xref: /freebsd/lib/libbe/be.c (revision 43d1e6ee299ad4e143d90d3ad374d1c24bd3306f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
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  *
16  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/mount.h>
34 #include <sys/stat.h>
35 #include <sys/ucred.h>
36 
37 #include <ctype.h>
38 #include <libgen.h>
39 #include <libzfs_core.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <time.h>
43 #include <unistd.h>
44 
45 #include "be.h"
46 #include "be_impl.h"
47 
48 struct be_destroy_data {
49 	libbe_handle_t		*lbh;
50 	char			*snapname;
51 };
52 
53 #if SOON
54 static int be_create_child_noent(libbe_handle_t *lbh, const char *active,
55     const char *child_path);
56 static int be_create_child_cloned(libbe_handle_t *lbh, const char *active);
57 #endif
58 
59 /* Arbitrary... should tune */
60 #define	BE_SNAP_SERIAL_MAX	1024
61 
62 /*
63  * Iterator function for locating the rootfs amongst the children of the
64  * zfs_be_root set by loader(8).  data is expected to be a libbe_handle_t *.
65  */
66 static int
67 be_locate_rootfs(libbe_handle_t *lbh)
68 {
69 	struct statfs sfs;
70 	struct extmnttab entry;
71 	zfs_handle_t *zfs;
72 
73 	/*
74 	 * Check first if root is ZFS; if not, we'll bail on rootfs capture.
75 	 * Unfortunately needed because zfs_path_to_zhandle will emit to
76 	 * stderr if / isn't actually a ZFS filesystem, which we'd like
77 	 * to avoid.
78 	 */
79 	if (statfs("/", &sfs) == 0) {
80 		statfs2mnttab(&sfs, &entry);
81 		if (strcmp(entry.mnt_fstype, MNTTYPE_ZFS) != 0)
82 			return (1);
83 	} else
84 		return (1);
85 	zfs = zfs_path_to_zhandle(lbh->lzh, "/", ZFS_TYPE_FILESYSTEM);
86 	if (zfs == NULL)
87 		return (1);
88 
89 	strlcpy(lbh->rootfs, zfs_get_name(zfs), sizeof(lbh->rootfs));
90 	zfs_close(zfs);
91 	return (0);
92 }
93 
94 /*
95  * Initializes the libbe context to operate in the root boot environment
96  * dataset, for example, zroot/ROOT.
97  */
98 libbe_handle_t *
99 libbe_init(const char *root)
100 {
101 	char altroot[MAXPATHLEN];
102 	libbe_handle_t *lbh;
103 	char *poolname, *pos;
104 	int pnamelen;
105 
106 	lbh = NULL;
107 	poolname = pos = NULL;
108 
109 	if ((lbh = calloc(1, sizeof(libbe_handle_t))) == NULL)
110 		goto err;
111 
112 	if ((lbh->lzh = libzfs_init()) == NULL)
113 		goto err;
114 
115 	/*
116 	 * Grab rootfs, we'll work backwards from there if an optional BE root
117 	 * has not been passed in.
118 	 */
119 	if (be_locate_rootfs(lbh) != 0) {
120 		if (root == NULL)
121 			goto err;
122 		*lbh->rootfs = '\0';
123 	}
124 	if (root == NULL) {
125 		/* Strip off the final slash from rootfs to get the be root */
126 		strlcpy(lbh->root, lbh->rootfs, sizeof(lbh->root));
127 		pos = strrchr(lbh->root, '/');
128 		if (pos == NULL)
129 			goto err;
130 		*pos = '\0';
131 	} else
132 		strlcpy(lbh->root, root, sizeof(lbh->root));
133 
134 	if ((pos = strchr(lbh->root, '/')) == NULL)
135 		goto err;
136 
137 	pnamelen = pos - lbh->root;
138 	poolname = malloc(pnamelen + 1);
139 	if (poolname == NULL)
140 		goto err;
141 
142 	strlcpy(poolname, lbh->root, pnamelen + 1);
143 	if ((lbh->active_phandle = zpool_open(lbh->lzh, poolname)) == NULL)
144 		goto err;
145 	free(poolname);
146 	poolname = NULL;
147 
148 	if (zpool_get_prop(lbh->active_phandle, ZPOOL_PROP_BOOTFS, lbh->bootfs,
149 	    sizeof(lbh->bootfs), NULL, true) != 0)
150 		goto err;
151 
152 	if (zpool_get_prop(lbh->active_phandle, ZPOOL_PROP_ALTROOT,
153 	    altroot, sizeof(altroot), NULL, true) == 0 &&
154 	    strcmp(altroot, "-") != 0)
155 		lbh->altroot_len = strlen(altroot);
156 
157 	return (lbh);
158 err:
159 	if (lbh != NULL) {
160 		if (lbh->active_phandle != NULL)
161 			zpool_close(lbh->active_phandle);
162 		if (lbh->lzh != NULL)
163 			libzfs_fini(lbh->lzh);
164 		free(lbh);
165 	}
166 	free(poolname);
167 	return (NULL);
168 }
169 
170 
171 /*
172  * Free memory allocated by libbe_init()
173  */
174 void
175 libbe_close(libbe_handle_t *lbh)
176 {
177 
178 	if (lbh->active_phandle != NULL)
179 		zpool_close(lbh->active_phandle);
180 	libzfs_fini(lbh->lzh);
181 	free(lbh);
182 }
183 
184 /*
185  * Proxy through to libzfs for the moment.
