gen/FreeBSD/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  * 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)
  34 static 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: lib/libc/gen/sysconf.c r168718 $");
  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 #include <sys/aio.h>
  45 #include <sys/semaphore.h>
  46
  47 #include <errno.h>
  48 #include <limits.h>
  49 #include <paths.h>
  50 #include <pthread.h>            /* we just need the limits */
  51 #include <time.h>
  52 #include <unistd.h>
  53
  54 #include "../../stdlib/FreeBSD/atexit.h"
  55 #include "../../stdtime/FreeBSD/tzfile.h"
  56
  57 #define _PATH_ZONEINFO  TZDIR   /* from tzfile.h */
  58
  59 /*
  60  * sysconf --
  61  *      get configurable system variables.
  62  *
  63  * XXX
  64  * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
  65  * not change during the lifetime of the calling process.  This would seem
  66  * to require that any change to system limits kill all running processes.
  67  * A workaround might be to cache the values when they are first retrieved
  68  * and then simply return the cached value on subsequent calls.  This is
  69  * less useful than returning up-to-date values, however.
  70  */
  71 long
  72 sysconf(name)
  73         int name;
  74 {
  75         struct rlimit rl;
  76         quad_t qdvalue; /* for kern.sysv.shmmin */
  77         size_t len;
  78         int mib[3], sverrno, value;
  79         long lvalue, defaultresult;
  80         const char *path;
  81
  82         defaultresult = -1;
  83
  84         switch (name) {
  85         case _SC_ARG_MAX:
  86                 mib[0] = CTL_KERN;
  87                 mib[1] = KERN_ARGMAX;
  88                 break;
  89         case _SC_CHILD_MAX:
  90                 if (getrlimit(RLIMIT_NPROC, &rl) != 0)
  91                         return (-1);
  92                 if (rl.rlim_cur == RLIM_INFINITY)
  93                         return (-1);
  94                 if (rl.rlim_cur > LONG_MAX) {
  95                         errno = EOVERFLOW;
  96                         return (-1);
  97                 }
  98                 return ((long)rl.rlim_cur);
  99         case _SC_CLK_TCK:
 100                 return (CLK_TCK);
 101         case _SC_NGROUPS_MAX:
 102                 mib[0] = CTL_KERN;
 103                 mib[1] = KERN_NGROUPS;
 104                 break;
 105         case _SC_OPEN_MAX:
 106         case _SC_STREAM_MAX:    /* assume fds run out before memory does */
 107                 if (getrlimit(RLIMIT_NOFILE, &rl) != 0)
 108                         return (-1);
 109 #if __LP64__
 110                 /*
 111                  * In 64 bit world, sysconf is able to correctly represent
 112                  * rlim_t values (8 bytes).
 113                  */
 114                 if (rl.rlim_cur > RLIM_INFINITY)
 115                         return (-1);
 116                 if (rl.rlim_cur > LONG_MAX) {
 117                         errno = EOVERFLOW;
 118                         return (-1);
 119                 }
 120                 lvalue = rl.rlim_cur;
 121 #else
 122                 /*
 123                  * In 32 bit world (watches), sysconf falls back to the
 124                  * old behavior: use (int) OPEN_MAX as max limit.  Ideally
 125                  * we would use maxfilesperproc as max limit, which is a
 126                  * system value adjusted by the kernel based on available
 127                  * RAM size. This value defaults to OPEN_MAX for systems
 128                  * with less than 8G of RAM.  So we use OPEN_MAX (defined
 129                  * in sys/syslimits.h) as max limit here in case
 130                  * applications with strict sandbox rules prevent libc
 131                  * from reading maxfilesperproc via sysctl.
