lib/libc/gen/sysconf.c

   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. 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  * @(#)sysconf.c        8.2 (Berkeley) 3/20/94
  33  * $FreeBSD: src/lib/libc/gen/sysconf.c,v 1.26 2008/02/27 05:56:57 wollman Exp $
  34  */
  35
  36 #include "namespace.h"
  37 #include <sys/param.h>
  38 #include <sys/time.h>
  39 #include <sys/sysctl.h>
  40 #include <sys/resource.h>
  41 #include <sys/socket.h>
  42
  43 #include <errno.h>
  44 #include <limits.h>
  45 #include <paths.h>
  46 #include <pthread.h>            /* we just need the limits */
  47 #include <semaphore.h>
  48 #include <time.h>
  49 #include <unistd.h>
  50 #include "un-namespace.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  */
  69 long
  70 sysconf(int name)
  71 {
  72         struct rlimit rl;
  73         size_t len;
  74         int mib[2], sverrno, value;
  75         long lvalue, defaultresult;
  76         const char *path;
  77
  78         defaultresult = -1;
  79
  80         switch (name) {
  81         case _SC_ARG_MAX:
  82                 mib[0] = CTL_KERN;
  83                 mib[1] = KERN_ARGMAX;
  84                 break;
  85         case _SC_CHILD_MAX:
  86                 if (getrlimit(RLIMIT_NPROC, &rl) != 0)
  87                         return (-1);
  88                 if (rl.rlim_cur == RLIM_INFINITY)
  89                         return (-1);
  90                 if (rl.rlim_cur > LONG_MAX) {
  91                         errno = EOVERFLOW;
  92                         return (-1);
  93                 }
  94                 return ((long)rl.rlim_cur);
  95         case _SC_CLK_TCK:
  96                 return (CLK_TCK);
  97         case _SC_NGROUPS_MAX:
  98                 mib[0] = CTL_KERN;
  99                 mib[1] = KERN_NGROUPS;
 100                 break;
 101         case _SC_OPEN_MAX:
 102                 if (getrlimit(RLIMIT_NOFILE, &rl) != 0)
 103                         return (-1);
 104                 if (rl.rlim_cur == RLIM_INFINITY)
 105                         return (-1);
 106                 if (rl.rlim_cur > LONG_MAX) {
 107                         errno = EOVERFLOW;
 108                         return (-1);
 109                 }
 110                 return ((long)rl.rlim_cur);
 111         case _SC_SEM_VALUE_MAX:
 112                 return (SEM_VALUE_MAX);
 113         case _SC_STREAM_MAX:
 114                 if (getrlimit(RLIMIT_NOFILE, &rl) != 0)
 115                         return (-1);
 116                 if (rl.rlim_cur == RLIM_INFINITY)
 117                         return (-1);
 118                 if (rl.rlim_cur > LONG_MAX) {
 119                         errno = EOVERFLOW;
 120                         return (-1);
 121                 }
 122                 /*
 123                  * struct __sFILE currently has a limitation that
 124                  * file descriptors must fit in a signed short.
 125                  * This doesn't precisely capture the letter of POSIX
 126                  * but approximates the spirit.
 127                  */
 128                 if (rl.rlim_cur > SHRT_MAX)
 129                         return (SHRT_MAX);
 130
 131                 return ((long)rl.rlim_cur);
 132         case _SC_JOB_CONTROL:
 133                 return (_POSIX_JOB_CONTROL);
 134         case _SC_SAVED_IDS:
 135                 /* XXX - must be 1 */
 136                 mib[0] = CTL_KERN;
 137                 mib[1] = KERN_SAVED_IDS;
 138                 goto yesno;
 139         case _SC_VERSION:
 140                 mib[0] = CTL_KERN;
 141                 mib[1] = KERN_POSIX1;
 142                 break;
 143         case _SC_BC_BASE_MAX:
 144                 return (BC_BASE_MAX);
 145         case _SC_BC_DIM_MAX:
 146                 return (BC_DIM_MAX);
 147         case _SC_BC_SCALE_MAX:
 148                 return (BC_SCALE_MAX);
 149         case _SC_BC_STRING_MAX:
 150                 return (BC_STRING_MAX);
 151         case _SC_COLL_WEIGHTS_MAX:
 152                 return (COLL_WEIGHTS_MAX);
 153         case _SC_EXPR_NEST_MAX:
 154                 return (EXPR_NEST_MAX);
 155         case _SC_LINE_MAX:
 156                 return (LINE_MAX);
 157         case _SC_RE_DUP_MAX:
 158                 return (RE_DUP_MAX);
 159         case _SC_2_VERSION:
 160                 /*
 161                  * This is something of a lie, but it would be silly at
 162                  * this point to try to deduce this from the contents
 163                  * of the filesystem.
