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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char rcsid[] = "$OpenBSD: sysconf.c,v 1.5 2003/06/02 20:18:35 millert Exp $"; 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <sys/param.h> 38 #include <sys/sysctl.h> 39 #include <sys/time.h> 40 #include <sys/resource.h> 41 42 #include <errno.h> 43 #include <unistd.h> 44 45 /* 46 * sysconf -- 47 * get configurable system variables. 48 * 49 * XXX 50 * POSIX 1003.1 (ISO/IEC 9945-1, 4.8.1.3) states that the variable values 51 * not change during the lifetime of the calling process. This would seem 52 * to require that any change to system limits kill all running processes. 53 * A workaround might be to cache the values when they are first retrieved 54 * and then simply return the cached value on subsequent calls. This is 55 * less useful than returning up-to-date values, however. 56 */ 57 long 58 sysconf(name) 59 int name; 60 { 61 struct rlimit rl; 62 size_t len; 63 int mib[2], value; 64 65 len = sizeof(value); 66 67 switch (name) { 68 /* 1003.1 */ 69 case _SC_ARG_MAX: 70 mib[0] = CTL_KERN; 71 mib[1] = KERN_ARGMAX; 72 break; 73 case _SC_CHILD_MAX: 74 return (getrlimit(RLIMIT_NPROC, &rl) ? -1 : rl.rlim_cur); 75 case _SC_CLK_TCK: 76 return (CLK_TCK); 77 case _SC_JOB_CONTROL: 78 mib[0] = CTL_KERN; 79 mib[1] = KERN_JOB_CONTROL; 80 goto yesno; 81 case _SC_NGROUPS_MAX: 82 mib[0] = CTL_KERN; 83 mib[1] = KERN_NGROUPS; 84 break; 85 case _SC_OPEN_MAX: 86 return (getrlimit(RLIMIT_NOFILE, &rl) ? -1 : rl.rlim_cur); 87 case _SC_STREAM_MAX: 88 mib[0] = CTL_USER; 89 mib[1] = USER_STREAM_MAX; 90 break; 91 case _SC_TZNAME_MAX: 92 mib[0] = CTL_USER; 93 mib[1] = USER_TZNAME_MAX; 94 break; 95 case _SC_SAVED_IDS: 96 mib[0] = CTL_KERN; 97 mib[1] = KERN_SAVED_IDS; 98 goto yesno; 99 case _SC_VERSION: 100 mib[0] = CTL_KERN; 101 mib[1] = KERN_POSIX1; 102 break; 103 104 /* 1003.1b */ 105 case _SC_PAGESIZE: 106 mib[0] = CTL_HW; 107 mib[1] = HW_PAGESIZE; 108 break; 109 case _SC_FSYNC: 110 mib[0] = CTL_KERN; 111 mib[1] = KERN_FSYNC; 112 goto yesno; 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 /* XPG 4.2 */ 185 case _SC_XOPEN_SHM: 186 mib[0] = CTL_KERN; 187 mib[1] = KERN_SYSVSHM; 188 189 yesno: if (sysctl(mib, 2, &value, &len, NULL, 0) == -1) 190 return (-1); 191 if (value == 0) 192 return (-1); 193 return (value); 194 break; 195 default: 196 errno = EINVAL; 197 return (-1); 198 } 199 return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value); 200 } 201