1 /* $OpenBSD: sysconf.c,v 1.27 2020/10/12 19:51:28 deraadt Exp $ */ 2 /*- 3 * Copyright (c) 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Sean Eric Fagan of Cygnus Support. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/types.h> 35 #include <sys/sem.h> 36 #include <sys/sysctl.h> 37 #include <sys/time.h> 38 #include <sys/resource.h> 39 #include <sys/socket.h> 40 41 #include <errno.h> 42 #include <grp.h> 43 #include <pthread.h> 44 #include <pwd.h> 45 #include <stdio.h> 46 #include <unistd.h> 47 48 /* 49 * sysconf -- 50 * get configurable system variables. 51 * 52 * XXX 53 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 54 * not change during the lifetime of the calling process. This would seem 55 * to require that any change to system limits kill all running processes. 56 * A workaround might be to cache the values when they are first retrieved 57 * and then simply return the cached value on subsequent calls. This is 58 * less useful than returning up-to-date values, however. 59 */ 60 long 61 sysconf(int name) 62 { 63 struct rlimit rl; 64 size_t len; 65 int mib[2], value, namelen, sverrno; 66 67 len = sizeof(value); 68 namelen = 2; 69 70 switch (name) { 71 /* 1003.1 */ 72 case _SC_ARG_MAX: 73 mib[0] = CTL_KERN; 74 mib[1] = KERN_ARGMAX; 75 break; 76 case _SC_CHILD_MAX: 77 if (getrlimit(RLIMIT_NPROC, &rl) != 0) 78 return (-1); 79 if (rl.rlim_cur == RLIM_INFINITY) 80 return (-1); 81 if (rl.rlim_cur > LONG_MAX) { 82 errno = EOVERFLOW; 83 return (-1); 84 } 85 return ((long)rl.rlim_cur); 86 case _SC_CLK_TCK: 87 return (CLK_TCK); 88 case _SC_JOB_CONTROL: 89 return (_POSIX_JOB_CONTROL); 90 case _SC_NGROUPS_MAX: 91 mib[0] = CTL_KERN; 92 mib[1] = KERN_NGROUPS; 93 break; 94 case _SC_OPEN_MAX: 95 if (getrlimit(RLIMIT_NOFILE, &rl) != 0) 96 return (-1); 97 if (rl.rlim_cur == RLIM_INFINITY) 98 return (-1); 99 if (rl.rlim_cur > LONG_MAX) { 100 errno = EOVERFLOW; 101 return (-1); 102 } 103 return ((long)rl.rlim_cur); 104 case _SC_STREAM_MAX: 105 if (getrlimit(RLIMIT_NOFILE, &rl) != 0) 106 return (-1); 107 if (rl.rlim_cur == RLIM_INFINITY) 108 return (-1); 109 if (rl.rlim_cur > LONG_MAX) { 110 errno = EOVERFLOW; 111 return (-1); 112 } 113 /* 114 * struct __sFILE currently has a limitation that 115 * file descriptors must fit in a signed short. 116 * This doesn't precisely capture the letter of POSIX 117 * but approximates the spirit. 118 */ 119 if (rl.rlim_cur > SHRT_MAX) 120 return (SHRT_MAX); 121 122 return ((long)rl.rlim_cur); 123 case _SC_TZNAME_MAX: 124 return (NAME_MAX); 125 case _SC_SAVED_IDS: 126 return (_POSIX_SAVED_IDS); 127 case _SC_VERSION: 128 mib[0] = CTL_KERN; 129 mib[1] = KERN_POSIX1; 130 break; 131 132 /* 1003.1b */ 133 case _SC_PAGESIZE: 134 if (_pagesize != 0) 135 return (_pagesize); 136 mib[0] = CTL_HW; 137 mib[1] = HW_PAGESIZE; 138 break; 139 case _SC_FSYNC: 140 return (_POSIX_FSYNC); 141 142 /* 1003.1c */ 143 case _SC_LOGIN_NAME_MAX: 144 return (LOGIN_NAME_MAX); 145 146 case _SC_THREAD_SAFE_FUNCTIONS: 147 return (_POSIX_THREAD_SAFE_FUNCTIONS); 148 149 case _SC_GETGR_R_SIZE_MAX: 150 return (_GR_BUF_LEN); 151 152 case _SC_GETPW_R_SIZE_MAX: 153 return (_PW_BUF_LEN); 154 155 /* 1003.2 */ 156 case _SC_BC_BASE_MAX: 157 return (BC_BASE_MAX); 158 case _SC_BC_DIM_MAX: 159 return (BC_DIM_MAX); 160 case _SC_BC_SCALE_MAX: 161 return (BC_SCALE_MAX); 162 case _SC_BC_STRING_MAX: 163 return (BC_STRING_MAX); 164 case _SC_COLL_WEIGHTS_MAX: 165 return (COLL_WEIGHTS_MAX); 166 case _SC_EXPR_NEST_MAX: 167 return (EXPR_NEST_MAX); 168 case _SC_LINE_MAX: 169 return (LINE_MAX); 170 case _SC_RE_DUP_MAX: 171 return (RE_DUP_MAX); 172 case _SC_2_VERSION: 173 return (_POSIX2_VERSION); 174 case _SC_2_C_BIND: 175 return (_POSIX2_C_BIND); 176 case _SC_2_C_DEV: 177 return (_POSIX2_C_DEV); 178 case _SC_2_CHAR_TERM: 179 return (_POSIX2_CHAR_TERM); 180 case _SC_2_FORT_DEV: 181 return (_POSIX2_FORT_DEV); 182 case _SC_2_FORT_RUN: 183 return (_POSIX2_FORT_RUN); 184 case _SC_2_LOCALEDEF: 185 return (_POSIX2_LOCALEDEF); 186 case _SC_2_SW_DEV: 187 return (_POSIX2_SW_DEV); 188 case _SC_2_UPE: 189 return (_POSIX2_UPE); 190 191 /* XPG 4.2 */ 192 case _SC_XOPEN_SHM: 193 mib[0] = CTL_KERN; 194 mib[1] = KERN_SYSVSHM; 195 if (sysctl(mib, namelen, &value, &len, NULL, 0) == -1) 196 return (-1); 197 if (value == 0) 198 return (-1); 199 return (value); 200 break; 201 case _SC_SEM_NSEMS_MAX: 202 return (-1); 203 case _SC_SEM_VALUE_MAX: 204 return (SEM_VALUE_MAX); 205 206 /* Unsorted */ 207 case _SC_HOST_NAME_MAX: 208 return (HOST_NAME_MAX); /* does not include \0 */ 209 case _SC_MONOTONIC_CLOCK: 210 return (_POSIX_MONOTONIC_CLOCK); 211 case _SC_2_PBS: 212 case _SC_2_PBS_ACCOUNTING: 213 case _SC_2_PBS_CHECKPOINT: 214 case _SC_2_PBS_LOCATE: 215 case _SC_2_PBS_MESSAGE: 216 case _SC_2_PBS_TRACK: 217 return (_POSIX2_PBS); 218 case _SC_ADVISORY_INFO: 219 return (_POSIX_ADVISORY_INFO); 220 case _SC_AIO_LISTIO_MAX: 221 case _SC_AIO_MAX: 222 case _SC_AIO_PRIO_DELTA_MAX: 223 return (-1); 224 case _SC_ASYNCHRONOUS_IO: 225 return (_POSIX_ASYNCHRONOUS_IO); 226 case _SC_ATEXIT_MAX: 227 return (-1); 228 case _SC_BARRIERS: 229 return (_POSIX_BARRIERS); 230 case _SC_CLOCK_SELECTION: 231 return (_POSIX_CLOCK_SELECTION); 232 case _SC_CPUTIME: 233 return (_POSIX_CPUTIME); 234 case _SC_DELAYTIMER_MAX: 235 return (-1); 236 case _SC_IOV_MAX: 237 return (IOV_MAX); 238 case _SC_IPV6: 239 #if _POSIX_IPV6 == 0 240 sverrno = errno; 241 value = socket(PF_INET6, SOCK_DGRAM, 0); 242 errno = sverrno; 243 if (value >= 0) { 244 HIDDEN(close)(value); 245 return (200112L); 246 } else 247 return (0); 248 #else 249 return (_POSIX_IPV6); 250 #endif 251 case _SC_MAPPED_FILES: 252 return (_POSIX_MAPPED_FILES); 253 case _SC_MEMLOCK: 254 return (_POSIX_MEMLOCK); 255 case _SC_MEMLOCK_RANGE: 256 return (_POSIX_MEMLOCK_RANGE); 257 case _SC_MEMORY_PROTECTION: 258 return (_POSIX_MEMORY_PROTECTION); 259 case _SC_MESSAGE_PASSING: 260 return (_POSIX_MESSAGE_PASSING); 261 