 164                  */
 165                 return (_POSIX2_VERSION);
 166         case _SC_2_C_BIND:
 167                 return (_POSIX2_C_BIND);
 168         case _SC_2_C_DEV:
 169                 return (_POSIX2_C_DEV);
 170         case _SC_2_CHAR_TERM:
 171                 return (_POSIX2_CHAR_TERM);
 172         case _SC_2_FORT_DEV:
 173                 return (_POSIX2_FORT_DEV);
 174         case _SC_2_FORT_RUN:
 175                 return (_POSIX2_FORT_RUN);
 176         case _SC_2_LOCALEDEF:
 177                 return (_POSIX2_LOCALEDEF);
 178         case _SC_2_SW_DEV:
 179                 return (_POSIX2_SW_DEV);
 180         case _SC_2_UPE:
 181                 return (_POSIX2_UPE);
 182         case _SC_TZNAME_MAX:
 183                 path = _PATH_ZONEINFO;
 184 do_NAME_MAX:
 185                 sverrno = errno;
 186                 errno = 0;
 187                 lvalue = pathconf(path, _PC_NAME_MAX);
 188                 if (lvalue == -1 && errno != 0)
 189                         return (-1);
 190                 errno = sverrno;
 191                 return (lvalue);
 192
 193         case _SC_ASYNCHRONOUS_IO:
 194 #if _POSIX_ASYNCHRONOUS_IO == 0
 195                 mib[0] = CTL_P1003_1B;
 196                 mib[1] = CTL_P1003_1B_ASYNCHRONOUS_IO;
 197                 break;
 198 #else
 199                 return (_POSIX_ASYNCHRONOUS_IO);
 200 #endif
 201         case _SC_MAPPED_FILES:
 202                 return (_POSIX_MAPPED_FILES);
 203         case _SC_MEMLOCK:
 204                 return (_POSIX_MEMLOCK);
 205         case _SC_MEMLOCK_RANGE:
 206                 return (_POSIX_MEMLOCK_RANGE);
 207         case _SC_MEMORY_PROTECTION:
 208                 return (_POSIX_MEMORY_PROTECTION);
 209         case _SC_MESSAGE_PASSING:
 210                 return (_POSIX_MESSAGE_PASSING);
 211         case _SC_PRIORITIZED_IO:
 212 #if _POSIX_PRIORITIZED_IO == 0
 213                 mib[0] = CTL_P1003_1B;
 214                 mib[1] = CTL_P1003_1B_PRIORITIZED_IO;
 215                 goto yesno;
 216 #else
 217                 return (_POSIX_PRIORITIZED_IO);
 218 #endif
 219         case _SC_PRIORITY_SCHEDULING:
 220 #if _POSIX_PRIORITY_SCHEDULING == 0
 221                 mib[0] = CTL_P1003_1B;
 222                 mib[1] = CTL_P1003_1B_PRIORITY_SCHEDULING;
 223                 goto yesno;
 224 #else
 225                 return (_POSIX_PRIORITY_SCHEDULING);
 226 #endif
 227         case _SC_REALTIME_SIGNALS:
 228 #if _POSIX_REALTIME_SIGNALS == 0
 229                 mib[0] = CTL_P1003_1B;
 230                 mib[1] = CTL_P1003_1B_REALTIME_SIGNALS;
 231                 goto yesno;
 232 #else
 233                 return (_POSIX_REALTIME_SIGNALS);
 234 #endif
 235         case _SC_SEMAPHORES:
 236 #if _POSIX_SEMAPHORES == 0
 237                 mib[0] = CTL_P1003_1B;
 238                 mib[1] = CTL_P1003_1B_SEMAPHORES;
 239                 goto yesno;
 240 #else
 241                 return (_POSIX_SEMAPHORES);
 242 #endif
 243         case _SC_FSYNC:
