1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2014 The FreeBSD Foundation
5 *
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD$");
34
35#include <sys/types.h>
36#include <sys/time.h>
37#include <sys/ioctl.h>
38#include <sys/param.h>
39#include <sys/linker.h>
40#include <sys/mount.h>
41#include <sys/socket.h>
42#include <sys/stat.h>
43#include <sys/wait.h>
44#include <sys/utsname.h>
45#include <assert.h>
46#include <ctype.h>
47#include <errno.h>
48#include <fcntl.h>
49#include <libgen.h>
50#include <libutil.h>
51#include <netdb.h>
52#include <signal.h>
53#include <stdbool.h>
54#include <stdint.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#include "common.h"
61#include "mntopts.h"
62
63static int
64unmount_by_statfs(const struct statfs *sb, bool force)
65{
66	char *fsid_str;
67	int error, ret, flags;
68
69	ret = asprintf(&fsid_str, "FSID:%d:%d",
70	    sb->f_fsid.val[0], sb->f_fsid.val[1]);
71	if (ret < 0)
72		log_err(1, "asprintf");
73
74	log_debugx("unmounting %s using %s", sb->f_mntonname, fsid_str);
75
76	flags = MNT_BYFSID;
77	if (force)
78		flags |= MNT_FORCE;
79	error = unmount(fsid_str, flags);
80	free(fsid_str);
81	if (error != 0)
82		log_warn("cannot unmount %s", sb->f_mntonname);
83	else
84		rpc_umntall();
85
86	return (error);
87}
88
89static const struct statfs *
90find_statfs(const struct statfs *mntbuf, int nitems, const char *mountpoint)
91{
92	int i;
93
94	for (i = 0; i < nitems; i++) {
95		if (strcmp(mntbuf[i].f_mntonname, mountpoint) == 0)
96			return (mntbuf + i);
97	}
98
99	return (NULL);
100}
101
102static void
103mount_autofs(const char *from, const char *fspath, const char *options,
104    const char *prefix)
105{
106	struct iovec *iov = NULL;
107	char errmsg[255];
108	int error, iovlen = 0;
109
110	create_directory(fspath);
111
112	log_debugx("mounting %s on %s, prefix \"%s\", options \"%s\"",
113	    from, fspath, prefix, options);
114	memset(errmsg, 0, sizeof(errmsg));
115
116	build_iovec(&iov, &iovlen, "fstype",
117	    __DECONST(void *, "autofs"), (size_t)-1);
118	build_iovec(&iov, &iovlen, "fspath",
119	    __DECONST(void *, fspath), (size_t)-1);
120	build_iovec(&iov, &iovlen, "from",
121	    __DECONST(void *, from), (size_t)-1);
122	build_iovec(&iov, &iovlen, "errmsg",
123	    errmsg, sizeof(errmsg));
124
125	/*
126	 * Append the options and mountpoint defined in auto_master(5);
127	 * this way automountd(8) does not need to parse it.
128	 */
129	build_iovec(&iov, &iovlen, "master_options",
130	    __DECONST(void *, options), (size_t)-1);
131	build_iovec(&iov, &iovlen, "master_prefix",
132	    __DECONST(void *, prefix), (size_t)-1);
133
134	error = nmount(iov, iovlen, 0);
135	if (error != 0) {
136		if (*errmsg != '\0') {
137			log_err(1, "cannot mount %s on %s: %s",
138			    from, fspath, errmsg);
139		} else {
140			log_err(1, "cannot mount %s on %s", from, fspath);
141		}
142	}
143}
144
145static void
146mount_if_not_already(const struct node *n, const char *map, const char *options,
147    const char *prefix, const struct statfs *mntbuf, int nitems)
148{
149	const struct statfs *sb;
150	char *mountpoint;
151	char *from;
152	int ret;
153
154	ret = asprintf(&from, "map %s", map);
155	if (ret < 0)
156		log_err(1, "asprintf");
157
158	mountpoint = node_path(n);
159	sb = find_statfs(mntbuf, nitems, mountpoint);
160	if (sb != NULL) {
161		if (strcmp(sb->f_fstypename, "autofs") != 0) {
162			log_debugx("unknown filesystem mounted "
163			    "on %s; mounting", mountpoint);
164			/*
165			 * XXX: Compare options and 'from',
166			 *	and update the mount if necessary.