186  */
187 void
188 be_nicenum(uint64_t num, char *buf, size_t buflen)
189 {
190 
191 	zfs_nicenum(num, buf, buflen);
192 }
193 
194 static int
195 be_destroy_cb(zfs_handle_t *zfs_hdl, void *data)
196 {
197 	char path[BE_MAXPATHLEN];
198 	struct be_destroy_data *bdd;
199 	zfs_handle_t *snap;
200 	int err;
201 
202 	bdd = (struct be_destroy_data *)data;
203 	if (bdd->snapname == NULL) {
204 		err = zfs_iter_children(zfs_hdl, be_destroy_cb, data);
205 		if (err != 0)
206 			return (err);
207 		return (zfs_destroy(zfs_hdl, false));
208 	}
209 	/* If we're dealing with snapshots instead, delete that one alone */
210 	err = zfs_iter_filesystems(zfs_hdl, be_destroy_cb, data);
211 	if (err != 0)
212 		return (err);
213 	/*
214 	 * This part is intentionally glossing over any potential errors,
215 	 * because there's a lot less potential for errors when we're cleaning
216 	 * up snapshots rather than a full deep BE.  The primary error case
217 	 * here being if the snapshot doesn't exist in the first place, which
218 	 * the caller will likely deem insignificant as long as it doesn't
219 	 * exist after the call.  Thus, such a missing snapshot shouldn't jam
220 	 * up the destruction.
221 	 */
222 	snprintf(path, sizeof(path), "%s@%s", zfs_get_name(zfs_hdl),
223 	    bdd->snapname);
224 	if (!zfs_dataset_exists(bdd->lbh->lzh, path, ZFS_TYPE_SNAPSHOT))
225 		return (0);
226 	snap = zfs_open(bdd->lbh->lzh, path, ZFS_TYPE_SNAPSHOT);
227 	if (snap != NULL)
228 		zfs_destroy(snap, false);
229 	return (0);
230 }
231 
232 /*
233  * Destroy the boot environment or snapshot specified by the name
234  * parameter. Options are or'd together with the possible values:
235  * BE_DESTROY_FORCE : forces operation on mounted datasets
236  * BE_DESTROY_ORIGIN: destroy the origin snapshot as well
237  */
238 int
239 be_destroy(libbe_handle_t *lbh, const char *name, int options)
240 {
241 	struct be_destroy_data bdd;
242 	char origin[BE_MAXPATHLEN], path[BE_MAXPATHLEN];
243 	zfs_handle_t *fs;
244 	char *snapdelim;
245 	int err, force, mounted;
246 	size_t rootlen;
247 
248 	bdd.lbh = lbh;
249 	bdd.snapname = NULL;
250 	force = options & BE_DESTROY_FORCE;
251 	*origin = '\0';
252 
253 	be_root_concat(lbh, name, path);
254 
255 	if ((snapdelim = strchr(path, '@')) == NULL) {
256 		if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_FILESYSTEM))
257 			return (set_error(lbh, BE_ERR_NOENT));
258 
259 		if (strcmp(path, lbh->rootfs) == 0 ||
260 		    strcmp(path, lbh->bootfs) == 0)
261 			return (set_error(lbh, BE_ERR_DESTROYACT));
262 
263 		fs = zfs_open(lbh->lzh, path, ZFS_TYPE_FILESYSTEM);
264 		if (fs == NULL)
265 			return (set_error(lbh, BE_ERR_ZFSOPEN));
266 
267 		if ((options & BE_DESTROY_ORIGIN) != 0 &&
268 		    zfs_prop_get(fs, ZFS_PROP_ORIGIN, origin, sizeof(origin),
269 		    NULL, NULL, 0, 1) != 0)
270 			return (set_error(lbh, BE_ERR_NOORIGIN));
271 
272 		/* Don't destroy a mounted dataset unless force is specified */
273 		if ((mounted = zfs_is_mounted(fs, NULL)) != 0) {
274 			if (force) {
275 				zfs_unmount(fs, NULL, 0);
276 			} else {
277 				free(bdd.snapname);
278 				return (set_error(lbh, BE_ERR_DESTROYMNT));
279 			}
280 		}
281 	} else {
282 		if (!zfs_dataset_exists(lbh->lzh, path, ZFS_TYPE_SNAPSHOT))
283 			return (set_error(lbh, BE_ERR_NOENT));
284 
285 		bdd.snapname = strdup(snapdelim + 1);
286 		if (bdd.snapname == NULL)
287 			return (set_error(lbh, BE_ERR_NOMEM));
288 		*snapdelim = '\0';
289 		fs = zfs_open(lbh->lzh, path, ZFS_TYPE_DATASET);
290 		if (fs == NULL) {
291 			free(bdd.snapname);
292 			return (set_error(lbh, BE_ERR_ZFSOPEN));
293 		}
294 	}
295 
296 	err = be_destroy_cb(fs, &bdd);
297 	zfs_close(fs);
298 	free(bdd.snapname);
299 	if (err != 0) {
300 		/* Children are still present or the mount is referenced */
301 		if (err == EBUSY)
302 			return (set_error(lbh, BE_ERR_DESTROYMNT));
303 		return (set_error(lbh, BE_ERR_UNKNOWN));
304 	}
305 
306 	if ((options & BE_DESTROY_ORIGIN) == 0)
307 		return (0);
308 
309 	/* The origin can't possibly be shorter than the BE root */
310 	rootlen = strlen(lbh->root);
311 	if (*origin == '\0' || strlen(origin) <= rootlen + 1)
312 		return (set_error(lbh, BE_ERR_INVORIGIN));
313 
314 	/*
315 	 * We'll be chopping off the BE root and running this back through
316 	 * be_destroy, so that we properly handle the origin snapshot whether
317 	 * it be that of a deep BE or not.
