sysconf.c revision 1.42
1 /* $NetBSD: sysconf.c,v 1.42 2019/10/16 20:43:18 maya 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94"; 39 #else 40 __RCSID("$NetBSD: sysconf.c,v 1.42 2019/10/16 20:43:18 maya Exp $"); 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include "namespace.h" 45 #include <sys/param.h> 46 #include <sys/sysctl.h> 47 #include <sys/time.h> 48 #include <sys/resource.h> 49 50 #include <errno.h> 51 #include <limits.h> 52 #include <time.h> 53 #include <unistd.h> 54 #include <paths.h> 55 #include <pwd.h> 56 57 #ifdef __weak_alias 58 __weak_alias(sysconf,__sysconf) 59 #endif 60 61 /* 62 * sysconf -- 63 * get configurable system variables. 64 * 65 * XXX 66 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 67 * not change during the lifetime of the calling process. This would seem 68 * to require that any change to system limits kill all running processes. 69 * A workaround might be to cache the values when they are first retrieved 70 * and then simply return the cached value on subsequent calls. This is 71 * less useful than returning up-to-date values, however. 72 */ 73 long 74 sysconf(int name) 75 { 76 struct rlimit rl; 77 size_t len; 78 uint64_t mem; 79 int mib[CTL_MAXNAME], value; 80 unsigned int mib_len; 81 struct clockinfo tmpclock; 82 static int clk_tck; 83 84 len = sizeof(value); 85 86 /* Default length of the MIB */ 87 mib_len = 2; 88 89 switch (name) { 90 91 /* 1003.1 */ 92 case _SC_ARG_MAX: 93 mib[0] = CTL_KERN; 94 mib[1] = KERN_ARGMAX; 95 break; 96 case _SC_CHILD_MAX: 97 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur); 98 case _O_SC_CLK_TCK: 99 /* 100 * For applications compiled when CLK_TCK was a compile-time 101 * constant. 102 */ 103 return 100; 104 case _SC_CLK_TCK: 105 /* 106 * Has to be handled specially because it returns a 107 * struct clockinfo instead of an integer. Also, since 108 * this might be called often by some things that 109 * don't grok CLK_TCK can be a macro expanding to a 110 * function, cache the value. 111 */ 112 if (clk_tck == 0) { 113 mib[0] = CTL_KERN; 114 mib[1] = KERN_CLOCKRATE; 115 len = sizeof(struct clockinfo); 116 clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0) 117 == -1 ? -1 : tmpclock.hz; 118 } 119 return(clk_tck); 120 case _SC_JOB_CONTROL: 121 mib[0] = CTL_KERN; 122 mib[1] = KERN_JOB_CONTROL; 123 goto yesno; 124 case _SC_NGROUPS_MAX: 125 mib[0] = CTL_KERN; 126 mib[1] = KERN_NGROUPS; 127 break; 128 case _SC_OPEN_MAX: 129 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur); 130 case _SC_STREAM_MAX: 131 mib[0] = CTL_USER; 132 mib[1] = USER_STREAM_MAX; 133 break; 134 case _SC_TZNAME_MAX: 135 mib[0] = CTL_USER; 136 mib[1] = USER_TZNAME_MAX; 