1 /* $NetBSD: sysconf.c,v 1.16 2002/06/30 09:45:40 bjh21 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)sysconf.c 8.2 (Berkeley) 3/20/94"; 43 #else 44 __RCSID("$NetBSD: sysconf.c,v 1.16 2002/06/30 09:45:40 bjh21 Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include "namespace.h" 49 #include <sys/param.h> 50 #include <sys/sysctl.h> 51 #include <sys/time.h> 52 #include <sys/resource.h> 53 54 #include <errno.h> 55 #include <time.h> 56 #include <unistd.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(name) 76 int name; 77 { 78 struct rlimit rl; 79 size_t len; 80 int mib[2], value; 81 struct clockinfo tmpclock; 82 static int clk_tck; 83 84 len = sizeof(value); 85 86 switch (name) { 87 /* 1003.1 */ 88 case _SC_ARG_MAX: 89 mib[0] = CTL_KERN; 90 mib[1] = KERN_ARGMAX; 91 break; 92 case _SC_CHILD_MAX: 93 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : (long)rl.rlim_cur); 94 case _O_SC_CLK_TCK: 95 /* 96 * For applications compiled when CLK_TCK was a compile-time 97 * constant. 98 */ 99 return 100; 100 case _SC_CLK_TCK: 101 /* 102 * Has to be handled specially because it returns a 103 * struct clockinfo instead of an integer. Also, since 104 * this might be called often by some things that 105 * don't grok CLK_TCK can be a macro expanding to a 106 * function, cache the value. 107 */ 108 if (clk_tck == 0) { 109 mib[0] = CTL_KERN; 110 mib[1] = KERN_CLOCKRATE; 111 len = sizeof(struct clockinfo); 112 clk_tck = sysctl(mib, 2, &tmpclock, &len, NULL, 0) 113 == -1 ? -1 : tmpclock.hz; 114 } 115 return(clk_tck); 116 case _SC_JOB_CONTROL: 117 mib[0] = CTL_KERN; 118 mib[1] = KERN_JOB_CONTROL; 119 goto yesno; 120 case _SC_NGROUPS_MAX: 121 mib[0] = CTL_KERN; 122 mib[1] = KERN_NGROUPS; 123 break; 124 case _SC_OPEN_MAX: 125 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : (long)rl.rlim_cur); 126 case _SC_STREAM_MAX: 127 mib[0] = CTL_USER; 128 mib[1] = USER_STREAM_MAX; 129 break; 130 case _SC_TZNAME_MAX: 131 mib[0] = CTL_USER; 132 mib[1] = USER_TZNAME_MAX; 133 break; 134 case _SC_SAVED_IDS: 135 mib[0] = CTL_KERN; 136 mib[1] = KERN_SAVED_IDS; 137 goto yesno; 138 case _SC_VERSION: 139 mib[0] = CTL_KERN; 140 mib[1] = KERN_POSIX1; 141 break; 142 143 /* 1003.1b */ 144 case _SC_PAGESIZE: 145 mib[0] = CTL_HW; 146 mib[1] = HW_PAGESIZE; 147 break; 148 case _SC_FSYNC: 149 mib[0] = CTL_KERN; 150 mib[1] = KERN_FSYNC; 151 goto yesno; 152 case _SC_SYNCHRONIZED_IO: 153 mib[0] = CTL_KERN; 154 mib[1] = KERN_SYNCHRONIZED_IO; 155 goto yesno; 156 case _SC_MAPPED_FILES: 157 mib[0] = CTL_KERN; 158 mib[1] = KERN_MAPPED_FILES; 159 goto yesno; 160 case _SC_MEMLOCK: 