318 	 */
319 	if (strncmp(origin, lbh->root, rootlen) != 0 || origin[rootlen] != '/')
320 		return (0);
321 
322 	return (be_destroy(lbh, origin + rootlen + 1,
323 	    options & ~BE_DESTROY_ORIGIN));
324 }
325 
326 static void
327 be_setup_snapshot_name(libbe_handle_t *lbh, char *buf, size_t buflen)
328 {
329 	time_t rawtime;
330 	int len, serial;
331 
332 	time(&rawtime);
333 	len = strlen(buf);
334 	len += strftime(buf + len, buflen - len, "@%F-%T", localtime(&rawtime));
335 	/* No room for serial... caller will do its best */
336 	if (buflen - len < 2)
337 		return;
338 
339 	for (serial = 0; serial < BE_SNAP_SERIAL_MAX; ++serial) {
340 		snprintf(buf + len, buflen - len, "-%d", serial);
341 		if (!zfs_dataset_exists(lbh->lzh, buf, ZFS_TYPE_SNAPSHOT))
342 			return;
343 	}
344 }
345 
346 int
347 be_snapshot(libbe_handle_t *lbh, const char *source, const char *snap_name,
348     bool recursive, char *result)
349 {
350 	char buf[BE_MAXPATHLEN];
351 	int err;
352 
353 	be_root_concat(lbh, source, buf);
354 
355 	if ((err = be_exists(lbh, buf)) != 0)
356 		return (set_error(lbh, err));
357 
358 	if (snap_name != NULL) {
359 		if (strlcat(buf, "@", sizeof(buf)) >= sizeof(buf))
360 			return (set_error(lbh, BE_ERR_INVALIDNAME));
361 
362 		if (strlcat(buf, snap_name, sizeof(buf)) >= sizeof(buf))
363 			return (set_error(lbh, BE_ERR_INVALIDNAME));
364 
365 		if (result != NULL)
366 			snprintf(result, BE_MAXPATHLEN, "%s@%s", source,
367 			    snap_name);
368 	} else {
369 		be_setup_snapshot_name(lbh, buf, sizeof(buf));
370 
371 		if (result != NULL && strlcpy(result, strrchr(buf, '/') + 1,
372 		    sizeof(buf)) >= sizeof(buf))
373 			return (set_error(lbh, BE_ERR_INVALIDNAME));
374 	}
375 
376 	if ((err = zfs_snapshot(lbh->lzh, buf, recursive, NULL)) != 0) {
377 		switch (err) {
378 		case EZFS_INVALIDNAME:
379 			return (set_error(lbh, BE_ERR_INVALIDNAME));
380 
381 		default:
382 			/*
383 			 * The other errors that zfs_ioc_snapshot might return
384 			 * shouldn't happen if we've set things up properly, so
385 			 * we'll gloss over them and call it UNKNOWN as it will
386 			 * require further triage.
