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 #include <sys/param.h>
35 #include <sys/sysctl.h>
36
37 #include <errno.h>
38 #include <limits.h>
39 #include <paths.h>
40 #include <stdio.h>
41 #include <unistd.h>
42 #include <string.h>
43
44 extern int __sysctl(const int *name, u_int namelen, void *oldp,
45 size_t *oldlenp, const void *newp, size_t newlen);
46
47 static int
set_user_str(void * dstp,size_t * dstlenp,const char * src,size_t len,size_t maxlen)48 set_user_str(void *dstp, size_t *dstlenp, const char *src, size_t len,
49 size_t maxlen)
50 {
51 int retval;
52
53 retval = 0;
54 if (dstp != NULL) {
55 if (len > maxlen) {
56 len = maxlen;
57 errno = ENOMEM;
58 retval = -1;
59 }
60 memcpy(dstp, src, len);
61 }
62 *dstlenp = len;
63 return (retval);
64 }
65
66 int
sysctl(const int * name,u_int namelen,void * oldp,size_t * oldlenp,const void * newp,size_t newlen)67 sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp,
68 const void *newp, size_t newlen)
69 {
70 int retval;
71 size_t orig_oldlen;
72
73 orig_oldlen = oldlenp != NULL ? *oldlenp : 0;
74 retval = __sysctl(name, namelen, oldp, oldlenp, newp, newlen);
75 /*
76 * Valid names under CTL_USER except USER_LOCALBASE have a dummy entry
77 * in the sysctl tree (to support name lookups and enumerations) with
78 * an empty/zero value, and the true value is supplied by this routine.
79 * For all such names, __sysctl() is used solely to validate the name.
80 *
81 * Return here unless there was a successful lookup for a CTL_USER name.
82 */
83 if (retval != 0 || name[0] != CTL_USER)
84 return (retval);
85
86 if (namelen != 2) {
87 errno = EINVAL;
88 return (-1);
89 }
90
91 /* Variables under CLT_USER that may be overridden by kernel values */
92 switch (name[1]) {
93 case USER_LOCALBASE:
94 if (oldlenp == NULL || *oldlenp > sizeof(""))
95 return (0);
96 return (set_user_str(oldp, oldlenp, _PATH_LOCALBASE,
97 sizeof(_PATH_LOCALBASE), orig_oldlen));
98 }
99
100 /* Variables under CLT_USER whose values are immutably defined below */
101 if (newp != NULL) {
102 errno = EPERM;
103 return (-1);
104 }
105
106 switch (name[1]) {
107 case USER_CS_PATH:
108 return (set_user_str(oldp, oldlenp, _PATH_STDPATH,
109 sizeof(_PATH_STDPATH), orig_oldlen));
110 }
111
112 if (oldp != NULL && *oldlenp < sizeof(int)) {
113 errno = ENOMEM;
114 return (-1);
115 }
116 *oldlenp = sizeof(int);
117 if (oldp == NULL)
118 return (0);
119
120 switch (name[1]) {
121 case USER_BC_BASE_MAX:
122 *(int *)oldp = BC_BASE_MAX;
123 return (0);
124 case USER_BC_DIM_MAX:
125 *(int *)oldp = BC_DIM_MAX;
126 return (0);
127 case USER_BC_SCALE_MAX:
128 *(int *)oldp = BC_SCALE_MAX;
129 return (0);
130 case USER_BC_STRING_MAX:
131 *(int *)oldp = BC_STRING_MAX;
132 return (0);
133 case USER_COLL_WEIGHTS_MAX:
134 *(int *)oldp = COLL_WEIGHTS_MAX;
135 return (0);
136 case USER_EXPR_NEST_MAX:
137 *(int *)oldp = EXPR_NEST_MAX;
138 return (0);
139 case USER_LINE_MAX:
140 *(int *)oldp = LINE_MAX;
141 return (0);
142 case USER_RE_DUP_MAX:
143 *(int *)oldp = RE_DUP_MAX;
144 return (0);
145 case USER_POSIX2_VERSION:
146 *(int *)oldp = _POSIX2_VERSION;
147 return (0);
148 case USER_POSIX2_C_BIND:
149 #ifdef POSIX2_C_BIND
150 *(int *)oldp = 1;
151 #else
152 *(int *)oldp = 0;
153 #endif
154 return (0);
155 case USER_POSIX2_C_DEV:
156 #ifdef POSIX2_C_DEV
157 *(int *)oldp = 1;
158 #else
159 *(int *)oldp = 0;
160 #endif
161 return (0);
162 case USER_POSIX2_CHAR_TERM:
163 #ifdef POSIX2_CHAR_TERM
164 *(int *)oldp = 1;
165 #else
166 *(int *)oldp = 0;
167 #endif
168 return (0);
169 case USER_POSIX2_FORT_DEV:
170 #ifdef POSIX2_FORT_DEV
171 *(int *)oldp = 1;
172 #else
173 *(int *)oldp = 0;
174 #endif
175 return (0);
176 case USER_POSIX2_FORT_RUN:
177 #ifdef POSIX2_FORT_RUN
178 *(int *)oldp = 1;
179 #else
180 *(int *)oldp = 0;
181 #endif
182 return (0);
183 case USER_POSIX2_LOCALEDEF:
184 #ifdef POSIX2_LOCALEDEF
185 *(int *)oldp = 1;
186 #else
187 *(int *)oldp = 0;
188 #endif
189 return (0);
190 case USER_POSIX2_SW_DEV:
191 #ifdef POSIX2_SW_DEV
192 *(int *)oldp = 1;
193 #else
194 *(int *)oldp = 0;
195 #endif
196 return (0);
197 case USER_POSIX2_UPE:
198 #ifdef POSIX2_UPE
199 *(int *)oldp = 1;
200 #else
201 *(int *)oldp = 0;
202 #endif
203 return (0);
204 case USER_STREAM_MAX:
205 *(int *)oldp = FOPEN_MAX;
206 return (0);
207 case USER_TZNAME_MAX:
208 *(int *)oldp = NAME_MAX;
209 return (0);
210 default:
211 errno = EINVAL;
212 return (-1);
213 }
214 /* NOTREACHED */
215 }
216