137 break; 138 case _SC_SAVED_IDS: 139 mib[0] = CTL_KERN; 140 mib[1] = KERN_SAVED_IDS; 141 goto yesno; 142 case _SC_VERSION: 143 mib[0] = CTL_KERN; 144 mib[1] = KERN_POSIX1; 145 break; 146 147 /* 1003.1b */ 148 case _SC_PAGESIZE: 149 return _getpagesize(); 150 case _SC_FSYNC: 151 mib[0] = CTL_KERN; 152 mib[1] = KERN_FSYNC; 153 goto yesno; 154 case _SC_SYNCHRONIZED_IO: 155 mib[0] = CTL_KERN; 156 mib[1] = KERN_SYNCHRONIZED_IO; 157 goto yesno; 158 case _SC_MAPPED_FILES: 159 mib[0] = CTL_KERN; 160 mib[1] = KERN_MAPPED_FILES; 161 goto yesno; 162 case _SC_MEMLOCK: 163 mib[0] = CTL_KERN; 164 mib[1] = KERN_MEMLOCK; 165 goto yesno; 166 case _SC_MEMLOCK_RANGE: 167 mib[0] = CTL_KERN; 168 mib[1] = KERN_MEMLOCK_RANGE; 169 goto yesno; 170 case _SC_MEMORY_PROTECTION: 171 mib[0] = CTL_KERN; 172 mib[1] = KERN_MEMORY_PROTECTION; 173 goto yesno; 174 case _SC_MONOTONIC_CLOCK: 175 mib[0] = CTL_KERN; 176 mib[1] = KERN_MONOTONIC_CLOCK; 177 goto yesno; 178 case _SC_SEMAPHORES: 179 mib[0] = CTL_KERN; 180 mib[1] = KERN_POSIX_SEMAPHORES; 181 goto yesno; 182 case _SC_TIMERS: 183 mib[0] = CTL_KERN; 184 mib[1] = KERN_POSIX_TIMERS; 185 goto yesno; 186 187 /* 1003.1c */ 188 case _SC_LOGIN_NAME_MAX: 189 mib[0] = CTL_KERN; 190 mib[1] = KERN_LOGIN_NAME_MAX; 191 break; 192 case _SC_THREADS: 193 mib[0] = CTL_KERN; 194 mib[1] = KERN_POSIX_THREADS; 195 goto yesno; 196 197 /* 1003.1j */ 198 case _SC_BARRIERS: 199 mib[0] = CTL_KERN; 200 mib[1] = KERN_POSIX_BARRIERS; 201 goto yesno; 202 case _SC_SPIN_LOCKS: 203 mib[0] = CTL_KERN; 204 mib[1] = KERN_POSIX_SPIN_LOCKS; 205 goto yesno; 206 /* Historical; Threads option in 1003.1-2001 */ 207 case _SC_READER_WRITER_LOCKS: 208 mib[0] = CTL_KERN; 209 mib[1] = KERN_POSIX_READER_WRITER_LOCKS; 210 goto yesno; 211 212 /* 1003.2 */ 213 case _SC_BC_BASE_MAX: 214 mib[0] = CTL_USER; 215 mib[1] = USER_BC_BASE_MAX; 216 break; 217 case _SC_BC_DIM_MAX: 218 mib[0] = CTL_USER; 219 mib[1] = USER_BC_DIM_MAX; 220 break; 221 case _SC_BC_SCALE_MAX: 222 mib[0] = CTL_USER; 223 mib[1] = USER_BC_SCALE_MAX; 224 break; 225 case _SC_BC_STRING_MAX: 226 mib[0] = CTL_USER; 227 mib[1] = USER_BC_STRING_MAX; 228 break; 229 case _SC_COLL_WEIGHTS_MAX: 230 mib[0] = CTL_USER; 231 mib[1] = USER_COLL_WEIGHTS_MAX; 232 break; 233 case _SC_EXPR_NEST_MAX: 234 mib[0] = CTL_USER; 235 mib[1] = USER_EXPR_NEST_MAX; 236 break; 237 case _SC_LINE_MAX: 238 mib[0] = CTL_USER; 239 mib[1] = USER_LINE_MAX; 240 break; 241 case _SC_RE_DUP_MAX: 242 mib[0] = CTL_USER; 243 mib[1] = USER_RE_DUP_MAX; 244 break; 245 case _SC_2_VERSION: 246 mib[0] = CTL_USER; 247 mib[1] = USER_POSIX2_VERSION; 248 break; 249 case _SC_2_C_BIND: 250 mib[0] = CTL_USER; 251 mib[1] = USER_POSIX2_C_BIND; 