1 /* $NetBSD: sysconf.c,v 1.44 2023/10/25 08:19:34 simonb 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 1.44 2023/10/25 08:19:34 simonb 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 : (long)rl.rlim_cur); 132 case _SC_STREAM_MAX: 133 mib[0] = CTL_USER; 134 mib[1] = USER_STREAM_MAX; 135 break; 136 case _SC_TZNAME_MAX: 137 mib[0] = CTL_USER; 138 mib[1] = USER_TZNAME_MAX; 139 break; 140 case _SC_SAVED_IDS: 141 mib[0] = CTL_KERN; 142 mib[1] = KERN_SAVED_IDS; 143 goto yesno; 144 case _SC_VERSION: 145 mib[0] = CTL_KERN; 146 mib[1] = KERN_POSIX1; 147 break; 148 149 /* 1003.1b */ 150 case _SC_PAGESIZE: 151 return _getpagesize(); 152 case _SC_FSYNC: 153 mib[0] = CTL_KERN; 154 mib[1] = KERN_FSYNC; 155 goto yesno; 156 case _SC_SYNCHRONIZED_IO: 157 mib[0] = CTL_KERN; 158 mib[1] = KERN_SYNCHRONIZED_IO; 159 goto yesno; 160 case _SC_MAPPED_FILES: 161 mib[0] = CTL_KERN; 162 mib[1] = KERN_MAPPED_FILES; 163 goto yesno; 164 case _SC_MEMLOCK: 165 mib[0] = CTL_KERN; 166 mib[1] = KERN_MEMLOCK; 167 goto yesno; 168 case _SC_MEMLOCK_RANGE: 169 mib[0] = CTL_KERN; 170 mib[1] = KERN_MEMLOCK_RANGE; 171 goto yesno; 172 case _SC_MEMORY_PROTECTION: 173 mib[0] = CTL_KERN; 174 mib[1] = KERN_MEMORY_PROTECTION; 175 goto yesno; 176 case _SC_MONOTONIC_CLOCK: 177 mib[0] = CTL_KERN; 178 mib[1] = KERN_MONOTONIC_CLOCK; 179 goto yesno; 180 case _SC_SEMAPHORES: 181 mib[0] = CTL_KERN; 182 mib[1] = KERN_POSIX_SEMAPHORES; 183 goto yesno; 184 case _SC_TIMERS: 185 mib[0] = CTL_KERN; 186 mib[1] = KERN_POSIX_TIMERS; 187 goto yesno; 188 189 /* 1003.1c */ 190 case _SC_LOGIN_NAME_MAX: 191 mib[0] = CTL_KERN; 192 mib[1] = KERN_LOGIN_NAME_MAX; 193 break; 194 case _SC_THREADS: 195 mib[0] = CTL_KERN; 196 mib[1] = KERN_POSIX_THREADS; 197 goto yesno; 198 199 /* 1003.1j */ 200 case _SC_BARRIERS: 201 mib[0] = CTL_KERN; 202 mib[1] = KERN_POSIX_BARRIERS; 203 goto yesno; 204 case _SC_SPIN_LOCKS: 205 mib[0] = CTL_KERN; 206 mib[1] = KERN_POSIX_SPIN_LOCKS; 207 goto yesno; 208 /* Historical; Threads option in 1003.1-2001 */ 209 case _SC_READER_WRITER_LOCKS: 210 mib[0] = CTL_KERN; 211 mib[1] = KERN_POSIX_READER_WRITER_LOCKS; 212 goto yesno; 213 214 /* 1003.2 */ 215 case _SC_BC_BASE_MAX: 216 mib[0] = CTL_USER; 217 mib[1] = USER_BC_BASE_MAX; 218 break; 219 case _SC_BC_DIM_MAX: 220 mib[0] = CTL_USER; 221 mib[1] = USER_BC_DIM_MAX; 222 break; 223 case _SC_BC_SCALE_MAX: 224 mib[0] = CTL_USER; 225 mib[1] = USER_BC_SCALE_MAX; 226 break; 227 case _SC_BC_STRING_MAX: 228 mib[0] = CTL_USER; 229 mib[1] = USER_BC_STRING_MAX; 230 break; 231 case _SC_COLL_WEIGHTS_MAX: 232 mib[0] = CTL_USER; 233 mib[1] = USER_COLL_WEIGHTS_MAX; 234 break; 235 case _SC_EXPR_NEST_MAX: 236 mib[0] = CTL_USER; 237 mib[1] = USER_EXPR_NEST_MAX; 238 break; 239 case _SC_LINE_MAX: 240 mib[0] = CTL_USER; 241 mib[1] = USER_LINE_MAX; 242 break; 243 case _SC_RE_DUP_MAX: 244 mib[0] = CTL_USER; 