xref: /freebsd/lib/libc/gen/sysctl.c (revision 732a02b4e77866604a120a275c082bb6221bd2ff)
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/cdefs.h>
33 __SCCSID("@(#)sysctl.c	8.2 (Berkeley) 1/4/94");
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/sysctl.h>
38 
39 #include <errno.h>
40 #include <limits.h>
41 #include <paths.h>
42 #include <stdio.h>
43 #include <unistd.h>
44 #include <string.h>
45 
46 extern int __sysctl(const int *name, u_int namelen, void *oldp,
47     size_t *oldlenp, const void *newp, size_t newlen);
48 
49 int
50 sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp,
51     const void *newp, size_t newlen)
52 {
53 	int retval;
54 	size_t orig_oldlen;
55 
56 	orig_oldlen = oldlenp ? *oldlenp : 0;
57 	retval = __sysctl(name, namelen, oldp, oldlenp, newp, newlen);
58 	/*
59 	 * All valid names under CTL_USER have a dummy entry in the sysctl
60 	 * tree (to support name lookups and enumerations) with an
61 	 * empty/zero value, and the true value is supplied by this routine.
62 	 * For all such names, __sysctl() is used solely to validate the
63 	 * name.
64 	 *
65 	 * Return here unless there was a successful lookup for a CTL_USER
66 	 * name.
67 	 */
68 	if (retval || name[0] != CTL_USER)
69 		return (retval);
70 
71 	if (newp != NULL) {
72 		errno = EPERM;
73 		return (-1);
74 	}
75 	if (namelen != 2) {
76 		errno = EINVAL;
77 		return (-1);
78 	}
79 
80 	switch (name[1]) {
81 	case USER_CS_PATH:
82 		if (oldp && orig_oldlen < sizeof(_PATH_STDPATH)) {
83 			errno = ENOMEM;
84 			return -1;
85 		}
86 		*oldlenp = sizeof(_PATH_STDPATH);
87 		if (oldp != NULL)
88 			memmove(oldp, _PATH_STDPATH, sizeof(_PATH_STDPATH));
89 		return (0);
90 	}
91 
92 	if (oldp && *oldlenp < sizeof(int)) {
93 		errno = ENOMEM;
94 		return (-1);
95 	}
96 	*oldlenp = sizeof(int);
97 	if (oldp == NULL)
98 		return (0);
99 
100 	switch (name[1]) {
101 	case USER_BC_BASE_MAX:
102 		*(int *)oldp = BC_BASE_MAX;
103 		return (0);
104 	case USER_BC_DIM_MAX:
105 		*(int *)oldp = BC_DIM_MAX;
106 		return (0);
107 	case USER_BC_SCALE_MAX:
108 		*(int *)oldp = BC_SCALE_MAX;
109 		return (0);
110 	case USER_BC_STRING_MAX:
111 		*(int *)oldp = BC_STRING_MAX;
112 		return (0);
113 	case USER_COLL_WEIGHTS_MAX:
114 		*(int *)oldp = COLL_WEIGHTS_MAX;
115 		return (0);
116 	case USER_EXPR_NEST_MAX:
117 		*(int *)oldp = EXPR_NEST_MAX;
118 		return (0);
119 	case USER_LINE_MAX:
120 		*(int *)oldp = LINE_MAX;
121 		return (0);
122 	case USER_RE_DUP_MAX:
123 		*(int *)oldp = RE_DUP_MAX;
124 		return (0);
125 	case USER_POSIX2_VERSION:
126 		*(int *)oldp = _POSIX2_VERSION;
127 		return (0);
128 	case USER_POSIX2_C_BIND:
129 #ifdef POSIX2_C_BIND
130 		*(int *)oldp = 1;
131 #else
132 		*(int *)oldp = 0;
133 #endif
134 		return (0);
135 	case USER_POSIX2_C_DEV:
136 #ifdef	POSIX2_C_DEV
137 		*(int *)oldp = 1;
138 #else
139 		*(int *)oldp = 0;
140 #endif
141 		return (0);
142 	case USER_POSIX2_CHAR_TERM:
143 #ifdef	POSIX2_CHAR_TERM
144 		*(int *)oldp = 1;
145 #else
146 		*(int *)oldp = 0;
147 #endif
148 		return (0);
149 	case USER_POSIX2_FORT_DEV:
150 #ifdef	POSIX2_FORT_DEV
151 		*(int *)oldp = 1;
152 #else
153 		*(int *)oldp = 0;
154 #endif
155 		return (0);
156 	case USER_POSIX2_FORT_RUN:
157 #ifdef	POSIX2_FORT_RUN
158 		*(int *)oldp = 1;
159 #else
160 		*(int *)oldp = 0;
161 #endif
162 		return (0);
163 	case USER_POSIX2_LOCALEDEF:
164 #ifdef	POSIX2_LOCALEDEF
165 		*(int *)oldp = 1;
166 #else
167 		*(int *)oldp = 0;
168 #endif
169 		return (0);
170 	case USER_POSIX2_SW_DEV:
171 #ifdef	POSIX2_SW_DEV
172 		*(int *)oldp = 1;
173 #else
174 		*(int *)oldp = 0;
175 #endif
176 		return (0);
177 	case USER_POSIX2_UPE:
178 #ifdef	POSIX2_UPE
179 		*(int *)oldp = 1;
180 #else
181 		*(int *)oldp = 0;
182 #endif
183 		return (0);
184 	case USER_STREAM_MAX:
185 		*(int *)oldp = FOPEN_MAX;
186 		return (0);
187 	case USER_TZNAME_MAX:
188 		*(int *)oldp = NAME_MAX;
189 		return (0);
190 	default:
191 		errno = EINVAL;
192 		return (-1);
193 	}
194 	/* NOTREACHED */
195 }
196