xref: /freebsd/lib/libc/gen/sysctl.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[] = "@(#)sysctl.c	8.2 (Berkeley) 1/4/94";
34 #endif /* LIBC_SCCS and not lint */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/sysctl.h>
40 
41 #include <errno.h>
42 #include <limits.h>
43 #include <paths.h>
44 #include <stdio.h>
45 #include <unistd.h>
46 #include <string.h>
47 
48 extern int __sysctl(const int *name, u_int namelen, void *oldp,
49     size_t *oldlenp, const void *newp, size_t newlen);
50 
51 int
52 sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp,
53     const void *newp, size_t newlen)
54 {
55 	int retval;
56 	size_t orig_oldlen;
57 
58 	orig_oldlen = oldlenp ? *oldlenp : 0;
59 	retval = __sysctl(name, namelen, oldp, oldlenp, newp, newlen);
60 	/*
61 	 * All valid names under CTL_USER have a dummy entry in the sysctl
62 	 * tree (to support name lookups and enumerations) with an
63 	 * empty/zero value, and the true value is supplied by this routine.
64 	 * For all such names, __sysctl() is used solely to validate the
65 	 * name.
66 	 *
67 	 * Return here unless there was a successful lookup for a CTL_USER
68 	 * name.
69 	 */
70 	if (retval || name[0] != CTL_USER)
71 		return (retval);
72 
73 	if (newp != NULL) {
74 		errno = EPERM;
75 		return (-1);
76 	}
77 	if (namelen != 2) {
78 		errno = EINVAL;
79 		return (-1);
80 	}
81 
82 	switch (name[1]) {
83 	case USER_CS_PATH:
84 		if (oldp && orig_oldlen < sizeof(_PATH_STDPATH)) {
85 			errno = ENOMEM;
86 			return -1;
87 		}
88 		*oldlenp = sizeof(_PATH_STDPATH);
89 		if (oldp != NULL)
90 			memmove(oldp, _PATH_STDPATH, sizeof(_PATH_STDPATH));
91 		return (0);
92 	}
93 
94 	if (oldp && *oldlenp < sizeof(int)) {
95 		errno = ENOMEM;
96 		return (-1);
97 	}
98 	*oldlenp = sizeof(int);
99 	if (oldp == NULL)
100 		return (0);
101 
102 	switch (name[1]) {
103 	case USER_BC_BASE_MAX:
104 		*(int *)oldp = BC_BASE_MAX;
105 		return (0);
106 	case USER_BC_DIM_MAX:
107 		*(int *)oldp = BC_DIM_MAX;
108 		return (0);
109 	case USER_BC_SCALE_MAX:
110 		*(int *)oldp = BC_SCALE_MAX;
111 		return (0);
112 	case USER_BC_STRING_MAX:
113 		*(int *)oldp = BC_STRING_MAX;
114 		return (0);
115 	case USER_COLL_WEIGHTS_MAX:
116 		*(int *)oldp = COLL_WEIGHTS_MAX;
117 		return (0);
118 	case USER_EXPR_NEST_MAX:
119 		*(int *)oldp = EXPR_NEST_MAX;
120 		return (0);
121 	case USER_LINE_MAX:
122 		*(int *)oldp = LINE_MAX;
123 		return (0);
124 	case USER_RE_DUP_MAX:
125 		*(int *)oldp = RE_DUP_MAX;
126 		return (0);
127 	case USER_POSIX2_VERSION:
128 		*(int *)oldp = _POSIX2_VERSION;
129 		return (0);
130 	case USER_POSIX2_C_BIND:
131 #ifdef POSIX2_C_BIND
132 		*(int *)oldp = 1;
133 #else
134 		*(int *)oldp = 0;
135 #endif
136 		return (0);
137 	case USER_POSIX2_C_DEV:
138 #ifdef	POSIX2_C_DEV
139 		*(int *)oldp = 1;
140 #else
141 		*(int *)oldp = 0;
142 #endif
143 		return (0);
144 	case USER_POSIX2_CHAR_TERM:
145 #ifdef	POSIX2_CHAR_TERM
146 		*(int *)oldp = 1;
147 #else
148 		*(int *)oldp = 0;
149 #endif
150 		return (0);
151 	case USER_POSIX2_FORT_DEV:
152 #ifdef	POSIX2_FORT_DEV
153 		*(int *)oldp = 1;
154 #else
155 		*(int *)oldp = 0;
156 #endif
157 		return (0);
158 	case USER_POSIX2_FORT_RUN:
159 #ifdef	POSIX2_FORT_RUN
160 		*(int *)oldp = 1;
161 #else
162 		*(int *)oldp = 0;
163 #endif
164 		return (0);
165 	case USER_POSIX2_LOCALEDEF:
166 #ifdef	POSIX2_LOCALEDEF
167 		*(int *)oldp = 1;
168 #else
169 		*(int *)oldp = 0;
170 #endif
171 		return (0);
172 	case USER_POSIX2_SW_DEV:
173 #ifdef	POSIX2_SW_DEV
174 		*(int *)oldp = 1;
175 #else
176 		*(int *)oldp = 0;
177 #endif
178 		return (0);
179 	case USER_POSIX2_UPE:
180 #ifdef	POSIX2_UPE
181 		*(int *)oldp = 1;
182 #else
183 		*(int *)oldp = 0;
184 #endif
185 		return (0);
186 	case USER_STREAM_MAX:
187 		*(int *)oldp = FOPEN_MAX;
188 		return (0);
189 	case USER_TZNAME_MAX:
190 		*(int *)oldp = NAME_MAX;
191 		return (0);
192 	default:
193 		errno = EINVAL;
194 		return (-1);
195 	}
196 	/* NOTREACHED */
197 }
198