefix;
230 
231 	/* null prefix and absolute suffix? */
232 	if (prefix[0] == 0 && suffix[0] == '/')
233 		return suffix;
234 
235 	/* avoid "//" */
236 	if (suffix[0] == '/' || suffix[0] == 0)
237 		snprintf(real_path, sizeof(real_path), "%s%s", prefix, suffix);
238 	else
239 		snprintf(real_path, sizeof(real_path), "%s/%s",
240 		    prefix, suffix);
241 	return (real_path);
242 }
243 
244 /*
245  * Do target prefix expansion on a pathname.
246  * XXX uses concat_paths and so returns result in a static buffer.
247  * The caller must copy if it wants to use the pathname past the
248  * next call to a target-prefixing  function, or to modify the inputs..
249  * Used only  internally so this is probably safe.
250  *
251  * Not static so other functions can generate target related file names.
252  */
253 const char *
254 target_expand(const char *tgtpath)
255 {
256 
257 	return concat_paths(target_prefix(), tgtpath);
258 }
259 
260 /* Make a directory, with a prefix like "/targetroot" or possibly just "". */
261 static void
262 make_prefixed_dir(const char *prefix, const char *path)
263 {
264 
265 	run_program(0, "/bin/mkdir -p %s", concat_paths(prefix, path));
266 }
267 
268 /* Make a directory with a pathname relative to the installation target. */
269 void
270 make_target_dir(const char *path)
271 {
272 
273 	make_prefixed_dir(target_prefix(), path);
274 }
275 
276 
277 static int
278 do_target_chdir(const char *dir, int must_succeed)
279 {
280 	const char *tgt_dir;
281 	int error;
282 
283 	error = 0;
284 	tgt_dir = target_expand(dir);
285 
286 #ifdef DEBUG
287 	printf("target_chdir (%s)\n", tgt_dir);
288 	//return (0);
289 #endif
290 	/* chdir returns -1 on error and sets errno. */
291 	if (chdir(tgt_dir) < 0)
292 		error = errno;
293 	if (logfp) {
294 		fprintf(logfp, "cd to %s\n", tgt_dir);
295 		fflush(logfp);
296 	}
297 	if (script) {
298 		scripting_fprintf(NULL, "cd %s\n", tgt_dir);
299 		fflush(script);
300 	}
301 
302 	if (error && must_succeed) {
303 		fprintf(stderr, msg_string(MSG_realdir),
304 		       target_prefix(), strerror(error));
305 		if (logfp)
306 			fprintf(logfp, msg_string(MSG_realdir),
307 			       target_prefix(), strerror(error));
308 		exit(1);
309 	}
310 	errno = error;
311 	return (error);
312 }
313 
314 void
315 target_chdir_or_die(const char *dir)
316 {
317 
318 	(void)do_target_chdir(dir, 1);
319 }
320 
321 #ifdef notdef
322 int
323 target_chdir(const char *dir)
324 {
325 
326 	return do_target_chdir(dir, 0);
327 }
328 #endif
329 
330 /*
331  * Copy a file from the current root into the target system,
332  * where the  destination pathname is relative to the target root.
333  * Does not check for copy-to-self when target is  current root.
334  */
335 int
336 cp_to_target(const char *srcpath, const char *tgt_path)
337 {
338 	const char *real_path = target_expand(tgt_path);
339 
340 	return run_program(0, "/bin/cp %s %s", srcpath, real_path);
341 }
342 
343 /*
344  * Duplicate a file from the current root to the same pathname
345  * in the target system.  Pathname must be an absolute pathname.
346  * If we're running in the target, do nothing.
347  */
348 void
349 dup_file_into_target(const char *filename)
350 {
351 
352 	if (!target_already_root())
353 		cp_to_target(filename, filename);
354 }
355 
356 
357 /*
358  * Do a mv where both pathnames are within the target filesystem.
359  */
360 void
361 mv_within_target_or_die(const char *frompath, const char *topath)
362 {
363 	char realfrom[STRSIZE];
364 	char realto[STRSIZE];
365 
366 	strlcpy(realfrom, target_expand(frompath), sizeof realfrom);
367 	strlcpy(realto, target_expand(topath), sizeof realto);
368 
369 	run_program(RUN_FATAL, "mv %s %s", realfrom, realto);
370 }
371 
372 /* Do a cp where both pathnames are within the target filesystem. */
373 int
374 cp_within_target(const char *frompath, const char *topath, int optional)
375 {
376 	char realfrom[STRSIZE];
377 	char realto[STRSIZE];
378 
379 	strncpy(realfrom, target_expand(frompath), STRSIZE);
380 	strncpy(realto, target_expand(topath), STRSIZE);
381 
382 	if (access(realfrom, R_OK) == -1 && optional)
383 		return 0;
384 	return (run_program(0, "cp -p %s %s", realfrom, realto));
385 }
386 
387 /* fopen a pathname in the target. */
388 FILE *
389 target_fopen(const char *filename, const char *type)
390 {
391 
392 	return fopen(target_expand(filename), type);
393 }
394 
395 /*
396  * Do a mount onto a mountpoint in the install target.
