1/*-
2 * Copyright (c) 2014 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Edward Tomasz Napierala under sponsorship
6 * from the FreeBSD Foundation.
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 AUTHOR 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 AUTHOR 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
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: releng/11.0/usr.sbin/autofs/automount.c 294670 2016-01-24 18:11:36Z trasz $");
33
34#include <sys/types.h>
35#include <sys/time.h>
36#include <sys/ioctl.h>
37#include <sys/param.h>
38#include <sys/linker.h>
39#include <sys/mount.h>
40#include <sys/socket.h>
41#include <sys/stat.h>
42#include <sys/wait.h>
43#include <sys/utsname.h>
44#include <assert.h>
45#include <ctype.h>
46#include <errno.h>
47#include <fcntl.h>
48#include <libgen.h>
49#include <libutil.h>
50#include <netdb.h>
51#include <signal.h>
52#include <stdbool.h>
53#include <stdint.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <unistd.h>
58
59#include "common.h"
60#include "mntopts.h"
61
62static int
63unmount_by_statfs(const struct statfs *sb, bool force)
64{
65	char *fsid_str;
66	int error, ret, flags;
67
68	ret = asprintf(&fsid_str, "FSID:%d:%d",
69	    sb->f_fsid.val[0], sb->f_fsid.val[1]);
70	if (ret < 0)
71		log_err(1, "asprintf");
72
73	log_debugx("unmounting %s using %s", sb->f_mntonname, fsid_str);
74
75	flags = MNT_BYFSID;
76	if (force)
77		flags |= MNT_FORCE;
78	error = unmount(fsid_str, flags);
79	free(fsid_str);
80	if (error != 0)
81		log_warn("cannot unmount %s", sb->f_mntonname);
82
83	return (error);
84}
85
86static const struct statfs *
87find_statfs(const struct statfs *mntbuf, int nitems, const char *mountpoint)
88{
89	int i;
90
91	for (i = 0; i < nitems; i++) {
92		if (strcmp(mntbuf[i].f_mntonname, mountpoint) == 0)
93			return (mntbuf + i);
94	}
95
96	return (NULL);
97}
98
99static void
100mount_autofs(const char *from, const char *fspath, const char *options,
101    const char *prefix)
102{
103	struct iovec *iov = NULL;
104	char errmsg[255];
105	int error, iovlen = 0;
106
107	create_directory(fspath);
108
109	log_debugx("mounting %s on %s, prefix \"%s\", options \"%s\"",
110	    from, fspath, prefix, options);
111	memset(errmsg, 0, sizeof(errmsg));
112
113	build_iovec(&iov, &iovlen, "fstype",
114	    __DECONST(void *, "autofs"), (size_t)-1);
115	build_iovec(&iov, &iovlen, "fspath",
116	    __DECONST(void *, fspath), (size_t)-1);
117	build_iovec(&iov, &iovlen, "from",
118	    __DECONST(void *, from), (size_t)-1);
119	build_iovec(&iov, &iovlen, "errmsg",
120	    errmsg, sizeof(errmsg));
121
122	/*
123	 * Append the options and mountpoint defined in auto_master(5);
124	 * this way automountd(8) does not need to parse it.
125	 */
126	build_iovec(&iov, &iovlen, "master_options",
127	    __DECONST(void *, options), (size_t)-1);
128	build_iovec(&iov, &iovlen, "master_prefix",
129	    __DECONST(void *, prefix), (size_t)-1);
130
131	error = nmount(iov, iovlen, 0);
132	if (error != 0) {
133		if (*errmsg != '\0') {
134			log_err(1, "cannot mount %s on %s: %s",
135			    from, fspath, errmsg);
136		} else {
137			log_err(1, "cannot mount %s on %s", from, fspath);
138		}
139	}
140}
141
142static void
143mount_if_not_already(const struct node *n, const char *map, const char *options,
144    const char *prefix, const struct statfs *mntbuf, int nitems)
145{
146	const struct statfs *sb;
147	char *mountpoint;
148	char *from;
149	int ret;
150
151	ret = asprintf(&from, "map %s", map);
152	if (ret < 0)
153		log_err(1, "asprintf");
154
155	mountpoint = node_path(n);
156	sb = find_statfs(mntbuf, nitems, mountpoint);
157	if (sb != NULL) {
158		if (strcmp(sb->f_fstypename, "autofs") != 0) {
159			log_debugx("unknown filesystem mounted "
160			    "on %s; mounting", mountpoint);
161			/*
162			 * XXX: Compare options and 'from',
163			 *	and update the mount if necessary.
