summaryrefslogtreecommitdiff
path: root/lib/libc/gen/sysconf.c
blob: 3be23f90bc0c6e4c3ff74652d1ec72e74d4b5386 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/*-
 * Copyright (c) 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Sean Eric Fagan of Cygnus Support.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char rcsid[] = "$OpenBSD: sysconf.c,v 1.4 1998/06/02 06:10:26 deraadt Exp $";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/resource.h>

#include <errno.h>
#include <unistd.h>

/*
 * sysconf --
 *	get configurable system variables.
 *
 * XXX
 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
 * not change during the lifetime of the calling process.  This would seem
 * to require that any change to system limits kill all running processes.
 * A workaround might be to cache the values when they are first retrieved
 * and then simply return the cached value on subsequent calls.  This is
 * less useful than returning up-to-date values, however.
 */
long
sysconf(name)
	int name;
{
	struct rlimit rl;
	size_t len;
	int mib[2], value;

	len = sizeof(value);

	switch (name) {
/* 1003.1 */
	case _SC_ARG_MAX:
		mib[0] = CTL_KERN;
		mib[1] = KERN_ARGMAX;
		break;
	case _SC_CHILD_MAX:
		return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : rl.rlim_cur);
	case _SC_CLK_TCK:
		return (CLK_TCK);
	case _SC_JOB_CONTROL:
		mib[0] = CTL_KERN;
		mib[1] = KERN_JOB_CONTROL;
		goto yesno;
	case _SC_NGROUPS_MAX:
		mib[0] = CTL_KERN;
		mib[1] = KERN_NGROUPS;
		break;
	case _SC_OPEN_MAX:
		return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : rl.rlim_cur);
	case _SC_STREAM_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_STREAM_MAX;
		break;
	case _SC_TZNAME_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_TZNAME_MAX;
		break;
	case _SC_SAVED_IDS:
		mib[0] = CTL_KERN;
		mib[1] = KERN_SAVED_IDS;
		goto yesno;
	case _SC_VERSION:
		mib[0] = CTL_KERN;
		mib[1] = KERN_POSIX1;
		break;

/* 1003.1b */
	case _SC_PAGESIZE:
		mib[0] = CTL_HW;
		mib[1] = HW_PAGESIZE;
		break;
	case _SC_FSYNC:
		mib[0] = CTL_KERN;
		mib[1] = KERN_FSYNC;
		goto yesno;

/* 1003.2 */
	case _SC_BC_BASE_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_BC_BASE_MAX;
		break;
	case _SC_BC_DIM_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_BC_DIM_MAX;
		break;
	case _SC_BC_SCALE_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_BC_SCALE_MAX;
		break;
	case _SC_BC_STRING_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_BC_STRING_MAX;
		break;
	case _SC_COLL_WEIGHTS_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_COLL_WEIGHTS_MAX;
		break;
	case _SC_EXPR_NEST_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_EXPR_NEST_MAX;
		break;
	case _SC_LINE_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_LINE_MAX;
		break;
	case _SC_RE_DUP_MAX:
		mib[0] = CTL_USER;
		mib[1] = USER_RE_DUP_MAX;
		break;
	case _SC_2_VERSION:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_VERSION;
		break;
	case _SC_2_C_BIND:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_C_BIND;
		goto yesno;
	case _SC_2_C_DEV:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_C_DEV;
		goto yesno;
	case _SC_2_CHAR_TERM:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_CHAR_TERM;
		goto yesno;
	case _SC_2_FORT_DEV:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_FORT_DEV;
		goto yesno;
	case _SC_2_FORT_RUN:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_FORT_RUN;
		goto yesno;
	case _SC_2_LOCALEDEF:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_LOCALEDEF;
		goto yesno;
	case _SC_2_SW_DEV:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_SW_DEV;
		goto yesno;
	case _SC_2_UPE:
		mib[0] = CTL_USER;
		mib[1] = USER_POSIX2_UPE;
		goto yesno;

/* XPG 4.2 */
	case _SC_XOPEN_SHM:
		mib[0] = CTL_KERN;
		mib[1] = KERN_SYSVSHM;

yesno:		if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
			return (-1);
		if (value == 0)
			return (-1);
		return (value);
		break;
	default:
		errno = EINVAL;
		return (-1);
	}
	return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 
}