 132                  */
 133                 if (rl.rlim_cur > OPEN_MAX)
 134                         lvalue = OPEN_MAX;
 135                 else
 136                         lvalue = (long)rl.rlim_cur;
 137 #endif
 138                 return lvalue;
 139         case _SC_JOB_CONTROL:
 140                 return (_POSIX_JOB_CONTROL);
 141         case _SC_SAVED_IDS:
 142                 /* XXX - must be 1 */
 143                 mib[0] = CTL_KERN;
 144                 mib[1] = KERN_SAVED_IDS;
 145                 goto yesno;
 146         case _SC_VERSION:
 147                 mib[0] = CTL_KERN;
 148                 mib[1] = KERN_POSIX1;
 149                 break;
 150         case _SC_BC_BASE_MAX:
 151                 return (BC_BASE_MAX);
 152         case _SC_BC_DIM_MAX:
 153                 return (BC_DIM_MAX);
 154         case _SC_BC_SCALE_MAX:
 155                 return (BC_SCALE_MAX);
 156         case _SC_BC_STRING_MAX:
 157                 return (BC_STRING_MAX);
 158         case _SC_COLL_WEIGHTS_MAX:
 159                 return (COLL_WEIGHTS_MAX);
 160         case _SC_EXPR_NEST_MAX:
 161                 return (EXPR_NEST_MAX);
 162         case _SC_LINE_MAX:
 163                 return (LINE_MAX);
 164         case _SC_RE_DUP_MAX:
 165                 return (RE_DUP_MAX);
 166         case _SC_2_VERSION:
 167                 /*
 168                  * This is something of a lie, but it would be silly at
 169                  * this point to try to deduce this from the contents
 170                  * of the filesystem.
 171                  */
 172                 return (_POSIX2_VERSION);
 173         case _SC_2_C_BIND:
 174                 return (_POSIX2_C_BIND);
 175         case _SC_2_C_DEV:
 176                 return (_POSIX2_C_DEV);
 177         case _SC_2_CHAR_TERM:
 178                 return (_POSIX2_CHAR_TERM);
 179         case _SC_2_FORT_DEV:
 180                 return (_POSIX2_FORT_DEV);
 181         case _SC_2_FORT_RUN:
 182                 return (_POSIX2_FORT_RUN);
 183         case _SC_2_LOCALEDEF:
 184                 return (_POSIX2_LOCALEDEF);
 185         case _SC_2_SW_DEV:
 186                 return (_POSIX2_SW_DEV);
 187         case _SC_2_UPE:
 188                 return (_POSIX2_UPE);
 189         case _SC_TZNAME_MAX:
 190                 path = _PATH_ZONEINFO;
 191 do_NAME_MAX:
 192                 sverrno = errno;
 193                 errno = 0;
 194                 lvalue = pathconf(path, _PC_NAME_MAX);
 195                 if (lvalue == -1 && errno != 0)
 196                         return (-1);
 197                 errno = sverrno;
 198                 return (lvalue);
 199
 200         case _SC_ASYNCHRONOUS_IO:
 201 #if _POSIX_ASYNCHRONOUS_IO == 0
 202                 mib[0] = CTL_P1003_1B;
 203                 mib[1] = CTL_P1003_1B_ASYNCHRONOUS_IO;
 204                 break;
 205 #else
 206                 return (_POSIX_ASYNCHRONOUS_IO);
 207 #endif
 208         case _SC_MAPPED_FILES:
 209                 return (_POSIX_MAPPED_FILES);
 210         case _SC_MEMLOCK:
 211                 return (_POSIX_MEMLOCK);
 212         case _SC_MEMLOCK_RANGE:
 213                 return (_POSIX_MEMLOCK_RANGE);
 214         case _SC_MEMORY_PROTECTION:
 215                 return (_POSIX_MEMORY_PROTECTION);
 216         case _SC_MESSAGE_PASSING:
 217 #if _POSIX_MESSAGE_PASSING == 0
 218                 mib[0] = CTL_P1003_1B;
 219                 mib[1] = CTL_P1003_1B_MESSAGE_PASSING;
 220                 goto yesno;
 221 #else
 222                 return (_POSIX_MESSAGE_PASSING);
 223 #endif
 224         case _SC_PRIORITIZED_IO:
 225 #if _POSIX_PRIORITIZED_IO == 0
 226                 mib[0] = CTL_P1003_1B;
