xref: /freebsd/lib/libutil/getlocalbase.c (revision 5596f836e7e04a272113e57b3a80f1f67c0fec7f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright 2020 Scott Long <scottl@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/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/types.h>
32 #include <sys/errno.h>
33 #include <sys/sysctl.h>
34 #include <sys/limits.h>
35 #include <stdlib.h>
36 #include <paths.h>
37 #include <libutil.h>
38 #include <string.h>
39 #include <unistd.h>
40 
41 ssize_t
42 getlocalbase(char *path, size_t pathlen)
43 {
44 	size_t tmplen;
45 	const char *tmppath;
46 
47 	if ((pathlen == 0) || (path == NULL)) {
48 		errno = EINVAL;
49 		return (-1);
50 	}
51 
52 	tmppath = NULL;
53 	tmplen = pathlen;
54 	if (issetugid() == 0)
55 		tmppath = getenv("LOCALBASE");
56 
57 	if ((tmppath == NULL) &&
58 	    (sysctlbyname("user.localbase", path, &tmplen, NULL, 0) == 0)) {
59 		return (tmplen);
60 	}
61 
62 	if (tmppath == NULL)
63 #ifdef _PATH_LOCALBASE
64 		tmppath = _PATH_LOCALBASE;
65 #else
66 		tmppath = "/usr/local";
67 #endif
68 
69 	tmplen = strlcpy(path, tmppath, pathlen);
70 	if ((tmplen < 0) || (tmplen >= pathlen)) {
71 		errno = ENOMEM;
72 		return (-1);
73 	}
74 
75 	/* It's unlikely that the buffer would be this big */
76 	if (tmplen >= SSIZE_MAX) {
77 		errno = ENOMEM;
78 		return (-1);
79 	}
80 
81 	return ((ssize_t)tmplen);
82 }
83