xref: /netbsd-src/usr.sbin/sysinst/target.c (revision a0698ed9d41653d7a2378819ad501a285ca0d401)
1 /*	$NetBSD: target.c,v 1.4 2018/11/09 15:20:36 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 1.4 2018/11/09 15:20:36 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 	if (ptn < 0)
190 		return 1;	/* device only check, or wedge */
191 
192 	mib[1] = KERN_ROOT_PARTITION;
193 	varlen = sizeof rootptn;
194 	rootptn = -1;
195 	if (sysctl(mib, 2, &rootptn, &varlen, NULL, 0) < 0)
196 		return 1;
197 
198 	return ptn == rootptn;
199 }
200 
201 /*
202  * Pathname  prefixing glue to support installation either
203  * from in-ramdisk miniroots or on-disk diskimages.
204  * If our root is on the target disk, the install target is mounted
205  * on /targetroot and we need to prefix installed pathnames with /targetroot.
206  * otherwise we are installing to the currently-active root and
207  * no prefix is needed.
208  */
209 const char *
210 target_prefix(void)
211 {
212 	/*
213 	 * XXX fetch sysctl variable for current root, and compare
214 	 * to the devicename of the install target disk.
215 	 */
216 	return(target_already_root() ? "" : targetroot_mnt);
217 }
218 
219 /*
220  * concatenate two pathnames.
221  * XXX returns either input args or result in a static buffer.
222  * The caller must copy if it wants to use the pathname past the
223  * next call to a target-prefixing  function, or to modify the inputs..
224  * Used only  internally so this is probably safe.
225  */
226 const char *
227 concat_paths(const char *prefix, const char *suffix)
228 {
229 	static char real_path[MAXPATHLEN];
230 
231 	/* absolute prefix and null suffix? */
232 	if (prefix[0] == '/' && suffix[0] == 0)
233 		return prefix;
234 
235 	/* null prefix and absolute suffix? */
236 	if (prefix[0] == 0 && suffix[0] == '/')
237 		return suffix;
238 
239 	/* avoid "//" */
240 	if (suffix[0] == '/' || suffix[0] == 0)
241 		snprintf(real_path, sizeof(real_path), "%s%s", prefix, suffix);
242 	else
243 		snprintf(real_path, sizeof(real_path), "%s/%s",
244 		    prefix, suffix);
245 	return (real_path);
246 }
247 
248 /*
249  * Do target prefix expansion on a pathname.
250  * XXX uses concat_paths and so returns result in a static buffer.
251  * The caller must copy if it wants to use the pathname past the
252  * next call to a target-prefixing  function, or to modify the inputs..
253  * Used only  internally so this is probably safe.
254  *
255  * Not static so other functions can generate target related file names.
256  */
257 const char *
258 target_expand(const char *tgtpath)
259 {
260 
261 	return concat_paths(target_prefix(), tgtpath);
262 }
263 
264 /* Make a directory, with a prefix like "/targetroot" or possibly just "". */
265 static void
266 make_prefixed_dir(const char *prefix, const char *path)
267 {
268 
269 	run_program(0, "/bin/mkdir -p %s", concat_paths(prefix, path));
270 }
271 
272 /* Make a directory with a pathname relative to the installation target. */
273 void
274 make_target_dir(const char *path)
275 {
276 
277 	make_prefixed_dir(target_prefix(), path);
278 }
279 
280 
281 static int
282 do_target_chdir(const char *dir, int must_succeed)
283 {
284 	const char *tgt_dir;
285 	int error;
286 
287 	error = 0;
288 	tgt_dir = target_expand(dir);
289 
290 #ifdef DEBUG
291 	printf("target_chdir (%s)\n", tgt_dir);
292 	//return (0);
293 #endif
294 	/* chdir returns -1 on error and sets errno. */
295 	if (chdir(tgt_dir) < 0)
296 		error = errno;
297 	if (logfp) {
298 		fprintf(logfp, "cd to %s\n", tgt_dir);
299 		fflush(logfp);
300 	}
301 	if (script) {
302 		scripting_fprintf(NULL, "cd %s\n", tgt_dir);
303 		fflush(script);
304 	}
305 
306 	if (error && must_succeed) {
307 		fprintf(stderr, msg_string(MSG_realdir),
308 		       target_prefix(), strerror(error));
309 		if (logfp)
310 			fprintf(logfp, msg_string(MSG_realdir),
311 			       target_prefix(), strerror(error));
312 		exit(1);
313 	}
314 	errno = error;
315 	return (error);
316 }
317 
318 void
319 target_chdir_or_die(const char *dir)
320 {
321 
322 	(void)do_target_chdir(dir, 1);
323 }
324 
325 #ifdef notdef
326 int
327 target_chdir(const char *dir)
328 {
329 
330 	return do_target_chdir(dir, 0);
331 }
332 #endif
333 
334 /*
335  * Copy a file from the current root into the target system,
336  * where the  destination pathname is relative to the target root.