167			 */
168		} else {
169			log_debugx("autofs already mounted "
170			    "on %s", mountpoint);
171			free(from);
172			free(mountpoint);
173			return;
174		}
175	} else {
176		log_debugx("nothing mounted on %s; mounting",
177		    mountpoint);
178	}
179
180	mount_autofs(from, mountpoint, options, prefix);
181	free(from);
182	free(mountpoint);
183}
184
185static void
186mount_unmount(struct node *root)
187{
188	struct statfs *mntbuf;
189	struct node *n, *n2;
190	int i, nitems;
191
192	nitems = getmntinfo(&mntbuf, MNT_WAIT);
193	if (nitems <= 0)
194		log_err(1, "getmntinfo");
195
196	log_debugx("unmounting stale autofs mounts");
197
198	for (i = 0; i < nitems; i++) {
199		if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
200			log_debugx("skipping %s, filesystem type is not autofs",
201			    mntbuf[i].f_mntonname);
202			continue;
203		}
204
205		n = node_find(root, mntbuf[i].f_mntonname);
206		if (n != NULL) {
207			log_debugx("leaving autofs mounted on %s",
208			    mntbuf[i].f_mntonname);
209			continue;
210		}
211
212		log_debugx("autofs mounted on %s not found "
213		    "in new configuration; unmounting", mntbuf[i].f_mntonname);
214		unmount_by_statfs(&(mntbuf[i]), false);
215	}
216
217	log_debugx("mounting new autofs mounts");
218
219	TAILQ_FOREACH(n, &root->n_children, n_next) {
220		if (!node_is_direct_map(n)) {
221			mount_if_not_already(n, n->n_map, n->n_options,
222			    n->n_key, mntbuf, nitems);
223			continue;
224		}
225
226		TAILQ_FOREACH(n2, &n->n_children, n_next) {
227			mount_if_not_already(n2, n->n_map, n->n_options,
228			    "/", mntbuf, nitems);
229		}
230	}
231}
232
233static void
234flush_autofs(const char *fspath)
235{
236	struct iovec *iov = NULL;
237	char errmsg[255];
238	int error, iovlen = 0;
239
240	log_debugx("flushing %s", fspath);
241	memset(errmsg, 0, sizeof(errmsg));
242
243	build_iovec(&iov, &iovlen, "fstype",
244	    __DECONST(void *, "autofs"), (size_t)-1);
245	build_iovec(&iov, &iovlen, "fspath",
246	    __DECONST(void *, fspath), (size_t)-1);
247	build_iovec(&iov, &iovlen, "errmsg",
248	    errmsg, sizeof(errmsg));
249
250	error = nmount(iov, iovlen, MNT_UPDATE);
251	if (error != 0) {
252		if (*errmsg != '\0') {
253			log_err(1, "cannot flush %s: %s",
254			    fspath, errmsg);
255		} else {
256			log_err(1, "cannot flush %s", fspath);
257		}
258	}
259}
260
261static void
262flush_caches(void)
263{
264	struct statfs *mntbuf;
265	int i, nitems;
266
267	nitems = getmntinfo(&mntbuf, MNT_WAIT);
268	if (nitems <= 0)
269		log_err(1, "getmntinfo");
270
271	log_debugx("flushing autofs caches");
272
273	for (i = 0; i < nitems; i++) {
274		if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
275			log_debugx("skipping %s, filesystem type is not autofs",
276			    mntbuf[i].f_mntonname);
277			continue;
278		}
279
280		flush_autofs(mntbuf[i].f_mntonname);
281	}
282}
283
284static void
285unmount_automounted(bool force)
286{
287	struct statfs *mntbuf;
288	int i, nitems;
289
290	nitems = getmntinfo(&mntbuf, MNT_WAIT);
291	if (nitems <= 0)
292		log_err(1, "getmntinfo");
293
294	log_debugx("unmounting automounted filesystems");
295
296	for (i = 0; i < nitems; i++) {
297		if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
298			log_debugx("skipping %s, filesystem type is autofs",
299			    mntbuf[i].f_mntonname);
300			continue;
301		}
302
303		if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
304			log_debugx("skipping %s, not automounted",
305			    mntbuf[i].f_mntonname);
306			continue;
307		}
308
309		unmount_by_statfs(&(mntbuf[i]), force);
310	}
311}
312
313static void
314usage_automount(void)
315{
316
317	fprintf(stderr, "usage: automount [-D name=value][-o opts][-Lcfuv]\n");
318	exit(1);
319}
320
321int
322main_automount(int argc, char **argv)
323{
324	struct node *root;
325	int ch, debug = 0, show_maps = 0;
326	char *options = NULL;
327	bool do_unmount = false, force_unmount = false, flush = false;
328
329	/*
330	 * Note that in automount(8), the only purpose of variable
331	 * handling is to aid in debugging maps (automount -L).
332	 */
333	defined_init();
334
335	while ((ch = getopt(argc, argv, "D:Lfco:uv")) != -1) {
336		switch (ch) {
337		case 'D':
338			defined_parse_and_add(optarg);
339			break;
340		case 'L':
341			show_maps++;
342			break;
343		case 'c':
344			flush = true;
345			break;
346		case 'f':
347			force_unmount = true;
348			break;
349		case 'o':
350			options = concat(options, ',', optarg);
351			break;
352		case 'u':
353			do_unmount = true;
354			break;
355		case 'v':
356			debug++;
357			break;
358		case '?':
359		default:
360			usage_automount();
361		}
362	}
363	argc -= optind;
364	if (argc != 0)
365		usage_automount();
366
367	if (force_unmount && !do_unmount)
368		usage_automount();
369
370	log_init(debug);
371
372	if (flush) {
373		flush_caches();
374		return (0);
375	}
376
377	if (do_unmount) {
378		unmount_automounted(force_unmount);
379		return (0);
380	}
381
382	root = node_new_root();
383	parse_master(root, AUTO_MASTER_PATH);
384
385	if (show_maps) {
386		if (show_maps > 1) {
387			node_expand_indirect_maps(root);
388			node_expand_ampersand(root, NULL);
389		}
390		node_expand_defined(root);
391		node_print(root, options);
392		return (0);
393	}
394
395	mount_unmount(root);
396
397	return (0);
398}
399