252 goto yesno; 253 case _SC_2_C_DEV: 254 mib[0] = CTL_USER; 255 mib[1] = USER_POSIX2_C_DEV; 256 goto yesno; 257 case _SC_2_CHAR_TERM: 258 mib[0] = CTL_USER; 259 mib[1] = USER_POSIX2_CHAR_TERM; 260 goto yesno; 261 case _SC_2_FORT_DEV: 262 mib[0] = CTL_USER; 263 mib[1] = USER_POSIX2_FORT_DEV; 264 goto yesno; 265 case _SC_2_FORT_RUN: 266 mib[0] = CTL_USER; 267 mib[1] = USER_POSIX2_FORT_RUN; 268 goto yesno; 269 case _SC_2_LOCALEDEF: 270 mib[0] = CTL_USER; 271 mib[1] = USER_POSIX2_LOCALEDEF; 272 goto yesno; 273 case _SC_2_SW_DEV: 274 mib[0] = CTL_USER; 275 mib[1] = USER_POSIX2_SW_DEV; 276 goto yesno; 277 case _SC_2_UPE: 278 mib[0] = CTL_USER; 279 mib[1] = USER_POSIX2_UPE; 280 goto yesno; 281 282 /* XPG 4.2 */ 283 case _SC_IOV_MAX: 284 mib[0] = CTL_KERN; 285 mib[1] = KERN_IOV_MAX; 286 break; 287 case _SC_XOPEN_SHM: 288 mib[0] = CTL_KERN; 289 mib[1] = KERN_SYSVIPC; 290 mib[2] = KERN_SYSVIPC_SHM; 291 mib_len = 3; 292 goto yesno; 293 294 /* 1003.1-2001, XSI Option Group */ 295 case _SC_AIO_LISTIO_MAX: 296 if (sysctlgetmibinfo("kern.aio_listio_max", &mib[0], &mib_len, 297 NULL, NULL, NULL, SYSCTL_VERSION)) 298 return -1; 299 break; 300 case _SC_AIO_MAX: 301 if (sysctlgetmibinfo("kern.aio_max", &mib[0], &mib_len, 302 NULL, NULL, NULL, SYSCTL_VERSION)) 303 return -1; 304 break; 305 case _SC_ASYNCHRONOUS_IO: 306 if (sysctlgetmibinfo("kern.posix_aio", &mib[0], &mib_len, 307 NULL, NULL, NULL, SYSCTL_VERSION)) 308 return -1; 309 goto yesno; 310 case _SC_MESSAGE_PASSING: 311 if (sysctlgetmibinfo("kern.posix_msg", &mib[0], &mib_len, 312 NULL, NULL, NULL, SYSCTL_VERSION)) 313 return -1; 314 goto yesno; 315 case _SC_MQ_OPEN_MAX: 316 if (sysctlgetmibinfo("kern.mqueue.mq_open_max", &mib[0], 317 &mib_len, NULL, NULL, NULL, SYSCTL_VERSION)) 318 return -1; 319 break; 320 case _SC_MQ_PRIO_MAX: 321 if (sysctlgetmibinfo("kern.mqueue.mq_prio_max", &mib[0], 322 &mib_len, NULL, NULL, NULL, SYSCTL_VERSION)) 323 return -1; 324 break; 325 case _SC_PRIORITY_SCHEDULING: 326 if (sysctlgetmibinfo("kern.posix_sched", &mib[0], &mib_len, 327 NULL, NULL, NULL, SYSCTL_VERSION)) 328 return -1; 329 goto yesno; 330 case _SC_ATEXIT_MAX: 331 mib[0] = CTL_USER; 332 mib[1] = USER_ATEXIT_MAX; 333 break; 334 335 /* 1003.1-2001, TSF */ 336 case _SC_GETGR_R_SIZE_MAX: 337 return _GETGR_R_SIZE_MAX; 338 case _SC_GETPW_R_SIZE_MAX: 339 return _GETPW_R_SIZE_MAX; 340 341 /* Unsorted */ 342 case _SC_RTSIG_MAX: 343 return SIGRTMAX - SIGRTMIN; 344 case _SC_HOST_NAME_MAX: 345 return MAXHOSTNAMELEN; 346 case _SC_PASS_MAX: 347 return _PASSWORD_LEN; 348 case _SC_REGEXP: 349 return _POSIX_REGEXP; 350 case _SC_SHARED_MEMORY_OBJECTS: 351 return _POSIX_SHARED_MEMORY_OBJECTS; 352 case _SC_SHELL: 353 return _POSIX_SHELL; 354 case _SC_SPAWN: 355 return _POSIX_SPAWN; 356 case _SC_SYMLOOP_MAX: 357 return MAXSYMLINKS; 358 359 yesno: if (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1) 360 return (-1); 361 if (value == 0) 362 return (-1); 363 return (value); 364 365 /* Extensions */ 366 case _SC_NPROCESSORS_CONF: 367 mib[0] = CTL_HW; 368 mib[1] = HW_NCPU; 369 break; 370 case _SC_NPROCESSORS_ONLN: 371 mib[0] = CTL_HW; 372 mib[1] = HW_NCPUONLINE; 373 break; 374 375 /* Linux/Solaris */ 376 case _SC_PHYS_PAGES: 377 len = sizeof(mem); 378 mib[0] = CTL_HW; 379 mib[1] = HW_PHYSMEM64; 380 return sysctl(mib, 2, &mem, &len, NULL, 0) == -1 ? -1 : 381 (long)(mem / _getpagesize()); 382 383 /* Native */ 384 case _SC_SCHED_RT_TS: 385 if (sysctlgetmibinfo("kern.sched.rtts", &mib[0], &mib_len, 386 NULL, NULL, NULL, SYSCTL_VERSION)) 387 return -1; 388 break; 389 case _SC_SCHED_PRI_MIN: 390 if (sysctlgetmibinfo("kern.sched.pri_min", &mib[0], &mib_len, 391 NULL, NULL, NULL, SYSCTL_VERSION)) 392 return -1; 393 break; 394 case _SC_SCHED_PRI_MAX: 395 if (sysctlgetmibinfo("kern.sched.pri_max", &mib[0], &mib_len, 396 NULL, NULL, NULL, SYSCTL_VERSION)) 397 return -1; 398 break; 399 case _SC_THREAD_DESTRUCTOR_ITERATIONS: 400 return _POSIX_THREAD_DESTRUCTOR_ITERATIONS; 401 case _SC_THREAD_KEYS_MAX: 402 return _POSIX_THREAD_KEYS_MAX; 403 case _SC_THREAD_STACK_MIN: 404 return _getpagesize(); 405 case _SC_THREAD_THREADS_MAX: 406 if (sysctlgetmibinfo("kern.maxproc", &mib[0], &mib_len, 407 NULL, NULL, NULL, SYSCTL_VERSION)) /* XXX */ 408 return -1; 409 goto yesno; 410 case _SC_THREAD_ATTR_STACKADDR: 411 return _POSIX_THREAD_ATTR_STACKADDR; 412 case _SC_THREAD_ATTR_STACKSIZE: 413 return _POSIX_THREAD_ATTR_STACKSIZE; 414 case _SC_THREAD_SAFE_FUNCTIONS: 415 return _POSIX_THREAD_SAFE_FUNCTIONS; 416 case _SC_THREAD_PRIO_PROTECT: 417 return _POSIX_THREAD_PRIO_PROTECT; 418 case _SC_THREAD_PRIORITY_SCHEDULING: 419 case _SC_THREAD_PRIO_INHERIT: 420 case _SC_THREAD_PROCESS_SHARED: 421 return -1; 422 case _SC_TTY_NAME_MAX: 423 return pathconf(_PATH_DEV, _PC_NAME_MAX); 424 case _SC_TIMER_MAX: 425 return _POSIX_TIMER_MAX; 426 case _SC_SEM_NSEMS_MAX: 427 return _POSIX_SEM_NSEMS_MAX; 428 case _SC_CPUTIME: 429 return _POSIX_CPUTIME; 430 case _SC_THREAD_CPUTIME: 431 return _POSIX_THREAD_CPUTIME; 432 case _SC_DELAYTIMER_MAX: 433 return _POSIX_DELAYTIMER_MAX; 434 case _SC_SIGQUEUE_MAX: 435 return _POSIX_SIGQUEUE_MAX; 436 case _SC_REALTIME_SIGNALS: 437 return 200112L; 438 default: 439 errno = EINVAL; 440 return (-1); 441 } 442 return (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1 ? -1 : value); 443 } 444
Indexes created Thu Sep 25 15:09:46 GMT 2025