sysconf.c revision 90039
1/*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Sean Eric Fagan of Cygnus Support. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#if defined(LIBC_SCCS) && !defined(lint) 38static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94"; 39#endif /* LIBC_SCCS and not lint */ 40#include <sys/cdefs.h> 41__FBSDID("$FreeBSD: head/lib/libc/gen/sysconf.c 90039 2002-02-01 00:57:29Z obrien $"); 42 43#include <sys/_posix.h> 44#include <sys/param.h> 45#include <sys/time.h> 46#include <sys/sysctl.h> 47#include <sys/resource.h> 48 49#include <errno.h> 50#include <time.h> 51#include <unistd.h> 52 53/* 54 * sysconf -- 55 * get configurable system variables. 56 * 57 * XXX 58 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 59 * not change during the lifetime of the calling process. This would seem 60 * to require that any change to system limits kill all running processes. 61 * A workaround might be to cache the values when they are first retrieved 62 * and then simply return the cached value on subsequent calls. This is 63 * less useful than returning up-to-date values, however. 64 */ 65long 66sysconf(name) 67 int name; 68{ 69 struct rlimit rl; 70 size_t len; 71 int mib[2], value; 72 long defaultresult; 73 74 len = sizeof(value); 75 defaultresult = -1; 76 77 switch (name) { 78/* 1003.1 */ 79 case _SC_ARG_MAX: 80 mib[0] = CTL_KERN; 81 mib[1] = KERN_ARGMAX; 82 break; 83 case _SC_CHILD_MAX: 84 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : rl.rlim_cur); 85 case _SC_CLK_TCK: 86 return (CLK_TCK); 87 case _SC_JOB_CONTROL: 88 mib[0] = CTL_KERN; 89 mib[1] = KERN_JOB_CONTROL; 90 goto yesno; 91 case _SC_NGROUPS_MAX: 92 mib[0] = CTL_KERN; 93 mib[1] = KERN_NGROUPS; 94 break; 95 case _SC_OPEN_MAX: 96 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : rl.rlim_cur); 97 case _SC_STREAM_MAX: 98 mib[0] = CTL_USER; 99 mib[1] = USER_STREAM_MAX; 100 break; 101 case _SC_TZNAME_MAX: 102 mib[0] = CTL_USER; 103 mib[1] = USER_TZNAME_MAX; 104 break; 105 case _SC_SAVED_IDS: 106 mib[0] = CTL_KERN; 107 mib[1] = KERN_SAVED_IDS; 108 goto yesno; 109 case _SC_VERSION: 110 mib[0] = CTL_KERN; 111 mib[1] = KERN_POSIX1; 112 break; 113 114/* 1003.2 */ 115 case _SC_BC_BASE_MAX: 116 mib[0] = CTL_USER; 117 mib[1] = USER_BC_BASE_MAX; 118 break; 119 case _SC_BC_DIM_MAX: 120 mib[0] = CTL_USER; 121 mib[1] = USER_BC_DIM_MAX; 122 break; 123 case _SC_BC_SCALE_MAX: 124 mib[0] = CTL_USER; 125 mib[1] = USER_BC_SCALE_MAX; 126 break; 127 case _SC_BC_STRING_MAX: 128 mib[0] = CTL_USER; 129 mib[1] = USER_BC_STRING_MAX; 130 break; 131 case _SC_COLL_WEIGHTS_MAX: 132 mib[0] = CTL_USER; 133 mib[1] = USER_COLL_WEIGHTS_MAX; 134 break; 135 case _SC_EXPR_NEST_MAX: 136 mib[0] = CTL_USER; 137 mib[1] = USER_EXPR_NEST_MAX; 138 break; 139 case _SC_LINE_MAX: 140 mib[0] = CTL_USER; 141 mib[1] = USER_LINE_MAX; 142 break; 143 case _SC_RE_DUP_MAX: 144 mib[0] = CTL_USER; 145 mib[1] = USER_RE_DUP_MAX; 146 break; 147 case _SC_2_VERSION: 148 mib[0] = CTL_USER; 149 mib[1] = USER_POSIX2_VERSION; 150 break; 151 case _SC_2_C_BIND: 152 mib[0] = CTL_USER; 153 mib[1] = USER_POSIX2_C_BIND; 154 goto yesno; 155 case _SC_2_C_DEV: 156 mib[0] = CTL_USER; 157 mib[1] = USER_POSIX2_C_DEV; 158 goto yesno; 159 case _SC_2_CHAR_TERM: 160 mib[0] = CTL_USER; 161 mib[1] = USER_POSIX2_CHAR_TERM; 162 goto yesno; 163 case _SC_2_FORT_DEV: 164 mib[0] = CTL_USER; 165 mib[1] = USER_POSIX2_FORT_DEV; 166 goto yesno; 167 case _SC_2_FORT_RUN: 168 mib[0] = CTL_USER; 169 mib[1] = USER_POSIX2_FORT_RUN; 170 goto yesno; 171 case _SC_2_LOCALEDEF: 172 mib[0] = CTL_USER; 173 mib[1] = USER_POSIX2_LOCALEDEF; 174 goto yesno; 175 case _SC_2_SW_DEV: 176 mib[0] = CTL_USER; 