 227                 mib[1] = CTL_P1003_1B_PRIORITIZED_IO;
 228                 goto yesno;
 229 #else
 230                 return (_POSIX_PRIORITIZED_IO);
 231 #endif
 232         case _SC_PRIORITY_SCHEDULING:
 233 #if _POSIX_PRIORITY_SCHEDULING == 0
 234                 mib[0] = CTL_P1003_1B;
 235                 mib[1] = CTL_P1003_1B_PRIORITY_SCHEDULING;
 236                 goto yesno;
 237 #else
 238                 return (_POSIX_PRIORITY_SCHEDULING);
 239 #endif
 240         case _SC_REALTIME_SIGNALS:
 241 #if _POSIX_REALTIME_SIGNALS == 0
 242                 mib[0] = CTL_P1003_1B;
 243                 mib[1] = CTL_P1003_1B_REALTIME_SIGNALS;
 244                 goto yesno;
 245 #else
 246                 return (_POSIX_REALTIME_SIGNALS);
 247 #endif
 248         case _SC_SEMAPHORES:
 249 #if _POSIX_SEMAPHORES == 0
 250                 mib[0] = CTL_P1003_1B;
 251                 mib[1] = CTL_P1003_1B_SEMAPHORES;
 252                 goto yesno;
 253 #else
 254                 return (_POSIX_SEMAPHORES);
 255 #endif
 256         case _SC_FSYNC:
 257                 return (_POSIX_FSYNC);
 258
 259         case _SC_SHARED_MEMORY_OBJECTS:
 260                 return (_POSIX_SHARED_MEMORY_OBJECTS);
 261         case _SC_SYNCHRONIZED_IO:
 262 #if _POSIX_SYNCHRONIZED_IO == 0
 263                 mib[0] = CTL_P1003_1B;
 264                 mib[1] = CTL_P1003_1B_SYNCHRONIZED_IO;
 265                 goto yesno;
 266 #else
 267                 return (_POSIX_SYNCHRONIZED_IO);
 268 #endif
 269         case _SC_TIMERS:
 270 #if _POSIX_TIMERS == 0
 271                 mib[0] = CTL_P1003_1B;
 272                 mib[1] = CTL_P1003_1B_TIMERS;
 273                 goto yesno;
 274 #else
 275                 return (_POSIX_TIMERS);
 276 #endif
 277         case _SC_AIO_LISTIO_MAX:
 278 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_AIO_LISTIO_MAX)
 279                 mib[0] = CTL_P1003_1B;
 280                 mib[1] = CTL_P1003_1B_AIO_LISTIO_MAX;
 281 #else
 282                 mib[0] = CTL_KERN;;
 283                 mib[1] = KERN_AIOMAX;
 284 #endif
 285                 break;
 286         case _SC_AIO_MAX:
 287 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_AIO_MAX)
 288                 mib[0] = CTL_P1003_1B;
 289                 mib[1] = CTL_P1003_1B_AIO_MAX;
 290 #else
 291                 mib[0] = CTL_KERN;;
 292                 mib[1] = KERN_AIOMAX;
 293 #endif
 294                 break;
 295         case _SC_AIO_PRIO_DELTA_MAX:
 296 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_AIO_PRIO_DELTA_MAX)
 297                 mib[0] = CTL_P1003_1B;
 298                 mib[1] = CTL_P1003_1B_AIO_PRIO_DELTA_MAX;
 299                 break;
 300 #else
 301                 return (-1);
 302 #endif
 303         case _SC_DELAYTIMER_MAX:
 304 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_DELAYTIMER_MAX)
 305                 mib[0] = CTL_P1003_1B;
 306                 mib[1] = CTL_P1003_1B_DELAYTIMER_MAX;
 307                 goto yesno;
 308 #else
 309                 return (-1);
 310 #endif
 311         case _SC_MQ_OPEN_MAX:
 312 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_MQ_OPEN_MAX)
 313                 mib[0] = CTL_P1003_1B;
 314                 mib[1] = CTL_P1003_1B_MQ_OPEN_MAX;
 315                 goto yesno;
 316 #else
 317                 return (-1);
 318 #endif
 319         case _SC_PAGESIZE:
 320                 defaultresult = getpagesize();
 321 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_PAGESIZE)
 322                 mib[0] = CTL_P1003_1B;
 323                 mib[1] = CTL_P1003_1B_PAGESIZE;
 324                 goto yesno;
 325 #else
 326                 return defaultresult;
 327 #endif
