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 ZFS_EXPORTS_FILE "/etc/zfs/exports"
48 #define ZFS_EXPORTS_LOCK ZFS_EXPORTS_FILE".lock"
49
50 /*
51 * This function translates options to a format acceptable by exports(5), eg.
52 *
53 * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \
54 * zfs.freebsd.org 69.147.83.54
55 *
56 * Accepted input formats:
57 *
58 * ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,zfs.freebsd.org
59 * ro network=192.168.0.0 mask=255.255.255.0 maproot=0 zfs.freebsd.org
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 \
62 * zfs.freebsd.org
63 *
64 * Recognized keywords:
65 *
66 * ro, maproot, mapall, mask, network, sec, alldirs, public, webnfs,
67 * index, quiet
68 */
69 static int
translate_opts(char * oldopts,FILE * out)70 translate_opts(char *oldopts, FILE *out)
71 {
72 static const char *const known_opts[] = { "ro", "maproot", "mapall",
73 "mask", "network", "sec", "alldirs", "public", "webnfs", "index",
74 "quiet" };
75 char *newopts, *o, *s = NULL;
76 unsigned int i;
77 size_t len, newopts_len;
78 int ret;
79
80 /*
81 * Calculate the length needed for the worst case of a single
82 * character option:
83 * - Add one to strlen(oldopts) so that the trailing nul is counted
84 * as a separator.
85 * - Multiply by 3/2 since the single character option plus separator
86 * is expanded to 3 characters.
87 * - Add one for the trailing nul. Needed for a single repetition of
88 * the single character option and certain other cases.
89 */
90 newopts_len = (strlen(oldopts) + 1) * 3 / 2 + 1;
91 newopts = malloc(newopts_len);
92 if (newopts == NULL)
93 return (EOF);
94 newopts[0] = '\0';
95 s = oldopts;
96 while ((o = strsep(&s, ", ")) != NULL) {
97 if (o[0] == '-')
98 o++;
99 if (o[0] == '\0')
100 continue;
101 for (i = 0; i < ARRAY_SIZE(known_opts); ++i) {
102 len = strlen(known_opts[i]);
103 if (strncmp(known_opts[i], o, len) == 0 &&
104 (o[len] == '\0' || o[len] == '=')) {
105 strlcat(newopts, "-", newopts_len);
106 break;
107 }
108 }
109 strlcat(newopts, o, newopts_len);
110 strlcat(newopts, " ", newopts_len);
111 }
112 ret = fputs(newopts, out);
113 free(newopts);
114 return (ret);
115 }
116
117 static int
nfs_enable_share_impl(sa_share_impl_t impl_share,FILE * tmpfile)118 nfs_enable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
119 {
120 const char *shareopts = impl_share->sa_shareopts;
121 if (strcmp(shareopts, "on") == 0)
122 shareopts = "";
123
124 boolean_t need_free, fnd_semi;
125 char *mp, *lineopts, *exportopts, *s;
126 size_t whitelen;
127 int rc = nfs_escape_mountpoint(impl_share->sa_mountpoint, &mp,
128 &need_free);
129 if (rc != SA_OK)
130 return (rc);
131
132 lineopts = strdup(shareopts);
133 if (lineopts == NULL)
134 return (SA_SYSTEM_ERR);
135 s = lineopts;
136 fnd_semi = B_FALSE;
137 while ((exportopts = strsep(&s, ";")) != NULL) {
138 if (s != NULL)
139 fnd_semi = B_TRUE;
140 /* Ignore only whitespace between ';' separated option sets. */
141 if (fnd_semi) {
142 whitelen = strspn(exportopts, "\t ");
143 if (exportopts[whitelen] == '\0')
144 continue;
145 }
146 if (fputs(mp, tmpfile) == EOF ||
147 fputc('\t', tmpfile) == EOF ||
148 translate_opts(exportopts, tmpfile) == EOF ||
149 fputc('\n', tmpfile) == EOF) {
150 fprintf(stderr, "failed to write to temporary file\n");
151 rc = SA_SYSTEM_ERR;
152 break;
153 }
154 }
155 free(lineopts);
156
157 if (need_free)
158 free(mp);
159 return (rc);
160 }
161
162 static int
nfs_enable_share(sa_share_impl_t impl_share)163 nfs_enable_share(sa_share_impl_t impl_share)
164 {
165 return (nfs_toggle_share(
166 ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share,
167 nfs_enable_share_impl));
168 }
169
170 static int
nfs_disable_share_impl(sa_share_impl_t impl_share,FILE * tmpfile)171 nfs_disable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
172 {
173 (void) impl_share, (void) tmpfile;
174 return (SA_OK);
175 }
176
177 static int
nfs_disable_share(sa_share_impl_t impl_share)178 nfs_disable_share(sa_share_impl_t impl_share)
179 {
180 return (nfs_toggle_share(
181 ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share,
182 nfs_disable_share_impl));
183 }
184
185 static boolean_t
nfs_is_shared(sa_share_impl_t impl_share)186 nfs_is_shared(sa_share_impl_t impl_share)
187 {
188 return (nfs_is_shared_impl(ZFS_EXPORTS_FILE, impl_share));
189 }
190
191 static int
nfs_validate_shareopts(const char * shareopts)192 nfs_validate_shareopts(const char *shareopts)
193 {
194 if (strlen(shareopts) == 0)
195 return (SA_SYNTAX_ERR);
196 return (SA_OK);
197 }
198
199 /*
200 * Commit the shares by restarting mountd.
201 */
202 static int
nfs_commit_shares(void)203 nfs_commit_shares(void)
204 {
205 struct pidfh *pfh;
206 pid_t mountdpid;
207
208 start:
209 pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
210 if (pfh != NULL) {
211 /* mountd(8) is not running. */
212 pidfile_remove(pfh);
213 return (SA_OK);
214 }
215 if (errno != EEXIST) {
216 /* Cannot open pidfile for some reason. */
217 return (SA_SYSTEM_ERR);
218 }
219 if (mountdpid == -1) {
220 /* mountd(8) exists, but didn't write the PID yet */
221 usleep(500);
222 goto start;
223 }
224 /* We have mountd(8) PID in mountdpid variable. */
225 kill(mountdpid, SIGHUP);
226 return (SA_OK);
227 }
228
229 static void
nfs_truncate_shares(void)230 nfs_truncate_shares(void)
231 {
232 nfs_reset_shares(ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE);
233 }
234
235 const sa_fstype_t libshare_nfs_type = {
236 .enable_share = nfs_enable_share,
237 .disable_share = nfs_disable_share,
238 .is_shared = nfs_is_shared,
239
240 .validate_shareopts = nfs_validate_shareopts,
241 .commit_shares = nfs_commit_shares,
242 .truncate_shares = nfs_truncate_shares,
243 };
244