/lib/libc/gen/sysconf.c
C | 415 lines | 326 code | 21 blank | 68 comment | 21 complexity | dfdf0e6ada5b52cd57f22e3b10712c04 MD5 | raw file
- /* $NetBSD: sysconf.c,v 1.34 2012/08/01 15:24:22 martin Exp $ */
- /*-
- * Copyright (c) 1993
- * The Regents of the University of California. All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Sean Eric Fagan of Cygnus Support.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
- #include <sys/cdefs.h>
- #if defined(LIBC_SCCS) && !defined(lint)
- #if 0
- static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94";
- #else
- __RCSID("$NetBSD: sysconf.c,v 1.34 2012/08/01 15:24:22 martin Exp $");
- #endif
- #endif /* LIBC_SCCS and not lint */
- #include "namespace.h"
- #include <sys/param.h>
- #include <sys/sysctl.h>
- #include <sys/time.h>
- #include <sys/resource.h>
- #include <errno.h>
- #include <limits.h>
- #include <time.h>
- #include <unistd.h>
- #include <paths.h>
- #include <pwd.h>
- #ifdef __weak_alias
- __weak_alias(sysconf,__sysconf)
- #endif
- /*
- * sysconf --
- * get configurable system variables.
- *
- * XXX
- * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
- * not change during the lifetime of the calling process. This would seem
- * to require that any change to system limits kill all running processes.
- * A workaround might be to cache the values when they are first retrieved
- * and then simply return the cached value on subsequent calls. This is
- * less useful than returning up-to-date values, however.
- */
- long
- sysconf(int name)
- {
- struct rlimit rl;
- size_t len;
- int mib[CTL_MAXNAME], value;
- unsigned int mib_len;
- struct clockinfo tmpclock;
- static int clk_tck;
- len = sizeof(value);
- /* Default length of the MIB */
- mib_len = 2;
- switch (name) {
- /* 1003.1 */
- case _SC_ARG_MAX:
- mib[0] = CTL_KERN;
- mib[1] = KERN_ARGMAX;
- break;
- case _SC_CHILD_MAX:
- return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur);
- case _O_SC_CLK_TCK:
- /*
- * For applications compiled when CLK_TCK was a compile-time
- * constant.
- */
- return 100;
- case _SC_CLK_TCK:
- /*
- * Has to be handled specially because it returns a
- * struct clockinfo instead of an integer. Also, since
- * this might be called often by some things that
- * don't grok CLK_TCK can be a macro expanding to a
- * function, cache the value.
- */
- if (clk_tck == 0) {
- mib[0] = CTL_KERN;
- mib[1] = KERN_CLOCKRATE;
- len = sizeof(struct clockinfo);
- clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0)
- == -1 ? -1 : tmpclock.hz;
- }
- return(clk_tck);
- case _SC_JOB_CONTROL:
- mib[0] = CTL_KERN;
- mib[1] = KERN_JOB_CONTROL;
- goto yesno;
- case _SC_NGROUPS_MAX:
- mib[0] = CTL_KERN;
- mib[1] = KERN_NGROUPS;
- break;
- case _SC_OPEN_MAX:
- return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur);
- case _SC_STREAM_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_STREAM_MAX;
- break;
- case _SC_TZNAME_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_TZNAME_MAX;
- break;
- case _SC_SAVED_IDS:
- mib[0] = CTL_KERN;
- mib[1] = KERN_SAVED_IDS;
- goto yesno;
- case _SC_VERSION:
- mib[0] = CTL_KERN;
- mib[1] = KERN_POSIX1;
- break;
- /* 1003.1b */
- case _SC_PAGESIZE:
- return _getpagesize();
