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. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * @(#)sysconf.c        8.2 (Berkeley) 3/20/94
  37  * $DragonFly: src/lib/libc/gen/sysconf.c,v 1.5 2008/02/21 12:47:54 hasso Exp $
  38  */
  39
  40 #include <sys/_posix.h>
  41 #include <sys/param.h>
  42 #include <sys/time.h>
  43 #include <sys/sysctl.h>
  44 #include <sys/resource.h>
  45
  46 #include <errno.h>
  47 #include <time.h>
  48 #include <unistd.h>
  49
  50 /*
  51  * sysconf --
  52  *      get configurable system variables.
  53  *
  54  * XXX
  55  * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values
  56  * not change during the lifetime of the calling process.  This would seem
  57  * to require that any change to system limits kill all running processes.
  58  * A workaround might be to cache the values when they are first retrieved
  59  * and then simply return the cached value on subsequent calls.  This is
  60  * less useful than returning up-to-date values, however.
  61  */
  62 long
  63 sysconf(int name)
  64 {
  65         struct rlimit rl;
  66         size_t len;
  67         int mib[2], value;
  68         long defaultresult;
  69
  70         len = sizeof(value);
  71         defaultresult = -1;
  72
  73         switch (name) {
  74 /* 1003.1 */
  75         case _SC_ARG_MAX:
  76                 mib[0] = CTL_KERN;
  77                 mib[1] = KERN_ARGMAX;
  78                 break;
  79         case _SC_CHILD_MAX:
  80                 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : rl.rlim_cur);
  81         case _SC_CLK_TCK:
  82                 return (CLK_TCK);
  83         case _SC_JOB_CONTROL:
  84                 mib[0] = CTL_KERN;
  85                 mib[1] = KERN_JOB_CONTROL;
  86                 goto yesno;
  87         case _SC_NGROUPS_MAX:
  88                 mib[0] = CTL_KERN;
  89                 mib[1] = KERN_NGROUPS;
  90                 break;
  91         case _SC_OPEN_MAX:
  92                 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : rl.rlim_cur);
  93         case _SC_STREAM_MAX:
  94                 mib[0] = CTL_USER;
  95                 mib[1] = USER_STREAM_MAX;
  96                 break;
  97         case _SC_TZNAME_MAX:
  98                 mib[0] = CTL_USER;
  99                 mib[1] = USER_TZNAME_MAX;
 100                 break;
 101         case _SC_SAVED_IDS:
 102                 mib[0] = CTL_KERN;
 103                 mib[1] = KERN_SAVED_IDS;
 104                 goto yesno;
 105         case _SC_VERSION:
 106                 mib[0] = CTL_KERN;
 107                 mib[1] = KERN_POSIX1;
 108                 break;
 109         case _SC_IOV_MAX:
 110                 mib[0] = CTL_KERN;
 111                 mib[1] = KERN_IOV_MAX;
 112                 break;
 113
 114 /* 1003.2 */
 115         case _SC_BC_BASE_MAX:
 116                 mib[0] = CTL_USER;
 117                 mib[1] = USER_BC_BASE_MAX;
 118                 break;
 119         case _SC_BC_DIM_MAX:
 120                 mib[0] = CTL_USER;
 121                 mib[1] = USER_BC_DIM_MAX;
 122                 break;
 123         case _SC_BC_SCALE_MAX:
 124                 mib[0] = CTL_USER;
 125                 mib[1] = USER_BC_SCALE_MAX;
 126                 break;
 127         case _SC_BC_STRING_MAX:
 128                 mib[0] = CTL_USER;
 129                 mib[1] = USER_BC_STRING_MAX;
 130                 break;
 131         case _SC_COLL_WEIGHTS_MAX:
 132                 mib[0] = CTL_USER;
