sysconf.c revision 1.45
1 /* $NetBSD: sysconf.c,v 1.45 2024/12/22 23:17:26 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Sean Eric Fagan of Cygnus Support. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94"; 39 #else 40 __RCSID("$NetBSD: sysconf.c,v 1.45 2024/12/22 23:17:26 riastradh Exp $"); 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include "namespace.h" 45 #include <sys/param.h> 46 #include <sys/sysctl.h> 47 #include <sys/time.h> 48 #include <sys/resource.h> 49 #include <uvm/uvm_extern.h> 50 51 #include <errno.h> 52 #include <limits.h> 53 #include <time.h> 54 #include <unistd.h> 55 #include <paths.h> 56 #include <pwd.h> 57 58 #ifdef __weak_alias 59 __weak_alias(sysconf,__sysconf) 60 #endif 61 62 /* 63 * sysconf -- 64 * get configurable system variables. 65 * 66 * XXX 67 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 68 * not change during the lifetime of the calling process. This would seem 69 * to require that any change to system limits kill all running processes. 70 * A workaround might be to cache the values when they are first retrieved 71 * and then simply return the cached value on subsequent calls. This is 72 * less useful than returning up-to-date values, however. 73 */ 74 long 75 sysconf(int name) 76 { 77 struct rlimit rl; 78 size_t len; 79 uint64_t mem; 80 int mib[CTL_MAXNAME], value; 81 unsigned int mib_len; 82 struct clockinfo tmpclock; 83 struct uvmexp_sysctl uvmexp; 84 static int clk_tck; 85 86 len = sizeof(value); 87 88 /* Default length of the MIB */ 89 mib_len = 2; 90 91 switch (name) { 92 93 /* 1003.1 */ 94 case _SC_ARG_MAX: 95 mib[0] = CTL_KERN; 96 mib[1] = KERN_ARGMAX; 97 break; 98 case _SC_CHILD_MAX: 99 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur); 100 case _O_SC_CLK_TCK: 101 /* 102 * For applications compiled when CLK_TCK was a compile-time 103 * constant. 104 */ 105 return 100; 106 case _SC_CLK_TCK: 107 /* 108 * Has to be handled specially because it returns a 109 * struct clockinfo instead of an integer. Also, since 110 * this might be called often by some things that 111 * don't grok CLK_TCK can be a macro expanding to a 112 * function, cache the value. 113 */ 114 if (clk_tck == 0) { 115 mib[0] = CTL_KERN; 116 mib[1] = KERN_CLOCKRATE; 117 len = sizeof(struct clockinfo); 118 clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0) 119 == -1 ? -1 : tmpclock.hz; 120 } 121 return(clk_tck); 122 case _SC_JOB_CONTROL: 123 mib[0] = CTL_KERN; 124 mib[1] = KERN_JOB_CONTROL; 125 goto yesno; 126 case _SC_NGROUPS_MAX: 127 mib[0] = CTL_KERN; 128 mib[1] = KERN_NGROUPS; 129 break; 130 case _SC_OPEN_MAX: 131 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 132 : (long)rl.rlim_cur); 133 case _SC_STREAM_MAX: 134 mib[0] = CTL_USER; 135 mib[1] = USER_STREAM_MAX; 