387 			 */
388 			if (errno == ENOTSUP)
389 				return (set_error(lbh, BE_ERR_NOPOOL));
390 			return (set_error(lbh, BE_ERR_UNKNOWN));
391 		}
392 	}
393 
394 	return (BE_ERR_SUCCESS);
395 }
396 
397 
398 /*
399  * Create the boot environment specified by the name parameter
400  */
401 int
402 be_create(libbe_handle_t *lbh, const char *name)
403 {
404 	int err;
405 
406 	err = be_create_from_existing(lbh, name, be_active_path(lbh));
407 
408 	return (set_error(lbh, err));
409 }
410 
411 static int
412 be_deep_clone_prop(int prop, void *cb)
413 {
414 	int err;
415         struct libbe_dccb *dccb;
416 	zprop_source_t src;
417 	char pval[BE_MAXPATHLEN];
418 	char source[BE_MAXPATHLEN];
419 	char *val;
420 
421 	dccb = cb;
422 	/* Skip some properties we don't want to touch */
423 	if (prop == ZFS_PROP_CANMOUNT)
424 		return (ZPROP_CONT);
425 
426 	/* Don't copy readonly properties */
427 	if (zfs_prop_readonly(prop))
428 		return (ZPROP_CONT);
429 
430 	if ((err = zfs_prop_get(dccb->zhp, prop, (char *)&pval,
431 	    sizeof(pval), &src, (char *)&source, sizeof(source), false)))
432 		/* Just continue if we fail to read a property */
433 		return (ZPROP_CONT);
434 
435 	/* Only copy locally defined properties */
436 	if (src != ZPROP_SRC_LOCAL)
437 		return (ZPROP_CONT);
438 
439 	/* Augment mountpoint with altroot, if needed */
440 	val = pval;
441 	if (prop == ZFS_PROP_MOUNTPOINT)
442 		val = be_mountpoint_augmented(dccb->lbh, val);
443 
444 	nvlist_add_string(dccb->props, zfs_prop_to_name(prop), val);
445 
446 	return (ZPROP_CONT);
447 }
448 
449 static int
450 be_deep_clone(zfs_handle_t *ds, void *data)
451 {
452 	int err;
453 	char be_path[BE_MAXPATHLEN];
454 	char snap_path[BE_MAXPATHLEN];
455 	const char *dspath;
456 	char *dsname;
457 	zfs_handle_t *snap_hdl;
458 	nvlist_t *props;
459 	struct libbe_deep_clone *isdc, sdc;
460 	struct libbe_dccb dccb;
461 
462 	isdc = (struct libbe_deep_clone *)data;
463 	dspath = zfs_get_name(ds);
464 	if ((dsname = strrchr(dspath, '/')) == NULL)
465 		return (BE_ERR_UNKNOWN);
466 	dsname++;
467 
468 	if (isdc->bename == NULL)
469 		snprintf(be_path, sizeof(be_path), "%s/%s", isdc->be_root, dsname);
470 	else
471 		snprintf(be_path, sizeof(be_path), "%s/%s", isdc->be_root, isdc->bename);
472 
473 	snprintf(snap_path, sizeof(snap_path), "%s@%s", dspath, isdc->snapname);
474 
475 	if (zfs_dataset_exists(isdc->lbh->lzh, be_path, ZFS_TYPE_DATASET))
476 		return (set_error(isdc->lbh, BE_ERR_EXISTS));
477 
478 	if ((snap_hdl =
479 	    zfs_open(isdc->lbh->lzh, snap_path, ZFS_TYPE_SNAPSHOT)) == NULL)
480 		return (set_error(isdc->lbh, BE_ERR_ZFSOPEN));
481 
482 	nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
483 	nvlist_add_string(props, "canmount", "noauto");
484 
485 	dccb.lbh = isdc->lbh;
486 	dccb.zhp = ds;
487 	dccb.props = props;
488 	if (zprop_iter(be_deep_clone_prop, &dccb, B_FALSE, B_FALSE,
489 	    ZFS_TYPE_FILESYSTEM) == ZPROP_INVAL)
490 		return (-1);
491 
492 	if ((err = zfs_clone(snap_hdl, be_path, props)) != 0)
493 		err = BE_ERR_ZFSCLONE;
494 
495 	nvlist_free(props);
496 	zfs_close(snap_hdl);
497 
498 	/* Failed to clone */
499 	if (err != BE_ERR_SUCCESS)
500 		return (set_error(isdc->lbh, err));
501 
502 	sdc.lbh = isdc->lbh;
503 	sdc.bename = NULL;
504 	sdc.snapname = isdc->snapname;
505 	sdc.be_root = (char *)&be_path;
506 
507 	err = zfs_iter_filesystems(ds, be_deep_clone, &sdc);
508 
509 	return (err);
510 }
511 
512 /*
513  * Create the boot environment from pre-existing snapshot
514  */
515 int
516 be_create_from_existing_snap(libbe_handle_t *lbh, const char *name,
517     const char *snap)
518 {
519 	int err;
520 	char be_path[BE_MAXPATHLEN];
521 	char snap_path[BE_MAXPATHLEN];
522 	const char *bename;
523 	char *parentname, *snapname;
524 	zfs_handle_t *parent_hdl;
525 	struct libbe_deep_clone sdc;
526 
527 	if ((err = be_validate_name(lbh, name)) != 0)