 133                 mib[1] = USER_COLL_WEIGHTS_MAX;
 134                 break;
 135         case _SC_EXPR_NEST_MAX:
 136                 mib[0] = CTL_USER;
 137                 mib[1] = USER_EXPR_NEST_MAX;
 138                 break;
 139         case _SC_LINE_MAX:
 140                 mib[0] = CTL_USER;
 141                 mib[1] = USER_LINE_MAX;
 142                 break;
 143         case _SC_RE_DUP_MAX:
 144                 mib[0] = CTL_USER;
 145                 mib[1] = USER_RE_DUP_MAX;
 146                 break;
 147         case _SC_2_VERSION:
 148                 mib[0] = CTL_USER;
 149                 mib[1] = USER_POSIX2_VERSION;
 150                 break;
 151         case _SC_2_C_BIND:
 152                 mib[0] = CTL_USER;
 153                 mib[1] = USER_POSIX2_C_BIND;
 154                 goto yesno;
 155         case _SC_2_C_DEV:
 156                 mib[0] = CTL_USER;
 157                 mib[1] = USER_POSIX2_C_DEV;
 158                 goto yesno;
 159         case _SC_2_CHAR_TERM:
 160                 mib[0] = CTL_USER;
 161                 mib[1] = USER_POSIX2_CHAR_TERM;
 162                 goto yesno;
 163         case _SC_2_FORT_DEV:
 164                 mib[0] = CTL_USER;
 165                 mib[1] = USER_POSIX2_FORT_DEV;
 166                 goto yesno;
 167         case _SC_2_FORT_RUN:
 168                 mib[0] = CTL_USER;
 169                 mib[1] = USER_POSIX2_FORT_RUN;
 170                 goto yesno;
 171         case _SC_2_LOCALEDEF:
 172                 mib[0] = CTL_USER;
 173                 mib[1] = USER_POSIX2_LOCALEDEF;
 174                 goto yesno;
 175         case _SC_2_SW_DEV:
 176                 mib[0] = CTL_USER;
 177                 mib[1] = USER_POSIX2_SW_DEV;
 178                 goto yesno;
 179         case _SC_2_UPE:
 180                 mib[0] = CTL_USER;
 181                 mib[1] = USER_POSIX2_UPE;
 182                 goto yesno;
 183
 184 #ifdef _P1003_1B_VISIBLE
 185         /* POSIX.1B */
 186
 187         case _SC_ASYNCHRONOUS_IO:
 188                 mib[0] = CTL_P1003_1B;
 189                 mib[1] = CTL_P1003_1B_ASYNCHRONOUS_IO;
 190                 goto yesno;
 191         case _SC_MAPPED_FILES:
 192                 mib[0] = CTL_P1003_1B;
 193                 mib[1] = CTL_P1003_1B_MAPPED_FILES;
 194                 goto yesno;
 195         case _SC_MEMLOCK:
 196                 mib[0] = CTL_P1003_1B;
 197                 mib[1] = CTL_P1003_1B_MEMLOCK;
 198                 goto yesno;
 199         case _SC_MEMLOCK_RANGE:
 200                 mib[0] = CTL_P1003_1B;
 201                 mib[1] = CTL_P1003_1B_MEMLOCK_RANGE;
 202                 goto yesno;
 203         case _SC_MEMORY_PROTECTION:
 204                 mib[0] = CTL_P1003_1B;
 205                 mib[1] = CTL_P1003_1B_MEMORY_PROTECTION;
 206                 goto yesno;
 207         case _SC_MESSAGE_PASSING:
 208                 mib[0] = CTL_P1003_1B;
 209                 mib[1] = CTL_P1003_1B_MESSAGE_PASSING;
 210                 goto yesno;
 211         case _SC_PRIORITIZED_IO:
 212                 mib[0] = CTL_P1003_1B;
 213                 mib[1] = CTL_P1003_1B_PRIORITIZED_IO;
 214                 goto yesno;
 215         case _SC_PRIORITY_SCHEDULING:
 216                 mib[0] = CTL_P1003_1B;
 217                 mib[1] = CTL_P1003_1B_PRIORITY_SCHEDULING;
 218                 goto yesno;
 219         case _SC_REALTIME_SIGNALS:
 220                 mib[0] = CTL_P1003_1B;
 221                 mib[1] = CTL_P1003_1B_REALTIME_SIGNALS;
