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 #include <sys/param.h>
30 #include <sys/sysctl.h>
31 #include <sys/limits.h>
32 #include <errno.h>
33 #include <stdlib.h>
34 #include <paths.h>
35 #include <libutil.h>
36 #include <unistd.h>
37
38 #ifndef LOCALBASE_PATH
39 #define LOCALBASE_PATH _PATH_LOCALBASE
40 #endif
41
42 #ifndef LOCALBASE_CTL_LEN
43 #define LOCALBASE_CTL_LEN MAXPATHLEN
44 #endif
45
46 /* Any prefix guaranteed to not be the start of a valid path name */
47 #define ILLEGAL_PREFIX "/dev/null/"
48
49 const char *
getlocalbase(void)50 getlocalbase(void)
51 {
52 #if LOCALBASE_CTL_LEN > 0
53 int localbase_oid[2] = {CTL_USER, USER_LOCALBASE};
54 static char localpath[LOCALBASE_CTL_LEN];
55 size_t localpathlen = LOCALBASE_CTL_LEN;
56 #endif
57 char *tmppath;
58 static const char *localbase = NULL;
59
60 if (localbase != NULL)
61 return (localbase);
62
63 if (issetugid() == 0) {
64 tmppath = getenv("LOCALBASE");
65 if (tmppath != NULL && tmppath[0] != '\0') {
66 localbase = tmppath;
67 return (localbase);
68 }
69 }
70
71 #if LOCALBASE_CTL_LEN > 0
72 if (sysctl(localbase_oid, 2, localpath, &localpathlen, NULL, 0) != 0) {
73 if (errno != ENOMEM)
74 localbase = LOCALBASE_PATH;
75 else
76 localbase = ILLEGAL_PREFIX;
77 } else {
78 if (localpath[0] != '\0')
79 localbase = localpath;
80 else
81 localbase = LOCALBASE_PATH;
82 }
83 #else
84 localbase = LOCALBASE_PATH;
85 #endif
86
87 return (localbase);
88 }
89