528 		return (set_error(lbh, err));
529 	if ((err = be_root_concat(lbh, snap, snap_path)) != 0)
530 		return (set_error(lbh, err));
531 	if ((err = be_validate_snap(lbh, snap_path)) != 0)
532 		return (set_error(lbh, err));
533 
534 	if ((err = be_root_concat(lbh, name, be_path)) != 0)
535 		return (set_error(lbh, err));
536 
537 	if ((bename = strrchr(name, '/')) == NULL)
538 		bename = name;
539 	else
540 		bename++;
541 
542 	if ((parentname = strdup(snap_path)) == NULL)
543 		return (set_error(lbh, BE_ERR_UNKNOWN));
544 
545 	snapname = strchr(parentname, '@');
546 	if (snapname == NULL) {
547 		free(parentname);
548 		return (set_error(lbh, BE_ERR_UNKNOWN));
549 	}
550 	*snapname = '\0';
551 	snapname++;
552 
553 	sdc.lbh = lbh;
554 	sdc.bename = bename;
555 	sdc.snapname = snapname;
556 	sdc.be_root = lbh->root;
557 
558 	parent_hdl = zfs_open(lbh->lzh, parentname, ZFS_TYPE_DATASET);
559 	err = be_deep_clone(parent_hdl, &sdc);
560 
561 	free(parentname);
562 	return (set_error(lbh, err));
563 }
564 
565 
566 /*
567  * Create a boot environment from an existing boot environment
568  */
569 int
570 be_create_from_existing(libbe_handle_t *lbh, const char *name, const char *old)
571 {
572 	int err;
573 	char buf[BE_MAXPATHLEN];
574 
575 	if ((err = be_snapshot(lbh, old, NULL, true, (char *)&buf)) != 0)
576 		return (set_error(lbh, err));
577 
578 	err = be_create_from_existing_snap(lbh, name, (char *)buf);
579 
580 	return (set_error(lbh, err));
581 }
582 
583 
584 /*
585  * Verifies that a snapshot has a valid name, exists, and has a mountpoint of
586  * '/'. Returns BE_ERR_SUCCESS (0), upon success, or the relevant BE_ERR_* upon
587  * failure. Does not set the internal library error state.
588  */
589 int
590 be_validate_snap(libbe_handle_t *lbh, const char *snap_name)
591 {
592 
593 	if (strlen(snap_name) >= BE_MAXPATHLEN)
594 		return (BE_ERR_PATHLEN);
595 
596 	if (!zfs_name_valid(snap_name, ZFS_TYPE_SNAPSHOT))
597 		return (BE_ERR_INVALIDNAME);
598 
599 	if (!zfs_dataset_exists(lbh->lzh, snap_name,
600 	    ZFS_TYPE_SNAPSHOT))
601 		return (BE_ERR_NOENT);
602 
603 	return (BE_ERR_SUCCESS);
604 }
605 
606 
607 /*
608  * Idempotently appends the name argument to the root boot environment path
609  * and copies the resulting string into the result buffer (which is assumed
610  * to be at least BE_MAXPATHLEN characters long. Returns BE_ERR_SUCCESS upon
611  * success, BE_ERR_PATHLEN if the resulting path is longer than BE_MAXPATHLEN,
612  * or BE_ERR_INVALIDNAME if the name is a path that does not begin with
613  * zfs_be_root. Does not set internal library error state.
614  */
615 int
616 be_root_concat(libbe_handle_t *lbh, const char *name, char *result)
617 {
618 	size_t name_len, root_len;
619 
620 	name_len = strlen(name);
621 	root_len = strlen(lbh->root);
622 
623 	/* Act idempotently; return be name if it is already a full path */
624 	if (strrchr(name, '/') != NULL) {
625 		if (strstr(name, lbh->root) != name)
626 			return (BE_ERR_INVALIDNAME);
627 
628 		if (name_len >= BE_MAXPATHLEN)
629 			return (BE_ERR_PATHLEN);
630 
631 		strlcpy(result, name, BE_MAXPATHLEN);
632 		return (BE_ERR_SUCCESS);
633 	} else if (name_len + root_len + 1 < BE_MAXPATHLEN) {
634 		snprintf(result, BE_MAXPATHLEN, "%s/%s", lbh->root,
635 		    name);
636 		return (BE_ERR_SUCCESS);
637 	}
638 
639 	return (BE_ERR_PATHLEN);
640 }
641 
642 
643 /*
644  * Verifies the validity of a boot environment name (A-Za-z0-9-_.). Returns
645  * BE_ERR_SUCCESS (0) if name is valid, otherwise returns BE_ERR_INVALIDNAME
646  * or BE_ERR_PATHLEN.
647  * Does not set internal library error state.
648  */
649 int
650 be_validate_name(libbe_handle_t *lbh, const char *name)
651 {
652 
653 	/*
654 	 * Impose the additional restriction that the entire dataset name must
655 	 * not exceed the maximum length of a dataset, i.e. MAXNAMELEN.