 328         case _SC_RTSIG_MAX:
 329 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_RTSIG_MAX)
 330                 mib[0] = CTL_P1003_1B;
 331                 mib[1] = CTL_P1003_1B_RTSIG_MAX;
 332                 goto yesno;
 333 #else
 334                 return (-1);
 335 #endif
 336         case _SC_SEM_NSEMS_MAX:
 337 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_RTSIG_MAX)
 338                 mib[0] = CTL_P1003_1B;
 339                 mib[1] = CTL_P1003_1B_SEM_NSEMS_MAX;
 340                 goto yesno;
 341 #else
 342                 len = sizeof(value);
 343                 return (sysctlbyname("kern.sysv.semmns", &value, &len, NULL, 0) == -1 ? -1 : value);
 344 #endif
 345
 346         case _SC_SEM_VALUE_MAX:
 347 #if SEM_VALUE_MAX == 0
 348                 mib[0] = CTL_P1003_1B;
 349                 mib[1] = CTL_P1003_1B_SEM_VALUE_MAX;
 350                 goto yesno;
 351 #else
 352                 return (SEM_VALUE_MAX);
 353 #endif
 354         case _SC_SIGQUEUE_MAX:
 355 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_SIGQUEUE_MAX)
 356                 mib[0] = CTL_P1003_1B;
 357                 mib[1] = CTL_P1003_1B_SIGQUEUE_MAX;
 358                 goto yesno;
 359 #else
 360                 return (-1);
 361 #endif
 362         case _SC_TIMER_MAX:
 363 #if defined(CTL_P1003_1B) && defined(CTL_P1003_1B_TIMER_MAX)
 364                 mib[0] = CTL_P1003_1B;
 365                 mib[1] = CTL_P1003_1B_TIMER_MAX;
 366 #else
 367                 return (-1);
 368 #endif
 369
 370 yesno:
 371                 len = sizeof(value);
 372                 if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 373                         return (-1);
 374                 if (value == 0)
 375                         return (defaultresult);
 376                 return ((long)value);
 377
 378         case _SC_2_PBS:
 379         case _SC_2_PBS_ACCOUNTING:
 380         case _SC_2_PBS_CHECKPOINT:
 381         case _SC_2_PBS_LOCATE:
 382         case _SC_2_PBS_MESSAGE:
 383         case _SC_2_PBS_TRACK:
 384 #if _POSIX2_PBS == 0
 385 #error "don't know how to determine _SC_2_PBS"
 386                 /*
 387                  * This probably requires digging through the filesystem
 388                  * to see if the appropriate package has been installed.
 389                  * Since we don't currently support this option at all,
 390                  * it's not worth the effort to write the code now.
 391                  * Figuring out which of the sub-options are supported
 392                  * would be even more difficult, so it's probably easier
 393                  * to always say ``no''.
 394                  */
 395 #else
 396                 return (_POSIX2_PBS);
 397 #endif
 398         case _SC_ADVISORY_INFO:
 399 #if _POSIX_ADVISORY_INFO == 0
 400 #error "_POSIX_ADVISORY_INFO"
 401 #else
 402                 return (_POSIX_ADVISORY_INFO);
 403 #endif
 404         case _SC_BARRIERS:
 405 #if _POSIX_BARRIERS == 0
 406 #error "_POSIX_BARRIERS"
 407 #else
 408                 return (_POSIX_BARRIERS);
 409 #endif
 410         case _SC_CLOCK_SELECTION:
 411 #if _POSIX_CLOCK_SELECTION == 0
 412 #error "_POSIX_CLOCK_SELECTION"
 413 #else
 414                 return (_POSIX_CLOCK_SELECTION);
 415 #endif
 416         case _SC_CPUTIME:
 417 #if _POSIX_CPUTIME == 0
 418 #error "_POSIX_CPUTIME"
 419 #else
 420                 return (_POSIX_CPUTIME);
 421 #endif
 422         case _SC_FILE_LOCKING:
 423         case _SC_GETGR_R_SIZE_MAX:
 424 /*              return sizeof(group) + group_name_max + group_passwd_max + max_group_member*(MAXLOGNAME+1); */
 425                 return 4096;    /* INT_MAX is too big for Perl */