case _SC_PRIORITIZED_IO: 262 return (_POSIX_PRIORITIZED_IO); 263 case _SC_PRIORITY_SCHEDULING: 264 return (_POSIX_PRIORITY_SCHEDULING); 265 case _SC_RAW_SOCKETS: 266 return (_POSIX_RAW_SOCKETS); 267 case _SC_READER_WRITER_LOCKS: 268 return (_POSIX_READER_WRITER_LOCKS); 269 case _SC_REALTIME_SIGNALS: 270 return (_POSIX_REALTIME_SIGNALS); 271 case _SC_REGEXP: 272 return (_POSIX_REGEXP); 273 case _SC_SEMAPHORES: 274 return (_POSIX_SEMAPHORES); 275 case _SC_SHARED_MEMORY_OBJECTS: 276 return (_POSIX_SHARED_MEMORY_OBJECTS); 277 case _SC_SHELL: 278 return (_POSIX_SHELL); 279 case _SC_SIGQUEUE_MAX: 280 return (-1); 281 case _SC_SPAWN: 282 return (_POSIX_SPAWN); 283 case _SC_SPIN_LOCKS: 284 return (_POSIX_SPIN_LOCKS); 285 case _SC_SPORADIC_SERVER: 286 return (_POSIX_SPORADIC_SERVER); 287 case _SC_SYNCHRONIZED_IO: 288 return (_POSIX_SYNCHRONIZED_IO); 289 case _SC_SYMLOOP_MAX: 290 return (SYMLOOP_MAX); 291 case _SC_THREAD_ATTR_STACKADDR: 292 return (_POSIX_THREAD_ATTR_STACKADDR); 293 case _SC_THREAD_ATTR_STACKSIZE: 294 return (_POSIX_THREAD_ATTR_STACKSIZE); 295 case _SC_THREAD_CPUTIME: 296 return (_POSIX_THREAD_CPUTIME); 297 case _SC_THREAD_DESTRUCTOR_ITERATIONS: 298 return (PTHREAD_DESTRUCTOR_ITERATIONS); 299 case _SC_THREAD_KEYS_MAX: 300 return (PTHREAD_KEYS_MAX); 301 case _SC_THREAD_PRIO_INHERIT: 302 return (_POSIX_THREAD_PRIO_INHERIT); 303 case _SC_THREAD_PRIO_PROTECT: 304 return (_POSIX_THREAD_PRIO_PROTECT); 305 case _SC_THREAD_PRIORITY_SCHEDULING: 306 return (_POSIX_THREAD_PRIORITY_SCHEDULING); 307 case _SC_THREAD_PROCESS_SHARED: 308 return (_POSIX_THREAD_PROCESS_SHARED); 309 case _SC_THREAD_ROBUST_PRIO_INHERIT: 310 return (_POSIX_THREAD_ROBUST_PRIO_INHERIT); 311 case _SC_THREAD_ROBUST_PRIO_PROTECT: 312 return (_POSIX_THREAD_ROBUST_PRIO_PROTECT); 313 case _SC_THREAD_SPORADIC_SERVER: 314 return (_POSIX_THREAD_SPORADIC_SERVER); 315 case _SC_THREAD_STACK_MIN: 316 return (PTHREAD_STACK_MIN); 317 case _SC_THREAD_THREADS_MAX: 318 return (PTHREAD_THREADS_MAX); 319 case _SC_THREADS: 320 return (_POSIX_THREADS); 321 case _SC_TIMEOUTS: 322 return (_POSIX_TIMEOUTS); 323 case _SC_TIMER_MAX: 324 return (-1); 325 case _SC_TIMERS: 326 return (_POSIX_TIMERS); 327 case _SC_TRACE: 328 case _SC_TRACE_EVENT_FILTER: 329 case _SC_TRACE_EVENT_NAME_MAX: 330 case _SC_TRACE_INHERIT: 331 case _SC_TRACE_LOG: 332 return (_POSIX_TRACE); 333 case _SC_TTY_NAME_MAX: 334 return (TTY_NAME_MAX); 335 case _SC_TYPED_MEMORY_OBJECTS: 336 return (_POSIX_TYPED_MEMORY_OBJECTS); 337 case _SC_V6_ILP32_OFF32: 338 return (_POSIX_V6_ILP32_OFF32); 339 case _SC_V6_ILP32_OFFBIG: 340 #if _POSIX_V6_ILP32_OFFBIG == 0 341 if (sizeof(int) * CHAR_BIT == 32 && 342 sizeof(long) * CHAR_BIT == 32 && 343 sizeof(void *) * CHAR_BIT == 32 && 344 sizeof(off_t) * CHAR_BIT >= 64) 345 return 1; 346 else 347 return -1; 348 #else 349 return (_POSIX_V6_ILP32_OFFBIG); 350 #endif 351 case _SC_V6_LP64_OFF64: 352 #if _POSIX_V6_LP64_OFF64 == 0 353 if (sizeof(int) * CHAR_BIT == 