136 break; 137 case _SC_TZNAME_MAX: 138 mib[0] = CTL_USER; 139 mib[1] = USER_TZNAME_MAX; 140 break; 141 case _SC_SAVED_IDS: 142 mib[0] = CTL_KERN; 143 mib[1] = KERN_SAVED_IDS; 144 goto yesno; 145 case _SC_VERSION: 146 mib[0] = CTL_KERN; 147 mib[1] = KERN_POSIX1; 148 break; 149 150 /* 1003.1b */ 151 case _SC_PAGESIZE: 152 return _getpagesize(); 153 case _SC_FSYNC: 154 mib[0] = CTL_KERN; 155 mib[1] = KERN_FSYNC; 156 goto yesno; 157 case _SC_SYNCHRONIZED_IO: 158 mib[0] = CTL_KERN; 159 mib[1] = KERN_SYNCHRONIZED_IO; 160 goto yesno; 161 case _SC_MAPPED_FILES: 162 mib[0] = CTL_KERN; 163 mib[1] = KERN_MAPPED_FILES; 164 goto yesno; 165 case _SC_MEMLOCK: 166 mib[0] = CTL_KERN; 167 mib[1] = KERN_MEMLOCK; 168 goto yesno; 169 case _SC_MEMLOCK_RANGE: 170 mib[0] = CTL_KERN; 171 mib[1] = KERN_MEMLOCK_RANGE; 172 goto yesno; 173 case _SC_MEMORY_PROTECTION: 174 mib[0] = CTL_KERN; 175 mib[1] = KERN_MEMORY_PROTECTION; 176 goto yesno; 177 case _SC_MONOTONIC_CLOCK: 178 mib[0] = CTL_KERN; 179 mib[1] = KERN_MONOTONIC_CLOCK; 180 goto yesno; 181 case _SC_SEMAPHORES: 182 mib[0] = CTL_KERN; 183 mib[1] = KERN_POSIX_SEMAPHORES; 184 goto yesno; 185 case _SC_TIMERS: 186 mib[0] = CTL_KERN; 187 mib[1] = KERN_POSIX_TIMERS; 188 goto yesno; 189 190 /* 1003.1c */ 191 case _SC_LOGIN_NAME_MAX: 192 mib[0] = CTL_KERN; 193 mib[1] = KERN_LOGIN_NAME_MAX; 194 break; 195 case _SC_THREADS: 196 mib[0] = CTL_KERN; 197 mib[1] = KERN_POSIX_THREADS; 198 goto yesno; 199 200 /* 1003.1j */ 201 case _SC_BARRIERS: 202 mib[0] = CTL_KERN; 203 mib[1] = KERN_POSIX_BARRIERS; 204 goto yesno; 205 case _SC_SPIN_LOCKS: 206 mib[0] = CTL_KERN; 207 mib[1] = KERN_POSIX_SPIN_LOCKS; 208 goto yesno; 209 /* Historical; Threads option in 1003.1-2001 */ 210 case _SC_READER_WRITER_LOCKS: 211 mib[0] = CTL_KERN; 212 mib[1] = KERN_POSIX_READER_WRITER_LOCKS; 213 goto yesno; 214 215 /* 1003.2 */ 216 case _SC_BC_BASE_MAX: 217 mib[0] = CTL_USER; 218 mib[1] = USER_BC_BASE_MAX; 219 break; 220 case _SC_BC_DIM_MAX: 221 mib[0] = CTL_USER; 222 mib[1] = USER_BC_DIM_MAX; 223 break; 224 case _SC_BC_SCALE_MAX: 225 mib[0] = CTL_USER; 226 mib[1] = USER_BC_SCALE_MAX; 227 break; 228 case _SC_BC_STRING_MAX: 229 mib[0] = CTL_USER; 230 mib[1] = USER_BC_STRING_MAX; 231 break; 232 case _SC_COLL_WEIGHTS_MAX: 233 mib[0] = CTL_USER; 234 mib[1] = USER_COLL_WEIGHTS_MAX; 235 break; 236 case _SC_EXPR_NEST_MAX: 237 mib[0] = CTL_USER; 238 mib[1] = USER_EXPR_NEST_MAX; 239 break; 240 case _SC_LINE_MAX: 241 mib[0] = CTL_USER; 242 mib[1] = USER_LINE_MAX; 243 break; 244 case _SC_RE_DUP_MAX: 245 mib[0] = CTL_USER; 246 mib[1] = USER_RE_DUP_MAX; 247 break; 248 case _SC_2_VERSION: 249 mib[0] = CTL_USER; 250 mib[1] = USER_POSIX2_VERSION; 251 break; 252 case _SC_2_C_BIND: 253 mib[0] = CTL_USER; 254 mib[1] = USER_POSIX2_C_BIND; 