xref: /netbsd-src/lib/libc/gen/sysctl.c (revision d20841bb642898112fe68f0ad3f7b26dddf56f07)
1 /*	$NetBSD: sysctl.c,v 1.15 2003/12/04 19:45:19 atatat Exp $	*/
2 
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 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)sysctl.c	8.2 (Berkeley) 1/4/94";
36 #else
37 __RCSID("$NetBSD: sysctl.c,v 1.15 2003/12/04 19:45:19 atatat Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "namespace.h"
42 #include <sys/param.h>
43 #include <sys/sysctl.h>
44 
45 #include <errno.h>
46 #include <paths.h>
47 #include <stdio.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include "extern.h"
51 
52 #ifdef __weak_alias
53 __weak_alias(sysctl,_sysctl)
54 #endif
55 
56 /*
57  * handles requests off the user subtree
58  */
59 static int user_sysctl(int *, u_int, void *, size_t *, const void *, size_t);
60 
61 #include <stdlib.h>
62 
63 int
64 sysctl(name, namelen, oldp, oldlenp, newp, newlen)
65 	int *name;
66 	unsigned int namelen;
67 	void *oldp;
68 	const void *newp;
69 	size_t *oldlenp, newlen;
70 {
71 	size_t oldlen, savelen;
72 	int error;
73 
74 	if (name[0] != CTL_USER)
75 		/* LINTED will fix when sysctl interface gets corrected */
76 		/* XXX when will that be? */
77 		return (__sysctl(name, namelen, oldp, oldlenp,
78 				 (void *)newp, newlen));
79 
80 	oldlen = (oldlenp == NULL) ? 0 : *oldlenp;
81 	savelen = oldlen;
82 	error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen);
83 
84 	if (error != 0) {
85 		errno = error;
86 		return (-1);
87 	}
88 
89 	if (oldlenp != NULL) {
90 		*oldlenp = oldlen;
91 		if (oldp != NULL && oldlen > savelen) {
92 			errno = ENOMEM;
93 			return (-1);
94 		}
95 	}
96 
97 	return (0);
98 }
99 
100 static int
101 user_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
102 	int *name;
103 	unsigned int namelen;
104 	void *oldp;
105 	const void *newp;
106 	size_t *oldlenp, newlen;
107 {
108 #define _INT(s, n, v) {						\
109 	.sysctl_flags = SYSCTL_IMMEDIATE|SYSCTL_PERMANENT|SYSCTL_READONLY| \
110 			SYSCTL_TYPE(CTLTYPE_INT),		\
111 	.sysctl_size = sizeof(int),				\
112 	.sysctl_name = (s),					\
113 	.sysctl_num = (n),					\
114 	.sysctl_un = { .scu_idata = (v), }, }
115 
116 	/*
117 	 * the nodes under the "user" node
118 	 */
119 	static const struct sysctlnode sysctl_usermib[] = {
120 #if defined(lint)
121 		/*
122 		 * lint doesn't like my initializers
123 		 */
124 		0
125 #else /* !lint */
126 		{
127 			.sysctl_flags = SYSCTL_READONLY|SYSCTL_PERMANENT|
128 				SYSCTL_TYPE(CTLTYPE_STRING),
129 			.sysctl_size = sizeof(_PATH_STDPATH),
130 			.sysctl_name = "cs_path",
131 			.sysctl_num = USER_CS_PATH,
132 			.sysctl_un = { .scu_data = _PATH_STDPATH, },
133 		},
134 		_INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX),
135 		_INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX),
136 		_INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX),
137 		_INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX),
138 		_INT("coll_weights_max", USER_COLL_WEIGHTS_MAX,
139 		     COLL_WEIGHTS_MAX),
140 		_INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX),
141 		_INT("line_max", USER_LINE_MAX, LINE_MAX),
142 		_INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX),
143 		_INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION),
144 #ifdef POSIX2_C_BIND
145 		_INT("posix2_c_bind", USER_POSIX2_C_BIND, 1),
146 #else
147 		_INT("posix2_c_bind", USER_POSIX2_C_BIND, 0),
148 #endif
149 #ifdef POSIX2_C_DEV
150 		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 1),
151 #else
152 		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 0),
153 #endif
154 #ifdef POSIX2_CHAR_TERM
155 		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1),
156 #else
157 		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0),
158 #endif
159 #ifdef POSIX2_FORT_DEV
160 		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1),
161 #else
162 		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0),
163 #endif
164 #ifdef POSIX2_FORT_RUN
165 		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1),
166 #else
167 		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0),
168 #endif
169 #ifdef POSIX2_LOCALEDEF
170 		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1),
171 #else
172 		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0),
173 #endif
174 #ifdef POSIX2_SW_DEV
175 		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1),
176 #else
177 		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0),
178 #endif
179 #ifdef POSIX2_UPE
180 		_INT("posix2_upe", USER_POSIX2_UPE, 1),
181 #else
182 		_INT("posix2_upe", USER_POSIX2_UPE, 0),
183 #endif
184 		_INT("stream_max", USER_STREAM_MAX, FOPEN_MAX),
185 		_INT("tzname_max", USER_TZNAME_MAX, NAME_MAX),
186 		_INT("atexit_max", USER_ATEXIT_MAX, -1),
187 #endif /* !lint */
188 	};
189 #undef _INT
190 
191 	static const int clen = sizeof(sysctl_usermib) /
192 		sizeof(sysctl_usermib[0]);
193 
194 	const struct sysctlnode *node;
195 	int ni;
196 	size_t l, sz;
197 
198 	/*
199 	 * none of these nodes are writable and they're all terminal (for now)
200 	 */
201 	if (newp != NULL || newlen != 0)
202 		return (EPERM);
203 	if (namelen != 1)
204 		return (EINVAL);
205 
206 	l = *oldlenp;
207 	if (name[0] == CTL_QUERY) {
208 		sz = clen * sizeof(struct sysctlnode);
209 		l = MIN(l, sz);
210 		if (oldp != NULL)
211 			memcpy(oldp, &sysctl_usermib[0], l);
212 		*oldlenp = sz;
213 		return (0);
214 	}
215 
216 	node = &sysctl_usermib[0];
217 	for (ni = 0; ni	< clen; ni++)
218 		if (name[0] == node[ni].sysctl_num)
219 			break;
220 	if (ni == clen)
221 		return (EOPNOTSUPP);
222 
223 	node = &node[ni];
224 	if (node->sysctl_flags & SYSCTL_IMMEDIATE) {
225 		switch (SYSCTL_TYPE(node->sysctl_flags)) {
226 		case CTLTYPE_INT:
227 			newp = &node->sysctl_idata;
228 			break;
229 		case CTLTYPE_QUAD:
230 			newp = &node->sysctl_qdata;
231 			break;
232 		default:
233 			return (EINVAL);
234 		}
235 	}
236 	else
237 		newp = node->sysctl_data;
238 
239 	l = MIN(l, node->sysctl_size);
240 	if (oldp != NULL)
241 		memcpy(oldp, newp, l);
242 	*oldlenp = node->sysctl_size;
243 
244 	return (0);
245 }
246