337  * Does not check for copy-to-self when target is  current root.
338  */
339 int
340 cp_to_target(const char *srcpath, const char *tgt_path)
341 {
342 	const char *real_path = target_expand(tgt_path);
343 
344 	return run_program(0, "/bin/cp %s %s", srcpath, real_path);
345 }
346 
347 /*
348  * Duplicate a file from the current root to the same pathname
349  * in the target system.  Pathname must be an absolute pathname.
350  * If we're running in the target, do nothing.
351  */
352 void
353 dup_file_into_target(const char *filename)
354 {
355 
356 	if (!target_already_root())
357 		cp_to_target(filename, filename);
358 }
359 
360 
361 /*
362  * Do a mv where both pathnames are within the target filesystem.
363  */
364 void
365 mv_within_target_or_die(const char *frompath, const char *topath)
366 {
367 	char realfrom[STRSIZE];
368 	char realto[STRSIZE];
369 
370 	strlcpy(realfrom, target_expand(frompath), sizeof realfrom);
371 	strlcpy(realto, target_expand(topath), sizeof realto);
372 
373 	run_program(RUN_FATAL, "mv %s %s", realfrom, realto);
374 }
375 
376 /* Do a cp where both pathnames are within the target filesystem. */
377 int
378 cp_within_target(const char *frompath, const char *topath, int optional)
379 {
380 	char realfrom[STRSIZE];
381 	char realto[STRSIZE];
382 
383 	strncpy(realfrom, target_expand(frompath), STRSIZE);
384 	strncpy(realto, target_expand(topath), STRSIZE);
385 
386 	if (access(realfrom, R_OK) == -1 && optional)
387 		return 0;
388 	return (run_program(0, "cp -p %s %s", realfrom, realto));
389 }
390 
391 /* fopen a pathname in the target. */
392 FILE *
393 target_fopen(const char *filename, const char *type)
394 {
395 
396 	return fopen(target_expand(filename), type);
397 }
398 
399 /*
400  * Do a mount onto a mountpoint in the install target.
401  * Record mountpoint so we can unmount when finished.
402  * NB: does not prefix mount-from, which probably breaks nullfs mounts.
403  */
404 int
405 target_mount_do(const char *opts, const char *from, const char *on)
406 {
407 	struct unwind_mount *m;
408 	int error;
409 	int len;
410 
411 	len = strlen(on);
412 	m = malloc(sizeof *m + len);
413 	if (m == 0)
414 		return (ENOMEM);	/* XXX */
415 
416 	memcpy(m->um_mountpoint, on, len + 1);
417 
418 #ifdef DEBUG_UNWIND
419 	endwin();
420 	fprintf(stderr, "mounting %s with unwind\n", on);
421 	backtowin();
422 #endif
423 
424 	error = run_program(0, "/sbin/mount %s %s %s%s",
425 			opts, from, target_prefix(), on);
426 	if (error) {
427 		free(m);
428 		return error;
429 	}
430 	m->um_prev = unwind_mountlist;
431 	unwind_mountlist = m;
432 	return 0;
433 }
434 
435 int
436 target_mount(const char *opts, const char *from, int ptn, const char *on)
437 {
438 	int error;
439 	char *frompath;
440 	asprintf (&frompath, "/dev/%s%c", from, (ptn < 0)? 0 : 'a' + ptn);
441 	if (frompath == 0)
442 		return (ENOMEM);
443 	error = target_mount_do(opts, frompath, on);
444 	free(frompath);
445 	return error;
446 }
447 
448 /*
449  * unwind the mount stack, unmounting mounted filesystems.
