1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1995
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 #include <sys/param.h>
33 #include <sys/mount.h>
34 #include <sys/sysctl.h>
35 #include <errno.h>
36 #include <stdbool.h>
37 #include <stdlib.h>
38 #include <string.h>
39
40 /*
41 * fusefs(5) file systems may have a "subtype" which gets appended to
42 * statfs(2)'s f_fstypename field on a per-mount basis. Allow getvfsbyname to
43 * match either the full "fusefs.foobar" or the more general "fusefs".
44 */
45 static bool
are_fusefs(const char * fsname,const char * vfc_name)46 are_fusefs(const char *fsname, const char *vfc_name)
47 {
48 const static char fusefs[] = "fusefs";
49 const static char fusefs_dot[] = "fusefs.";
50
51 return (strncmp(fsname, fusefs_dot, sizeof(fusefs_dot) - 1) == 0 &&
52 strcmp(fusefs, vfc_name) == 0);
53 }
54
55 /*
56 * Given a filesystem name, determine if it is resident in the kernel,
57 * and if it is resident, return its xvfsconf structure.
58 */
59 int
getvfsbyname(const char * fsname,struct xvfsconf * vfcp)60 getvfsbyname(const char *fsname, struct xvfsconf *vfcp)
61 {
62 struct xvfsconf *xvfsp;
63 size_t buflen;
64 int cnt, i;
65
66 if (sysctlbyname("vfs.conflist", NULL, &buflen, NULL, 0) < 0)
67 return (-1);
68 xvfsp = malloc(buflen);
69 if (xvfsp == NULL)
70 return (-1);
71 if (sysctlbyname("vfs.conflist", xvfsp, &buflen, NULL, 0) < 0) {
72 free(xvfsp);
73 return (-1);
74 }
75 cnt = buflen / sizeof(struct xvfsconf);
76 for (i = 0; i < cnt; i++) {
77 if (strcmp(fsname, xvfsp[i].vfc_name) == 0 ||
78 are_fusefs(fsname, xvfsp[i].vfc_name)) {
79 memcpy(vfcp, xvfsp + i, sizeof(struct xvfsconf));
80 free(xvfsp);
81 return (0);
82 }
83 }
84 free(xvfsp);
85 errno = ENOENT;
86 return (-1);
87 }
88