1/*
2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * Copyright (c) 2020, 2022 by Delphix. All rights reserved.
27 */
28
29#include <sys/param.h>
30#include <sys/vfs.h>
31
32#include <assert.h>
33#include <errno.h>
34#include <fcntl.h>
35#include <libutil.h>
36#include <signal.h>
37#include <stdio.h>
38#include <string.h>
39#include <unistd.h>
40#include <libintl.h>
41
42#include <libshare.h>
43#include "libshare_impl.h"
44#include "nfs.h"
45
46#define	_PATH_MOUNTDPID	"/var/run/mountd.pid"
47#define	OPTSSIZE	1024
48#define	MAXLINESIZE	(PATH_MAX + OPTSSIZE)
49#define	ZFS_EXPORTS_FILE	"/etc/zfs/exports"
50#define	ZFS_EXPORTS_LOCK	ZFS_EXPORTS_FILE".lock"
51
52/*
53 * This function translates options to a format acceptable by exports(5), eg.
54 *
55 *	-ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \
56 *	zfs.freebsd.org 69.147.83.54
57 *
58 * Accepted input formats:
59 *
60 *	ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,zfs.freebsd.org
61 *	ro network=192.168.0.0 mask=255.255.255.0 maproot=0 zfs.freebsd.org
62 *	-ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,zfs.freebsd.org
63 *	-ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \
64 *	zfs.freebsd.org
65 *
66 * Recognized keywords:
67 *
68 *	ro, maproot, mapall, mask, network, sec, alldirs, public, webnfs,
69 *	index, quiet
70 */
71static int
72translate_opts(const char *shareopts, FILE *out)
73{
74	static const char *const known_opts[] = { "ro", "maproot", "mapall",
75	    "mask", "network", "sec", "alldirs", "public", "webnfs", "index",
76	    "quiet" };
77	char oldopts[OPTSSIZE], newopts[OPTSSIZE];
78	char *o, *s = NULL;
79	unsigned int i;
80	size_t len;
81
82	strlcpy(oldopts, shareopts, sizeof (oldopts));
83	newopts[0] = '\0';
84	s = oldopts;
85	while ((o = strsep(&s, "-, ")) != NULL) {
86		if (o[0] == '\0')
87			continue;
88		for (i = 0; i < ARRAY_SIZE(known_opts); ++i) {
89			len = strlen(known_opts[i]);
90			if (strncmp(known_opts[i], o, len) == 0 &&
91			    (o[len] == '\0' || o[len] == '=')) {
92				strlcat(newopts, "-", sizeof (newopts));
93				break;
94			}
95		}
96		strlcat(newopts, o, sizeof (newopts));
97		strlcat(newopts, " ", sizeof (newopts));
98	}
99	return (fputs(newopts, out));
100}
101
102static int
103nfs_enable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
104{
105	const char *shareopts = impl_share->sa_shareopts;
106	if (strcmp(shareopts, "on") == 0)
107		shareopts = "";
108
109	boolean_t need_free;
110	char *mp;
111	int rc  = nfs_escape_mountpoint(impl_share->sa_mountpoint, &mp,
112	    &need_free);
113	if (rc != SA_OK)
114		return (rc);
115
116	if (fputs(mp, tmpfile) == EOF ||
117	    fputc('\t', tmpfile) == EOF ||
118	    translate_opts(shareopts, tmpfile) == EOF ||
119	    fputc('\n', tmpfile) == EOF) {
120		fprintf(stderr, "failed to write to temporary file\n");
121		rc = SA_SYSTEM_ERR;
122	}
123
124	if (need_free)
125		free(mp);
126	return (rc);
127}
128
129static int
130nfs_enable_share(sa_share_impl_t impl_share)
131{
132	return (nfs_toggle_share(
133	    ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share,
134	    nfs_enable_share_impl));
135}
136
137static int
138nfs_disable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
139{
140	(void) impl_share, (void) tmpfile;
141	return (SA_OK);
142}
143
144static int
145nfs_disable_share(sa_share_impl_t impl_share)
146{
147	return (nfs_toggle_share(
148	    ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share,
149	    nfs_disable_share_impl));
150}
151
152static boolean_t
153nfs_is_shared(sa_share_impl_t impl_share)
154{
155	return (nfs_is_shared_impl(ZFS_EXPORTS_FILE, impl_share));
156}
157
158static int
159nfs_validate_shareopts(const char *shareopts)
160{
161	if (strlen(shareopts) == 0)
162		return (SA_SYNTAX_ERR);
163	return (SA_OK);
164}
165
166/*
167 * Commit the shares by restarting mountd.
168 */
169static int
170nfs_commit_shares(void)
171{
172	struct pidfh *pfh;
173	pid_t mountdpid;
174
175start:
176	pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
177	if (pfh != NULL) {
178		/* mountd(8) is not running. */
179		pidfile_remove(pfh);
180		return (SA_OK);
181	}
182	if (errno != EEXIST) {
183		/* Cannot open pidfile for some reason. */
184		return (SA_SYSTEM_ERR);
185	}
186	if (mountdpid == -1) {
187		/* mountd(8) exists, but didn't write the PID yet */
188		usleep(500);
189		goto start;
190	}
191	/* We have mountd(8) PID in mountdpid variable. */
192	kill(mountdpid, SIGHUP);
193	return (SA_OK);
194}
195
196static void
197nfs_truncate_shares(void)
198{
199	nfs_reset_shares(ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE);
200}
201
202const sa_fstype_t libshare_nfs_type = {
203	.enable_share = nfs_enable_share,
204	.disable_share = nfs_disable_share,
205	.is_shared = nfs_is_shared,
206
207	.validate_shareopts = nfs_validate_shareopts,
208	.commit_shares = nfs_commit_shares,
209	.truncate_shares = nfs_truncate_shares,
210};
211