656 	 */
657 	if (strlen(lbh->root) + 1 + strlen(name) > MAXNAMELEN)
658 		return (BE_ERR_PATHLEN);
659 
660 	if (!zfs_name_valid(name, ZFS_TYPE_DATASET))
661 		return (BE_ERR_INVALIDNAME);
662 
663 	return (BE_ERR_SUCCESS);
664 }
665 
666 
667 /*
668  * usage
669  */
670 int
671 be_rename(libbe_handle_t *lbh, const char *old, const char *new)
672 {
673 	char full_old[BE_MAXPATHLEN];
674 	char full_new[BE_MAXPATHLEN];
675 	zfs_handle_t *zfs_hdl;
676 	int err;
677 
678 	/*
679 	 * be_validate_name is documented not to set error state, so we should
680 	 * do so here.
681 	 */
682 	if ((err = be_validate_name(lbh, new)) != 0)
683 		return (set_error(lbh, err));
684 	if ((err = be_root_concat(lbh, old, full_old)) != 0)
685 		return (set_error(lbh, err));
686 	if ((err = be_root_concat(lbh, new, full_new)) != 0)
687 		return (set_error(lbh, err));
688 
689 	if (!zfs_dataset_exists(lbh->lzh, full_old, ZFS_TYPE_DATASET))
690 		return (set_error(lbh, BE_ERR_NOENT));
691 
692 	if (zfs_dataset_exists(lbh->lzh, full_new, ZFS_TYPE_DATASET))
693 		return (set_error(lbh, BE_ERR_EXISTS));
694 
695 	if ((zfs_hdl = zfs_open(lbh->lzh, full_old,
696 	    ZFS_TYPE_FILESYSTEM)) == NULL)
697 		return (set_error(lbh, BE_ERR_ZFSOPEN));
698 
699 	/* recurse, nounmount, forceunmount */
700 	struct renameflags flags = {
701 		.nounmount = 1,
702 	};
703 
704 	err = zfs_rename(zfs_hdl, NULL, full_new, flags);
705 
706 	zfs_close(zfs_hdl);
707 	if (err != 0)
708 		return (set_error(lbh, BE_ERR_UNKNOWN));
709 	return (0);
710 }
711 
712 
713 int
714 be_export(libbe_handle_t *lbh, const char *bootenv, int fd)
715 {
716 	char snap_name[BE_MAXPATHLEN];
717 	char buf[BE_MAXPATHLEN];
718 	zfs_handle_t *zfs;
719 	int err;
720 
721 	if ((err = be_snapshot(lbh, bootenv, NULL, true, snap_name)) != 0)
722 		/* Use the error set by be_snapshot */
723 		return (err);
724 
725 	be_root_concat(lbh, snap_name, buf);
726 
727 	if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_DATASET)) == NULL)
728 		return (set_error(lbh, BE_ERR_ZFSOPEN));
729 
730 	err = zfs_send_one(zfs, NULL, fd, 0);
731 	zfs_close(zfs);
732 
733 	return (err);
734 }
735 
736 
737 int
738 be_import(libbe_handle_t *lbh, const char *bootenv, int fd)
739 {
740 	char buf[BE_MAXPATHLEN];
741 	nvlist_t *props;
742 	zfs_handle_t *zfs;
743 	recvflags_t flags = { .nomount = 1 };
744 	int err;
745 
746 	be_root_concat(lbh, bootenv, buf);
747 
748 	if ((err = zfs_receive(lbh->lzh, buf, NULL, &flags, fd, NULL)) != 0) {
749 		switch (err) {
750 		case EINVAL:
751 			return (set_error(lbh, BE_ERR_NOORIGIN));
752 		case ENOENT:
753 			return (set_error(lbh, BE_ERR_NOENT));
754 		case EIO:
755 			return (set_error(lbh, BE_ERR_IO));
756 		default:
757 			return (set_error(lbh, BE_ERR_UNKNOWN));
758 		}
759 	}
760 
761 	if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_FILESYSTEM)) == NULL)
762 		return (set_error(lbh, BE_ERR_ZFSOPEN));
763 
764 	nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
765 	nvlist_add_string(props, "canmount", "noauto");
766 	nvlist_add_string(props, "mountpoint", "/");
767 
768 	err = zfs_prop_set_list(zfs, props);
769 	nvlist_free(props);
770 
771 	zfs_close(zfs);
772 
773 	if (err != 0)
774 		return (set_error(lbh, BE_ERR_UNKNOWN));
775 
776 	return (0);
777 }
778 
779 #if SOON
780 static int
781 be_create_child_noent(libbe_handle_t *lbh, const char *active,
782     const char *child_path)
783 {
784 	nvlist_t *props;
785 	zfs_handle_t *zfs;
786 	int err;
787 
788 	nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
789 	nvlist_add_string(props, "canmount", "noauto");
790 	nvlist_add_string(props, "mountpoint", child_path);
791 
792 	/* Create */
793 	if ((err = zfs_create(lbh->lzh, active, ZFS_TYPE_DATASET,
794 	    props)) != 0) {
795 		switch (err) {
796 		case EZFS_EXISTS:
797 			return (set_error(lbh, BE_ERR_EXISTS));
798 		case EZFS_NOENT:
799 			return (set_error(lbh, BE_ERR_NOENT));
800 		case EZFS_BADTYPE:
801 		case EZFS_BADVERSION:
802 			return (set_error(lbh, BE_ERR_NOPOOL));
803 		case EZFS_BADPROP:
804 		default:
805 			/* We set something up wrong, probably... */
806 			return (set_error(lbh, BE_ERR_UNKNOWN));
807 		}
808 	}
809 	nvlist_free(props);
810 
811 	if ((zfs = zfs_open(lbh->lzh, active, ZFS_TYPE_DATASET)) == NULL)
812 		return (set_error(lbh, BE_ERR_ZFSOPEN));
813 
814 	/* Set props */
815 	if ((err = zfs_prop_set(zfs, "canmount", "noauto")) != 0) {
816 		zfs_close(zfs);
817 		/*
818 		 * Similar to other cases, this shouldn't fail unless we've
819 		 * done something wrong.  This is a new dataset that shouldn't
820 		 * have been mounted anywhere between creation and now.
