sysconf.c revision 103730
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 103730 2002-09-21 02:14:04Z wollman $"); 42 43#include <sys/param.h> 44#include <sys/time.h> 45#include <sys/sysctl.h> 46#include <sys/resource.h> 47 48#include <errno.h> 49#include <limits.h> 50#include <paths.h> 51#include <pthread.h> /* we just need the limits */ 52#include <time.h> 53#include <unistd.h> 54 55#include "../stdlib/atexit.h" 56#include "../stdtime/tzfile.h" 57 58#define _PATH_ZONEINFO TZDIR /* from tzfile.h */ 59 60/* 61 * sysconf -- 62 * get configurable system variables. 63 * 64 * XXX 65 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 66 * not change during the lifetime of the calling process. This would seem 67 * to require that any change to system limits kill all running processes. 68 * A workaround might be to cache the values when they are first retrieved 69 * and then simply return the cached value on subsequent calls. This is 70 * less useful than returning up-to-date values, however. 71 */ 72long 73sysconf(name) 74 int name; 75{ 76 struct rlimit rl; 77 size_t len; 78 int mib[2], sverrno, value; 79 long defaultresult; 80 const char *path; 81 82 len = sizeof(value); 83 defaultresult = -1; 84 85 switch (name) { 86 case _SC_ARG_MAX: 87 mib[0] = CTL_KERN; 88 mib[1] = KERN_ARGMAX; 89 break; 90 case _SC_CHILD_MAX: 91 if (getrlimit(RLIMIT_NPROC, &rl) != 0) 92 return (-1); 93 if (rl.rlim_cur == RLIM_INFINITY) 94 return (-1); 95 if (rl.rlim_cur > LONG_MAX) { 96 errno = EOVERFLOW; 97 return (-1); 98 } 99 return ((long)rl.rlim_cur); 100 case _SC_CLK_TCK: 101 return (CLK_TCK); 102 case _SC_NGROUPS_MAX: 103 mib[0] = CTL_KERN; 104 mib[1] = KERN_NGROUPS; 105 break; 106 case _SC_OPEN_MAX: 107 case _SC_STREAM_MAX: /* assume fds run out before memory does */ 108 if (getrlimit(RLIMIT_NOFILE, &rl) != 0) 109 return (-1); 110 if (rl.rlim_cur == RLIM_INFINITY) 111 return (-1); 112 if (rl.rlim_cur > LONG_MAX) { 113 errno = EOVERFLOW; 114 return (-1); 115 } 116 return ((long)rl.rlim_cur); 117 case _SC_JOB_CONTROL: 118 return (_POSIX_JOB_CONTROL); 119 case _SC_SAVED_IDS: 120 /* XXX - must be 1 */ 121 mib[0] = CTL_KERN; 122 mib[1] = KERN_SAVED_IDS; 123 goto yesno; 124 case _SC_VERSION: 125 mib[0] = CTL_KERN; 126 mib[1] = KERN_POSIX1; 127 break; 128 case _SC_BC_BASE_MAX: 129 return (BC_BASE_MAX); 130 case _SC_BC_DIM_MAX: 131 return (BC_DIM_MAX); 132 case _SC_BC_SCALE_MAX: 133 return (BC_SCALE_MAX); 134 case _SC_BC_STRING_MAX: 135 return (BC_STRING_MAX); 136 case _SC_COLL_WEIGHTS_MAX: 137 return (COLL_WEIGHTS_MAX); 138 case _SC_EXPR_NEST_MAX: 139 return (EXPR_NEST_MAX); 140 case _SC_LINE_MAX: 141 return (LINE_MAX); 142 case _SC_RE_DUP_MAX: 143 return (RE_DUP_MAX); 144 case _SC_2_VERSION: 145 /* 146 * This is something of a lie, but it would be silly at 147 * this point to try to deduce this from the contents 148 * of the filesystem. 