397  * Record mountpoint so we can unmount when finished.
398  * NB: does not prefix mount-from, which probably breaks nullfs mounts.
399  */
400 int
401 target_mount_do(const char *opts, const char *from, const char *on)
402 {
403 	struct unwind_mount *m;
404 	int error;
405 	int len;
406 
407 	len = strlen(on);
408 	m = malloc(sizeof *m + len);
409 	if (m == 0)
410 		return (ENOMEM);	/* XXX */
411 
412 	memcpy(m->um_mountpoint, on, len + 1);
413 
414 #ifdef DEBUG_UNWIND
415 	endwin();
416 	fprintf(stderr, "mounting %s with unwind\n", on);
417 	backtowin();
418 #endif
419 
420 	error = run_program(0, "/sbin/mount %s %s %s%s",
421 			opts, from, target_prefix(), on);
422 	if (error) {
423 		free(m);
424 		return error;
425 	}
426 	m->um_prev = unwind_mountlist;
427 	unwind_mountlist = m;
428 	return 0;
429 }
430 
431 int
432 target_mount(const char *opts, const char *from, int ptn, const char *on)
433 {
434 	int error;
435 	char *frompath;
436 	asprintf (&frompath, "/dev/%s%c", from, (ptn < 0)? 0 : 'a' + ptn);
437 	if (frompath == 0)
438 		return (ENOMEM);
439 	error = target_mount_do(opts, frompath, on);
440 	free(frompath);
441 	return error;
442 }
443 
444 /*
445  * unwind the mount stack, unmounting mounted filesystems.
446  * For now, ignore any errors in unmount.
447  * (Why would we be unable to unmount?  The user has suspended
448  *  us and forked shell sitting somewhere in the target root?)
449  */
450 void
451 unwind_mounts(void)
452 {
453 	struct unwind_mount *m;
454 	static volatile int unwind_in_progress = 0;
455 
456 	/* signal safety */
457 	if (unwind_in_progress)
458 		return;
459 	unwind_in_progress = 1;
460 
461 	while ((m = unwind_mountlist) != NULL) {
462 		unwind_mountlist = m->um_prev;
463 #ifdef DEBUG_UNWIND
464 		endwin();
465 		fprintf(stderr, "unmounting %s\n", m->um_mountpoint);
466 		backtowin();
467 #endif
468 		run_program(0, "/sbin/umount %s%s",
469 			target_prefix(), m->um_mountpoint);
470 		free(m);
471 	}
472 	unwind_in_progress = 0;
473 }
474 
475 int
476 target_collect_file(int kind, char **buffer, const char *name)
477 {
478 	const char *realname = target_expand(name);
479 
480 #ifdef	DEBUG
481 	printf("collect real name %s\n", realname);
482 #endif
483 	return collect(kind, buffer, "%s", realname);
484 }
485 
486 /*
487  * Verify a pathname already exists in the target root filesystem,
488  * by running  test "testflag" on the expanded target pathname.
489  */
490 int
491 target_test(unsigned int mode, const char *path)
492 {
493 	const char *real_path = target_expand(path);
494 	register int result;
495 
496 	result = !file_mode_match(real_path, mode);
497 	scripting_fprintf(NULL, "if [ $? != 0 ]; then echo \"%s does not exist!\"; fi\n", real_path);
498 
499 #if defined(DEBUG)
500 	printf("target_test(%o, %s) returning %d\n", mode, real_path, result);
501 #endif
502 	return (result);
503 }
504 
505 /*
506  * Verify a directory already exists in the target root
507  * filesystem. Do not create the directory if it doesn't  exist.
508  * Assumes that sysinst has already mounted the target root.
509  */
510 int
511 target_test_dir(const char *path)
512 {
513 
514  	return target_test(S_IFDIR, path);
515 }
516 
517 /*
518  * Verify an ordinary file already exists in the target root
519  * filesystem. Do not create the directory if it doesn't  exist.
520  * Assumes that sysinst has already mounted the target root.
521  */
522 int
523 target_test_file(const char *path)
524 {
525 
526  	return target_test(S_IFREG, path);
527 }
528 
529 int
530 target_test_symlink(const char *path)
531 {
532 
533  	return target_test(S_IFLNK, path);
534 }
535 
536 int
537 target_file_exists_p(const char *path)
538 {
539 
540 	return (target_test_file(path) == 0);
541 }
542 
543 int
544 target_dir_exists_p(const char *path)
545 {
546 
547 	return (target_test_dir(path) == 0);
548 }
549 
550 int
551 target_symlink_exists_p(const char *path)
552 {
553 
554 	return (target_test_symlink(path) == 0);
555 }
556 
557 int
558 target_mounted(void)
559 {
560 	return (unwind_mountlist != NULL);
561 }
562