sysconf.c revision 168718
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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94"; 35#endif /* LIBC_SCCS and not lint */ 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: head/lib/libc/gen/sysconf.c 168718 2007-04-14 13:06:57Z pjd $"); 38 39#include <sys/param.h> 40#include <sys/time.h> 41#include <sys/sysctl.h> 42#include <sys/resource.h> 43#include <sys/socket.h> 44 45#include <errno.h> 46#include <limits.h> 47#include <paths.h> 48#include <pthread.h> /* we just need the limits */ 49#include <time.h> 50#include <unistd.h> 51 52#include "../stdlib/atexit.h" 53#include "../stdtime/tzfile.h" 54 55#define _PATH_ZONEINFO TZDIR /* from tzfile.h */ 56 57/* 58 * sysconf -- 59 * get configurable system variables. 60 * 61 * XXX 62 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 63 * not change during the lifetime of the calling process. This would seem 64 * to require that any change to system limits kill all running processes. 65 * A workaround might be to cache the values when they are first retrieved 66 * and then simply return the cached value on subsequent calls. This is 67 * less useful than returning up-to-date values, however. 68 */ 69long 70sysconf(name) 71 int name; 72{ 73 struct rlimit rl; 74 size_t len; 75 int mib[2], sverrno, value; 76 long lvalue, defaultresult; 77 const char *path; 78 79 defaultresult = -1; 80 81 switch (name) { 82 case _SC_ARG_MAX: 83 mib[0] = CTL_KERN; 84 mib[1] = KERN_ARGMAX; 85 break; 86 case _SC_CHILD_MAX: 87 if (getrlimit(RLIMIT_NPROC, &rl) != 0) 88 return (-1); 89 if (rl.rlim_cur == RLIM_INFINITY) 90 return (-1); 91 if (rl.rlim_cur > LONG_MAX) { 92 errno = EOVERFLOW; 93 return (-1); 94 } 95 return ((long)rl.rlim_cur); 96 case _SC_CLK_TCK: 97 return (CLK_TCK); 98 case _SC_NGROUPS_MAX: 99 mib[0] = CTL_KERN; 100 mib[1] = KERN_NGROUPS; 101 break; 102 case _SC_OPEN_MAX: 103 case _SC_STREAM_MAX: /* assume fds run out before memory does */ 104 if (getrlimit(RLIMIT_NOFILE, &rl) != 0) 105 return (-1); 106 if (rl.rlim_cur == RLIM_INFINITY) 107 return (-1); 108 if (rl.rlim_cur > LONG_MAX) { 109 errno = EOVERFLOW; 110 return (-1); 111 } 112 return ((long)rl.rlim_cur); 113 case _SC_JOB_CONTROL: 114 return (_POSIX_JOB_CONTROL); 115 case _SC_SAVED_IDS: 116 /* XXX - must be 1 */ 117 mib[0] = CTL_KERN; 118 mib[1] = KERN_SAVED_IDS; 119 goto yesno; 120 case _SC_VERSION: 121 mib[0] = CTL_KERN; 122 mib[1] = KERN_POSIX1; 123 break; 124 case _SC_BC_BASE_MAX: 125 return (BC_BASE_MAX); 126 case _SC_BC_DIM_MAX: 127 return (BC_DIM_MAX); 128 case _SC_BC_SCALE_MAX: 129 return (BC_SCALE_MAX); 130 case _SC_BC_STRING_MAX: 131 return (BC_STRING_MAX); 132 case _SC_COLL_WEIGHTS_MAX: 133 return (COLL_WEIGHTS_MAX); 134 case _SC_EXPR_NEST_MAX: 135 return (EXPR_NEST_MAX); 136 case _SC_LINE_MAX: 137 return (LINE_MAX); 138 case _SC_RE_DUP_MAX: 139 return (RE_DUP_MAX); 140 case _SC_2_VERSION: 141 /* 142 * This is something of a lie, but it would be silly at 143 * this point to try to deduce this from the contents 144 * of the filesystem. 