- case _SC_FSYNC:
- mib[0] = CTL_KERN;
- mib[1] = KERN_FSYNC;
- goto yesno;
- case _SC_SYNCHRONIZED_IO:
- mib[0] = CTL_KERN;
- mib[1] = KERN_SYNCHRONIZED_IO;
- goto yesno;
- case _SC_MAPPED_FILES:
- mib[0] = CTL_KERN;
- mib[1] = KERN_MAPPED_FILES;
- goto yesno;
- case _SC_MEMLOCK:
- mib[0] = CTL_KERN;
- mib[1] = KERN_MEMLOCK;
- goto yesno;
- case _SC_MEMLOCK_RANGE:
- mib[0] = CTL_KERN;
- mib[1] = KERN_MEMLOCK_RANGE;
- goto yesno;
- case _SC_MEMORY_PROTECTION:
- mib[0] = CTL_KERN;
- mib[1] = KERN_MEMORY_PROTECTION;
- goto yesno;
- case _SC_MONOTONIC_CLOCK:
- mib[0] = CTL_KERN;
- mib[1] = KERN_MONOTONIC_CLOCK;
- goto yesno;
- case _SC_SEMAPHORES:
- mib[0] = CTL_KERN;
- mib[1] = KERN_POSIX_SEMAPHORES;
- goto yesno;
- case _SC_TIMERS:
- mib[0] = CTL_KERN;
- mib[1] = KERN_POSIX_TIMERS;
- goto yesno;
- /* 1003.1c */
- case _SC_LOGIN_NAME_MAX:
- mib[0] = CTL_KERN;
- mib[1] = KERN_LOGIN_NAME_MAX;
- break;
- case _SC_THREADS:
- mib[0] = CTL_KERN;
- mib[1] = KERN_POSIX_THREADS;
- goto yesno;
- /* 1003.1j */
- case _SC_BARRIERS:
- mib[0] = CTL_KERN;
- mib[1] = KERN_POSIX_BARRIERS;
- goto yesno;
- case _SC_SPIN_LOCKS:
- mib[0] = CTL_KERN;
- mib[1] = KERN_POSIX_SPIN_LOCKS;
- goto yesno;
- /* Historical; Threads option in 1003.1-2001 */
- case _SC_READER_WRITER_LOCKS:
- mib[0] = CTL_KERN;
- mib[1] = KERN_POSIX_READER_WRITER_LOCKS;
- goto yesno;
- /* 1003.2 */
- case _SC_BC_BASE_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_BC_BASE_MAX;
- break;
- case _SC_BC_DIM_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_BC_DIM_MAX;
- break;
- case _SC_BC_SCALE_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_BC_SCALE_MAX;
- break;
- case _SC_BC_STRING_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_BC_STRING_MAX;
- break;
- case _SC_COLL_WEIGHTS_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_COLL_WEIGHTS_MAX;
- break;
- case _SC_EXPR_NEST_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_EXPR_NEST_MAX;
- break;
- case _SC_LINE_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_LINE_MAX;
- break;
- case _SC_RE_DUP_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_RE_DUP_MAX;
- break;
- case _SC_2_VERSION:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_VERSION;
- break;
- case _SC_2_C_BIND:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_C_BIND;
- goto yesno;
- case _SC_2_C_DEV:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_C_DEV;
- goto yesno;
- case _SC_2_CHAR_TERM:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_CHAR_TERM;
- goto yesno;
- case _SC_2_FORT_DEV:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_FORT_DEV;
- goto yesno;
- case _SC_2_FORT_RUN:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_FORT_RUN;
- goto yesno;
- case _SC_2_LOCALEDEF:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_LOCALEDEF;
- goto yesno;
- case _SC_2_SW_DEV:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_SW_DEV;
- goto yesno;
- case _SC_2_UPE:
- mib[0] = CTL_USER;
- mib[1] = USER_POSIX2_UPE;
- goto yesno;
- /* XPG 4.2 */
- case _SC_IOV_MAX:
- mib[0] = CTL_KERN;
- mib[1] = KERN_IOV_MAX;
- break;
- case _SC_XOPEN_SHM:
- mib[0] = CTL_KERN;
- mib[1] = KERN_SYSVIPC;
- mib[2] = KERN_SYSVIPC_SHM;
- mib_len = 3;
- goto yesno;