 222                 goto yesno;
 223         case _SC_SEMAPHORES:
 224                 mib[0] = CTL_P1003_1B;
 225                 mib[1] = CTL_P1003_1B_SEMAPHORES;
 226                 goto yesno;
 227         case _SC_FSYNC:
 228                 mib[0] = CTL_P1003_1B;
 229                 mib[1] = CTL_P1003_1B_FSYNC;
 230                 goto yesno;
 231         case _SC_SHARED_MEMORY_OBJECTS:
 232                 mib[0] = CTL_P1003_1B;
 233                 mib[1] = CTL_P1003_1B_SHARED_MEMORY_OBJECTS;
 234                 goto yesno;
 235         case _SC_SYNCHRONIZED_IO:
 236                 mib[0] = CTL_P1003_1B;
 237                 mib[1] = CTL_P1003_1B_SYNCHRONIZED_IO;
 238                 goto yesno;
 239         case _SC_TIMERS:
 240                 mib[0] = CTL_P1003_1B;
 241                 mib[1] = CTL_P1003_1B_TIMERS;
 242                 goto yesno;
 243         case _SC_AIO_LISTIO_MAX:
 244                 mib[0] = CTL_P1003_1B;
 245                 mib[1] = CTL_P1003_1B_AIO_LISTIO_MAX;
 246                 goto yesno;
 247         case _SC_AIO_MAX:
 248                 mib[0] = CTL_P1003_1B;
 249                 mib[1] = CTL_P1003_1B_AIO_MAX;
 250                 goto yesno;
 251         case _SC_AIO_PRIO_DELTA_MAX:
 252                 mib[0] = CTL_P1003_1B;
 253                 mib[1] = CTL_P1003_1B_AIO_PRIO_DELTA_MAX;
 254                 goto yesno;
 255         case _SC_DELAYTIMER_MAX:
 256                 mib[0] = CTL_P1003_1B;
 257                 mib[1] = CTL_P1003_1B_DELAYTIMER_MAX;
 258                 goto yesno;
 259         case _SC_MQ_OPEN_MAX:
 260                 mib[0] = CTL_P1003_1B;
 261                 mib[1] = CTL_P1003_1B_MQ_OPEN_MAX;
 262                 goto yesno;
 263         case _SC_PAGESIZE:
 264                 defaultresult = getpagesize();
 265                 mib[0] = CTL_P1003_1B;
 266                 mib[1] = CTL_P1003_1B_PAGESIZE;
 267                 goto yesno;
 268         case _SC_RTSIG_MAX:
 269                 mib[0] = CTL_P1003_1B;
 270                 mib[1] = CTL_P1003_1B_RTSIG_MAX;
 271                 goto yesno;
 272         case _SC_SEM_NSEMS_MAX:
 273                 mib[0] = CTL_P1003_1B;
 274                 mib[1] = CTL_P1003_1B_SEM_NSEMS_MAX;
 275                 goto yesno;
 276         case _SC_SEM_VALUE_MAX:
 277                 mib[0] = CTL_P1003_1B;
 278                 mib[1] = CTL_P1003_1B_SEM_VALUE_MAX;
 279                 goto yesno;
 280         case _SC_SIGQUEUE_MAX:
 281                 mib[0] = CTL_P1003_1B;
 282                 mib[1] = CTL_P1003_1B_SIGQUEUE_MAX;
 283                 goto yesno;
 284         case _SC_TIMER_MAX:
 285                 mib[0] = CTL_P1003_1B;
 286                 mib[1] = CTL_P1003_1B_TIMER_MAX;
 287                 goto yesno;
 288 #endif /* _P1003_1B_VISIBLE */
 289         case _SC_NPROCESSORS_CONF:
 290         case _SC_NPROCESSORS_ONLN:
 291                 mib[0] = CTL_HW;
 292                 mib[1] = HW_NCPU;
 293                 goto yesno;
 294
 295 yesno:          if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 296                         return (-1);
 297                 if (value == 0)
 298                         return (defaultresult);
 299                 return (value);
 300                 break;
 301         default:
 302                 errno = EINVAL;
 303                 return (-1);
 304         }
 305         return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value);
 306 }