 244                 return (_POSIX_FSYNC);
 245
 246         case _SC_SHARED_MEMORY_OBJECTS:
 247                 return (_POSIX_SHARED_MEMORY_OBJECTS);
 248         case _SC_SYNCHRONIZED_IO:
 249 #if _POSIX_SYNCHRONIZED_IO == 0
 250                 mib[0] = CTL_P1003_1B;
 251                 mib[1] = CTL_P1003_1B_SYNCHRONIZED_IO;
 252                 goto yesno;
 253 #else
 254                 return (_POSIX_SYNCHRONIZED_IO);
 255 #endif
 256         case _SC_TIMERS:
 257 #if _POSIX_TIMERS == 0
 258                 mib[0] = CTL_P1003_1B;
 259                 mib[1] = CTL_P1003_1B_TIMERS;
 260                 goto yesno;
 261 #else
 262                 return (_POSIX_TIMERS);
 263 #endif
 264         case _SC_AIO_LISTIO_MAX:
 265                 mib[0] = CTL_P1003_1B;
 266                 mib[1] = CTL_P1003_1B_AIO_LISTIO_MAX;
 267                 break;
 268         case _SC_AIO_MAX:
 269                 mib[0] = CTL_P1003_1B;
 270                 mib[1] = CTL_P1003_1B_AIO_MAX;
 271                 break;
 272         case _SC_AIO_PRIO_DELTA_MAX:
 273                 mib[0] = CTL_P1003_1B;
 274                 mib[1] = CTL_P1003_1B_AIO_PRIO_DELTA_MAX;
 275                 break;
 276         case _SC_DELAYTIMER_MAX:
 277                 mib[0] = CTL_P1003_1B;
 278                 mib[1] = CTL_P1003_1B_DELAYTIMER_MAX;
 279                 goto yesno;
 280         case _SC_PAGESIZE:
 281                 defaultresult = getpagesize();
 282                 mib[0] = CTL_P1003_1B;
 283                 mib[1] = CTL_P1003_1B_PAGESIZE;
 284                 goto yesno;
 285         case _SC_RTSIG_MAX:
 286                 mib[0] = CTL_P1003_1B;
 287                 mib[1] = CTL_P1003_1B_RTSIG_MAX;
 288                 goto yesno;
 289         case _SC_SEM_NSEMS_MAX:
 290                 mib[0] = CTL_P1003_1B;
 291                 mib[1] = CTL_P1003_1B_SEM_NSEMS_MAX;
 292                 goto yesno;
 293         case _SC_SIGQUEUE_MAX:
 294                 mib[0] = CTL_P1003_1B;
 295                 mib[1] = CTL_P1003_1B_SIGQUEUE_MAX;
 296                 goto yesno;
 297         case _SC_TIMER_MAX:
 298                 mib[0] = CTL_P1003_1B;
 299                 mib[1] = CTL_P1003_1B_TIMER_MAX;
 300 yesno:
 301                 len = sizeof(value);
 302                 if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 303                         return (-1);
 304                 if (value == 0)
 305                         return (defaultresult);
 306                 return ((long)value);
 307
 308         case _SC_2_PBS:
 309         case _SC_2_PBS_ACCOUNTING:
 310         case _SC_2_PBS_CHECKPOINT:
 311         case _SC_2_PBS_LOCATE:
 312         case _SC_2_PBS_MESSAGE:
 313         case _SC_2_PBS_TRACK:
 314 #if _POSIX2_PBS == 0
 315 #error "don't know how to determine _SC_2_PBS"
 316                 /*
 317                  * This probably requires digging through the filesystem
 318                  * to see if the appropriate package has been installed.