145 */ 146 return (_POSIX2_VERSION); 147 case _SC_2_C_BIND: 148 return (_POSIX2_C_BIND); 149 case _SC_2_C_DEV: 150 return (_POSIX2_C_DEV); 151 case _SC_2_CHAR_TERM: 152 return (_POSIX2_CHAR_TERM); 153 case _SC_2_FORT_DEV: 154 return (_POSIX2_FORT_DEV); 155 case _SC_2_FORT_RUN: 156 return (_POSIX2_FORT_RUN); 157 case _SC_2_LOCALEDEF: 158 return (_POSIX2_LOCALEDEF); 159 case _SC_2_SW_DEV: 160 return (_POSIX2_SW_DEV); 161 case _SC_2_UPE: 162 return (_POSIX2_UPE); 163 case _SC_TZNAME_MAX: 164 path = _PATH_ZONEINFO; 165do_NAME_MAX: 166 sverrno = errno; 167 errno = 0; 168 lvalue = pathconf(path, _PC_NAME_MAX); 169 if (lvalue == -1 && errno != 0) 170 return (-1); 171 errno = sverrno; 172 return (lvalue); 173 174 case _SC_ASYNCHRONOUS_IO: 175#if _POSIX_ASYNCHRONOUS_IO == 0 176 mib[0] = CTL_P1003_1B; 177 mib[1] = CTL_P1003_1B_ASYNCHRONOUS_IO; 178 break; 179#else 180 return (_POSIX_ASYNCHRONOUS_IO); 181#endif 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 break; 255 case _SC_AIO_MAX: 256 mib[0] = CTL_P1003_1B; 257 mib[1] = CTL_P1003_1B_AIO_MAX; 258 break; 259 case _SC_AIO_PRIO_DELTA_MAX: 260 mib[0] = CTL_P1003_1B; 261 mib[1] = CTL_P1003_1B_AIO_PRIO_DELTA_MAX; 262 break; 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; 295yesno: 296 len = sizeof(value); 297 if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 298 return (-1); 299 if (value == 0) 300 return (defaultresult); 301 return ((long)value); 302 303 case _SC_2_PBS: 304 case _SC_2_PBS_ACCOUNTING: 305 case _SC_2_PBS_CHECKPOINT: 306 case _SC_2_PBS_LOCATE: 307 case _SC_2_PBS_MESSAGE: 308 case _SC_2_PBS_TRACK: 309#if _POSIX2_PBS == 0 310#error "don't know how to determine _SC_2_PBS" 311 /* 312 * This probably requires digging through the filesystem 313 * to see if the appropriate package has been installed. 314 * Since we don't currently support this option at all, 315 * it's not worth the effort to write the code now. 316 * Figuring out which of the sub-options are supported 317 * would be even more difficult, so it's probably easier 318 * to always say ``no''. 319 */ 320#else 321 return (_POSIX2_PBS); 322#endif 323 case _SC_ADVISORY_INFO: 324#if _POSIX_ADVISORY_INFO == 0 325#error "_POSIX_ADVISORY_INFO" 326#else 327 return (_POSIX_ADVISORY_INFO); 328#endif 329 case _SC_BARRIERS: 330#if _POSIX_BARRIERS == 0 331#error "_POSIX_BARRIERS" 332#else 333 return (_POSIX_BARRIERS); 334#endif 335 case _SC_CLOCK_SELECTION: 336#if _POSIX_CLOCK_SELECTION == 0 337#error "_POSIX_CLOCK_SELECTION" 338#else 339 return (_POSIX_CLOCK_SELECTION); 340#endif 341 case _SC_CPUTIME: 342#if _POSIX_CPUTIME == 0 343#error "_POSIX_CPUTIME" 344#else 345 return (_POSIX_CPUTIME); 346#endif 347#ifdef notdef 348 case _SC_FILE_LOCKING: 349 /* 350 * XXX - The standard doesn't tell us how to define 351 * _POSIX_FILE_LOCKING, so we can't answer this one. 352 */ 353#endif 354#if _POSIX_THREAD_SAFE_FUNCTIONS > -1 355 case _SC_GETGR_R_SIZE_MAX: 356 case _SC_GETPW_R_SIZE_MAX: 357#error "somebody needs to implement this" 358#endif 359 case _SC_HOST_NAME_MAX: 360 return (MAXHOSTNAMELEN - 1); /* does