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/10.3/usr.sbin/autofs/automount.c 283239 2015-05-21 13:37:48Z 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 <netdb.h>
50#include <signal.h>
51#include <stdbool.h>
52#include <stdint.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <unistd.h>
57
58#include <libutil.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
84	return (error);
85}
86
87static const struct statfs *
88find_statfs(const struct statfs *mntbuf, int nitems, const char *mountpoint)
89{
90	int i;
91
92	for (i = 0; i < nitems; i++) {
93		if (strcmp(mntbuf[i].f_mntonname, mountpoint) == 0)
94			return (mntbuf + i);
95	}
96
97	return (NULL);
98}
99
100static void
101mount_autofs(const char *from, const char *fspath, const char *options,
102    const char *prefix)
103{
104	struct iovec *iov = NULL;
105	char errmsg[255];
106	int error, iovlen = 0;
107
108	create_directory(fspath);
109
110	log_debugx("mounting %s on %s, prefix \"%s\", options \"%s\"",
111	    from, fspath, prefix, options);
112	memset(errmsg, 0, sizeof(errmsg));
113
114	build_iovec(&iov, &iovlen, "fstype",
115	    __DECONST(void *, "autofs"), (size_t)-1);
116	build_iovec(&iov, &iovlen, "fspath",
117	    __DECONST(void *, fspath), (size_t)-1);
118	build_iovec(&iov, &iovlen, "from",
119	    __DECONST(void *, from), (size_t)-1);
120	build_iovec(&iov, &iovlen, "errmsg",
121	    errmsg, sizeof(errmsg));
122
123	/*
124	 * Append the options and mountpoint defined in auto_master(5);
125	 * this way automountd(8) does not need to parse it.
126	 */
127	build_iovec(&iov, &iovlen, "master_options",
128	    __DECONST(void *, options), (size_t)-1);
129	build_iovec(&iov, &iovlen, "master_prefix",
130	    __DECONST(void *, prefix), (size_t)-1);
131
132	error = nmount(iov, iovlen, 0);
133	if (error != 0) {
134		if (*errmsg != '\0') {
135			log_err(1, "cannot mount %s on %s: %s",
136			    from, fspath, errmsg);
137		} else {
138			log_err(1, "cannot mount %s on %s", from, fspath);
139		}
140	}
141}
142
143static void
144mount_if_not_already(const struct node *n, const char *map, const char *options,
145    const char *prefix, const struct statfs *mntbuf, int nitems)
146{
147	const struct statfs *sb;
148	char *mountpoint;
149	char *from;
150	int ret;
151
152	ret = asprintf(&from, "map %s", map);
153	if (ret < 0)
154		log_err(1, "asprintf");
155
156	mountpoint = node_path(n);
157	sb = find_statfs(mntbuf, nitems, mountpoint);
158	if (sb != NULL) {
159		if (strcmp(sb->f_fstypename, "autofs") != 0) {
160			log_debugx("unknown filesystem mounted "
161			    "on %s; mounting", mountpoint);
162			/*
163			 * XXX: Compare options and 'from',
164			 *	and update the mount if necessary.
165			 */
166		} else {
167			log_debugx("autofs already mounted "
168			    "on %s", mountpoint);
169			free(from);
170			free(mountpoint);
171			return;
172		}
173	} else {
174		log_debugx("nothing mounted on %s; mounting",
175		    mountpoint);
176	}
177
178	mount_autofs(from, mountpoint, options, prefix);
179	free(from);
180	free(mountpoint);
181}
182
183static void
184mount_unmount(struct node *root)
185{
186	struct statfs *mntbuf;
187	struct node *n, *n2;
188	int i, nitems;
189
190	nitems = getmntinfo(&mntbuf, MNT_WAIT);
191	if (nitems <= 0)
192		log_err(1, "getmntinfo");
193
194	log_debugx("unmounting stale autofs mounts");
195
196	for (i = 0; i < nitems; i++) {
197		if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
198			log_debugx("skipping %s, filesystem type is not autofs",
199			    mntbuf[i].f_mntonname);
200			continue;
201		}
202
203		n = node_find(root, mntbuf[i].f_mntonname);
204		if (n != NULL) {
205			log_debugx("leaving autofs mounted on %s",
206			    mntbuf[i].f_mntonname);
207			continue;
208		}
209
210		log_debugx("autofs mounted on %s not found "
211		    "in new configuration; unmounting", mntbuf[i].f_mntonname);
212		unmount_by_statfs(&(mntbuf[i]), false);
213	}
214
215	log_debugx("mounting new autofs mounts");
216
217	TAILQ_FOREACH(n, &root->n_children, n_next) {
