sysctl.c revision 1.35
1/* $NetBSD: sysctl.c,v 1.35 2015/02/05 16:05:20 christos Exp $ */ 2 3/*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33#if defined(LIBC_SCCS) && !defined(lint) 34#if 0 35static char sccsid[] = "@(#)sysctl.c 8.2 (Berkeley) 1/4/94"; 36#else 37__RCSID("$NetBSD: sysctl.c,v 1.35 2015/02/05 16:05:20 christos Exp $"); 38#endif 39#endif /* LIBC_SCCS and not lint */ 40 41#include "namespace.h" 42#include <sys/param.h> 43#define __COMPAT_SYSCTL 44#include <sys/sysctl.h> 45 46#include <assert.h> 47#include <errno.h> 48#include <paths.h> 49#include <stdio.h> 50#include <string.h> 51#include <unistd.h> 52#include "extern.h" 53 54#ifdef __weak_alias 55__weak_alias(sysctl,_sysctl) 56#endif 57 58/* 59 * handles requests off the user subtree 60 */ 61static int user_sysctl(const int *, u_int, void *, size_t *, 62 const void *, size_t); 63 64/* 65 * copies out individual nodes taking target version into account 66 */ 67static size_t __cvt_node_out(uint, const struct sysctlnode *, void **, 68 size_t *); 69 70#include <stdlib.h> 71 72int 73sysctl(const int *name, unsigned int namelen, 74 void *oldp, size_t *oldlenp, 75 const void *newp, size_t newlen) 76{ 77 size_t oldlen, savelen; 78 int error; 79 80 if (name[0] != CTL_USER) 81 return (__sysctl(name, namelen, oldp, oldlenp, 82 newp, newlen)); 83 84 oldlen = (oldlenp == NULL) ? 0 : *oldlenp; 85 savelen = oldlen; 86 error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen); 87 88 if (error != 0) { 89 errno = error; 90 return (-1); 91 } 92 93 if (oldlenp != NULL) { 94 *oldlenp = oldlen; 95 if (oldp != NULL && oldlen > savelen) { 96 errno = ENOMEM; 97 return (-1); 98 } 99 } 100 101 return (0); 102} 103 104static int 105user_sysctl(const int *name, unsigned int namelen, 106 void *oldp, size_t *oldlenp, 107 const void *newp, size_t newlen) 108{ 109#define _INT(s, n, v, d) { \ 110 .sysctl_flags = CTLFLAG_IMMEDIATE|CTLFLAG_PERMANENT| \ 111 CTLTYPE_INT|SYSCTL_VERSION, \ 112 .sysctl_size = sizeof(int), \ 113 .sysctl_name = (s), \ 114 .sysctl_num = (n), \ 115 .sysctl_un.scu_idata = (v), \ 116 .sysctl_desc = (d), \ 117 } 118 119 /* 120 * the nodes under the "user" node 121 */ 122 static const struct sysctlnode sysctl_usermib[] = { 123#if defined(lint) 124 /* 125 * lint doesn't like my initializers 126 */ 127 0 128#else /* !lint */ 129 { 130 .sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT| 131 CTLTYPE_STRING, 132 .sysctl_size = sizeof(_PATH_STDPATH), 133 .sysctl_name = "cs_path", 134 .sysctl_num = USER_CS_PATH, 135 .sysctl_data = __UNCONST(_PATH_STDPATH), 136 .sysctl_desc = __UNCONST( 137 "A value for the PATH environment variable " 138 "that finds all the standard utilities"), 139 }, 140 _INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX, 141 "The maximum ibase/obase values in the bc(1) utility"), 142 _INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX, 143 "The maximum array size in the bc(1) utility"), 144 _INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX, 145 "The maximum scale value in the bc(1) utility"), 146 _INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX, 147 "The maximum string length in the bc(1) utility"), 148 _INT("coll_weights_max", USER_COLL_WEIGHTS_MAX, 149 COLL_WEIGHTS_MAX, "The maximum number of weights that can " 150 "be assigned to any entry of the LC_COLLATE order keyword " 151 "in the locale definition file"), 152 _INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX, 153 "The maximum number of expressions that can be nested " 154 "within