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/param.h>
33#include <sys/sysctl.h>
34
35#include <errno.h>
36#include <limits.h>
37#include <paths.h>
38#include <stdio.h>
39#include <unistd.h>
40#include <string.h>
41
42extern int __sysctl(const int *name, u_int namelen, void *oldp,
43    size_t *oldlenp, const void *newp, size_t newlen);
44
45static int
46set_user_str(void *dstp, size_t *dstlenp, const char *src, size_t len,
47    size_t maxlen)
48{
49	int retval;
50
51	retval = 0;
52	if (dstp != NULL) {
53		if (len > maxlen) {
54			len = maxlen;
55			errno = ENOMEM;
56			retval = -1;
57		}
58		memcpy(dstp, src, len);
59	}
60	*dstlenp = len;
61	return (retval);
62}
63
64int
65sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp,
66    const void *newp, size_t newlen)
67{
68	int retval;
69	size_t orig_oldlen;
70
71	orig_oldlen = oldlenp != NULL ? *oldlenp : 0;
72	retval = __sysctl(name, namelen, oldp, oldlenp, newp, newlen);
73	/*
74	 * Valid names under CTL_USER except USER_LOCALBASE have a dummy entry
75	 * in the sysctl tree (to support name lookups and enumerations) with
76	 * an empty/zero value, and the true value is supplied by this routine.
77	 * For all such names, __sysctl() is used solely to validate the name.
78	 *
79	 * Return here unless there was a successful lookup for a CTL_USER name.
80	 */
81	if (retval != 0 || name[0] != CTL_USER)
82		return (retval);
83
84	if (namelen != 2) {
85		errno = EINVAL;
86		return (-1);
87	}
88
89	/* Variables under CLT_USER that may be overridden by kernel values */
90	switch (name[1]) {
91	case USER_LOCALBASE:
92		if (oldlenp == NULL || *oldlenp > sizeof(""))
93			return (0);
94		return (set_user_str(oldp, oldlenp, _PATH_LOCALBASE,
95			sizeof(_PATH_LOCALBASE), orig_oldlen));
96	}
97
98	/* Variables under CLT_USER whose values are immutably defined below */
99	if (newp != NULL) {
100		errno = EPERM;
101		return (-1);
102	}
103
104	switch (name[1]) {
105	case USER_CS_PATH:
106		return (set_user_str(oldp, oldlenp, _PATH_STDPATH,
107		    sizeof(_PATH_STDPATH), orig_oldlen));
108	}
109
110	if (oldp != NULL && *oldlenp < sizeof(int)) {
111		errno = ENOMEM;
112		return (-1);
113	}
114	*oldlenp = sizeof(int);
115	if (oldp == NULL)
116		return (0);
117
118	switch (name[1]) {
119	case USER_BC_BASE_MAX:
120		*(int *)oldp = BC_BASE_MAX;
121		return (0);
122	case USER_BC_DIM_MAX:
123		*(int *)oldp = BC_DIM_MAX;
124		return (0);
125	case USER_BC_SCALE_MAX:
126		*(int *)oldp = BC_SCALE_MAX;
127		return (0);
128	case USER_BC_STRING_MAX:
129		*(int *)oldp = BC_STRING_MAX;
130		return (0);
131	case USER_COLL_WEIGHTS_MAX:
132		*(int *)oldp = COLL_WEIGHTS_MAX;
133		return (0);
134	case USER_EXPR_NEST_MAX:
135		*(int *)oldp = EXPR_NEST_MAX;
136		return (0);
137	case USER_LINE_MAX:
138		*(int *)oldp = LINE_MAX;
139		return (0);
140	case USER_RE_DUP_MAX:
141		*(int *)oldp = RE_DUP_MAX;
142		return (0);
143	case USER_POSIX2_VERSION:
144		*(int *)oldp = _POSIX2_VERSION;
145		return (0);
146	case USER_POSIX2_C_BIND:
147#ifdef POSIX2_C_BIND
148		*(int *)oldp = 1;
149#else
150		*(int *)oldp = 0;
151#endif
152		return (0);
153	case USER_POSIX2_C_DEV:
154#ifdef	POSIX2_C_DEV
155		*(int *)oldp = 1;
156#else
157		*(int *)oldp = 0;
158#endif
159		return (0);
160	case USER_POSIX2_CHAR_TERM:
161#ifdef	POSIX2_CHAR_TERM
162		*(int *)oldp = 1;
163#else
164		*(int *)oldp = 0;
165#endif
166		return (0);
167	case USER_POSIX2_FORT_DEV:
168#ifdef	POSIX2_FORT_DEV
169		*(int *)oldp = 1;
170#else
171		*(int *)oldp = 0;
172#endif
173		return (0);
174	case USER_POSIX2_FORT_RUN:
175#ifdef	POSIX2_FORT_RUN
176		*(int *)oldp = 1;
177#else
178		*(int *)oldp = 0;
179#endif
180		return (0);
181	case USER_POSIX2_LOCALEDEF:
182#ifdef	POSIX2_LOCALEDEF
183		*(int *)oldp = 1;
184#else
185		*(int *)oldp = 0;
186#endif
187		return (0);
188	case USER_POSIX2_SW_DEV:
189#ifdef	POSIX2_SW_DEV
190		*(int *)oldp = 1;
191#else
192		*(int *)oldp = 0;
193#endif
194		return (0);
195	case USER_POSIX2_UPE:
196#ifdef	POSIX2_UPE
197		*(int *)oldp = 1;
198#else
199		*(int *)oldp = 0;
200#endif
201		return (0);
202	case USER_STREAM_MAX:
203		*(int *)oldp = FOPEN_MAX;
204		return (0);
205	case USER_TZNAME_MAX:
206		*(int *)oldp = NAME_MAX;
207		return (0);
208	default:
209		errno = EINVAL;
210		return (-1);
211	}
212	/* NOTREACHED */
213}
214