149 */ 150 return (_POSIX2_VERSION); 151 case _SC_2_C_BIND: 152 return (_POSIX2_C_BIND); 153 case _SC_2_C_DEV: 154 return (_POSIX2_C_DEV); 155 case _SC_2_CHAR_TERM: 156 return (_POSIX2_CHAR_TERM); 157 case _SC_2_FORT_DEV: 158 return (_POSIX2_FORT_DEV); 159 case _SC_2_FORT_RUN: 160 return (_POSIX2_FORT_RUN); 161 case _SC_2_LOCALEDEF: 162 return (_POSIX2_LOCALEDEF); 163 case _SC_2_SW_DEV: 164 return (_POSIX2_SW_DEV); 165 case _SC_2_UPE: 166 return (_POSIX2_UPE); 167 case _SC_TZNAME_MAX: 168 path = _PATH_ZONEINFO; 169do_NAME_MAX: 170 sverrno = errno; 171 errno = 0; 172 value = pathconf(path, _PC_NAME_MAX); 173 if (value == -1 && errno != 0) 174 return (-1); 175 errno = sverrno; 176 return (value); 177 178 case _SC_ASYNCHRONOUS_IO: 179 mib[0] = CTL_P1003_1B; 180 mib[1] = CTL_P1003_1B_ASYNCHRONOUS_IO; 181 goto yesno; 182 case _SC_MAPPED_FILES: 183 return (_POSIX_MAPPED_FILES); 184 case _SC_MEMLOCK: 185 return (_POSIX_MEMLOCK); 186 case _SC_MEMLOCK_RANGE: 187 return (_POSIX_MEMLOCK_RANGE); 188 case _SC_MEMORY_PROTECTION: 189 return (_POSIX_MEMORY_PROTECTION); 190 case _SC_MESSAGE_PASSING: 191#if _POSIX_MESSAGE_PASSING == 0 192 mib[0] = CTL_P1003_1B; 193 mib[1] = CTL_P1003_1B_MESSAGE_PASSING; 194 goto yesno; 195#else 196 return (_POSIX_MESSAGE_PASSING); 197#endif 198 case _SC_PRIORITIZED_IO: 199#if _POSIX_PRIORITIZED_IO == 0 200 mib[0] = CTL_P1003_1B; 201 mib[1] = CTL_P1003_1B_PRIORITIZED_IO; 202 goto yesno; 203#else 204 return (_POSIX_PRIORITIZED_IO); 205#endif 206 case _SC_PRIORITY_SCHEDULING: 207#if _POSIX_PRIORITY_SCHEDULING == 0 208 mib[0] = CTL_P1003_1B; 209 mib[1] = CTL_P1003_1B_PRIORITY_SCHEDULING; 210 goto yesno; 211#else 212 return (_POSIX_PRIORITY_SCHEDULING); 213#endif 214 case _SC_REALTIME_SIGNALS: 215#if _POSIX_REALTIME_SIGNALS == 0 216 mib[0] = CTL_P1003_1B; 217 mib[1] = CTL_P1003_1B_REALTIME_SIGNALS; 218 goto yesno; 219#else 220 return (_POSIX_REALTIME_SIGNALS); 221#endif 222 case _SC_SEMAPHORES: 223#if _POSIX_SEMAPHORES == 0 224 mib[0] = CTL_P1003_1B; 225 mib[1] = CTL_P1003_1B_SEMAPHORES; 226 goto yesno; 227#else 228 return (_POSIX_SEMAPHORES); 229#endif 230 case _SC_FSYNC: 231 return (_POSIX_FSYNC); 232 233 case _SC_SHARED_MEMORY_OBJECTS: 234 return (_POSIX_SHARED_MEMORY_OBJECTS); 235 case _SC_SYNCHRONIZED_IO: 236#if _POSIX_SYNCHRONIZED_IO == 0 237 mib[0] = CTL_P1003_1B; 238 mib[1] = CTL_P1003_1B_SYNCHRONIZED_IO; 239 goto yesno; 240#else 241 return (_POSIX_SYNCHRONIZED_IO); 242#endif 243 case _SC_TIMERS: 244#if _POSIX_TIMERS == 0 245 mib[0] = CTL_P1003_1B; 246 mib[1] = CTL_P1003_1B_TIMERS; 247 goto yesno; 248#else 249 return (_POSIX_TIMERS); 250#endif 251 case _SC_AIO_LISTIO_MAX: 252 mib[0] = CTL_P1003_1B; 253 mib[1] = CTL_P1003_1B_AIO_LISTIO_MAX; 