 319                  * Since we don't currently support this option at all,
 320                  * it's not worth the effort to write the code now.
 321                  * Figuring out which of the sub-options are supported
 322                  * would be even more difficult, so it's probably easier
 323                  * to always say ``no''.
 324                  */
 325 #else
 326                 return (_POSIX2_PBS);
 327 #endif
 328         case _SC_ADVISORY_INFO:
 329 #if _POSIX_ADVISORY_INFO == 0
 330 #error "_POSIX_ADVISORY_INFO"
 331 #else
 332                 return (_POSIX_ADVISORY_INFO);
 333 #endif
 334         case _SC_BARRIERS:
 335 #if _POSIX_BARRIERS == 0
 336 #error "_POSIX_BARRIERS"
 337 #else
 338                 return (_POSIX_BARRIERS);
 339 #endif
 340         case _SC_CLOCK_SELECTION:
 341 #if _POSIX_CLOCK_SELECTION == 0
 342 #error "_POSIX_CLOCK_SELECTION"
 343 #else
 344                 return (_POSIX_CLOCK_SELECTION);
 345 #endif
 346         case _SC_CPUTIME:
 347 #if _POSIX_CPUTIME == 0
 348 #error "_POSIX_CPUTIME"
 349 #else
 350                 return (_POSIX_CPUTIME);
 351 #endif
 352 #ifdef notdef
 353         case _SC_FILE_LOCKING:
 354                 /*
 355                  * XXX - The standard doesn't tell us how to define
 356                  * _POSIX_FILE_LOCKING, so we can't answer this one.
 357                  */
 358 #endif
 359         case _SC_GETGR_R_SIZE_MAX:
 360         case _SC_GETPW_R_SIZE_MAX:
 361                 return (-1);
 362         case _SC_HOST_NAME_MAX:
 363                 return (MAXHOSTNAMELEN - 1); /* does not include \0 */
 364         case _SC_LOGIN_NAME_MAX:
 365                 return (MAXLOGNAME);
 366         case _SC_MONOTONIC_CLOCK:
 367 #if _POSIX_MONOTONIC_CLOCK == 0
 368 #error "_POSIX_MONOTONIC_CLOCK"
 369 #else
 370                 return (_POSIX_MONOTONIC_CLOCK);
 371 #endif
 372         case _SC_MQ_OPEN_MAX:
 373                 len = sizeof(lvalue);
 374                 if (sysctlbyname("kern.mqueue.mq_open_max", &lvalue, &len,
 375                         NULL, 0) == -1)
 376                         return (-1);
 377                 return (lvalue);
 378
 379         case _SC_MQ_PRIO_MAX:
 380                 len = sizeof(lvalue);
 381                 if (sysctlbyname("kern.mqueue.mq_prio_max", &lvalue, &len,
 382                         NULL, 0) == -1)
 383                         return (-1);
 384                 return (lvalue);
 385
 386         case _SC_READER_WRITER_LOCKS:
 387                 return (_POSIX_READER_WRITER_LOCKS);
 388         case _SC_REGEXP:
 389                 return (_POSIX_REGEXP);
 390         case _SC_SHELL:
 391                 return (_POSIX_SHELL);
 392         case _SC_SPAWN:
 393                 return (_POSIX_SPAWN);
 394         case _SC_SPIN_LOCKS:
 395                 return (_POSIX_SPIN_LOCKS);
 396         case _SC_SPORADIC_SERVER:
 397 #if _POSIX_SPORADIC_SERVER == 0
 398 #error "_POSIX_SPORADIC_SERVER"
 399 #else
 400                 return (_POSIX_SPORADIC_SERVER);
 401 #endif
 402         case _SC_THREAD_ATTR_STACKADDR:
 403                 return (_POSIX_THREAD_ATTR_STACKADDR);
 404         case _SC_THREAD_ATTR_STACKSIZE:
 405                 return (_POSIX_THREAD_ATTR_STACKSIZE);
