1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2017 Kyle J. Kneitinger <kyle@kneit.in>
5 * Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
6 * Copyright (c) 2019 Wes Maag <wes@jwmaag.org>
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
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#include <sys/cdefs.h>
31#include <sys/mntent.h>
32
33#include "be.h"
34#include "be_impl.h"
35
36struct be_mountcheck_info {
37	const char *path;
38	char *name;
39};
40
41struct be_mount_info {
42	libbe_handle_t *lbh;
43	const char *be;
44	const char *mountpoint;
45	int mntflags;
46	int deepmount;
47	int depth;
48};
49
50static int
51be_mountcheck_cb(zfs_handle_t *zfs_hdl, void *data)
52{
53	struct be_mountcheck_info *info;
54	char *mountpoint;
55
56	if (data == NULL)
57		return (1);
58	info = (struct be_mountcheck_info *)data;
59	if (!zfs_is_mounted(zfs_hdl, &mountpoint))
60		return (0);
61	if (strcmp(mountpoint, info->path) == 0) {
62		info->name = strdup(zfs_get_name(zfs_hdl));
63		free(mountpoint);
64		return (1);
65	}
66	free(mountpoint);
67	return (0);
68}
69
70/*
71 * Called from be_mount, uses the given zfs_handle and attempts to
72 * mount it at the passed mountpoint. If the deepmount flag is set, continue
73 * calling the function for each child dataset.
74 */
75static int
76be_mount_iter(zfs_handle_t *zfs_hdl, void *data)
77{
78	int err;
79	char *mountpoint;
80	char tmp[BE_MAXPATHLEN], zfs_mnt[BE_MAXPATHLEN];
81	struct be_mount_info *info;
82
83	info = (struct be_mount_info *)data;
84
85	if (zfs_is_mounted(zfs_hdl, &mountpoint)) {
86		free(mountpoint);
87		return (0);
88	}
89
90	/*
91	 * canmount and mountpoint are both ignored for the BE dataset, because
92	 * the rest of the system (kernel and loader) will effectively do the
93	 * same.
94	 */
95	if (info->depth == 0) {
96		snprintf(tmp, BE_MAXPATHLEN, "%s", info->mountpoint);
97	} else {
98		if (zfs_prop_get_int(zfs_hdl, ZFS_PROP_CANMOUNT) ==
99		    ZFS_CANMOUNT_OFF)
100			return (0);
101
102		if (zfs_prop_get(zfs_hdl, ZFS_PROP_MOUNTPOINT, zfs_mnt,
103		    BE_MAXPATHLEN, NULL, NULL, 0, 1))
104			return (1);
105
106		/*
107		 * We've encountered mountpoint=none at some intermediate
108		 * dataset (e.g. zroot/var) that will have children that may
109		 * need to be mounted.  Skip mounting it, but iterate through
110		 * the children.
111		 */
112		if (strcmp("none", zfs_mnt) == 0)
113			goto skipmount;
114
115		mountpoint = be_mountpoint_augmented(info->lbh, zfs_mnt);
116		snprintf(tmp, BE_MAXPATHLEN, "%s%s", info->mountpoint,
117		    mountpoint);
118	}
119
120	if ((err = zfs_mount_at(zfs_hdl, NULL, info->mntflags, tmp)) != 0) {
121		switch (errno) {
122		case ENAMETOOLONG:
123			return (set_error(info->lbh, BE_ERR_PATHLEN));
124		case ELOOP:
125		case ENOENT:
126		case ENOTDIR:
127			return (set_error(info->lbh, BE_ERR_BADPATH));
128		case EPERM:
129			return (set_error(info->lbh, BE_ERR_PERMS));
130		case EBUSY:
131			return (set_error(info->lbh, BE_ERR_PATHBUSY));
132		default:
133			return (set_error(info->lbh, BE_ERR_UNKNOWN));
134		}
135	}
136
137	if (!info->deepmount)
138		return (0);
139
140skipmount:
141	++info->depth;
142	err = zfs_iter_filesystems(zfs_hdl, be_mount_iter, info);
143	--info->depth;
144	return (err);
145}
146
147
148static int
149be_umount_iter(zfs_handle_t *zfs_hdl, void *data)
150{
151
152	int err;
153	char *mountpoint;
154	struct be_mount_info *info;
155
156	info = (struct be_mount_info *)data;
157
158	++info->depth;
159	if((err = zfs_iter_filesystems(zfs_hdl, be_umount_iter, info)) != 0) {
160		return (err);
161	}
162	--info->depth;
163
164	if (!zfs_is_mounted(zfs_hdl, &mountpoint)) {
165		return (0);
166	}
167	free(mountpoint);
168
169	if (zfs_unmount(zfs_hdl, NULL, info->mntflags) != 0) {
170		switch (errno) {
171		case ENAMETOOLONG:
172			return (set_error(info->lbh, BE_ERR_PATHLEN));
173		case ELOOP:
174		case ENOENT:
175		case ENOTDIR:
176			return (set_error(info->lbh, BE_ERR_BADPATH));
177		case EPERM:
178			return (set_error(info->lbh, BE_ERR_PERMS));
179		case EBUSY:
180			return (set_error(info->lbh, BE_ERR_PATHBUSY));