821 		 */
822 		if (err == EZFS_NOMEM)
823 			return (set_error(lbh, BE_ERR_NOMEM));
824 		return (set_error(lbh, BE_ERR_UNKNOWN));
825 	}
826 	zfs_close(zfs);
827 	return (BE_ERR_SUCCESS);
828 }
829 
830 static int
831 be_create_child_cloned(libbe_handle_t *lbh, const char *active)
832 {
833 	char buf[BE_MAXPATHLEN], tmp[BE_MAXPATHLEN];;
834 	zfs_handle_t *zfs;
835 	int err;
836 
837 	/* XXX TODO ? */
838 
839 	/*
840 	 * Establish if the existing path is a zfs dataset or just
841 	 * the subdirectory of one
842 	 */
843 	strlcpy(tmp, "tmp/be_snap.XXXXX", sizeof(tmp));
844 	if (mktemp(tmp) == NULL)
845 		return (set_error(lbh, BE_ERR_UNKNOWN));
846 
847 	be_root_concat(lbh, tmp, buf);
848 	printf("Here %s?\n", buf);
849 	if ((err = zfs_snapshot(lbh->lzh, buf, false, NULL)) != 0) {
850 		switch (err) {
851 		case EZFS_INVALIDNAME:
852 			return (set_error(lbh, BE_ERR_INVALIDNAME));
853 
854 		default:
855 			/*
856 			 * The other errors that zfs_ioc_snapshot might return
857 			 * shouldn't happen if we've set things up properly, so
858 			 * we'll gloss over them and call it UNKNOWN as it will
859 			 * require further triage.
860 			 */
861 			if (errno == ENOTSUP)
862 				return (set_error(lbh, BE_ERR_NOPOOL));
863 			return (set_error(lbh, BE_ERR_UNKNOWN));
864 		}
865 	}
866 
867 	/* Clone */
868 	if ((zfs = zfs_open(lbh->lzh, buf, ZFS_TYPE_SNAPSHOT)) == NULL)
869 		return (BE_ERR_ZFSOPEN);
870 
871 	if ((err = zfs_clone(zfs, active, NULL)) != 0)
872 		/* XXX TODO correct error */
873 		return (set_error(lbh, BE_ERR_UNKNOWN));
874 
875 	/* set props */
876 	zfs_close(zfs);
877 	return (BE_ERR_SUCCESS);
878 }
879 
880 int
881 be_add_child(libbe_handle_t *lbh, const char *child_path, bool cp_if_exists)
882 {
883 	struct stat sb;
884 	char active[BE_MAXPATHLEN], buf[BE_MAXPATHLEN];
885 	nvlist_t *props;
886 	const char *s;
887 
888 	/* Require absolute paths */
889 	if (*child_path != '/')
890 		return (set_error(lbh, BE_ERR_BADPATH));
891 
892 	strlcpy(active, be_active_path(lbh), BE_MAXPATHLEN);
893 	strcpy(buf, active);
894 
895 	/* Create non-mountable parent dataset(s) */
896 	s = child_path;
897 	for (char *p; (p = strchr(s+1, '/')) != NULL; s = p) {
898 		size_t len = p - s;
899 		strncat(buf, s, len);
900 
901 		nvlist_alloc(&props, NV_UNIQUE_NAME, KM_SLEEP);
902 		nvlist_add_string(props, "canmount", "off");
903 		nvlist_add_string(props, "mountpoint", "none");
904 		zfs_create(lbh->lzh, buf, ZFS_TYPE_DATASET, props);
905 		nvlist_free(props);
906 	}
907 
908 	/* Path does not exist as a descendent of / yet */
909 	if (strlcat(active, child_path, BE_MAXPATHLEN) >= BE_MAXPATHLEN)
910 		return (set_error(lbh, BE_ERR_PATHLEN));
911 
912 	if (stat(child_path, &sb) != 0) {
913 		/* Verify that error is ENOENT */
914 		if (errno != ENOENT)
915 			return (set_error(lbh, BE_ERR_UNKNOWN));
916 		return (be_create_child_noent(lbh, active, child_path));
917 	} else if (cp_if_exists)
918 		/* Path is already a descendent of / and should be copied */
919 		return (be_create_child_cloned(lbh, active));
920 	return (set_error(lbh, BE_ERR_EXISTS));
921 }
922 #endif	/* SOON */
923 
924 static int