 406         case _SC_THREAD_CPUTIME:
 407                 return (_POSIX_THREAD_CPUTIME);
 408         case _SC_THREAD_DESTRUCTOR_ITERATIONS:
 409                 return (PTHREAD_DESTRUCTOR_ITERATIONS);
 410         case _SC_THREAD_KEYS_MAX:
 411                 return (PTHREAD_KEYS_MAX);
 412         case _SC_THREAD_PRIO_INHERIT:
 413                 return (_POSIX_THREAD_PRIO_INHERIT);
 414         case _SC_THREAD_PRIO_PROTECT:
 415                 return (_POSIX_THREAD_PRIO_PROTECT);
 416         case _SC_THREAD_PRIORITY_SCHEDULING:
 417                 return (_POSIX_THREAD_PRIORITY_SCHEDULING);
 418         case _SC_THREAD_PROCESS_SHARED:
 419                 return (_POSIX_THREAD_PROCESS_SHARED);
 420         case _SC_THREAD_ROBUST_PRIO_INHERIT:
 421                 return (_POSIX_THREAD_ROBUST_PRIO_INHERIT);
 422         case _SC_THREAD_ROBUST_PRIO_PROTECT:
 423                 return (_POSIX_THREAD_ROBUST_PRIO_PROTECT);
 424         case _SC_THREAD_SAFE_FUNCTIONS:
 425                 return (_POSIX_THREAD_SAFE_FUNCTIONS);
 426         case _SC_THREAD_SPORADIC_SERVER:
 427                 return (_POSIX_THREAD_SPORADIC_SERVER);
 428         case _SC_THREAD_STACK_MIN:
 429                 return (PTHREAD_STACK_MIN);
 430         case _SC_THREAD_THREADS_MAX:
 431                 return (PTHREAD_THREADS_MAX); /* XXX wrong type! */
 432         case _SC_TIMEOUTS:
 433                 return (_POSIX_TIMEOUTS);
 434         case _SC_THREADS:
 435                 return (_POSIX_THREADS);
 436         case _SC_TRACE:
 437 #if _POSIX_TRACE == 0
 438 #error "_POSIX_TRACE"
 439                 /* While you're implementing this, also do the ones below. */
 440 #else
 441                 return (_POSIX_TRACE);
 442 #endif
 443 #if _POSIX_TRACE > -1
 444         case _SC_TRACE_EVENT_FILTER:
 445                 return (_POSIX_TRACE_EVENT_FILTER);
 446         case _SC_TRACE_INHERIT:
 447                 return (_POSIX_TRACE_INHERIT);
 448         case _SC_TRACE_LOG:
 449                 return (_POSIX_TRACE_LOG);
 450 #endif
 451         case _SC_TTY_NAME_MAX:
 452                 path = _PATH_DEV;
 453                 goto do_NAME_MAX;
 454         case _SC_TYPED_MEMORY_OBJECTS:
 455 #if _POSIX_TYPED_MEMORY_OBJECTS == 0
 456 #error "_POSIX_TYPED_MEMORY_OBJECTS"
 457 #else
 458                 return (_POSIX_TYPED_MEMORY_OBJECTS);
 459 #endif
 460         case _SC_V6_ILP32_OFF32:
 461 #if _V6_ILP32_OFF32 == 0
 462                 if (sizeof(int) * CHAR_BIT == 32 &&
 463                     sizeof(int) == sizeof(long) &&
 464                     sizeof(long) == sizeof(void *) &&
 465                     sizeof(void *) == sizeof(off_t))
 466                         return 1;
 467                 else
 468                         return -1;
 469 #else
 470                 return (_V6_ILP32_OFF32);
 471 #endif
 472         case _SC_V6_ILP32_OFFBIG:
 473 #if _V6_ILP32_OFFBIG == 0
 474                 if (sizeof(int) * CHAR_BIT == 32 &&
 475                     sizeof(int) == sizeof(long) &&
 476                     sizeof(long) == sizeof(void *) &&
 477                     sizeof(off_t) * CHAR_BIT >= 64)
 478                         return 1;
 479                 else
 480                         return -1;
 481 #else