177 mib[1] = USER_POSIX2_SW_DEV; 178 goto yesno; 179 case _SC_2_UPE: 180 mib[0] = CTL_USER; 181 mib[1] = USER_POSIX2_UPE; 182 goto yesno; 183 184#ifdef _P1003_1B_VISIBLE 185 /* POSIX.1B */ 186 187 case _SC_ASYNCHRONOUS_IO: 188 mib[0] = CTL_P1003_1B; 189 mib[1] = CTL_P1003_1B_ASYNCHRONOUS_IO; 190 goto yesno; 191 case _SC_MAPPED_FILES: 192 mib[0] = CTL_P1003_1B; 193 mib[1] = CTL_P1003_1B_MAPPED_FILES; 194 goto yesno; 195 case _SC_MEMLOCK: 196 mib[0] = CTL_P1003_1B; 197 mib[1] = CTL_P1003_1B_MEMLOCK; 198 goto yesno; 199 case _SC_MEMLOCK_RANGE: 200 mib[0] = CTL_P1003_1B; 201 mib[1] = CTL_P1003_1B_MEMLOCK_RANGE; 202 goto yesno; 203 case _SC_MEMORY_PROTECTION: 204 mib[0] = CTL_P1003_1B; 205 mib[1] = CTL_P1003_1B_MEMORY_PROTECTION; 206 goto yesno; 207 case _SC_MESSAGE_PASSING: 208 mib[0] = CTL_P1003_1B; 209 mib[1] = CTL_P1003_1B_MESSAGE_PASSING; 210 goto yesno; 211 case _SC_PRIORITIZED_IO: 212 mib[0] = CTL_P1003_1B; 213 mib[1] = CTL_P1003_1B_PRIORITIZED_IO; 214 goto yesno; 215 case _SC_PRIORITY_SCHEDULING: 216 mib[0] = CTL_P1003_1B; 217 mib[1] = CTL_P1003_1B_PRIORITY_SCHEDULING; 218 goto yesno; 219 case _SC_REALTIME_SIGNALS: 220 mib[0] = CTL_P1003_1B; 221 mib[1] = CTL_P1003_1B_REALTIME_SIGNALS; 222 goto yesno; 223 case _SC_SEMAPHORES: 224 mib[0] = CTL_P1003_1B; 225 mib[1] = CTL_P1003_1B_SEMAPHORES; 226 goto yesno; 227 case _SC_FSYNC: 228 mib[0] = CTL_P1003_1B; 229 mib[1] = CTL_P1003_1B_FSYNC; 230 goto yesno; 231 case _SC_SHARED_MEMORY_OBJECTS: 232 mib[0] = CTL_P1003_1B; 233 mib[1] = CTL_P1003_1B_SHARED_MEMORY_OBJECTS; 234 goto yesno; 235 case _SC_SYNCHRONIZED_IO: 236 mib[0] = CTL_P1003_1B; 237 mib[1] = CTL_P1003_1B_SYNCHRONIZED_IO; 238 goto yesno; 239 case _SC_TIMERS: 240 mib[0] = CTL_P1003_1B; 241 mib[1] = CTL_P1003_1B_TIMERS; 242 goto yesno; 243 case _SC_AIO_LISTIO_MAX: 244 mib[0] = CTL_P1003_1B; 245 mib[1] = CTL_P1003_1B_AIO_LISTIO_MAX; 246 goto yesno; 247 case _SC_AIO_MAX: 248 mib[0] = CTL_P1003_1B; 249 mib[1] = CTL_P1003_1B_AIO_MAX; 250 goto yesno; 251 case _SC_AIO_PRIO_DELTA_MAX: 252 mib[0] = CTL_P1003_1B; 253 mib[1] = CTL_P1003_1B_AIO_PRIO_DELTA_MAX; 254 goto yesno; 255 case _SC_DELAYTIMER_MAX: 256 mib[0] = CTL_P1003_1B; 257 mib[1] = CTL_P1003_1B_DELAYTIMER_MAX; 258 goto yesno; 259 case _SC_MQ_OPEN_MAX: 260 mib[0] = CTL_P1003_1B; 261 mib[1] = CTL_P1003_1B_MQ_OPEN_MAX; 262 goto yesno; 263 case _SC_PAGESIZE: 264 defaultresult = getpagesize(); 265 mib[0] = CTL_P1003_1B; 266 mib[1] = CTL_P1003_1B_PAGESIZE; 267 goto yesno; 268 case _SC_RTSIG_MAX: 269 mib[0] = CTL_P1003_1B; 270 mib[1] = CTL_P1003_1B_RTSIG_MAX; 271 goto yesno; 272 case _SC_SEM_NSEMS_MAX: 273 mib[0] = CTL_P1003_1B; 274 mib[1] = CTL_P1003_1B_SEM_NSEMS_MAX; 275 goto yesno; 276 case _SC_SEM_VALUE_MAX: 277 mib[0] = CTL_P1003_1B; 278 mib[1] = CTL_P1003_1B_SEM_VALUE_MAX; 279 goto yesno; 280 case _SC_SIGQUEUE_MAX: 281 mib[0] = CTL_P1003_1B; 282 mib[1] = CTL_P1003_1B_SIGQUEUE_MAX; 283 goto yesno; 284 case _SC_TIMER_MAX: 285 mib[0] = CTL_P1003_1B; 286 mib[1] = CTL_P1003_1B_TIMER_MAX; 287 goto yesno; 288#endif /* _P1003_1B_VISIBLE */ 289 290#if defined(_SC_NPROCESSORS_CONF) && defined(_SC_NPROCESSORS_ONLN) 291 case _SC_NPROCESSORS_CONF: 292 case _SC_NPROCESSORS_ONLN: 293 mib[0] = CTL_HW; 294 mib[1] = HW_NCPU; 295 break; 296#endif 297 298#ifdef _SC_IOV_MAX 299 case _SC_IOV_MAX: 300 mib[0] = CTL_KERN; 301 mib[1] = KERN_IOV_MAX; 302 break; 303#endif 304 305yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 306 return (-1); 307 if (value == 0) 308 return (defaultresult); 309 return (value); 310 break; 311 default: 312 errno = EINVAL; 313 return (-1); 314 } 315 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 316} 317