254 goto yesno; 255 case _SC_AIO_MAX: 256 mib[0] = CTL_P1003_1B; 257 mib[1] = CTL_P1003_1B_AIO_MAX; 258 goto yesno; 259 case _SC_AIO_PRIO_DELTA_MAX: 260 mib[0] = CTL_P1003_1B; 261 mib[1] = CTL_P1003_1B_AIO_PRIO_DELTA_MAX; 262 goto yesno; 263 case _SC_DELAYTIMER_MAX: 264 mib[0] = CTL_P1003_1B; 265 mib[1] = CTL_P1003_1B_DELAYTIMER_MAX; 266 goto yesno; 267 case _SC_MQ_OPEN_MAX: 268 mib[0] = CTL_P1003_1B; 269 mib[1] = CTL_P1003_1B_MQ_OPEN_MAX; 270 goto yesno; 271 case _SC_PAGESIZE: 272 defaultresult = getpagesize(); 273 mib[0] = CTL_P1003_1B; 274 mib[1] = CTL_P1003_1B_PAGESIZE; 275 goto yesno; 276 case _SC_RTSIG_MAX: 277 mib[0] = CTL_P1003_1B; 278 mib[1] = CTL_P1003_1B_RTSIG_MAX; 279 goto yesno; 280 case _SC_SEM_NSEMS_MAX: 281 mib[0] = CTL_P1003_1B; 282 mib[1] = CTL_P1003_1B_SEM_NSEMS_MAX; 283 goto yesno; 284 case _SC_SEM_VALUE_MAX: 285 mib[0] = CTL_P1003_1B; 286 mib[1] = CTL_P1003_1B_SEM_VALUE_MAX; 287 goto yesno; 288 case _SC_SIGQUEUE_MAX: 289 mib[0] = CTL_P1003_1B; 290 mib[1] = CTL_P1003_1B_SIGQUEUE_MAX; 291 goto yesno; 292 case _SC_TIMER_MAX: 293 mib[0] = CTL_P1003_1B; 294 mib[1] = CTL_P1003_1B_TIMER_MAX; 295 296yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 297 return (-1); 298 if (value == 0) 299 return (defaultresult); 300 return (value); 301 302 case _SC_2_PBS: 303 case _SC_2_PBS_ACCOUNTING: 304 case _SC_2_PBS_CHECKPOINT: 305 case _SC_2_PBS_LOCATE: 306 case _SC_2_PBS_MESSAGE: 307 case _SC_2_PBS_TRACK: 308#if _POSIX2_PBS == 0 309#error "don't know how to determine _SC_2_PBS" 310 /* 311 * This probably requires digging through the filesystem 312 * to see if the appropriate package has been installed. 313 * Since we don't currently support this option at all, 314 * it's not worth the effort to write the code now. 315 * Figuring out which of the sub-options are supported 316 * would be even more difficult, so it's probably easier 317 * to always say ``no''. 318 */ 319#else 320 return (_POSIX2_PBS); 321#endif 322 case _SC_ADVISORY_INFO: 323#if _POSIX_ADVISORY_INFO == 0 324#error "_POSIX_ADVISORY_INFO" 325#else 326 return (_POSIX_ADVISORY_INFO); 327#endif 328 case _SC_BARRIERS: 329#if _POSIX_BARRIERS == 0 330#error "_POSIX_BARRIERS" 331#else 332 return (_POSIX_BARRIERS); 333#endif 334 case _SC_CLOCK_SELECTION: 335#if _POSIX_CLOCK_SELECTION == 0 336#error "_POSIX_CLOCK_SELECTION" 337#else 338 return (_POSIX_CLOCK_SELECTION); 339#endif 340 case _SC_CPUTIME: 341#if _POSIX_CPUTIME == 0 342#error "_POSIX_CPUTIME" 343#else 344 return (_POSIX_CPUTIME); 345#endif 346#ifdef notdef 347 case _SC_FILE_LOCKING: 348 /* 349 * XXX - The standard doesn't tell us how to define 350 * _POSIX_FILE_LOCKING, so we can't answer this one. 351 */ 352#endif 353#if _POSIX_THREAD_SAFE_FUNCTIONS > -1 354 case _SC_GETGR_R_SIZE_MAX: 355 case _SC_GETPW_R_SIZE_MAX: 