 426         case _SC_GETPW_R_SIZE_MAX:
 427                 return 4096;
 428         case _SC_HOST_NAME_MAX:
 429                 return (MAXHOSTNAMELEN - 1); /* does not include \0 */
 430         case _SC_LOGIN_NAME_MAX:
 431                 return (MAXLOGNAME);
 432         case _SC_MONOTONIC_CLOCK:
 433 #if _POSIX_MONOTONIC_CLOCK == 0
 434 #error "_POSIX_MONOTONIC_CLOCK"
 435 #else
 436                 return (_POSIX_MONOTONIC_CLOCK);
 437 #endif
 438         case _SC_MQ_PRIO_MAX:
 439                 return (-1);
 440         case _SC_READER_WRITER_LOCKS:
 441                 return (_POSIX_READER_WRITER_LOCKS);
 442         case _SC_REGEXP:
 443                 return (_POSIX_REGEXP);
 444         case _SC_SHELL:
 445                 return (_POSIX_SHELL);
 446         case _SC_SPAWN:
 447                 return (_POSIX_SPAWN);
 448         case _SC_SPIN_LOCKS:
 449                 return (_POSIX_SPIN_LOCKS);
 450         case _SC_SPORADIC_SERVER:
 451 #if _POSIX_SPORADIC_SERVER == 0
 452 #error "_POSIX_SPORADIC_SERVER"
 453 #else
 454                 return (_POSIX_SPORADIC_SERVER);
 455 #endif
 456         case _SC_THREAD_ATTR_STACKADDR:
 457                 return (_POSIX_THREAD_ATTR_STACKADDR);
 458         case _SC_THREAD_ATTR_STACKSIZE:
 459                 return (_POSIX_THREAD_ATTR_STACKSIZE);
 460         case _SC_THREAD_CPUTIME:
 461                 return (_POSIX_THREAD_CPUTIME);
 462         case _SC_THREAD_DESTRUCTOR_ITERATIONS:
 463                 return (PTHREAD_DESTRUCTOR_ITERATIONS);
 464         case _SC_THREAD_KEYS_MAX:
 465                 return (PTHREAD_KEYS_MAX);
 466         case _SC_THREAD_PRIO_INHERIT:
 467                 return (_POSIX_THREAD_PRIO_INHERIT);
 468         case _SC_THREAD_PRIO_PROTECT:
 469                 return (_POSIX_THREAD_PRIO_PROTECT);
 470         case _SC_THREAD_PRIORITY_SCHEDULING:
 471                 return (_POSIX_THREAD_PRIORITY_SCHEDULING);
 472         case _SC_THREAD_PROCESS_SHARED:
 473                 return (_POSIX_THREAD_PROCESS_SHARED);
 474         case _SC_THREAD_SAFE_FUNCTIONS:
 475                 return (_POSIX_THREAD_SAFE_FUNCTIONS);
 476         case _SC_THREAD_SPORADIC_SERVER:
 477                 return (_POSIX_THREAD_SPORADIC_SERVER);
 478         case _SC_THREAD_STACK_MIN:
 479                 return (PTHREAD_STACK_MIN);
 480         case _SC_THREAD_THREADS_MAX:
 481 #ifdef PTHREAD_THREADS_MAX
 482                 return (PTHREAD_THREADS_MAX); /* XXX wrong type! */
 483 #else
 484                 return (-1);
 485 #endif
 486         case _SC_TIMEOUTS:
 487                 return (_POSIX_TIMEOUTS);
 488         case _SC_THREADS:
 489                 return (_POSIX_THREADS);
 490         case _SC_TRACE:
 491 #if _POSIX_TRACE == 0
 492 #error "_POSIX_TRACE"
 493                 /* While you're implementing this, also do the ones below. */
 494 #else
 495                 return (_POSIX_TRACE);
 496 #endif
 497         case _SC_TRACE_EVENT_FILTER:
 498                 return (_POSIX_TRACE_EVENT_FILTER);
 499         case _SC_TRACE_INHERIT:
 500                 return (_POSIX_TRACE_INHERIT);
 501         case _SC_TRACE_LOG:
 502                 return (_POSIX_TRACE_LOG);
 503         case _SC_TTY_NAME_MAX:
 504                 path = "/"; // should be _PATH_DEV (PR-3624562)
 505                 goto do_NAME_MAX;
 506         case _SC_TYPED_MEMORY_OBJECTS:
 507 #if _POSIX_TYPED_MEMORY_OBJECTS == 0
 508 #error "_POSIX_TYPED_MEMORY_OBJECTS"
 509 #else
 510                 return (_POSIX_TYPED_MEMORY_OBJECTS);
 511 #endif
 512         case _SC_V6_ILP32_OFF32:
 513 #if _V6_ILP32_OFF32 == 0
 514                 if (sizeof(int) * CHAR_BIT == 32 &&
 515                     sizeof(int) == sizeof(long) &&
