/* $NetBSD: sysconf.c,v 1.43 2019/12/15 20:25:25 joerg 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 1.43 2019/12/15 20:25:25 joerg 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;
uint64_t mem;
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_RTSIG_MAX:
return SIGRTMAX - SIGRTMIN;
case _SC_HOST_NAME_MAX:
return MAXHOSTNAMELEN;
case _SC_PASS_MAX:
return _PASSWORD_LEN;
case _SC_REGEXP:
return _POSIX_REGEXP;
case _SC_SHARED_MEMORY_OBJECTS:
return _POSIX_SHARED_MEMORY_OBJECTS;
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;
/* Linux/Solaris */
case _SC_PHYS_PAGES:
len = sizeof(mem);
mib[0] = CTL_HW;
mib[1] = HW_PHYSMEM64;
return sysctl(mib, 2, &mem, &len, NULL, 0) == -1 ? -1 :
(long)(mem / _getpagesize());
/* 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_PRIO_PROTECT:
return _POSIX_THREAD_PRIO_PROTECT;
case _SC_THREAD_PRIORITY_SCHEDULING:
case _SC_THREAD_PRIO_INHERIT:
case _SC_THREAD_PROCESS_SHARED:
return -1;
case _SC_TTY_NAME_MAX:
return pathconf(_PATH_DEV, _PC_NAME_MAX);
case _SC_TIMER_MAX:
return _POSIX_TIMER_MAX;
case _SC_SEM_NSEMS_MAX:
return LONG_MAX;
case _SC_CPUTIME:
return _POSIX_CPUTIME;
case _SC_THREAD_CPUTIME:
return _POSIX_THREAD_CPUTIME;
case _SC_DELAYTIMER_MAX:
return _POSIX_DELAYTIMER_MAX;
case _SC_SIGQUEUE_MAX:
return _POSIX_SIGQUEUE_MAX;
case _SC_REALTIME_SIGNALS:
return 200112L;
default:
errno = EINVAL;
return (-1);
}
return (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1 ? -1 : value);
}