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 static int
set_user_str(void * dstp,size_t * dstlenp,const char * src,size_t len,size_t maxlen)50 set_user_str(void *dstp, size_t *dstlenp, const char *src, size_t len,
51 size_t maxlen)
52 {
53 int retval;
54
55 retval = 0;
56 if (dstp != NULL) {
57 if (len > maxlen) {
58 len = maxlen;
59 errno = ENOMEM;
60 retval = -1;
61 }
62 memcpy(dstp, src, len);
63 }
64 *dstlenp = len;
65 return (retval);
66 }
67
68 int
sysctl(const int * name,u_int namelen,void * oldp,size_t * oldlenp,const void * newp,size_t newlen)69 sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp,
70 const void *newp, size_t newlen)
71 {
72 int retval;
73 size_t orig_oldlen;
74
75 orig_oldlen = oldlenp != NULL ? *oldlenp : 0;
76 retval = __sysctl(name, namelen, oldp, oldlenp, newp, newlen);
77 /*
78 * Valid names under CTL_USER except USER_LOCALBASE have a dummy entry
79 * in the sysctl tree (to support name lookups and enumerations) with
80 * an empty/zero value, and the true value is supplied by this routine.
81 * For all such names, __sysctl() is used solely to validate the name.
82 *
83 * Return here unless there was a successful lookup for a CTL_USER name.
84 */
85 if (retval != 0 || name[0] != CTL_USER)
86 return (retval);
87
88 if (namelen != 2) {
89 errno = EINVAL;
90 return (-1);
91 }
92
93 /* Variables under CLT_USER that may be overridden by kernel values */
94 switch (name[1]) {
95 case USER_LOCALBASE:
96 if (oldlenp == NULL || *oldlenp > sizeof(""))
97 return (0);
98 return (set_user_str(oldp, oldlenp, _PATH_LOCALBASE,
99 sizeof(_PATH_LOCALBASE), orig_oldlen));
100 }
101
102 /* Variables under CLT_USER whose values are immutably defined below */
103 if (newp != NULL) {
104 errno = EPERM;
105 return (-1);
106 }
107
108 switch (name[1]) {
109 case USER_CS_PATH:
110 return (set_user_str(oldp, oldlenp, _PATH_STDPATH,
111 sizeof(_PATH_STDPATH), orig_oldlen));
112 }
113
114 if (oldp != NULL && *oldlenp < sizeof(int)) {
115 errno = ENOMEM;
116 return (-1);
117 }
118 *oldlenp = sizeof(int);
119 if (oldp == NULL)
120 return (0);
121
122 switch (name[1]) {
123 case USER_BC_BASE_MAX:
124 *(int *)oldp = BC_BASE_MAX;
125 return (0);
126 case USER_BC_DIM_MAX:
127 *(int *)oldp = BC_DIM_MAX;
128 return (0);
129 case USER_BC_SCALE_MAX:
130 *(int *)oldp = BC_SCALE_MAX;
131 return (0);
132 case USER_BC_STRING_MAX:
133 *(int *)oldp = BC_STRING_MAX;
134 return (0);
135 case USER_COLL_WEIGHTS_MAX:
136 *(int *)oldp = COLL_WEIGHTS_MAX;
137 return (0);
138 case USER_EXPR_NEST_MAX:
139 *(int *)oldp = EXPR_NEST_MAX;
140 return (0);
141 case USER_LINE_MAX:
142 *(int *)oldp = LINE_MAX;
143 return (0);
144 case USER_RE_DUP_MAX:
145 *(int *)oldp = RE_DUP_MAX;
146 return (0);
147 case USER_POSIX2_VERSION:
148 *(int *)oldp = _POSIX2_VERSION;
149 return (0);
150 case USER_POSIX2_C_BIND:
151 #ifdef POSIX2_C_BIND
152 *(int *)oldp = 1;
153 #else
154 *(int *)oldp = 0;
155 #endif
156 return (0);
157 case USER_POSIX2_C_DEV:
158 #ifdef POSIX2_C_DEV
159 *(int *)oldp = 1;
160 #else
161 *(int *)oldp = 0;
162 #endif
163 return (0);
164 case USER_POSIX2_CHAR_TERM:
165 #ifdef POSIX2_CHAR_TERM
166 *(int *)oldp = 1;
167 #else
168 *(int *)oldp = 0;
169 #endif
170 return (0);
171 case USER_POSIX2_FORT_DEV:
172 #ifdef POSIX2_FORT_DEV
173 *(int *)oldp = 1;
174 #else
175 *(int *)oldp = 0;
176 #endif
177 return (0);
178 case USER_POSIX2_FORT_RUN:
179 #ifdef POSIX2_FORT_RUN
180 *(int *)oldp = 1;
181 #else
182 *(int *)oldp = 0;
183 #endif
184 return (0);
185 case USER_POSIX2_LOCALEDEF:
186 #ifdef POSIX2_LOCALEDEF
187 *(int *)oldp = 1;
188 #else
189 *(int *)oldp = 0;
190 #endif
191 return (0);
192 case USER_POSIX2_SW_DEV:
193 #ifdef POSIX2_SW_DEV
194 *(int *)oldp = 1;
195 #else
196 *(int *)oldp = 0;
197 #endif
198 return (0);
199 case USER_POSIX2_UPE:
200 #ifdef POSIX2_UPE
201 *(int *)oldp = 1;
202 #else
203 *(int *)oldp = 0;
204 #endif
205 return (0);
206 case USER_STREAM_MAX:
207 *(int *)oldp = FOPEN_MAX;
208 return (0);
209 case USER_TZNAME_MAX:
210 *(int *)oldp = NAME_MAX;
211 return (0);
212 default:
213 errno = EINVAL;
214 return (-1);
215 }
216 /* NOTREACHED */
217 }
218