1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #if 0
33 #ifndef lint
34 static char sccsid[] = "@(#)getmntopts.c 8.3 (Berkeley) 3/29/95";
35 #endif /* not lint */
36 #endif
37 #include <sys/cdefs.h>
38 #include <sys/param.h>
39 #include <sys/mount.h>
40 #include <sys/stat.h>
41 #include <sys/uio.h>
42
43 #include <err.h>
44 #include <errno.h>
45 #include <paths.h>
46 #include <stdarg.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50
51 #include "mntopts.h"
52
53 int getmnt_silent = 0;
54
55 void
getmntopts(const char * options,const struct mntopt * m0,int * flagp,int * altflagp)56 getmntopts(const char *options, const struct mntopt *m0, int *flagp,
57 int *altflagp)
58 {
59 const struct mntopt *m;
60 int negative, len;
61 char *opt, *optbuf, *p;
62 int *thisflagp;
63
64 /* Copy option string, since it is about to be torn asunder... */
65 if ((optbuf = strdup(options)) == NULL)
66 err(1, NULL);
67
68 for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
69 /* Check for "no" prefix. */
70 if (opt[0] == 'n' && opt[1] == 'o') {
71 negative = 1;
72 opt += 2;
73 } else
74 negative = 0;
75
76 /*
77 * for options with assignments in them (ie. quotas)
78 * ignore the assignment as it's handled elsewhere
79 */
80 p = strchr(opt, '=');
81 if (p != NULL)
82 *++p = '\0';
83
84 /* Scan option table. */
85 for (m = m0; m->m_option != NULL; ++m) {
86 len = strlen(m->m_option);
87 if (strncasecmp(opt, m->m_option, len) == 0)
88 if (opt[len] == '\0' || opt[len] == '=')
89 break;
90 }
91
92 /* Save flag, or fail if option is not recognized. */
93 if (m->m_option) {
94 thisflagp = m->m_altloc ? altflagp : flagp;
95 if (negative == m->m_inverse)
96 *thisflagp |= m->m_flag;
97 else
98 *thisflagp &= ~m->m_flag;
99 } else if (!getmnt_silent) {
100 errx(1, "-o %s: option not supported", opt);
101 }
102 }
103
104 free(optbuf);
105 }
106
107 void
rmslashes(char * rrpin,char * rrpout)108 rmslashes(char *rrpin, char *rrpout)
109 {
110 char *rrpoutstart;
111
112 *rrpout = *rrpin;
113 for (rrpoutstart = rrpout; *rrpin != '\0'; *rrpout++ = *rrpin++) {
114
115 /* skip all double slashes */
116 while (*rrpin == '/' && *(rrpin + 1) == '/')
117 rrpin++;
118 }
119
120 /* remove trailing slash if necessary */
121 if (rrpout - rrpoutstart > 1 && *(rrpout - 1) == '/')
122 *(rrpout - 1) = '\0';
123 else
124 *rrpout = '\0';
125 }
126
127 int
checkpath(const char * path,char * resolved)128 checkpath(const char *path, char *resolved)
129 {
130 struct stat sb;
131
132 if (realpath(path, resolved) == NULL || stat(resolved, &sb) != 0)
133 return (1);
134 if (!S_ISDIR(sb.st_mode)) {
135 errno = ENOTDIR;
136 return (1);
137 }
138 return (0);
139 }
140
141 int
checkpath_allow_file(const char * path,char * resolved)142 checkpath_allow_file(const char *path, char *resolved)
143 {
144 struct stat sb;
145
146 if (realpath(path, resolved) == NULL || stat(resolved, &sb) != 0)
147 return (1);
148 if (!S_ISDIR(sb.st_mode) && !S_ISREG(sb.st_mode)) {
149 errno = ENOTDIR;
150 return (1);
151 }
152 return (0);
153 }
154
155 /*
156 * Get the mount point information for name. Name may be mount point name
157 * or device name (with or without /dev/ preprended).
