1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright 2020 Stefan Eßer <[email protected]>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include <sys/param.h>
32 #include <sys/sysctl.h>
33 #include <sys/limits.h>
34 #include <errno.h>
35 #include <stdlib.h>
36 #include <paths.h>
37 #include <libutil.h>
38 #include <unistd.h>
39
40 #ifndef _PATH_LOCALBASE
41 #define _PATH_LOCALBASE "/usr/local"
42 #endif
43
44 #ifndef LOCALBASE_CTL_LEN
45 #define LOCALBASE_CTL_LEN MAXPATHLEN
46 #endif
47
48 /* Any prefix guaranteed to not be the start of a valid path name */
49 #define ILLEGAL_PREFIX "/dev/null/"
50
51 const char *
getlocalbase(void)52 getlocalbase(void)
53 {
54 #if LOCALBASE_CTL_LEN > 0
55 int localbase_oid[2] = {CTL_USER, USER_LOCALBASE};
56 static char localpath[LOCALBASE_CTL_LEN];
57 size_t localpathlen = LOCALBASE_CTL_LEN;
58 #endif
59 char *tmppath;
60 static const char *localbase = NULL;
61
62 if (localbase != NULL)
63 return (localbase);
64
65 if (issetugid() == 0) {
66 tmppath = getenv("LOCALBASE");
67 if (tmppath != NULL && tmppath[0] != '\0') {
68 localbase = tmppath;
69 return (localbase);
70 }
71 }
72
73 #if LOCALBASE_CTL_LEN > 0
74 if (sysctl(localbase_oid, 2, localpath, &localpathlen, NULL, 0) != 0) {
75 if (errno != ENOMEM)
76 localbase = _PATH_LOCALBASE;
77 else
78 localbase = ILLEGAL_PREFIX;
79 } else {
80 if (localpath[0] != '\0')
81 localbase = localpath;
82 else
83 localbase = _PATH_LOCALBASE;
84 }
85 #else
86 localbase = _PATH_LOCALBASE;
87 #endif
88
89 return (localbase);
90 }
91