- /* 1003.1-2001, XSI Option Group */
- case _SC_AIO_LISTIO_MAX:
- if (sysctlgetmibinfo("kern.aio_listio_max", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- break;
- case _SC_AIO_MAX:
- if (sysctlgetmibinfo("kern.aio_max", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- break;
- case _SC_ASYNCHRONOUS_IO:
- if (sysctlgetmibinfo("kern.posix_aio", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- goto yesno;
- case _SC_MESSAGE_PASSING:
- if (sysctlgetmibinfo("kern.posix_msg", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- goto yesno;
- case _SC_MQ_OPEN_MAX:
- if (sysctlgetmibinfo("kern.mqueue.mq_open_max", &mib[0],
- &mib_len, NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- break;
- case _SC_MQ_PRIO_MAX:
- if (sysctlgetmibinfo("kern.mqueue.mq_prio_max", &mib[0],
- &mib_len, NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- break;
- case _SC_PRIORITY_SCHEDULING:
- if (sysctlgetmibinfo("kern.posix_sched", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- goto yesno;
- case _SC_ATEXIT_MAX:
- mib[0] = CTL_USER;
- mib[1] = USER_ATEXIT_MAX;
- break;
- /* 1003.1-2001, TSF */
- case _SC_GETGR_R_SIZE_MAX:
- return _GETGR_R_SIZE_MAX;
- case _SC_GETPW_R_SIZE_MAX:
- return _GETPW_R_SIZE_MAX;
- /* Unsorted */
- case _SC_HOST_NAME_MAX:
- return MAXHOSTNAMELEN;
- case _SC_PASS_MAX:
- return _PASSWORD_LEN;
- case _SC_REGEXP:
- return _POSIX_REGEXP;
- case _SC_SHELL:
- return _POSIX_SHELL;
- case _SC_SPAWN:
- return _POSIX_SPAWN;
- case _SC_SYMLOOP_MAX:
- return MAXSYMLINKS;
- yesno: if (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1)
- return (-1);
- if (value == 0)
- return (-1);
- return (value);
- /* Extensions */
- case _SC_NPROCESSORS_CONF:
- mib[0] = CTL_HW;
- mib[1] = HW_NCPU;
- break;
- case _SC_NPROCESSORS_ONLN:
- mib[0] = CTL_HW;
- mib[1] = HW_NCPUONLINE;
- break;
- /* Native */
- case _SC_SCHED_RT_TS:
- if (sysctlgetmibinfo("kern.sched.rtts", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- break;
- case _SC_SCHED_PRI_MIN:
- if (sysctlgetmibinfo("kern.sched.pri_min", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- break;
- case _SC_SCHED_PRI_MAX:
- if (sysctlgetmibinfo("kern.sched.pri_max", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION))
- return -1;
- break;
- case _SC_THREAD_DESTRUCTOR_ITERATIONS:
- return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
- case _SC_THREAD_KEYS_MAX:
- return _POSIX_THREAD_KEYS_MAX;
- case _SC_THREAD_STACK_MIN:
- return _getpagesize();
- case _SC_THREAD_THREADS_MAX:
- if (sysctlgetmibinfo("kern.maxproc", &mib[0], &mib_len,
- NULL, NULL, NULL, SYSCTL_VERSION)) /* XXX */
- return -1;
- goto yesno;
- case _SC_THREAD_ATTR_STACKADDR:
- return _POSIX_THREAD_ATTR_STACKADDR;
- case _SC_THREAD_ATTR_STACKSIZE:
- return _POSIX_THREAD_ATTR_STACKSIZE;
- case _SC_THREAD_SAFE_FUNCTIONS:
- return _POSIX_THREAD_SAFE_FUNCTIONS;
- case _SC_THREAD_PRIORITY_SCHEDULING:
- case _SC_THREAD_PRIO_INHERIT:
- case _SC_THREAD_PRIO_PROTECT:
- case _SC_THREAD_PROCESS_SHARED:
- return -1;
- case _SC_TTY_NAME_MAX:
- return pathconf(_PATH_DEV, _PC_NAME_MAX);
- default:
- errno = EINVAL;
- return (-1);
- }
- return (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1 ? -1 : value);
- }