245 mib[1] = USER_RE_DUP_MAX; 246 break; 247 case _SC_2_VERSION: 248 mib[0] = CTL_USER; 249 mib[1] = USER_POSIX2_VERSION; 250 break; 251 case _SC_2_C_BIND: 252 mib[0] = CTL_USER; 253 mib[1] = USER_POSIX2_C_BIND; 254 goto yesno; 255 case _SC_2_C_DEV: 256 mib[0] = CTL_USER; 257 mib[1] = USER_POSIX2_C_DEV; 258 goto yesno; 259 case _SC_2_CHAR_TERM: 260 mib[0] = CTL_USER; 261 mib[1] = USER_POSIX2_CHAR_TERM; 262 goto yesno; 263 case _SC_2_FORT_DEV: 264 mib[0] = CTL_USER; 265 mib[1] = USER_POSIX2_FORT_DEV; 266 goto yesno; 267 case _SC_2_FORT_RUN: 268 mib[0] = CTL_USER; 269 mib[1] = USER_POSIX2_FORT_RUN; 270 goto yesno; 271 case _SC_2_LOCALEDEF: 272 mib[0] = CTL_USER; 273 mib[1] = USER_POSIX2_LOCALEDEF; 274 goto yesno; 275 case _SC_2_SW_DEV: 276 mib[0] = CTL_USER; 277 mib[1] = USER_POSIX2_SW_DEV; 278 goto yesno; 279 case _SC_2_UPE: 280 mib[0] = CTL_USER; 281 mib[1] = USER_POSIX2_UPE; 282 goto yesno; 283 284 /* XPG 4.2 */ 285 case _SC_IOV_MAX: 286 mib[0] = CTL_KERN; 287 mib[1] = KERN_IOV_MAX; 288 break; 289 case _SC_XOPEN_SHM: 290 mib[0] = CTL_KERN; 291 mib[1] = KERN_SYSVIPC; 292 mib[2] = KERN_SYSVIPC_SHM; 293 mib_len = 3; 294 goto yesno; 295 296 /* 1003.1-2001, XSI Option Group */ 297 case _SC_AIO_LISTIO_MAX: 298 if (sysctlgetmibinfo("kern.aio_listio_max", &mib[0], &mib_len, 299 NULL, NULL, NULL, SYSCTL_VERSION)) 300 return -1; 301 break; 302 case _SC_AIO_MAX: 303 if (sysctlgetmibinfo("kern.aio_max", &mib[0], &mib_len, 304 NULL, NULL, NULL, SYSCTL_VERSION)) 305 return -1; 306 break; 307 case _SC_ASYNCHRONOUS_IO: 308 if (sysctlgetmibinfo("kern.posix_aio", &mib[0], &mib_len, 309 NULL, NULL, NULL, SYSCTL_VERSION)) 310 return -1; 311 goto yesno; 312 case _SC_MESSAGE_PASSING: 313 if (sysctlgetmibinfo("kern.posix_msg", &mib[0], &mib_len, 314 NULL, NULL, NULL, SYSCTL_VERSION)) 315 return -1; 316 goto yesno; 317 case _SC_MQ_OPEN_MAX: 318 if (sysctlgetmibinfo("kern.mqueue.mq_open_max", &mib[0], 319 &mib_len, NULL, NULL, NULL, SYSCTL_VERSION)) 320 return -1; 321 break; 322 case _SC_MQ_PRIO_MAX: 323 if (sysctlgetmibinfo("kern.mqueue.mq_prio_max", &mib[0], 324 &mib_len, NULL, NULL, NULL, SYSCTL_VERSION)) 325 return -1; 326 break; 327 case _SC_PRIORITY_SCHEDULING: 328 if (sysctlgetmibinfo("kern.posix_sched", &mib[0], &mib_len, 329 NULL, NULL, NULL, SYSCTL_VERSION)) 330 return -1; 331 goto yesno; 332 case _SC_ATEXIT_MAX: 333 mib[0] = CTL_USER; 334 mib[1] = USER_ATEXIT_MAX; 335 break; 336 337 /* 1003.1-2001, TSF */ 338 case _SC_GETGR_R_SIZE_MAX: 339 return _GETGR_R_SIZE_MAX; 340 case _SC_GETPW_R_SIZE_MAX: 341 return _GETPW_R_SIZE_MAX; 342 343 /* Unsorted */ 344 case _SC_RTSIG_MAX: 345 return SIGRTMAX - SIGRTMIN; 346 case _SC_HOST_NAME_MAX: 347 return MAXHOSTNAMELEN; 348 case _SC_PASS_MAX: 349 return _PASSWORD_LEN; 350 case _SC_REGEXP: 351 return _POSIX_REGEXP; 352 case _SC_SHARED_MEMORY_OBJECTS: 353 return _POSIX_SHARED_MEMORY_OBJECTS; 354 case _SC_SHELL: 355 return _POSIX_SHELL; 356 case _SC_SPAWN: 357 return _POSIX_SPAWN; 358 case _SC_SYMLOOP_MAX: 359 return MAXSYMLINKS; 360 361 yesno: if (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1) 362 return (-1); 363 if (value == 0) 364 return (-1); 365 return (value); 366 367 /* Extensions */ 368 case _SC_NPROCESSORS_CONF: 369 mib[0] = CTL_HW; 370 mib[1] = HW_NCPU; 371 break; 372 case _SC_NPROCESSORS_ONLN: 373 mib[0] = CTL_HW; 374 mib[1] = HW_NCPUONLINE; 375 break; 376 377 /* Linux/Solaris */ 378 case _SC_PHYS_PAGES: 379 len = sizeof(mem); 380 mib[0] = CTL_HW; 381 mib[1] = HW_PHYSMEM64; 382 return sysctl(mib, 2, &mem, &len, NULL, 0) == -1 ? -1 : 383 (long)(mem / _getpagesize()); 384 385 case _SC_AVPHYS_PAGES: 386 len = sizeof(uvmexp); 387 mib[0] = CTL_VM; 388 mib[1] = VM_UVMEXP2; 389 return sysctl(mib, 2, &uvmexp, &len, NULL, 0) == -1 ? -1 : 390 (long)(uvmexp.free); 391 392 /* Native */ 393 case _SC_SCHED_RT_TS: 394 if (sysctlgetmibinfo("kern.sched.rtts", &mib[0], &mib_len, 395 NULL, NULL, NULL, SYSCTL_VERSION)) 396 return -1; 397 break; 398 case _SC_SCHED_PRI_MIN: 399 if (sysctlgetmibinfo("kern.sched.pri_min", &mib[0], &mib_len, 400 NULL, NULL, NULL, SYSCTL_VERSION)) 401 return -1; 402 break; 403 case _SC_SCHED_PRI_MAX: 404 if (sysctlgetmibinfo("kern.sched.pri_max", &mib[0], &mib_len, 405 NULL, NULL, NULL, SYSCTL_VERSION)) 406 return -1; 407 break; 408 case _SC_THREAD_DESTRUCTOR_ITERATIONS: 409 return _POSIX_THREAD_DESTRUCTOR_ITERATIONS; 410 case _SC_THREAD_KEYS_MAX: 411 return _POSIX_THREAD_KEYS_MAX; 412 case _SC_THREAD_STACK_MIN: 413 return _getpagesize(); 414 case _SC_THREAD_THREADS_MAX: 415 if (sysctlgetmibinfo("kern.maxproc", &mib[0], &mib_len, 416 NULL, NULL, NULL, SYSCTL_VERSION)) /* XXX */ 417 return -1; 418 goto yesno; 419 case _SC_THREAD_ATTR_STACKADDR: 420 return _POSIX_THREAD_ATTR_STACKADDR; 421 case _SC_THREAD_ATTR_STACKSIZE: 422 return _POSIX_THREAD_ATTR_STACKSIZE; 423 case _SC_THREAD_SAFE_FUNCTIONS: 424 return _POSIX_THREAD_SAFE_FUNCTIONS; 425 case _SC_THREAD_PRIO_PROTECT: 426 return _POSIX_THREAD_PRIO_PROTECT; 427 case _SC_THREAD_PRIORITY_SCHEDULING: 428 case _SC_THREAD_PRIO_INHERIT: 429 case _SC_THREAD_PROCESS_SHARED: 430 return -1; 431 case _SC_TTY_NAME_MAX: 432 return pathconf(_PATH_DEV, _PC_NAME_MAX); 433 case _SC_TIMER_MAX: 434 return _POSIX_TIMER_MAX; 435 case _SC_SEM_NSEMS_MAX: 436 return LONG_MAX; 437 case _SC_CPUTIME: 438 return _POSIX_CPUTIME; 439 case _SC_THREAD_CPUTIME: 440 return _POSIX_THREAD_CPUTIME; 441 case _SC_DELAYTIMER_MAX: 442 return _POSIX_DELAYTIMER_MAX; 443 case _SC_SIGQUEUE_MAX: 444 return _POSIX_SIGQUEUE_MAX; 445 case _SC_REALTIME_SIGNALS: 446 return 200112L; 447 default: 448 errno = EINVAL; 449 return (-1); 450 } 451 return (sysctl(mib, mib_len, &value, &len, NULL, 0) == -1 ? -1 : value); 452 } 453