xref: /freebsd/lib/libc/gen/confstr.c (revision 4b9d6057)
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 #include <sys/param.h>
33 
34 #include <errno.h>
35 #include <limits.h>
36 #include <paths.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 
41 size_t
42 confstr(int name, char *buf, size_t len)
43 {
44 	const char *p;
45 	const char UPE[] = "unsupported programming environment";
46 
47 	switch (name) {
48 	case _CS_PATH:
49 		p = _PATH_STDPATH;
50 		goto docopy;
51 
52 		/*
53 		 * POSIX/SUS ``Programming Environments'' stuff
54 		 *
55 		 * We don't support more than one programming environment
56 		 * on any platform (yet), so we just return the empty
57 		 * string for the environment we are compiled for,
58 		 * and the string "unsupported programming environment"
59 		 * for anything else.  (The Standard says that if these
60 		 * values are used on a system which does not support
61 		 * this environment -- determined via sysconf() -- then
62 		 * the value we return is unspecified.  So, we return
63 		 * something which will cause obvious breakage.)
64 		 */
65 	case _CS_POSIX_V6_ILP32_OFF32_CFLAGS:
66 	case _CS_POSIX_V6_ILP32_OFF32_LDFLAGS:
67 	case _CS_POSIX_V6_ILP32_OFF32_LIBS:
68 	case _CS_POSIX_V6_LPBIG_OFFBIG_CFLAGS:
69 	case _CS_POSIX_V6_LPBIG_OFFBIG_LDFLAGS:
70 	case _CS_POSIX_V6_LPBIG_OFFBIG_LIBS:
71 		/*
72 		 * These two environments are never supported.
73 		 */
74 		p = UPE;
75 		goto docopy;
76 
77 	case _CS_POSIX_V6_ILP32_OFFBIG_CFLAGS:
78 	case _CS_POSIX_V6_ILP32_OFFBIG_LDFLAGS:
79 	case _CS_POSIX_V6_ILP32_OFFBIG_LIBS:
80 		if (sizeof(long) * CHAR_BIT == 32 &&
81 		    sizeof(off_t) > sizeof(long))
82 			p = "";
83 		else
84 			p = UPE;
85 		goto docopy;
86 
87 	case _CS_POSIX_V6_LP64_OFF64_CFLAGS:
88 	case _CS_POSIX_V6_LP64_OFF64_LDFLAGS:
89 	case _CS_POSIX_V6_LP64_OFF64_LIBS:
90 		if (sizeof(long) * CHAR_BIT >= 64 &&
91 		    sizeof(void *) * CHAR_BIT >= 64 &&
92 		    sizeof(int) * CHAR_BIT >= 32 &&
93 		    sizeof(off_t) >= sizeof(long))
94 			p = "";
95 		else
96 			p = UPE;
97 		goto docopy;
98 
99 	case _CS_POSIX_V6_WIDTH_RESTRICTED_ENVS:
100 		/* XXX - should have more complete coverage */
101 		if (sizeof(long) * CHAR_BIT >= 64)
102 			p = "_POSIX_V6_LP64_OFF64";
103 		else
104 			p = "_POSIX_V6_ILP32_OFFBIG";
105 		goto docopy;
106 
107 docopy:
108 		if (len != 0 && buf != NULL)
109 			strlcpy(buf, p, len);
110 		return (strlen(p) + 1);
111 
112 	default:
113 		errno = EINVAL;
114 		return (0);
115 	}
116 	/* NOTREACHED */
117 }
118