 482                 return (_V6_ILP32_OFFBIG);
 483 #endif
 484         case _SC_V6_LP64_OFF64:
 485 #if _V6_LP64_OFF64 == 0
 486                 if (sizeof(int) * CHAR_BIT == 32 &&
 487                     sizeof(long) * CHAR_BIT == 64 &&
 488                     sizeof(long) == sizeof(void *) &&
 489                     sizeof(void *) == sizeof(off_t))
 490                         return 1;
 491                 else
 492                         return -1;
 493 #else
 494                 return (_V6_LP64_OFF64);
 495 #endif
 496         case _SC_V6_LPBIG_OFFBIG:
 497 #if _V6_LPBIG_OFFBIG == 0
 498                 if (sizeof(int) * CHAR_BIT >= 32 &&
 499                     sizeof(long) * CHAR_BIT >= 64 &&
 500                     sizeof(void *) * CHAR_BIT >= 64 &&
 501                     sizeof(off_t) * CHAR_BIT >= 64)
 502                         return 1;
 503                 else
 504                         return -1;
 505 #else
 506                 return (_V6_LPBIG_OFFBIG);
 507 #endif
 508         case _SC_V7_ILP32_OFF32:
 509 #if _V7_ILP32_OFF32 == 0
 510                 if (sizeof(int) * CHAR_BIT == 32 &&
 511                     sizeof(int) == sizeof(long) &&
 512                     sizeof(long) == sizeof(void *) &&
 513                     sizeof(void *) == sizeof(off_t))
 514                         return 1;
 515                 else
 516                         return -1;
 517 #else
 518                 return (_V7_ILP32_OFF32);
 519 #endif
 520         case _SC_V7_ILP32_OFFBIG:
 521 #if _V7_ILP32_OFFBIG == 0
 522                 if (sizeof(int) * CHAR_BIT == 32 &&
 523                     sizeof(int) == sizeof(long) &&
 524                     sizeof(long) == sizeof(void *) &&
 525                     sizeof(off_t) * CHAR_BIT >= 64)
 526                         return 1;
 527                 else
 528                         return -1;
 529 #else
 530                 return (_V7_ILP32_OFFBIG);
 531 #endif
 532         case _SC_V7_LP64_OFF64:
 533 #if _V7_LP64_OFF64 == 0
 534                 if (sizeof(int) * CHAR_BIT == 32 &&
 535                     sizeof(long) * CHAR_BIT == 64 &&
 536                     sizeof(long) == sizeof(void *) &&
 537                     sizeof(void *) == sizeof(off_t))
 538                         return 1;
 539                 else
 540                         return -1;
 541 #else
 542                 return (_V7_LP64_OFF64);
 543 #endif
 544         case _SC_V7_LPBIG_OFFBIG:
 545 #if _V7_LPBIG_OFFBIG == 0
 546                 if (sizeof(int) * CHAR_BIT >= 32 &&
 547                     sizeof(long) * CHAR_BIT >= 64 &&
 548                     sizeof(void *) * CHAR_BIT >= 64 &&
 549                     sizeof(off_t) * CHAR_BIT >= 64)
 550                         return 1;
 551                 else
 552                         return -1;
 553 #else
 554                 return (_V7_LPBIG_OFFBIG);
 555 #endif
 556         case _SC_ATEXIT_MAX:
 557                 return (ATEXIT_SIZE);
 558         case _SC_IOV_MAX:
 559                 mib[0] = CTL_KERN;
 560                 mib[1] = KERN_IOV_MAX;
 561                 break;
 562         case _SC_XOPEN_CRYPT:
 563                 return (_XOPEN_CRYPT);
 564         case _SC_XOPEN_ENH_I18N:
 565                 return (_XOPEN_ENH_I18N);