not include \0 */ 361 case _SC_LOGIN_NAME_MAX: 362 return (MAXLOGNAME); 363 case _SC_MONOTONIC_CLOCK: 364#if _POSIX_MONOTONIC_CLOCK == 0 365#error "_POSIX_MONOTONIC_CLOCK" 366#else 367 return (_POSIX_MONOTONIC_CLOCK); 368#endif 369#if _POSIX_MESSAGE_PASSING > -1 370 case _SC_MQ_PRIO_MAX: 371 return (MQ_PRIO_MAX); 372#endif 373 case _SC_READER_WRITER_LOCKS: 374 return (_POSIX_READER_WRITER_LOCKS); 375 case _SC_REGEXP: 376 return (_POSIX_REGEXP); 377 case _SC_SHELL: 378 return (_POSIX_SHELL); 379 case _SC_SPAWN: 380 return (_POSIX_SPAWN); 381 case _SC_SPIN_LOCKS: 382 return (_POSIX_SPIN_LOCKS); 383 case _SC_SPORADIC_SERVER: 384#if _POSIX_SPORADIC_SERVER == 0 385#error "_POSIX_SPORADIC_SERVER" 386#else 387 return (_POSIX_SPORADIC_SERVER); 388#endif 389 case _SC_THREAD_ATTR_STACKADDR: 390 return (_POSIX_THREAD_ATTR_STACKADDR); 391 case _SC_THREAD_ATTR_STACKSIZE: 392 return (_POSIX_THREAD_ATTR_STACKSIZE); 393 case _SC_THREAD_CPUTIME: 394 return (_POSIX_THREAD_CPUTIME); 395 case _SC_THREAD_DESTRUCTOR_ITERATIONS: 396 return (PTHREAD_DESTRUCTOR_ITERATIONS); 397 case _SC_THREAD_KEYS_MAX: 398 return (PTHREAD_KEYS_MAX); 399 case _SC_THREAD_PRIO_INHERIT: 400 return (_POSIX_THREAD_PRIO_INHERIT); 401 case _SC_THREAD_PRIO_PROTECT: 402 return (_POSIX_THREAD_PRIO_PROTECT); 403 case _SC_THREAD_PRIORITY_SCHEDULING: 404 return (_POSIX_THREAD_PRIORITY_SCHEDULING); 405 case _SC_THREAD_PROCESS_SHARED: 406 return (_POSIX_THREAD_PROCESS_SHARED); 407 case _SC_THREAD_SAFE_FUNCTIONS: 408 return (_POSIX_THREAD_SAFE_FUNCTIONS); 409 case _SC_THREAD_STACK_MIN: 410 return (PTHREAD_STACK_MIN); 411 case _SC_THREAD_THREADS_MAX: 412 return (PTHREAD_THREADS_MAX); /* XXX wrong type! */ 413 case _SC_TIMEOUTS: 414 return (_POSIX_TIMEOUTS); 415 case _SC_THREADS: 416 return (_POSIX_THREADS); 417 case _SC_TRACE: 418#if _POSIX_TRACE == 0 419#error "_POSIX_TRACE" 420 /* While you're implementing this, also do the ones below. */ 421#else 422 return (_POSIX_TRACE); 423#endif 424#if _POSIX_TRACE > -1 425 case _SC_TRACE_EVENT_FILTER: 426 return (_POSIX_TRACE_EVENT_FILTER); 427 case _SC_TRACE_INHERIT: 428 return (_POSIX_TRACE_INHERIT); 429 case _SC_TRACE_LOG: 430 return (_POSIX_TRACE_LOG); 431#endif 432 case _SC_TTY_NAME_MAX: 433 path = _PATH_DEV; 434 goto do_NAME_MAX; 435 case _SC_TYPED_MEMORY_OBJECTS: 436#if _POSIX_TYPED_MEMORY_OBJECTS == 0 437#error "_POSIX_TYPED_MEMORY_OBJECTS" 438#else 439 return (_POSIX_TYPED_MEMORY_OBJECTS); 440#endif 441 case _SC_V6_ILP32_OFF32: 442#if _V6_ILP32_OFF32 == 0 443 if (sizeof(int) * CHAR_BIT == 32 && 444 sizeof(int) == sizeof(long) && 445 sizeof(long) == sizeof(void *) && 446 sizeof(void *) == sizeof(off_t)) 447 return 1; 448 else 449 return -1; 450#else 451 return (_V6_ILP32_OFF32); 452#endif 453 case _SC_V6_ILP32_OFFBIG: 454#if _V6_ILP32_OFFBIG == 0 455 if (sizeof(int) * CHAR_BIT == 32 && 456 sizeof(int) == sizeof(long) && 457 sizeof(long) == sizeof(void *) && 458 sizeof(off_t) * CHAR_BIT >= 64) 459 return 1; 460 else 461 return -1; 462#else 463 return (_V6_ILP32_OFFBIG); 464#endif 465 case _SC_V6_LP64_OFF64: 