xref: /freebsd/lib/libc/gen/confstr.c (revision 52f72944b8f5abb2386eae924357dee8aea17d5b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1993
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 #if defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)confstr.c	8.1 (Berkeley) 6/4/93";
34 #endif /* LIBC_SCCS and not lint */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 
40 #include <errno.h>
41 #include <limits.h>
42 #include <paths.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 
47 size_t
48 confstr(int name, char *buf, size_t len)
49 {
50 	const char *p;
51 	const char UPE[] = "unsupported programming environment";
52 
53 	switch (name) {
54 	case _CS_PATH:
55 		p = _PATH_STDPATH;
56 		goto docopy;
57 
58 		/*
59 		 * POSIX/SUS ``Programming Environments'' stuff
60 		 *
61 		 * We don't support more than one programming environment
62 		 * on any platform (yet), so we just return the empty
63 		 * string for the environment we are compiled for,
64 		 * and the string "unsupported programming environment"
65 		 * for anything else.  (The Standard says that if these
66 		 * values are used on a system which does not support
67 		 * this environment -- determined via sysconf() -- then
68 		 * the value we return is unspecified.  So, we return
69 		 * something which will cause obvious breakage.)
70 		 */
71 	case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
72 	case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
73 	case _CS_POSIX_V6_ILP32_OFF32_LIBS:
74 	case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
75 	case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
76 	case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
77 		/*
78 		 * These two environments are never supported.
79 		 */
80 		p = UPE;
81 		goto docopy;
82 
83 	case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
84 	case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
85 	case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
86 		if (sizeof(long) * CHAR_BIT == 32 &&
87 		    sizeof(off_t) > sizeof(long))
88 			p = "";
89 		else
90 			p = UPE;
91 		goto docopy;
92 
93 	case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
94 	case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
95 	case _CS_POSIX_V6_LP64_OFF64_LIBS:
96 		if (sizeof(long) * CHAR_BIT >= 64 &&
97 		    sizeof(void *) * CHAR_BIT >= 64 &&
98 		    sizeof(int) * CHAR_BIT >= 32 &&
99 		    sizeof(off_t) >= sizeof(long))
100 			p = "";
101 		else
102 			p = UPE;
103 		goto docopy;
104 
105 	case _CS_POSIX_V6_WIDTH_RESTRICTED_ENVS:
106 		/* XXX - should have more complete coverage */
107 		if (sizeof(long) * CHAR_BIT >= 64)
108 			p = "_POSIX_V6_LP64_OFF64";
109 		else
110 			p = "_POSIX_V6_ILP32_OFFBIG";
111 		goto docopy;
112 
113 docopy:
114 		if (len != 0 && buf != NULL)
115 			strlcpy(buf, p, len);
116 		return (strlen(p) + 1);
117 
118 	default:
119 		errno = EINVAL;
120 		return (0);
121 	}
122 	/* NOTREACHED */
123 }
124