32 && 354 sizeof(long) * CHAR_BIT == 64 && 355 sizeof(void *) * CHAR_BIT == 64 && 356 sizeof(off_t) * CHAR_BIT == 64) 357 return 1; 358 else 359 return -1; 360 #else 361 return (_POSIX_V6_LP64_OFF64); 362 #endif 363 case _SC_V6_LPBIG_OFFBIG: 364 #if _POSIX_V6_LPBIG_OFFBIG == 0 365 if (sizeof(int) * CHAR_BIT >= 32 && 366 sizeof(long) * CHAR_BIT >= 64 && 367 sizeof(void *) * CHAR_BIT >= 64 && 368 sizeof(off_t) * CHAR_BIT >= 64) 369 return 1; 370 else 371 return -1; 372 #else 373 return (_POSIX_V6_LPBIG_OFFBIG); 374 #endif 375 case _SC_V7_ILP32_OFF32: 376 return (_POSIX_V7_ILP32_OFF32); 377 case _SC_V7_ILP32_OFFBIG: 378 #if _POSIX_V7_ILP32_OFFBIG == 0 379 if (sizeof(int) * CHAR_BIT == 32 && 380 sizeof(long) * CHAR_BIT == 32 && 381 sizeof(void *) * CHAR_BIT == 32 && 382 sizeof(off_t) * CHAR_BIT >= 64) 383 return 1; 384 else 385 return -1; 386 #else 387 return (_POSIX_V7_ILP32_OFFBIG); 388 #endif 389 case _SC_V7_LP64_OFF64: 390 #if _POSIX_V7_LP64_OFF64 == 0 391 if (sizeof(int) * CHAR_BIT == 32 && 392 sizeof(long) * CHAR_BIT == 64 && 393 sizeof(void *) * CHAR_BIT == 64 && 394 sizeof(off_t) * CHAR_BIT == 64) 395 return 1; 396 else 397 return -1; 398 #else 399 return (_POSIX_V7_LP64_OFF64); 400 #endif 401 case _SC_V7_LPBIG_OFFBIG: 402 #if _POSIX_V7_LPBIG_OFFBIG == 0 403 if (sizeof(int) * CHAR_BIT >= 32 && 404 sizeof(long) * CHAR_BIT >= 64 && 405 sizeof(void *) * CHAR_BIT >= 64 && 406 sizeof(off_t) * CHAR_BIT >= 64) 407 return 1; 408 else 409 return -1; 410 #else 411 return (_POSIX_V7_LPBIG_OFFBIG); 412 #endif 413 case _SC_XOPEN_CRYPT: 414 return (_XOPEN_CRYPT); 415 case _SC_XOPEN_ENH_I18N: 416 return (_XOPEN_ENH_I18N); 417 case _SC_XOPEN_LEGACY: 418 return (_XOPEN_LEGACY); 419 case _SC_XOPEN_REALTIME: 420 return (_XOPEN_REALTIME); 421 case _SC_XOPEN_REALTIME_THREADS: 422 return (_XOPEN_REALTIME_THREADS); 423 case _SC_XOPEN_STREAMS: 424 return (_XOPEN_STREAMS); 425 case _SC_XOPEN_UNIX: 426 return (_XOPEN_UNIX); 427 case _SC_XOPEN_UUCP: 428 return (_XOPEN_UUCP); 429 #ifdef _XOPEN_VERSION 430 case _SC_XOPEN_VERSION: 431 return (_XOPEN_VERSION); 432 #endif 433 434 /* Extensions */ 435 case _SC_PHYS_PAGES: 436 { 437 int64_t physmem; 438 439 mib[0] = CTL_HW; 440 mib[1] = HW_PHYSMEM64; 441 len = sizeof(physmem); 442 if (sysctl(mib, namelen, &physmem, &len, NULL, 0) == -1) 443 return (-1); 444 return (physmem / getpagesize()); 445 } 446 case _SC_AVPHYS_PAGES: 447 { 448 struct uvmexp uvmexp; 449 450 mib[0] = CTL_VM; 451 mib[1] = VM_UVMEXP; 452 len = sizeof(uvmexp); 453 if (sysctl(mib, namelen, &uvmexp, &len, NULL, 0) == -1) 454 return (-1); 455 return (uvmexp.free); 456 } 457 458 case _SC_NPROCESSORS_CONF: 459 mib[0] = CTL_HW; 460 mib[1] = HW_NCPU; 461 break; 462 case _SC_NPROCESSORS_ONLN: 463 mib[0] = CTL_HW; 464 mib[1] = HW_NCPUONLINE; 465 break; 466 467 default: 468 errno = EINVAL; 469 return (-1); 470 } 471 return (sysctl(mib, namelen, &value, &len, NULL, 0) == -1 ? -1 : value); 472 } 473 DEF_WEAK(sysconf); 474