255 goto yesno; 256 case _SC_2_C_DEV: 257 mib[0] = CTL_USER; 258 mib[1] = USER_POSIX2_C_DEV; 259 goto yesno; 260 case _SC_2_CHAR_TERM: 261 mib[0] = CTL_USER; 262 mib[1] = USER_POSIX2_CHAR_TERM; 263 goto yesno; 264 case _SC_2_FORT_DEV: 265 mib[0] = CTL_USER; 266 mib[1] = USER_POSIX2_FORT_DEV; 267 goto yesno; 268 case _SC_2_FORT_RUN: 269 mib[0] = CTL_USER; 270 mib[1] = USER_POSIX2_FORT_RUN; 271 goto yesno; 272 case _SC_2_LOCALEDEF: 273 mib[0] = CTL_USER; 274 mib[1] = USER_POSIX2_LOCALEDEF; 275 goto yesno; 276 case _SC_2_SW_DEV: 277 mib[0] = CTL_USER; 278 mib[1] = USER_POSIX2_SW_DEV; 279 goto yesno; 280 case _SC_2_UPE: 281 mib[0] = CTL_USER; 282 mib[1] = USER_POSIX2_UPE; 283 goto yesno; 284 285 /* XPG 4.2 */ 286 case _SC_IOV_MAX: 287 mib[0] = CTL_KERN; 288 mib[1] = KERN_IOV_MAX; 289 break; 290 case _SC_XOPEN_SHM: 291 mib[0] = CTL_KERN; 292 mib[1] = KERN_SYSVIPC; 293 mib[2] = KERN_SYSVIPC_SHM; 294 mib_len = 3; 295 goto yesno; 296 297 /* 1003.1-2001, XSI Option Group */ 298 case _SC_AIO_LISTIO_MAX: 299 if (sysctlgetmibinfo("kern.aio_listio_max", &mib[0], &mib_len, 300 NULL, NULL, NULL, SYSCTL_VERSION)) 301 return -1; 302 break; 303 case _SC_AIO_MAX: 304 if (sysctlgetmibinfo("kern.aio_max", &mib[0], &mib_len, 305 NULL, NULL, NULL, SYSCTL_VERSION)) 306 return -1; 307 break; 308 case _SC_ASYNCHRONOUS_IO: 309 if (sysctlgetmibinfo("kern.posix_aio", &mib[0], &mib_len, 310 NULL, NULL, NULL, SYSCTL_VERSION)) 311 return -1; 312 goto yesno; 313 case _SC_MESSAGE_PASSING: 314 if (sysctlgetmibinfo("kern.posix_msg", &mib[0], &mib_len, 315 NULL, NULL, NULL, SYSCTL_VERSION)) 316 return -1; 317 goto yesno; 318 case _SC_MQ_OPEN_MAX: 319 if (sysctlgetmibinfo("kern.mqueue.mq_open_max", &mib[0], 320 &mib_len, NULL, NULL, NULL, SYSCTL_VERSION)) 321 return -1; 322 break; 323 case _SC_MQ_PRIO_MAX: 324 if (sysctlgetmibinfo("kern.mqueue.mq_prio_max", &mib[0], 325 &mib_len, NULL, NULL, NULL, SYSCTL_VERSION)) 326 return -1; 327 break; 328 case _SC_PRIORITY_SCHEDULING: 329 if (sysctlgetmibinfo("kern.posix_sched", &mib[0], &mib_len, 330 NULL, NULL, NULL, SYSCTL_VERSION)) 331 return -1; 332 goto yesno; 333 case _SC_ATEXIT_MAX: 334 mib[0] = CTL_USER; 335 mib[1] = USER_ATEXIT_MAX; 336 break; 337 338 /* 1003.1-2001, TSF */ 339 case _SC_GETGR_R_SIZE_MAX: 340 return _GETGR_R_SIZE_MAX; 341 case _SC_GETPW_R_SIZE_MAX: 342 return _GETPW_R_SIZE_MAX; 343 344 /* Unsorted */ 345 case _SC_RTSIG_MAX: 346 return SIGRTMAX - SIGRTMIN; 347 case _SC_HOST_NAME_MAX: 348 return MAXHOSTNAMELEN; 349 case _SC_PASS_MAX: 350 return _PASSWORD_LEN; 351 case _SC_REGEXP: 352 return _POSIX_REGEXP; 353 case _SC_SHARED_MEMORY_OBJECTS: 354 return _POSIX_SHARED_MEMORY_OBJECTS; 355 case _SC_SHELL: 356 return _POSIX_SHELL; 357 case _SC_SPAWN: 358 return _POSIX_SPAWN; 359 case _SC_SYMLOOP_MAX: 360 return MAXSYMLINKS; 361 362 yesno: if (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1) 363 return -1; 364 if (value == 0) 365 return -1; 366 return value; 367 368 /* Extensions */ 369 case _SC_NPROCESSORS_CONF: 370 mib[0] = CTL_HW; 371 mib[1] = HW_NCPU; 372 break; 373 case _SC_NPROCESSORS_ONLN: 374 mib[0] = CTL_HW; 375 mib[1] = HW_NCPUONLINE; 376 break; 377 378 /* Linux/Solaris */ 379 case _SC_PHYS_PAGES: 380 len = sizeof(mem); 381 mib[0] = CTL_HW; 382 mib[1] = HW_PHYSMEM64; 383 return (sysctl(mib, 2, &mem, &len, NULL, 0) == -1 ? -1 384 : (long)(mem / _getpagesize())); 385 386 case _SC_AVPHYS_PAGES: 387 len = sizeof(uvmexp); 388 mib[0] = CTL_VM; 389 mib[1] = VM_UVMEXP2; 390 return (sysctl(mib, 2, &uvmexp, &len, NULL, 0) == -1 ? -1 391 : (long)(uvmexp.free)); 392 393 /* Native */ 394 case _SC_SCHED_RT_TS: 395 if (sysctlgetmibinfo("kern.sched.rtts", &mib[0], &mib_len, 396 NULL, NULL, NULL, SYSCTL_VERSION)) 397 return -1; 398 break; 399 case _SC_SCHED_PRI_MIN: 400 if (sysctlgetmibinfo("kern.sched.pri_min", &mib[0], &mib_len, 401 NULL, NULL, NULL, SYSCTL_VERSION)) 402 return -1; 403 break; 404 case _SC_SCHED_PRI_MAX: 405 if (sysctlgetmibinfo("kern.sched.pri_max", &mib[0], &mib_len, 406 NULL, NULL, NULL, SYSCTL_VERSION)) 407 return -1; 408 break; 409 case _SC_THREAD_DESTRUCTOR_ITERATIONS: 410 return _POSIX_THREAD_DESTRUCTOR_ITERATIONS; 411 case _SC_THREAD_KEYS_MAX: 412 return _POSIX_THREAD_KEYS_MAX; 413 case _SC_THREAD_STACK_MIN: 414 return _getpagesize(); 415 case _SC_THREAD_THREADS_MAX: 416 if (sysctlgetmibinfo("kern.maxproc", &mib[0], &mib_len, 417 NULL, NULL, NULL, SYSCTL_VERSION)) /* XXX */ 418 return -1; 419 goto yesno; 420 case _SC_THREAD_ATTR_STACKADDR: 421 return _POSIX_THREAD_ATTR_STACKADDR; 422 case _SC_THREAD_ATTR_STACKSIZE: 423 return _POSIX_THREAD_ATTR_STACKSIZE; 424 case _SC_THREAD_SAFE_FUNCTIONS: 425 return _POSIX_THREAD_SAFE_FUNCTIONS; 426 case _SC_THREAD_PRIO_PROTECT: 427 return _POSIX_THREAD_PRIO_PROTECT; 428 case _SC_THREAD_PRIORITY_SCHEDULING: 429 case _SC_THREAD_PRIO_INHERIT: 430 case _SC_THREAD_PROCESS_SHARED: 431 return -1; 432 case _SC_TTY_NAME_MAX: 433 return pathconf(_PATH_DEV, _PC_NAME_MAX); 434 case _SC_TIMER_MAX: 435 return _POSIX_TIMER_MAX; 436 case _SC_SEM_NSEMS_MAX: 437 return LONG_MAX; 438 case _SC_CPUTIME: 439 return _POSIX_CPUTIME; 440 case _SC_THREAD_CPUTIME: 441 return _POSIX_THREAD_CPUTIME; 442 case _SC_DELAYTIMER_MAX: 443 return _POSIX_DELAYTIMER_MAX; 444 case _SC_SIGQUEUE_MAX: 445 return _POSIX_SIGQUEUE_MAX; 446 case _SC_REALTIME_SIGNALS: 447 return 200112L; 448 default: 449 errno = EINVAL; 450 return -1; 451 } 452 return (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1 ? -1 453 : value); 454 } 455
Indexes created Thu Sep 25 16:09:42 GMT 2025