466#if _V6_LP64_OFF64 == 0 467 if (sizeof(int) * CHAR_BIT == 32 && 468 sizeof(long) * CHAR_BIT == 64 && 469 sizeof(long) == sizeof(void *) && 470 sizeof(void *) == sizeof(off_t)) 471 return 1; 472 else 473 return -1; 474#else 475 return (_V6_LP64_OFF64); 476#endif 477 case _SC_V6_LPBIG_OFFBIG: 478#if _V6_LPBIG_OFFBIG == 0 479 if (sizeof(int) * CHAR_BIT >= 32 && 480 sizeof(long) * CHAR_BIT >= 64 && 481 sizeof(void *) * CHAR_BIT >= 64 && 482 sizeof(off_t) * CHAR_BIT >= 64) 483 return 1; 484 else 485 return -1; 486#else 487 return (_V6_LPBIG_OFFBIG); 488#endif 489 case _SC_ATEXIT_MAX: 490 return (ATEXIT_SIZE); 491 case _SC_IOV_MAX: 492 mib[0] = CTL_KERN; 493 mib[1] = KERN_IOV_MAX; 494 break; 495 case _SC_XOPEN_CRYPT: 496 return (_XOPEN_CRYPT); 497 case _SC_XOPEN_ENH_I18N: 498 return (_XOPEN_ENH_I18N); 499 case _SC_XOPEN_LEGACY: 500 return (_XOPEN_LEGACY); 501 case _SC_XOPEN_REALTIME: 502#if _XOPEN_REALTIME == 0 503 sverrno = errno; 504 value = sysconf(_SC_ASYNCHRONOUS_IO) > 0 && 505 sysconf(_SC_MEMLOCK) > 0 && 506 sysconf(_SC_MEMLOCK_RANGE) > 0 && 507 sysconf(_SC_MESSAGE_PASSING) > 0 && 508 sysconf(_SC_PRIORITY_SCHEDULING) > 0 && 509 sysconf(_SC_REALTIME_SIGNALS) > 0 && 510 sysconf(_SC_SEMAPHORES) > 0 && 511 sysconf(_SC_SHARED_MEMORY_OBJECTS) > 0 && 512 sysconf(_SC_SYNCHRONIZED_IO) > 0 && 513 sysconf(_SC_TIMERS) > 0; 514 errno = sverrno; 515 if (value) 516 return (200112L); 517 else 518 return (-1); 519#else 520 return (_XOPEN_REALTIME); 521#endif 522 case _SC_XOPEN_REALTIME_THREADS: 523#if _XOPEN_REALTIME_THREADS == 0 524#error "_XOPEN_REALTIME_THREADS" 525#else 526 return (_XOPEN_REALTIME_THREADS); 527#endif 528 case _SC_XOPEN_SHM: 529 len = sizeof(lvalue); 530 sverrno = errno; 531 if (sysctlbyname("kern.ipc.shmmin", &lvalue, &len, NULL, 532 0) == -1) { 533 errno = sverrno; 534 return (-1); 535 } 536 errno = sverrno; 537 return (1); 538 case _SC_XOPEN_STREAMS: 539 return (_XOPEN_STREAMS); 540 case _SC_XOPEN_UNIX: 541 return (_XOPEN_UNIX); 542#ifdef _XOPEN_VERSION 543 case _SC_XOPEN_VERSION: 544 return (_XOPEN_VERSION); 545#endif 546#ifdef _XOPEN_XCU_VERSION 547 case _SC_XOPEN_XCU_VERSION: 548 return (_XOPEN_XCU_VERSION); 549#endif 550 case _SC_SYMLOOP_MAX: 551 return (MAXSYMLINKS); 552 case _SC_RAW_SOCKETS: 553 return (_POSIX_RAW_SOCKETS); 554 case _SC_IPV6: 555#if _POSIX_IPV6 == 0 556 sverrno = errno; 557 value = socket(PF_INET6, SOCK_DGRAM, 0); 558 errno = sverrno; 559 if (value >= 0) { 560 close(value); 561 return (200112L); 562 } else 563 return (0); 564#else 565 return (_POSIX_IPV6); 566#endif 567 568 case _SC_NPROCESSORS_CONF: 569 case _SC_NPROCESSORS_ONLN: 570 mib[0] = CTL_HW; 571 mib[1] = HW_NCPU; 572 break; 573 574#ifdef _SC_PHYS_PAGES 575 case _SC_PHYS_PAGES: 576 len = sizeof(lvalue); 577 if (sysctlbyname("hw.availpages", &lvalue, &len, NULL, 0) == -1) 578 return (-1); 579 return (lvalue); 580#endif 581 582 default: 583 errno = EINVAL; 584 return (-1); 585 } 586 len = sizeof(value); 587 if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 588 value = -1; 589 return ((long)value); 590} 591