218		if (!node_is_direct_map(n)) {
219			mount_if_not_already(n, n->n_map, n->n_options,
220			    n->n_key, mntbuf, nitems);
221			continue;
222		}
223
224		TAILQ_FOREACH(n2, &n->n_children, n_next) {
225			mount_if_not_already(n2, n->n_map, n->n_options,
226			    "/", mntbuf, nitems);
227		}
228	}
229}
230
231static void
232flush_autofs(const char *fspath)
233{
234	struct iovec *iov = NULL;
235	char errmsg[255];
236	int error, iovlen = 0;
237
238	log_debugx("flushing %s", fspath);
239	memset(errmsg, 0, sizeof(errmsg));
240
241	build_iovec(&iov, &iovlen, "fstype",
242	    __DECONST(void *, "autofs"), (size_t)-1);
243	build_iovec(&iov, &iovlen, "fspath",
244	    __DECONST(void *, fspath), (size_t)-1);
245	build_iovec(&iov, &iovlen, "errmsg",
246	    errmsg, sizeof(errmsg));
247
248	error = nmount(iov, iovlen, MNT_UPDATE);
249	if (error != 0) {
250		if (*errmsg != '\0') {
251			log_err(1, "cannot flush %s: %s",
252			    fspath, errmsg);
253		} else {
254			log_err(1, "cannot flush %s", fspath);
255		}
256	}
257}
258
259static void
260flush_caches(void)
261{
262	struct statfs *mntbuf;
263	int i, nitems;
264
265	nitems = getmntinfo(&mntbuf, MNT_WAIT);
266	if (nitems <= 0)
267		log_err(1, "getmntinfo");
268
269	log_debugx("flushing autofs caches");
270
271	for (i = 0; i < nitems; i++) {
272		if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
273			log_debugx("skipping %s, filesystem type is not autofs",
274			    mntbuf[i].f_mntonname);
275			continue;
276		}
277
278		flush_autofs(mntbuf[i].f_mntonname);
279	}
280}
281
282static void
283unmount_automounted(bool force)
284{
285	struct statfs *mntbuf;
286	int i, nitems;
287
288	nitems = getmntinfo(&mntbuf, MNT_WAIT);
289	if (nitems <= 0)
290		log_err(1, "getmntinfo");
291
292	log_debugx("unmounting automounted filesystems");
293
294	for (i = 0; i < nitems; i++) {
295		if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
296			log_debugx("skipping %s, filesystem type is autofs",
297			    mntbuf[i].f_mntonname);
298			continue;
299		}
300
301		if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
302			log_debugx("skipping %s, not automounted",
303			    mntbuf[i].f_mntonname);
304			continue;
305		}
306
307		unmount_by_statfs(&(mntbuf[i]), force);
308	}
309}
310
311static void
312usage_automount(void)
313{
314
315	fprintf(stderr, "usage: automount [-D name=value][-o opts][-Lcfuv]\n");
316	exit(1);
317}
318
319int
320main_automount(int argc, char **argv)
321{
322	struct node *root;
323	int ch, debug = 0, show_maps = 0;
324	char *options = NULL;
325	bool do_unmount = false, force_unmount = false, flush = false;
326
327	/*
328	 * Note that in automount(8), the only purpose of variable
329	 * handling is to aid in debugging maps (automount -L).
330	 */
331	defined_init();
332
333	while ((ch = getopt(argc, argv, "D:Lfco:uv")) != -1) {
334		switch (ch) {
335		case 'D':
336			defined_parse_and_add(optarg);
337			break;
338		case 'L':
339			show_maps++;
340			break;
341		case 'c':
342			flush = true;
343			break;
344		case 'f':
345			force_unmount = true;
346			break;
347		case 'o':
348			options = concat(options, ',', optarg);
349			break;
350		case 'u':
351			do_unmount = true;
352			break;
353		case 'v':
354			debug++;
355			break;
356		case '?':
357		default:
358			usage_automount();
359		}
360	}
361	argc -= optind;
362	if (argc != 0)
363		usage_automount();
364
365	if (force_unmount && !do_unmount)
366		usage_automount();
367
368	log_init(debug);
369
370	if (flush) {
371		flush_caches();
372		return (0);
373	}
374
375	if (do_unmount) {
376		unmount_automounted(force_unmount);
377		return (0);
378	}
379
380	root = node_new_root();
381	parse_master(root, AUTO_MASTER_PATH);
382
383	if (show_maps) {
384		if (show_maps > 1) {
385			node_expand_indirect_maps(root);
386			node_expand_ampersand(root, NULL);
387		}
388		node_expand_defined(root);
389		node_print(root, options);
390		return (0);
391	}
392
393	mount_unmount(root);
394
395	return (0);
396}
397