 516                     sizeof(long) == sizeof(void *) &&
 517                     sizeof(void *) == sizeof(off_t))
 518                         return 1;
 519                 else
 520                         return -1;
 521 #else
 522                 return (_V6_ILP32_OFF32);
 523 #endif
 524         case _SC_V6_ILP32_OFFBIG:
 525 #if _V6_ILP32_OFFBIG == 0
 526                 if (sizeof(int) * CHAR_BIT == 32 &&
 527                     sizeof(int) == sizeof(long) &&
 528                     sizeof(long) == sizeof(void *) &&
 529                     sizeof(off_t) * CHAR_BIT >= 64)
 530                         return 1;
 531                 else
 532                         return -1;
 533 #else
 534                 return (_V6_ILP32_OFFBIG);
 535 #endif
 536         case _SC_V6_LP64_OFF64:
 537 #if _V6_LP64_OFF64 == 0
 538                 if (sizeof(int) * CHAR_BIT == 32 &&
 539                     sizeof(long) * CHAR_BIT == 64 &&
 540                     sizeof(long) == sizeof(void *) &&
 541                     sizeof(void *) == sizeof(off_t))
 542                         return 1;
 543                 else
 544                         return -1;
 545 #else
 546                 return (_V6_LP64_OFF64);
 547 #endif
 548         case _SC_V6_LPBIG_OFFBIG:
 549 #if _V6_LPBIG_OFFBIG == 0
 550                 if (sizeof(int) * CHAR_BIT >= 32 &&
 551                     sizeof(long) * CHAR_BIT >= 64 &&
 552                     sizeof(void *) * CHAR_BIT >= 64 &&
 553                     sizeof(off_t) * CHAR_BIT >= 64)
 554                         return 1;
 555                 else
 556                         return -1;
 557 #else
 558                 return (_V6_LPBIG_OFFBIG);
 559 #endif
 560         case _SC_ATEXIT_MAX:
 561                 return (INT_MAX);       /* unlimited */
 562         case _SC_IOV_MAX:
 563 #ifdef KERN_IOV_MAX
 564                 mib[0] = CTL_KERN;
 565                 mib[1] = KERN_IOV_MAX;
 566                 break;
 567 #else
 568                 return (IOV_MAX);
 569 #endif
 570         case _SC_XOPEN_CRYPT:
 571                 return (_XOPEN_CRYPT);
 572         case _SC_XOPEN_ENH_I18N:
 573                 return (_XOPEN_ENH_I18N);
 574         case _SC_XOPEN_LEGACY:
 575                 return (_XOPEN_LEGACY);
 576         case _SC_XOPEN_REALTIME:
 577 #if _XOPEN_REALTIME == 0
 578                 sverrno = errno;
 579                 value = sysconf(_SC_ASYNCHRONOUS_IO) > 0 &&
 580                         sysconf(_SC_MEMLOCK) > 0 &&
 581                         sysconf(_SC_MEMLOCK_RANGE) > 0 &&
 582                         sysconf(_SC_MESSAGE_PASSING) > 0 &&
 583                         sysconf(_SC_PRIORITY_SCHEDULING) > 0 &&
 584                         sysconf(_SC_REALTIME_SIGNALS) > 0 &&
 585                         sysconf(_SC_SEMAPHORES) > 0 &&
 586                         sysconf(_SC_SHARED_MEMORY_OBJECTS) > 0 &&
 587                         sysconf(_SC_SYNCHRONIZED_IO) > 0 &&
 588                         sysconf(_SC_TIMERS) > 0;
 589                 errno = sverrno;
 590                 if (value)
 591                         return (200112L);
 592                 else
 593                         return (-1);
 594 #else
 595                 return (_XOPEN_REALTIME);
 596 #endif
 597         case _SC_XOPEN_REALTIME_THREADS:
 598 #if _XOPEN_REALTIME_THREADS == 0
 599 #error "_XOPEN_REALTIME_THREADS"
 600 #else
 601                 return (_XOPEN_REALTIME_THREADS);
 602 #endif
 603         case _SC_XOPEN_SHM:
 604                 sverrno = errno;
 605                 len = sizeof(qdvalue);
 606                 if (sysctlbyname("kern.sysv.shmmin", &qdvalue, &len, NULL,
 607                     0) == -1) {