 566         case _SC_XOPEN_LEGACY:
 567                 return (_XOPEN_LEGACY);
 568         case _SC_XOPEN_REALTIME:
 569 #if _XOPEN_REALTIME == 0
 570                 sverrno = errno;
 571                 value = sysconf(_SC_ASYNCHRONOUS_IO) > 0 &&
 572                         sysconf(_SC_MEMLOCK) > 0 &&
 573                         sysconf(_SC_MEMLOCK_RANGE) > 0 &&
 574                         sysconf(_SC_MESSAGE_PASSING) > 0 &&
 575                         sysconf(_SC_PRIORITY_SCHEDULING) > 0 &&
 576                         sysconf(_SC_REALTIME_SIGNALS) > 0 &&
 577                         sysconf(_SC_SEMAPHORES) > 0 &&
 578                         sysconf(_SC_SHARED_MEMORY_OBJECTS) > 0 &&
 579                         sysconf(_SC_SYNCHRONIZED_IO) > 0 &&
 580                         sysconf(_SC_TIMERS) > 0;
 581                 errno = sverrno;
 582                 if (value)
 583                         return (200112L);
 584                 else
 585                         return (-1);
 586 #else
 587                 return (_XOPEN_REALTIME);
 588 #endif
 589         case _SC_XOPEN_REALTIME_THREADS:
 590 #if _XOPEN_REALTIME_THREADS == 0
 591 #error "_XOPEN_REALTIME_THREADS"
 592 #else
 593                 return (_XOPEN_REALTIME_THREADS);
 594 #endif
 595         case _SC_XOPEN_SHM:
 596                 return (_XOPEN_SHM);
 597         case _SC_XOPEN_STREAMS:
 598                 return (_XOPEN_STREAMS);
 599         case _SC_XOPEN_UNIX:
 600                 return (_XOPEN_UNIX);
 601 #ifdef _XOPEN_VERSION
 602         case _SC_XOPEN_VERSION:
 603                 return (_XOPEN_VERSION);
 604 #endif
 605 #ifdef _XOPEN_XCU_VERSION
 606         case _SC_XOPEN_XCU_VERSION:
 607                 return (_XOPEN_XCU_VERSION);
 608 #endif
 609         case _SC_SYMLOOP_MAX:
 610                 return (MAXSYMLINKS);
 611         case _SC_RAW_SOCKETS:
 612                 return (_POSIX_RAW_SOCKETS);
 613         case _SC_IPV6:
 614 #if _POSIX_IPV6 == 0
 615                 sverrno = errno;
 616                 value = _socket(PF_INET6, SOCK_DGRAM, 0);
 617                 errno = sverrno;
 618                 if (value >= 0) {
 619                         _close(value);
 620                         return (200112L);
 621                 } else
 622                         return (0);
 623 #else
 624                 return (_POSIX_IPV6);
 625 #endif
 626
 627         case _SC_NPROCESSORS_CONF:
 628         case _SC_NPROCESSORS_ONLN:
 629                 mib[0] = CTL_HW;
 630                 mib[1] = HW_NCPU;
 631                 break;
 632
 633 #ifdef _SC_PHYS_PAGES
 634         case _SC_PHYS_PAGES:
 635                 len = sizeof(lvalue);
 636                 if (sysctlbyname("hw.availpages", &lvalue, &len, NULL, 0) == -1)
 637                         return (-1);
 638                 return (lvalue);
 639 #endif
 640
 641         case _SC_LEVEL1_DCACHE_LINESIZE:
 642                 return (__VM_CACHELINE_SIZE);
 643
 644         default:
 645                 errno = EINVAL;
 646                 return (-1);
 647         }
 648         len = sizeof(value);
 649         if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 650                 value = -1;
 651         return ((long)value);
 652 }