parenthesis by the expr(1) utility"), 155 _INT("line_max", USER_LINE_MAX, LINE_MAX, "The maximum length " 156 "in bytes of a text-processing utility's input line"), 157 _INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX, "The maximum " 158 "number of repeated occurrences of a regular expression " 159 "permitted when using interval notation"), 160 _INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION, 161 "The version of POSIX 1003.2 with which the system " 162 "attempts to comply"), 163#ifdef _POSIX2_C_BIND 164 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 1, 165 "Whether the system's C-language development facilities " 166 "support the C-Language Bindings Option"), 167#else 168 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 0, 169 "Whether the system's C-language development facilities " 170 "support the C-Language Bindings Option"), 171#endif 172#ifdef POSIX2_C_DEV 173 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 1, 174 "Whether the system supports the C-Language Development " 175 "Utilities Option"), 176#else 177 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 0, 178 "Whether the system supports the C-Language Development " 179 "Utilities Option"), 180#endif 181#ifdef POSIX2_CHAR_TERM 182 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1, 183 "Whether the system supports at least one terminal type " 184 "capable of all operations described in POSIX 1003.2"), 185#else 186 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0, 187 "Whether the system supports at least one terminal type " 188 "capable of all operations described in POSIX 1003.2"), 189#endif 190#ifdef POSIX2_FORT_DEV 191 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1, 192 "Whether the system supports the FORTRAN Development " 193 "Utilities Option"), 194#else 195 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0, 196 "Whether the system supports the FORTRAN Development " 197 "Utilities Option"), 198#endif 199#ifdef POSIX2_FORT_RUN 200 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1, 201 "Whether the system supports the FORTRAN Runtime " 202 "Utilities Option"), 203#else 204 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0, 205 "Whether the system supports the FORTRAN Runtime " 206 "Utilities Option"), 207#endif 208#ifdef POSIX2_LOCALEDEF 209 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1, 210 "Whether the system supports the creation of locales"), 211#else 212 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0, 213 "Whether the system supports the creation of locales"), 214#endif 215#ifdef POSIX2_SW_DEV 216 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1, 217 "Whether the system supports the Software Development " 218 "Utilities Option"), 219#else 220 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0, 221 "Whether the system supports the Software Development " 222 "Utilities Option"), 223#endif 224#ifdef POSIX2_UPE 225 _INT("posix2_upe", USER_POSIX2_UPE, 1, 226 "Whether the system supports the User Portability " 227 "Utilities Option"), 228#else 229 _INT("posix2_upe", USER_POSIX2_UPE, 0, 230 "Whether the system supports the User Portability " 231 "Utilities Option"), 232#endif 233 _INT("stream_max", USER_STREAM_MAX, FOPEN_MAX, 234 "The minimum maximum number of streams that a process " 235 "may have open at any one time"), 236 _INT("tzname_max", USER_TZNAME_MAX, NAME_MAX, 237 "The minimum maximum number of types supported for the " 238 "name of a timezone"), 239 _INT("atexit_max", USER_ATEXIT_MAX, -1, 