161 mib[0] = CTL_KERN; 162 mib[1] = KERN_MEMLOCK; 163 goto yesno; 164 case _SC_MEMLOCK_RANGE: 165 mib[0] = CTL_KERN; 166 mib[1] = KERN_MEMLOCK_RANGE; 167 goto yesno; 168 case _SC_MEMORY_PROTECTION: 169 mib[0] = CTL_KERN; 170 mib[1] = KERN_MEMORY_PROTECTION; 171 goto yesno; 172 case _SC_MONOTONIC_CLOCK: 173 mib[0] = CTL_KERN; 174 mib[1] = KERN_MONOTONIC_CLOCK; 175 goto yesno; 176 177 /* 1003.1c */ 178 case _SC_LOGIN_NAME_MAX: 179 mib[0] = CTL_KERN; 180 mib[1] = KERN_LOGIN_NAME_MAX; 181 break; 182 183 /* 1003.2 */ 184 case _SC_BC_BASE_MAX: 185 mib[0] = CTL_USER; 186 mib[1] = USER_BC_BASE_MAX; 187 break; 188 case _SC_BC_DIM_MAX: 189 mib[0] = CTL_USER; 190 mib[1] = USER_BC_DIM_MAX; 191 break; 192 case _SC_BC_SCALE_MAX: 193 mib[0] = CTL_USER; 194 mib[1] = USER_BC_SCALE_MAX; 195 break; 196 case _SC_BC_STRING_MAX: 197 mib[0] = CTL_USER; 198 mib[1] = USER_BC_STRING_MAX; 199 break; 200 case _SC_COLL_WEIGHTS_MAX: 201 mib[0] = CTL_USER; 202 mib[1] = USER_COLL_WEIGHTS_MAX; 203 break; 204 case _SC_EXPR_NEST_MAX: 205 mib[0] = CTL_USER; 206 mib[1] = USER_EXPR_NEST_MAX; 207 break; 208 case _SC_LINE_MAX: 209 mib[0] = CTL_USER; 210 mib[1] = USER_LINE_MAX; 211 break; 212 case _SC_RE_DUP_MAX: 213 mib[0] = CTL_USER; 214 mib[1] = USER_RE_DUP_MAX; 215 break; 216 case _SC_2_VERSION: 217 mib[0] = CTL_USER; 218 mib[1] = USER_POSIX2_VERSION; 219 break; 220 case _SC_2_C_BIND: 221 mib[0] = CTL_USER; 222 mib[1] = USER_POSIX2_C_BIND; 223 goto yesno; 224 case _SC_2_C_DEV: 225 mib[0] = CTL_USER; 226 mib[1] = USER_POSIX2_C_DEV; 227 goto yesno; 228 case _SC_2_CHAR_TERM: 229 mib[0] = CTL_USER; 230 mib[1] = USER_POSIX2_CHAR_TERM; 231 goto yesno; 232 case _SC_2_FORT_DEV: 233 mib[0] = CTL_USER; 234 mib[1] = USER_POSIX2_FORT_DEV; 235 goto yesno; 236 case _SC_2_FORT_RUN: 237 mib[0] = CTL_USER; 238 mib[1] = USER_POSIX2_FORT_RUN; 239 goto yesno; 240 case _SC_2_LOCALEDEF: 241 mib[0] = CTL_USER; 242 mib[1] = USER_POSIX2_LOCALEDEF; 243 goto yesno; 244 case _SC_2_SW_DEV: 245 mib[0] = CTL_USER; 246 mib[1] = USER_POSIX2_SW_DEV; 247 goto yesno; 248 case _SC_2_UPE: 249 mib[0] = CTL_USER; 250 mib[1] = USER_POSIX2_UPE; 251 goto yesno; 252 253 /* XPG 4.2 */ 254 case _SC_IOV_MAX: 255 mib[0] = CTL_KERN; 256 mib[1] = KERN_IOV_MAX; 257 break; 258 case _SC_XOPEN_SHM: 259 mib[0] = CTL_KERN; 260 mib[1] = KERN_SYSVSHM; 261 yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 262 return (-1); 263 if (value == 0) 264 return (-1); 265 return (value); 266 /*NOTREACHED*/ 267 break; 268 default: 269 errno = EINVAL; 270 return (-1); 271 } 272 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 273 } 274