925 be_set_nextboot(libbe_handle_t *lbh, nvlist_t *config, uint64_t pool_guid,
926     const char *zfsdev)
927 {
928 	nvlist_t **child;
929 	uint64_t vdev_guid;
930 	int c, children;
931 
932 	if (nvlist_lookup_nvlist_array(config, ZPOOL_CONFIG_CHILDREN, &child,
933 	    &children) == 0) {
934 		for (c = 0; c < children; ++c)
935 			if (be_set_nextboot(lbh, child[c], pool_guid, zfsdev) != 0)
936 				return (1);
937 		return (0);
938 	}
939 
940 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
941 	    &vdev_guid) != 0) {
942 		return (1);
943 	}
944 
945 	if (zpool_nextboot(lbh->lzh, pool_guid, vdev_guid, zfsdev) != 0) {
946 		perror("ZFS_IOC_NEXTBOOT failed");
947 		return (1);
948 	}
949 
950 	return (0);
951 }
952 
953 /*
954  * Deactivate old BE dataset; currently just sets canmount=noauto
955  */
956 static int
957 be_deactivate(libbe_handle_t *lbh, const char *ds)
958 {
959 	zfs_handle_t *zfs;
960 
961 	if ((zfs = zfs_open(lbh->lzh, ds, ZFS_TYPE_DATASET)) == NULL)
962 		return (1);
963 	if (zfs_prop_set(zfs, "canmount", "noauto") != 0)
964 		return (1);
965 	zfs_close(zfs);
966 	return (0);
967 }
968 
969 int
970 be_activate(libbe_handle_t *lbh, const char *bootenv, bool temporary)
971 {
972 	char be_path[BE_MAXPATHLEN];
973 	char buf[BE_MAXPATHLEN];
974 	nvlist_t *config, *dsprops, *vdevs;
975 	char *origin;
976 	uint64_t pool_guid;
977 	zfs_handle_t *zhp;
978 	int err;
979 
980 	be_root_concat(lbh, bootenv, be_path);
981 
982 	/* Note: be_exists fails if mountpoint is not / */
983 	if ((err = be_exists(lbh, be_path)) != 0)
984 		return (set_error(lbh, err));
985 
986 	if (temporary) {
987 		config = zpool_get_config(lbh->active_phandle, NULL);
988 		if (config == NULL)
989 			/* config should be fetchable... */
990 			return (set_error(lbh, BE_ERR_UNKNOWN));
991 
992 		if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
993 		    &pool_guid) != 0)
994 			/* Similarly, it shouldn't be possible */
995 			return (set_error(lbh, BE_ERR_UNKNOWN));
996 
997 		/* Expected format according to zfsbootcfg(8) man */
998 		snprintf(buf, sizeof(buf), "zfs:%s:", be_path);
999 
1000 		/* We have no config tree */
1001 		if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
1002 		    &vdevs) != 0)
1003 			return (set_error(lbh, BE_ERR_NOPOOL));
1004 
1005 		return (be_set_nextboot(lbh, vdevs, pool_guid, buf));
1006 	} else {
1007 		if (be_deactivate(lbh, lbh->bootfs) != 0)
1008 			return (-1);
1009 
1010 		/* Obtain bootenv zpool */
1011 		err = zpool_set_prop(lbh->active_phandle, "bootfs", be_path);
1012 		if (err)
1013 			return (-1);
1014 
1015 		zhp = zfs_open(lbh->lzh, be_path, ZFS_TYPE_FILESYSTEM);
1016 		if (zhp == NULL)
1017 			return (-1);
1018 
1019 		if (be_prop_list_alloc(&dsprops) != 0)
1020 			return (-1);
1021 
1022 		if (be_get_dataset_props(lbh, be_path, dsprops) != 0) {
1023 			nvlist_free(dsprops);
1024 			return (-1);
1025 		}
1026 
1027 		if (nvlist_lookup_string(dsprops, "origin", &origin) == 0)
1028 			err = zfs_promote(zhp);
1029 		nvlist_free(dsprops);
1030 
1031 		zfs_close(zhp);
1032 
1033 		if (err)
1034 			return (-1);
1035 	}
1036 
1037 	return (BE_ERR_SUCCESS);
1038 }
1039