181		default:
182			return (set_error(info->lbh, BE_ERR_UNKNOWN));
183		}
184	}
185	return (0);
186}
187
188/*
189 * usage
190 */
191int
192be_mounted_at(libbe_handle_t *lbh, const char *path, nvlist_t *details)
193{
194	char be[BE_MAXPATHLEN];
195	zfs_handle_t *root_hdl;
196	struct be_mountcheck_info info;
197	prop_data_t propinfo;
198
199	bzero(&be, BE_MAXPATHLEN);
200	if ((root_hdl = zfs_open(lbh->lzh, lbh->root,
201	    ZFS_TYPE_FILESYSTEM)) == NULL)
202		return (BE_ERR_ZFSOPEN);
203
204	info.path = path;
205	info.name = NULL;
206	zfs_iter_filesystems(root_hdl, be_mountcheck_cb, &info);
207	zfs_close(root_hdl);
208
209	if (info.name != NULL) {
210		if (details != NULL) {
211			if ((root_hdl = zfs_open(lbh->lzh, info.name,
212			    ZFS_TYPE_FILESYSTEM)) == NULL) {
213				free(info.name);
214				return (BE_ERR_ZFSOPEN);
215			}
216
217			propinfo.lbh = lbh;
218			propinfo.list = details;
219			propinfo.single_object = false;
220			propinfo.bootonce = NULL;
221			prop_list_builder_cb(root_hdl, &propinfo);
222			zfs_close(root_hdl);
223		}
224		free(info.name);
225		return (0);
226	}
227	return (1);
228}
229
230/*
231 * usage
232 */
233int
234be_mount(libbe_handle_t *lbh, const char *bootenv, const char *mountpoint,
235    int flags, char *result_loc)
236{
237	char be[BE_MAXPATHLEN];
238	char mnt_temp[BE_MAXPATHLEN];
239	int mntflags, mntdeep;
240	int err;
241	struct be_mount_info info;
242	zfs_handle_t *zhdl;
243
244	if ((err = be_root_concat(lbh, bootenv, be)) != 0)
245		return (set_error(lbh, err));
246
247	if ((err = be_exists(lbh, bootenv)) != 0)
248		return (set_error(lbh, err));
249
250	if (is_mounted(lbh->lzh, be, NULL))
251		return (set_error(lbh, BE_ERR_MOUNTED));
252
253	mntdeep = (flags & BE_MNT_DEEP) ? 1 : 0;
254	mntflags = (flags & BE_MNT_FORCE) ? MNT_FORCE : 0;
255
256	/* Create mountpoint if it is not specified */
257	if (mountpoint == NULL) {
258		strlcpy(mnt_temp, "/tmp/be_mount.XXXX", sizeof(mnt_temp));
259		if (mkdtemp(mnt_temp) == NULL)
260			return (set_error(lbh, BE_ERR_IO));
261	}
262
263	if ((zhdl = zfs_open(lbh->lzh, be, ZFS_TYPE_FILESYSTEM)) == NULL)
264		return (set_error(lbh, BE_ERR_ZFSOPEN));
265
266	info.lbh = lbh;
267	info.be = be;
268	info.mountpoint = (mountpoint == NULL) ? mnt_temp : mountpoint;
269	info.mntflags = mntflags;
270	info.deepmount = mntdeep;
271	info.depth = 0;
272
273	if((err = be_mount_iter(zhdl, &info) != 0)) {
274		zfs_close(zhdl);
275		return (err);
276	}
277	zfs_close(zhdl);
278
279	if (result_loc != NULL)
280		strlcpy(result_loc, mountpoint == NULL ? mnt_temp : mountpoint,
281		    BE_MAXPATHLEN);
282
283	return (BE_ERR_SUCCESS);
284}
285
286/*
287 * usage
288 */
289int
290be_unmount(libbe_handle_t *lbh, const char *bootenv, int flags)
291{
292	int err;
293	char be[BE_MAXPATHLEN];
294	zfs_handle_t *root_hdl;
295	struct be_mount_info info;
296
297	if ((err = be_root_concat(lbh, bootenv, be)) != 0)
298		return (set_error(lbh, err));
299
300	if ((root_hdl = zfs_open(lbh->lzh, be, ZFS_TYPE_FILESYSTEM)) == NULL)
301		return (set_error(lbh, BE_ERR_ZFSOPEN));
302
303	info.lbh = lbh;
304	info.be = be;
305	info.mountpoint = NULL;
306	info.mntflags = (flags & BE_MNT_FORCE) ? MS_FORCE : 0;
307	info.depth = 0;
308
309	if ((err = be_umount_iter(root_hdl, &info)) != 0) {
310		zfs_close(root_hdl);
311		return (err);
312	}
313
314	zfs_close(root_hdl);
315	return (BE_ERR_SUCCESS);
316}
317
318/*
319 * This function will blow away the input buffer as needed if we're discovered
320 * to be looking at a root-mount.  If the mountpoint is naturally beyond the
321 * root, however, the buffer may be left intact and a pointer to the section
322 * past altroot will be returned instead for the caller's perusal.
323 */
324char *
325be_mountpoint_augmented(libbe_handle_t *lbh, char *mountpoint)
326{
327
328	if (lbh->altroot_len == 0)
329		return (mountpoint);
330	if (mountpoint == NULL || *mountpoint == '\0')
331		return (mountpoint);
332
333	if (mountpoint[lbh->altroot_len] == '\0') {
334		*(mountpoint + 1) = '\0';
335		return (mountpoint);
336	} else
337		return (mountpoint + lbh->altroot_len);
338}
339