450  * For now, ignore any errors in unmount.
451  * (Why would we be unable to unmount?  The user has suspended
452  *  us and forked shell sitting somewhere in the target root?)
453  */
454 void
455 unwind_mounts(void)
456 {
457 	struct unwind_mount *m;
458 	static volatile int unwind_in_progress = 0;
459 
460 	/* signal safety */
461 	if (unwind_in_progress)
462 		return;
463 	unwind_in_progress = 1;
464 
465 	while ((m = unwind_mountlist) != NULL) {
466 		unwind_mountlist = m->um_prev;
467 #ifdef DEBUG_UNWIND
468 		endwin();
469 		fprintf(stderr, "unmounting %s\n", m->um_mountpoint);
470 		backtowin();
471 #endif
472 		run_program(0, "/sbin/umount %s%s",
473 			target_prefix(), m->um_mountpoint);
474 		free(m);
475 	}
476 	unwind_in_progress = 0;
477 }
478 
479 int
480 target_collect_file(int kind, char **buffer, const char *name)
481 {
482 	const char *realname = target_expand(name);
483 
484 #ifdef	DEBUG
485 	printf("collect real name %s\n", realname);
486 #endif
487 	return collect(kind, buffer, "%s", realname);
488 }
489 
490 /*
491  * Verify a pathname already exists in the target root filesystem,
492  * by running  test "testflag" on the expanded target pathname.
493  */
494 int
495 target_test(unsigned int mode, const char *path)
496 {
497 	const char *real_path = target_expand(path);
498 	register int result;
499 
500 	result = !file_mode_match(real_path, mode);
501 	scripting_fprintf(NULL, "if [ $? != 0 ]; then echo \"%s does not exist!\"; fi\n", real_path);
502 
503 #if defined(DEBUG)
504 	printf("target_test(%o, %s) returning %d\n", mode, real_path, result);
505 #endif
506 	return (result);
507 }
508 
509 /*
510  * Verify a directory already exists in the target root
511  * filesystem. Do not create the directory if it doesn't  exist.
512  * Assumes that sysinst has already mounted the target root.
513  */
514 int
515 target_test_dir(const char *path)
516 {
517 
518  	return target_test(S_IFDIR, path);
519 }
520 
521 /*
522  * Verify an ordinary file already exists in the target root
523  * filesystem. Do not create the directory if it doesn't  exist.
524  * Assumes that sysinst has already mounted the target root.
525  */
526 int
527 target_test_file(const char *path)
528 {
529 
530  	return target_test(S_IFREG, path);
531 }
532 
533 int
534 target_test_symlink(const char *path)
535 {
536 
537  	return target_test(S_IFLNK, path);
538 }
539 
540 int
541 target_file_exists_p(const char *path)
542 {
543 
544 	return (target_test_file(path) == 0);
545 }
546 
547 int
548 target_dir_exists_p(const char *path)
549 {
550 
551 	return (target_test_dir(path) == 0);
552 }
553 
554 int
555 target_symlink_exists_p(const char *path)
556 {
557 
558 	return (target_test_symlink(path) == 0);
559 }
560 
561 int
562 target_mounted(void)
563 {
564 	return (unwind_mountlist != NULL);
565 }
566