356#error "somebody needs to implement this" 357#endif 358 case _SC_HOST_NAME_MAX: 359 return (MAXHOSTNAMELEN - 1); /* does not include \0 */ 360 case _SC_LOGIN_NAME_MAX: 361 return (MAXLOGNAME); 362 case _SC_MONOTONIC_CLOCK: 363#if _POSIX_MONOTONIC_CLOCK == 0 364#error "_POSIX_MONOTONIC_CLOCK" 365#else 366 return (_POSIX_MONOTONIC_CLOCK); 367#endif 368#if _POSIX_MESSAGE_PASSING > -1 369 case _SC_MQ_PRIO_MAX: 370 return (MQ_PRIO_MAX); 371#endif 372 case _SC_READER_WRITER_LOCKS: 373 return (_POSIX_READER_WRITER_LOCKS); 374 case _SC_REGEXP: 375 return (_POSIX_REGEXP); 376 case _SC_SHELL: 377 return (_POSIX_SHELL); 378 case _SC_SPAWN: 379 return (_POSIX_SPAWN); 380 case _SC_SPIN_LOCKS: 381 return (_POSIX_SPIN_LOCKS); 382 case _SC_SPORADIC_SERVER: 383#if _POSIX_SPORADIC_SERVER == 0 384#error "_POSIX_SPORADIC_SERVER" 385#else 386 return (_POSIX_SPORADIC_SERVER); 387#endif 388 case _SC_THREAD_ATTR_STACKADDR: 389 return (_POSIX_THREAD_ATTR_STACKADDR); 390 case _SC_THREAD_ATTR_STACKSIZE: 391 return (_POSIX_THREAD_ATTR_STACKSIZE); 392 case _SC_THREAD_CPUTIME: 393 return (_POSIX_THREAD_CPUTIME); 394 case _SC_THREAD_DESTRUCTOR_ITERATIONS: 395 return (PTHREAD_DESTRUCTOR_ITERATIONS); 396 case _SC_THREAD_KEYS_MAX: 397 return (PTHREAD_KEYS_MAX); 398 case _SC_THREAD_PRIO_INHERIT: 399 return (_POSIX_THREAD_PRIO_INHERIT); 400 case _SC_THREAD_PRIO_PROTECT: 401 return (_POSIX_THREAD_PRIO_PROTECT); 402 case _SC_THREAD_PRIORITY_SCHEDULING: 403 return (_POSIX_THREAD_PRIORITY_SCHEDULING); 404 case _SC_THREAD_PROCESS_SHARED: 405 return (_POSIX_THREAD_PROCESS_SHARED); 406 case _SC_THREAD_SAFE_FUNCTIONS: 407 return (_POSIX_THREAD_SAFE_FUNCTIONS); 408 case _SC_THREAD_STACK_MIN: 409 return (PTHREAD_STACK_MIN); 410 case _SC_THREAD_THREADS_MAX: 411 return (PTHREAD_THREADS_MAX); /* XXX wrong type! */ 412 case _SC_TIMEOUTS: 413 return (_POSIX_TIMEOUTS); 414 case _SC_THREADS: 415 return (_POSIX_THREADS); 416 case _SC_TRACE: 417#if _POSIX_TRACE == 0 418#error "_POSIX_TRACE" 419 /* While you're implementing this, also do the ones below. */ 420#else 421 return (_POSIX_TRACE); 422#endif 423#if _POSIX_TRACE > -1 424 case _SC_TRACE_EVENT_FILTER: 425 return (_POSIX_TRACE_EVENT_FILTER); 426 case _SC_TRACE_INHERIT: 427 return (_POSIX_TRACE_INHERIT); 428 case _SC_TRACE_LOG: 429 return (_POSIX_TRACE_LOG); 430#endif 431 case _SC_TTY_NAME_MAX: 432 path = _PATH_DEV; 433 goto do_NAME_MAX; 434 case _SC_TYPED_MEMORY_OBJECTS: 435#if _POSIX_TYPED_MEMORY_OBJECTS == 0 436#error "_POSIX_TYPED_MEMORY_OBJECTS" 437#else 438 return (_POSIX_TYPED_MEMORY_OBJECTS); 439#endif 440 case _SC_V6_ILP32_OFF32: 441#if _V6_ILP32_OFF32 == 0 442 if (sizeof(int) * CHAR_BIT == 32 && 443 sizeof(int) == sizeof(long) && 444 sizeof(long) == sizeof(void *) && 445 sizeof(void *) == sizeof(off_t)) 446 return 1; 