240 "The maximum number of functions that may be registered " 241 "with atexit(3)"), 242#endif /* !lint */ 243 }; 244#undef _INT 245 246 static const int clen = sizeof(sysctl_usermib) / 247 sizeof(sysctl_usermib[0]); 248 249 const struct sysctlnode *node; 250 int ni; 251 size_t l, sz; 252 253 /* 254 * none of these nodes are writable and they're all terminal (for now) 255 */ 256 if (namelen != 1) 257 return (EINVAL); 258 259 l = *oldlenp; 260 if (name[0] == CTL_QUERY) { 261 uint v; 262 node = newp; 263 if (node == NULL) 264 return (EINVAL); 265 else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 && 266 newlen == sizeof(struct sysctlnode)) 267 v = SYSCTL_VERS_1; 268 else 269 return (EINVAL); 270 271 sz = 0; 272 for (ni = 0; ni < clen; ni++) 273 sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l); 274 *oldlenp = sz; 275 return (0); 276 } 277 278 if (name[0] == CTL_DESCRIBE) { 279 /* 280 * XXX make sure this is larger than the largest 281 * "user" description 282 */ 283 char buf[192]; 284 struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp; 285 size_t d; 286 287 node = newp; 288 if (node != NULL && 289 (SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 || 290 newlen != sizeof(struct sysctlnode))) 291 return (EINVAL); 292 293 sz = 0; 294 for (ni = 0; ni < clen; ni++) { 295 memset(&buf[0], 0, sizeof(buf)); 296 if (node != NULL && 297 node->sysctl_num != sysctl_usermib[ni].sysctl_num) 298 continue; 299 d1->descr_num = sysctl_usermib[ni].sysctl_num; 300 d1->descr_ver = sysctl_usermib[ni].sysctl_ver; 301 if (sysctl_usermib[ni].sysctl_desc == NULL) 302 d1->descr_len = 1; 303 else { 304 size_t dlen; 305 (void)strlcpy(d1->descr_str, 306 sysctl_usermib[ni].sysctl_desc, 307 sizeof(buf) - sizeof(*d1)); 308 dlen = strlen(d1->descr_str) + 1; 309 _DIAGASSERT(__type_fit(uint32_t, dlen)); 310 d1->descr_len = (uint32_t)dlen; 311 } 312 d = (size_t)__sysc_desc_adv(NULL, d1->descr_len); 313 if (d2 != NULL) 314 memcpy(d2, d1, d); 315 sz += d; 316 d2 = (struct sysctldesc *)(void *)((char *)d2 + d); 317 if (node != NULL) 318 break; 319 } 320 *oldlenp = sz; 321 if (sz == 0 && node != NULL) 322 return (ENOENT); 323 return (0); 324 325 } 326 327 /* 328 * none of these nodes are writable 329 */ 330 if (newp != NULL || newlen != 0) 331 return (EPERM); 332 333 node = &sysctl_usermib[0]; 334 for (ni = 0; ni < clen; ni++) 335 if (name[0] == node[ni].sysctl_num) 336 break; 337 if (ni == clen) 338 return (EOPNOTSUPP); 339 340 node = &node[ni]; 341 if (node->sysctl_flags & CTLFLAG_IMMEDIATE) { 342 switch (SYSCTL_TYPE(node->sysctl_flags)) { 343 case CTLTYPE_INT: 344 newp = &node->sysctl_idata; 345 break; 346 case CTLTYPE_QUAD: 347 newp = &node->sysctl_qdata; 348 break; 349 default: 350 return (EINVAL); 351 } 352 } 353 else 354 newp = node->sysctl_data; 355 356 l = MIN(l, node->sysctl_size); 357 if (oldp != NULL) 358 memcpy(oldp, newp, l); 359 *oldlenp = node->sysctl_size; 360 361 return (0); 362} 363 364static size_t 365__cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l) 366{ 367 const void *src = n; 368 size_t sz; 369 370 switch (v) { 371#if (SYSCTL_VERSION != SYSCTL_VERS_1) 372#error __cvt_node_out: no support for SYSCTL_VERSION 373#endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */ 374 375 case SYSCTL_VERSION: 376 sz = sizeof(struct sysctlnode); 377 break; 378 379 default: 380 sz = 0; 381 break; 382 } 383 384 if (sz > 0 && *o != NULL && *l >= sz) { 385 memcpy(*o, src, sz); 386 *o = sz + (caddr_t)*o; 387 *l -= sz; 388 } 389 390 return(sz); 391} 392