158 */
159 struct statfs *
getmntpoint(const char * name)160 getmntpoint(const char *name)
161 {
162 struct stat devstat, mntdevstat;
163 char device[sizeof(_PATH_DEV) - 1 + MNAMELEN];
164 char *ddevname;
165 struct statfs *mntbuf, *statfsp;
166 int i, mntsize, isdev;
167 u_long len;
168
169 if (stat(name, &devstat) != 0)
170 return (NULL);
171 if (S_ISCHR(devstat.st_mode) || S_ISBLK(devstat.st_mode))
172 isdev = 1;
173 else
174 isdev = 0;
175 mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
176 for (i = 0; i < mntsize; i++) {
177 statfsp = &mntbuf[i];
178 if (isdev == 0) {
179 if (strcmp(name, statfsp->f_mntonname))
180 continue;
181 return (statfsp);
182 }
183 ddevname = statfsp->f_mntfromname;
184 if (*ddevname != '/') {
185 if ((len = strlen(_PATH_DEV) + strlen(ddevname) + 1) >
186 sizeof(statfsp->f_mntfromname) ||
187 len > sizeof(device))
188 continue;
189 strncpy(device, _PATH_DEV, len);
190 strncat(device, ddevname, len);
191 if (stat(device, &mntdevstat) == 0)
192 strncpy(statfsp->f_mntfromname, device, len);
193 }
194 if (stat(ddevname, &mntdevstat) == 0 &&
195 mntdevstat.st_rdev == devstat.st_rdev)
196 return (statfsp);
197 }
198 return (NULL);
199 }
200
201 /*
202 * If possible reload a mounted filesystem.
203 * When prtmsg != NULL print a warning if a reload is attempted, but fails.
204 * Return 0 on success, 1 on failure.
205 */
206 int
207 chkdoreload(struct statfs *mntp,
208 void (*prtmsg)(const char *, ...) __printflike(1,2))
209 {
210 struct iovec *iov;
211 int iovlen, error;
212 char errmsg[255];
213
214 /*
215 * If the filesystem is not mounted it does not need to be reloaded.
216 * If it is mounted for writing, then it could not have been opened
217 * for writing by a utility, so does not need to be reloaded.
218 */
219 if (mntp == NULL || (mntp->f_flags & MNT_RDONLY) == 0)
220 return (0);
221
222 /*
223 * We modified a mounted file system. Do a mount update on
224 * it so we can continue using it as safely as possible.
225 */
226 iov = NULL;
227 iovlen = 0;
228 errmsg[0] = '\0';
229 build_iovec(&iov, &iovlen, "fstype", __DECONST(void *, "ffs"), 4);
230 build_iovec(&iov, &iovlen, "from", mntp->f_mntfromname, (size_t)-1);
231 build_iovec(&iov, &iovlen, "fspath", mntp->f_mntonname, (size_t)-1);
232 build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
233 build_iovec(&iov, &iovlen, "update", NULL, 0);
234 build_iovec(&iov, &iovlen, "reload", NULL, 0);
235 /*
236 * XX: We need the following line until we clean up
237 * nmount parsing of root mounts and NFS root mounts.
238 */
239 build_iovec(&iov, &iovlen, "ro", NULL, 0);
240 error = nmount(iov, iovlen, mntp->f_flags);
241 free_iovec(&iov, &iovlen);
242 if (error == 0)
243 return (0);
244 if (prtmsg != NULL)
245 prtmsg("mount reload of '%s' failed: %s %s\n\n",
246 mntp->f_mntonname, strerror(errno), errmsg);
247 return (1);
248 }
249
250 void
build_iovec(struct iovec ** iov,int * iovlen,const char * name,void * val,size_t len)251 build_iovec(struct iovec **iov, int *iovlen, const char *name, void *val,
252 size_t len)
253 {
254 int i;
255
256 if (*iovlen < 0)
257 return;
258 i = *iovlen;
259 *iov = realloc(*iov, sizeof **iov * (i + 2));
260 if (*iov == NULL) {
261 *iovlen = -1;
262 return;
263 }
264 (*iov)[i].iov_base = strdup(name);
265 (*iov)[i].iov_len = strlen(name) + 1;
266 i++;
267 (*iov)[i].iov_base = val;
268 if (len == (size_t)-1) {
269 if (val != NULL)
270 len = strlen(val) + 1;
271 else
272 len = 0;
273 }
274 (*iov)[i].iov_len = (int)len;
275 *iovlen = ++i;
276 }
277
278 /*
279 * This function is needed for compatibility with parameters
280 * which used to use the mount_argf() command for the old mount() syscall.
281 */
282 void
build_iovec_argf(struct iovec ** iov,int * iovlen,const char * name,const char * fmt,...)283 build_iovec_argf(struct iovec **iov, int *iovlen, const char *name,
284 const char *fmt, ...)
285 {
286 va_list ap;
287 char val[255] = { 0 };
288
289 va_start(ap, fmt);
290 vsnprintf(val, sizeof(val), fmt, ap);
291 va_end(ap);
292 build_iovec(iov, iovlen, name, strdup(val), (size_t)-1);
293 }
294
295 /*
296 * Free the iovec and reset to NULL with zero length. Useful for calling
297 * nmount in a loop.
298 */
299 void
free_iovec(struct iovec ** iov,int * iovlen)300 free_iovec(struct iovec **iov, int *iovlen)
301 {
302 int i;
303
304 for (i = 0; i < *iovlen; i += 2)
305 free((*iov)[i].iov_base);
306 free(*iov);
307 }
308