1 /* $NetBSD: sysconf.c,v 1.14 2002/01/31 00:32:47 kleink Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Sean Eric Fagan of Cygnus Support. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94"; 43 #else 44 __RCSID("$NetBSD: sysconf.c,v 1.14 2002/01/31 00:32:47 kleink Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include "namespace.h" 49 #include <sys/param.h> 50 #include <sys/sysctl.h> 51 #include <sys/time.h> 52 #include <sys/resource.h> 53 54 #include <errno.h> 55 #include <time.h> 56 #include <unistd.h> 57 58 #ifdef __weak_alias 59 __weak_alias(sysconf,__sysconf) 60 #endif 61 62 /* 63 * sysconf -- 64 * get configurable system variables. 65 * 66 * XXX 67 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 68 * not change during the lifetime of the calling process. This would seem 69 * to require that any change to system limits kill all running processes. 70 * A workaround might be to cache the values when they are first retrieved 71 * and then simply return the cached value on subsequent calls. This is 72 * less useful than returning up-to-date values, however. 73 */ 74 long 75 sysconf(name) 76 int name; 77 { 78 struct rlimit rl; 79 size_t len; 80 int mib[2], value; 81 82 len = sizeof(value); 83 84 switch (name) { 85 /* 1003.1 */ 86 case _SC_ARG_MAX: 87 mib[0] = CTL_KERN; 88 mib[1] = KERN_ARGMAX; 89 break; 90 case _SC_CHILD_MAX: 91 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur); 92 case _SC_CLK_TCK: 93 return (CLK_TCK); 94 case _SC_JOB_CONTROL: 95 mib[0] = CTL_KERN; 96 mib[1] = KERN_JOB_CONTROL; 97 goto yesno; 98 case _SC_NGROUPS_MAX: 99 mib[0] = CTL_KERN; 100 mib[1] = KERN_NGROUPS; 101 break; 102 case _SC_OPEN_MAX: 103 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur); 104 case _SC_STREAM_MAX: 105 mib[0] = CTL_USER; 106 mib[1] = USER_STREAM_MAX; 107 break; 108 case _SC_TZNAME_MAX: 109 mib[0] = CTL_USER; 110 mib[1] = USER_TZNAME_MAX; 111 break; 112 case _SC_SAVED_IDS: 113 mib[0] = CTL_KERN; 114 mib[1] = KERN_SAVED_IDS; 115 goto yesno; 116 case _SC_VERSION: 117 mib[0] = CTL_KERN; 118 mib[1] = KERN_POSIX1; 119 break; 120 121 /* 1003.1b */ 122 case _SC_PAGESIZE: 123 mib[0] = CTL_HW; 124 mib[1] = HW_PAGESIZE; 125 break; 126 case _SC_FSYNC: 127 mib[0] = CTL_KERN; 128 mib[1] = KERN_FSYNC; 129 goto yesno; 130 case _SC_SYNCHRONIZED_IO: 131 mib[0] = CTL_KERN; 132 mib[1] = KERN_SYNCHRONIZED_IO; 133 goto yesno; 134 case _SC_MAPPED_FILES: 135 mib[0] = CTL_KERN; 136 mib[1] = KERN_MAPPED_FILES; 137 goto yesno; 138 case _SC_MEMLOCK: 139 mib[0] = CTL_KERN; 140 mib[1] = KERN_MEMLOCK; 141 goto yesno; 142 case _SC_MEMLOCK_RANGE: 143 mib[0] = CTL_KERN; 144 mib[1] = KERN_MEMLOCK_RANGE; 145 goto yesno; 146 case _SC_MEMORY_PROTECTION: 147 mib[0] = CTL_KERN; 148 mib[1] = KERN_MEMORY_PROTECTION; 149 goto yesno; 150 case _SC_MONOTONIC_CLOCK: 151 mib[0] = CTL_KERN; 152 mib[1] = KERN_MONOTONIC_CLOCK; 153 goto yesno; 154 155 /* 1003.1c */ 156 case _SC_LOGIN_NAME_MAX: 157 mib[0] = CTL_KERN; 158 mib[1] = KERN_LOGIN_NAME_MAX; 159 break; 160 161 /* 1003.2 */ 162 case _SC_BC_BASE_MAX: 163 mib[0] = CTL_USER; 164 mib[1] = USER_BC_BASE_MAX; 165 break; 166 case _SC_BC_DIM_MAX: 167 mib[0] = CTL_USER; 168 mib[1] = USER_BC_DIM_MAX; 169 break; 170 case _SC_BC_SCALE_MAX: 171 mib[0] = CTL_USER; 172 mib[1] = USER_BC_SCALE_MAX; 173 break; 174 case _SC_BC_STRING_MAX: 175 mib[0] = CTL_USER; 176 mib[1] = USER_BC_STRING_MAX; 177 break; 178 case _SC_COLL_WEIGHTS_MAX: 179 mib[0] = CTL_USER; 180 mib[1] = USER_COLL_WEIGHTS_MAX; 181 break; 182 case _SC_EXPR_NEST_MAX: 183 mib[0] = CTL_USER; 184 mib[1] = USER_EXPR_NEST_MAX; 185 break; 186 case _SC_LINE_MAX: 187 mib[0] = CTL_USER; 188 mib[1] = USER_LINE_MAX; 189 break; 190 case _SC_RE_DUP_MAX: 191 mib[0] = CTL_USER; 192 mib[1] = USER_RE_DUP_MAX; 193 break; 194 case _SC_2_VERSION: 195 mib[0] = CTL_USER; 196 mib[1] = USER_POSIX2_VERSION; 197 break; 198 case _SC_2_C_BIND: 199 mib[0] = CTL_USER; 200 mib[1] = USER_POSIX2_C_BIND; 201 goto yesno; 202 case _SC_2_C_DEV: 203 mib[0] = CTL_USER; 204 mib[1] = USER_POSIX2_C_DEV; 205 goto yesno; 206 case _SC_2_CHAR_TERM: 207 mib[0] = CTL_USER; 208 mib[1] = USER_POSIX2_CHAR_TERM; 209 goto yesno; 210 case _SC_2_FORT_DEV: 211 mib[0] = CTL_USER; 212 mib[1] = USER_POSIX2_FORT_DEV; 213 goto yesno; 214 case _SC_2_FORT_RUN: 215 mib[0] = CTL_USER; 216 mib[1] = USER_POSIX2_FORT_RUN; 217 goto yesno; 218 case _SC_2_LOCALEDEF: 219 mib[0] = CTL_USER; 220 mib[1] = USER_POSIX2_LOCALEDEF; 221 goto yesno; 222 case _SC_2_SW_DEV: 223 mib[0] = CTL_USER; 224 mib[1] = USER_POSIX2_SW_DEV; 225 goto yesno; 226 case _SC_2_UPE: 227 mib[0] = CTL_USER; 228 mib[1] = USER_POSIX2_UPE; 229 goto yesno; 230 231 /* XPG 4.2 */ 232 case _SC_IOV_MAX: 233 mib[0] = CTL_KERN; 234 mib[1] = KERN_IOV_MAX; 235 break; 236 case _SC_XOPEN_SHM: 237 mib[0] = CTL_KERN; 238 mib[1] = KERN_SYSVSHM; 239 yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 240 return (-1); 241 if (value == 0) 242 return (-1); 243 return (value); 244 /*NOTREACHED*/ 245 break; 246 default: 247 errno = EINVAL; 248 return (-1); 249 } 250 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 251 } 252