447 else 448 return -1; 449#else 450 return (_V6_ILP32_OFF32); 451#endif 452 case _SC_V6_ILP32_OFFBIG: 453#if _V6_ILP32_OFFBIG == 0 454 if (sizeof(int) * CHAR_BIT == 32 && 455 sizeof(int) == sizeof(long) && 456 sizeof(long) == sizeof(void *) && 457 sizeof(off_t) * CHAR_BIT >= 64) 458 return 1; 459 else 460 return -1; 461#else 462 return (_V6_ILP32_OFFBIG); 463#endif 464 case _SC_V6_LP64_OFF64: 465#if _V6_LP64_OFF64 == 0 466 if (sizeof(int) * CHAR_BIT == 32 && 467 sizeof(long) * CHAR_BIT == 64 && 468 sizeof(long) == sizeof(void *) && 469 sizeof(void *) == sizeof(off_t)) 470 return 1; 471 else 472 return -1; 473#else 474 return (_V6_LP64_OFF64); 475#endif 476 case _SC_V6_LPBIG_OFFBIG: 477#if _V6_LPBIG_OFFBIG == 0 478 if (sizeof(int) * CHAR_BIT >= 32 && 479 sizeof(long) * CHAR_BIT >= 64 && 480 sizeof(void *) * CHAR_BIT >= 64 && 481 sizeof(off_t) * CHAR_BIT >= 64) 482 return 1; 483 else 484 return -1; 485#else 486 return (_V6_LPBIG_OFFBIG); 487#endif 488 case _SC_ATEXIT_MAX: 489 return (ATEXIT_SIZE); 490 case _SC_IOV_MAX: 491 mib[0] = CTL_KERN; 492 mib[1] = KERN_IOV_MAX; 493 break; 494 case _SC_XOPEN_CRYPT: 495 return (_XOPEN_CRYPT); 496 case _SC_XOPEN_ENH_I18N: 497 return (_XOPEN_ENH_I18N); 498 case _SC_XOPEN_LEGACY: 499 return (_XOPEN_LEGACY); 500 case _SC_XOPEN_REALTIME: 501#if _XOPEN_REALTIME == 0 502 sverrno = errno; 503 value = sysconf(_SC_ASYNCHRONOUS_IO) > 0 && 504 sysconf(_SC_MEMLOCK) > 0 && 505 sysconf(_SC_MEMLOCK_RANGE) > 0 && 506 sysconf(_SC_MESSAGE_PASSING) > 0 && 507 sysconf(_SC_PRIORITY_SCHEDULING) > 0 && 508 sysconf(_SC_REALTIME_SIGNALS) > 0 && 509 sysconf(_SC_SEMAPHORES) > 0 && 510 sysconf(_SC_SHARED_MEMORY_OBJECTS) > 0 && 511 sysconf(_SC_SYNCHRONIZED_IO) > 0 && 512 sysconf(_SC_TIMERS) > 0; 513 errno = sverrno; 514 if (value) 515 return (200112L); 516 else 517 return (-1); 518#else 519 return (_XOPEN_REALTIME); 520#endif 521 case _SC_XOPEN_REALTIME_THREADS: 522#if _XOPEN_REALTIME_THREADS == 0 523#error "_XOPEN_REALTIME_THREADS" 524#else 525 return (_XOPEN_REALTIME_THREADS); 526#endif 527 case _SC_XOPEN_SHM: 528 sverrno = errno; 529 if (sysctlbyname("kern.ipc.shmmin", &value, &len, NULL, 530 0) == -1) { 531 errno = sverrno; 532 return (-1); 533 } 534 errno = sverrno; 535 return (1); 536 case _SC_XOPEN_STREAMS: 537 return (_XOPEN_STREAMS); 538 case _SC_XOPEN_UNIX: 539 return (_XOPEN_UNIX); 540#ifdef _XOPEN_VERSION 541 case _SC_XOPEN_VERSION: 542 return (_XOPEN_VERSION); 543#endif 544#ifdef _XOPEN_XCU_VERSION 545 case _SC_XOPEN_XCU_VERSION: 546 return (_XOPEN_XCU_VERSION); 547#endif 548 549 case _SC_NPROCESSORS_CONF: 550 case _SC_NPROCESSORS_ONLN: 551 mib[0] = CTL_HW; 552 mib[1] = HW_NCPU; 553 break; 554 555 default: 556 errno = EINVAL; 557 return (-1); 558 } 559 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 560} 561