164			 */
165		} else {
166			log_debugx("autofs already mounted "
167			    "on %s", mountpoint);
168			free(from);
169			free(mountpoint);
170			return;
171		}
172	} else {
173		log_debugx("nothing mounted on %s; mounting",
174		    mountpoint);
175	}
176
177	mount_autofs(from, mountpoint, options, prefix);
178	free(from);
179	free(mountpoint);
180}
181
182static void
183mount_unmount(struct node *root)
184{
185	struct statfs *mntbuf;
186	struct node *n, *n2;
187	int i, nitems;
188
189	nitems = getmntinfo(&mntbuf, MNT_WAIT);
190	if (nitems <= 0)
191		log_err(1, "getmntinfo");
192
193	log_debugx("unmounting stale autofs mounts");
194
195	for (i = 0; i < nitems; i++) {
196		if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
197			log_debugx("skipping %s, filesystem type is not autofs",
198			    mntbuf[i].f_mntonname);
199			continue;
200		}
201
202		n = node_find(root, mntbuf[i].f_mntonname);
203		if (n != NULL) {
204			log_debugx("leaving autofs mounted on %s",
205			    mntbuf[i].f_mntonname);
206			continue;
207		}
208
209		log_debugx("autofs mounted on %s not found "
210		    "in new configuration; unmounting", mntbuf[i].f_mntonname);
211		unmount_by_statfs(&(mntbuf[i]), false);
212	}
213
214	log_debugx("mounting new autofs mounts");
215
216	TAILQ_FOREACH(n, &root->n_children, n_next) {
217		if (!node_is_direct_map(n)) {
218			mount_if_not_already(n, n->n_map, n->n_options,
219			    n->n_key, mntbuf, nitems);
220			continue;
221		}
222
223		TAILQ_FOREACH(n2, &n->n_children, n_next) {
224			mount_if_not_already(n2, n->n_map, n->n_options,
225			    "/", mntbuf, nitems);
226		}
227	}
228}
229
230static void
231flush_autofs(const char *fspath)
232{
233	struct iovec *iov = NULL;
234	char errmsg[255];
235	int error, iovlen = 0;
236
237	log_debugx("flushing %s", fspath);
238	memset(errmsg, 0, sizeof(errmsg));
239
240	build_iovec(&iov, &iovlen, "fstype",
241	    __DECONST(void *, "autofs"), (size_t)-1);
242	build_iovec(&iov, &iovlen, "fspath",
243	    __DECONST(void *, fspath), (size_t)-1);
244	build_iovec(&iov, &iovlen, "errmsg",
245	    errmsg, sizeof(errmsg));
246
247	error = nmount(iov, iovlen, MNT_UPDATE);
248	if (error != 0) {
249		if (*errmsg != '\0') {
250			log_err(1, "cannot flush %s: %s",
251			    fspath, errmsg);
252		} else {
253			log_err(1, "cannot flush %s", fspath);
254		}
255	}
256}
257
258static void
259flush_caches(void)
260{
261	struct statfs *mntbuf;
262	int i, nitems;
263
264	nitems = getmntinfo(&mntbuf, MNT_WAIT);
265	if (nitems <= 0)
266		log_err(1, "getmntinfo");
267
268	log_debugx("flushing autofs caches");
269
270	for (i = 0; i < nitems; i++) {
271		if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
272			log_debugx("skipping %s, filesystem type is not autofs",
273			    mntbuf[i].f_mntonname);
274			continue;
275		}
276
277		flush_autofs(mntbuf[i].f_mntonname);
278	}
279}
280
281static void
282unmount_automounted(bool force)
283{
284	struct statfs *mntbuf;
285	int i, nitems;
286
287	nitems = getmntinfo(&mntbuf, MNT_WAIT);
288	if (nitems <= 0)
289		log_err(1, "getmntinfo");
290
291	log_debugx("unmounting automounted filesystems");
292
293	for (i = 0; i < nitems; i++) {
294		if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
295			log_debugx("skipping %s, filesystem type is autofs",
296			    mntbuf[i].f_mntonname);
297			continue;
298		}
299
300		if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
301			log_debugx("skipping %s, not automounted",
302			    mntbuf[i].f_mntonname);
303			continue;
304		}
305
306		unmount_by_statfs(&(mntbuf[i]), force);
307	}
308}
309
310static void
311usage_automount(void)
312{
313
314	fprintf(stderr, "usage: automount [-D name=value][-o opts][-Lcfuv]\n");
315	exit(1);
316}
317
318int
319main_automount(int argc, char **argv)
320{
321	struct node *root;
322	int ch, debug = 0, show_maps = 0;
323	char *options = NULL;
324	bool do_unmount = false, force_unmount = false, flush = false;
325
326	/*
327	 * Note that in automount(8), the only purpose of variable
328	 * handling is to aid in debugging maps (automount -L).
329	 */
330	defined_init();
331
332	while ((ch = getopt(argc, argv, "D:Lfco:uv")) != -1) {
333		switch (ch) {
334		case 'D':
335			defined_parse_and_add(optarg);
336			break;
337		case 'L':
338			show_maps++;
339			break;
340		case 'c':
341			flush = true;
342			break;
343		case 'f':
344			force_unmount = true;
345			break;
346		case 'o':
347			options = concat(options, ',', optarg);
348			break;
349		case 'u':
350			do_unmount = true;
351			break;
352		case 'v':
353			debug++;
354			break;
355		case '?':
356		default:
357			usage_automount();
358		}
359	}
360	argc -= optind;
361	if (argc != 0)
362		usage_automount();
363
364	if (force_unmount && !do_unmount)
365		usage_automount();
366
367	log_init(debug);
368
369	if (flush) {
370		flush_caches();
371		return (0);
372	}
373
374	if (do_unmount) {
375		unmount_automounted(force_unmount);
376		return (0);
377	}
378
379	root = node_new_root();
380	parse_master(root, AUTO_MASTER_PATH);
381
382	if (show_maps) {
383		if (show_maps > 1) {
384			node_expand_indirect_maps(root);
385			node_expand_ampersand(root, NULL);
386		}
387		node_expand_defined(root);
388		node_print(root, options);
389		return (0);
390	}
391
392	mount_unmount(root);
393
394	return (0);
395}
396