1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright 2020 Stefan Eßer <se@freebsd.org>
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/param.h>
29 #include <sys/sysctl.h>
30 #include <sys/limits.h>
31 #include <errno.h>
32 #include <stdlib.h>
33 #include <paths.h>
34 #include <libutil.h>
35 #include <unistd.h>
36
37 #ifndef LOCALBASE_PATH
38 #define LOCALBASE_PATH _PATH_LOCALBASE
39 #endif
40
41 #ifndef LOCALBASE_CTL_LEN
42 #define LOCALBASE_CTL_LEN MAXPATHLEN
43 #endif
44
45 /* Any prefix guaranteed to not be the start of a valid path name */
46 #define ILLEGAL_PREFIX "/dev/null/"
47
48 const char *
getlocalbase(void)49 getlocalbase(void)
50 {
51 #if LOCALBASE_CTL_LEN > 0
52 int localbase_oid[2] = {CTL_USER, USER_LOCALBASE};
53 static char localpath[LOCALBASE_CTL_LEN];
54 size_t localpathlen = LOCALBASE_CTL_LEN;
55 #endif
56 char *tmppath;
57 static const char *localbase = NULL;
58
59 if (localbase != NULL)
60 return (localbase);
61
62 if (issetugid() == 0) {
63 tmppath = getenv("LOCALBASE");
64 if (tmppath != NULL && tmppath[0] != '\0') {
65 localbase = tmppath;
66 return (localbase);
67 }
68 }
69
70 #if LOCALBASE_CTL_LEN > 0
71 if (sysctl(localbase_oid, 2, localpath, &localpathlen, NULL, 0) != 0) {
72 if (errno != ENOMEM)
73 localbase = LOCALBASE_PATH;
74 else
75 localbase = ILLEGAL_PREFIX;
76 } else {
77 if (localpath[0] != '\0')
78 localbase = localpath;
79 else
80 localbase = LOCALBASE_PATH;
81 }
82 #else
83 localbase = LOCALBASE_PATH;
84 #endif
85
86 return (localbase);
87 }
88