 608                         errno = sverrno;
 609                         return (-1);
 610                 }
 611                 errno = sverrno;
 612                 return (1);
 613         case _SC_XOPEN_STREAMS:
 614                 return (_XOPEN_STREAMS);
 615         case _SC_XOPEN_UNIX:
 616                 return (_XOPEN_UNIX);
 617 #ifdef _XOPEN_VERSION
 618         case _SC_XOPEN_VERSION:
 619                 return (_XOPEN_VERSION);
 620 #endif
 621 #ifdef _XOPEN_XCU_VERSION
 622         case _SC_XOPEN_XCU_VERSION:
 623                 return (_XOPEN_XCU_VERSION);
 624 #endif
 625         case _SC_SYMLOOP_MAX:
 626                 return (MAXSYMLINKS);
 627         case _SC_RAW_SOCKETS:
 628                 return (_POSIX_RAW_SOCKETS);
 629         case _SC_IPV6:
 630 #if _POSIX_IPV6 == 0
 631                 sverrno = errno;
 632                 value = socket(PF_INET6, SOCK_DGRAM, 0);
 633                 errno = sverrno;
 634                 if (value >= 0) {
 635                         close(value);
 636                         return (200112L);
 637                 } else
 638                         return (0);
 639 #else
 640                 return (_POSIX_IPV6);
 641 #endif
 642
 643 #ifdef _SC_NPROCESSORS_CONF
 644         case _SC_NPROCESSORS_CONF:
 645 #endif
 646 #ifdef _SC_NPROCESSORS_ONLN
 647         case _SC_NPROCESSORS_ONLN:
 648 #endif
 649 #if defined(_SC_NPROCESSORS_CONF) || defined(_SC_NPROCESSORS_ONLN)
 650                 mib[0] = CTL_HW;
 651                 mib[1] = HW_NCPU;
 652                 break;
 653 #endif
 654         case _SC_XBS5_ILP32_OFF32:
 655                 return (_XBS5_ILP32_OFF32);
 656         case _SC_XBS5_ILP32_OFFBIG:
 657                 return (_XBS5_ILP32_OFFBIG);
 658         case _SC_XBS5_LP64_OFF64:
 659                 return (_XBS5_LP64_OFF64);
 660         case _SC_XBS5_LPBIG_OFFBIG:
 661                 return (_XBS5_LPBIG_OFFBIG);
 662         case _SC_SS_REPL_MAX:
 663                 return (_POSIX_SS_REPL_MAX);
 664         case _SC_TRACE_EVENT_NAME_MAX:
 665                 return (_POSIX_TRACE_EVENT_NAME_MAX);
 666         case _SC_TRACE_NAME_MAX:
 667                 return (_POSIX_TRACE_NAME_MAX);
 668         case _SC_TRACE_SYS_MAX:
 669                 return (_POSIX_TRACE_SYS_MAX);
 670         case _SC_TRACE_USER_EVENT_MAX:
 671                 return (_POSIX_TRACE_USER_EVENT_MAX);
 672         case _SC_PASS_MAX:
 673                 return (PASS_MAX);
 674
 675 #ifdef _SC_PHYS_PAGES
 676         case _SC_PHYS_PAGES:
 677 #ifdef __APPLE__
 678                 {
 679                         long memsize;
 680                         long pagesize;
 681
 682                         len = sizeof(memsize);
 683                         if (sysctlbyname("hw.memsize", &memsize, &len, NULL, 0) == -1)
 684                                 return (-1);
 685
 686                         len = sizeof(pagesize);
 687                         if (sysctlbyname("hw.pagesize", &pagesize, &len, NULL, 0) == -1)
 688                                 return (-1);
 689
 690                         return (memsize / pagesize);
 691                 }
 692 #else
 693                 len = sizeof(lvalue);
 694                 if (sysctlbyname("hw.availpages", &lvalue, &len, NULL, 0) == -1)
 695                         return (-1);
 696                 return (lvalue);
 697 #endif
 698 #endif
 699
 700         default:
 701                 errno = EINVAL;
 702                 return (-1);
 703         }
 704         len = sizeof(value);
 705         if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 706                 value = -1;
 707         return ((long)value);
 708 }