automount.c revision 270897 
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: stable/10/usr.sbin/autofs/automount.c 270897 2014-08-31 21:48:12Z 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,
145    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, n->n_options, n->n_key);
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, *n3;
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, mntbuf, nitems);
220			continue;
221		}
222
223		TAILQ_FOREACH(n2, &n->n_children, n_next) {
224			TAILQ_FOREACH(n3, &n2->n_children, n_next) {
225				mount_if_not_already(n3, n->n_map,
226				    mntbuf, nitems);
227			}
228		}
229	}
230}
231
232static void
233unmount_automounted(bool force)
234{
235	struct statfs *mntbuf;
236	int i, nitems;
237
238	nitems = getmntinfo(&mntbuf, MNT_WAIT);
239	if (nitems <= 0)
240		log_err(1, "getmntinfo");
241
242	log_debugx("unmounting automounted filesystems");
243
244	for (i = 0; i < nitems; i++) {
245		if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
246			log_debugx("skipping %s, filesystem type is autofs",
247			    mntbuf[i].f_mntonname);
248			continue;
249		}
250
251		if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
252			log_debugx("skipping %s, not automounted",
253			    mntbuf[i].f_mntonname);
254			continue;
255		}
256
257		unmount_by_statfs(&(mntbuf[i]), force);
258	}
259}
260
261static void
262usage_automount(void)
263{
264
265	fprintf(stderr, "usage: automount [-D name=value][-o opts][-Lfuv]\n");
266	exit(1);
267}
268
269int
270main_automount(int argc, char **argv)
271{
272	struct node *root;
273	int ch, debug = 0, show_maps = 0;
274	char *options = NULL;
275	bool do_unmount = false, force_unmount = false;
276
277	/*
278	 * Note that in automount(8), the only purpose of variable
279	 * handling is to aid in debugging maps (automount -L).
280	 */
281	defined_init();
282
283	while ((ch = getopt(argc, argv, "D:Lfo:uv")) != -1) {
284		switch (ch) {
285		case 'D':
286			defined_parse_and_add(optarg);
287			break;
288		case 'L':
289			show_maps++;
290			break;
291		case 'f':
292			force_unmount = true;
293			break;
294		case 'o':
295			if (options == NULL) {
296				options = checked_strdup(optarg);
297			} else {
298				options =
299				    separated_concat(options, optarg, ',');
300			}
301			break;
302		case 'u':
303			do_unmount = true;
304			break;
305		case 'v':
306			debug++;
307			break;
308		case '?':
309		default:
310			usage_automount();
311		}
312	}
313	argc -= optind;
314	if (argc != 0)
315		usage_automount();
316
317	if (force_unmount && !do_unmount)
318		usage_automount();
319
320	log_init(debug);
321
322	if (do_unmount) {
323		unmount_automounted(force_unmount);
324		return (0);
325	}
326
327	root = node_new_root();
328	parse_master(root, AUTO_MASTER_PATH);
329
330	if (show_maps) {
331		if (options != NULL) {
332			root->n_options = separated_concat(options,
333			    root->n_options, ',');
334		}
335		if (show_maps > 1) {
336			node_expand_indirect_maps(root);
337			node_expand_ampersand(root, NULL);
338		}
339		node_expand_defined(root);
340		node_print(root);
341		return (0);
342	}
343
344	mount_unmount(root);
345
346	return (0);
347}
348