1 /* $NetBSD: sysctl.c,v 1.38 2021/03/30 15:31:51 rillig 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 35 static char sccsid[] = "@(#)sysctl.c 8.2 (Berkeley) 1/4/94"; 36 #else 37 __RCSID("$NetBSD: sysctl.c,v 1.38 2021/03/30 15:31:51 rillig 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 */ 61 static 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 */ 67 static size_t __cvt_node_out(uint, const struct sysctlnode *, void **, 68 size_t *); 69 70 #include <stdlib.h> 71 72 int 73 sysctl(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 } 103 104 static int 105 user_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 { 124 .sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT| 125 CTLTYPE_STRING, 126 .sysctl_size = sizeof(_PATH_STDPATH), 127 .sysctl_name = "cs_path", 128 .sysctl_num = USER_CS_PATH, 129 .sysctl_data = __UNCONST(_PATH_STDPATH), 130 .sysctl_desc = __UNCONST( 131 "A value for the PATH environment variable " 132 "that finds all the standard utilities"), 133 }, 134 _INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX, 135 "The maximum ibase/obase values in the bc(1) utility"), 136 _INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX, 137 "The maximum array size in the bc(1) utility"), 138 _INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX, 139 "The maximum scale value in the bc(1) utility"), 140 _INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX, 141 "The maximum string length in the bc(1) utility"), 142 _INT("coll_weights_max", USER_COLL_WEIGHTS_MAX, 143 COLL_WEIGHTS_MAX, "The maximum number of weights that can " 144 "be assigned to any entry of the LC_COLLATE order keyword " 145 "in the locale definition file"), 146 _INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX, 147 "The maximum number of expressions that can be nested " 148 "within parenthesis by the expr(1) utility"), 149 _INT("line_max", USER_LINE_MAX, LINE_MAX, "The maximum length " 150 "in bytes of a text-processing utility's input line"), 151 _INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX, "The maximum " 152 "number of repeated occurrences of a regular expression " 153 "permitted when using interval notation"), 154 _INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION, 155 "The version of POSIX 1003.2 with which the system " 156 "attempts to comply"), 157 #ifdef _POSIX2_C_BIND 158 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 1, 159 "Whether the system's C-language development facilities " 160 "support the C-Language Bindings Option"), 161 #else 162 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 0, 163 "Whether the system's C-language development facilities " 164 "support the C-Language Bindings Option"), 165 #endif 166 #ifdef POSIX2_C_DEV 167 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 1, 168 "Whether the system supports the C-Language Development " 169 "Utilities Option"), 170 #else 171 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 0, 172 "Whether the system supports the C-Language Development " 173 "Utilities Option"), 174 #endif 175 #ifdef POSIX2_CHAR_TERM 176 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1, 177 "Whether the system supports at least one terminal type " 178 "capable of all operations described in POSIX 1003.2"), 179 #else 180 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0, 181 "Whether the system supports at least one terminal type " 182 "capable of all operations described in POSIX 1003.2"), 183 #endif 184 #ifdef POSIX2_FORT_DEV 185 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1, 186 "Whether the system supports the FORTRAN Development " 187 "Utilities Option"), 188 #else 189 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0, 190 "Whether the system supports the FORTRAN Development " 191 "Utilities Option"), 192 #endif 193 #ifdef POSIX2_FORT_RUN 194 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1, 195 "Whether the system supports the FORTRAN Runtime " 196 "Utilities Option"), 197 #else 198 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0, 199 "Whether the system supports the FORTRAN Runtime " 200 "Utilities Option"), 201 #endif 202 #ifdef POSIX2_LOCALEDEF 203 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1, 204 "Whether the system supports the creation of locales"), 205 #else 206 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0, 207 "Whether the system supports the creation of locales"), 208 #endif 209 #ifdef POSIX2_SW_DEV 210 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1, 211 "Whether the system supports the Software Development " 212 "Utilities Option"), 213 #else 214 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0, 215 "Whether the system supports the Software Development " 216 "Utilities Option"), 217 #endif 218 #ifdef POSIX2_UPE 219 _INT("posix2_upe", USER_POSIX2_UPE, 1, 220 "Whether the system supports the User Portability " 221 "Utilities Option"), 222 #else 223 _INT("posix2_upe", USER_POSIX2_UPE, 0, 224 "Whether the system supports the User Portability " 225 "Utilities Option"), 226 #endif 227 _INT("stream_max", USER_STREAM_MAX, FOPEN_MAX, 228 "The minimum maximum number of streams that a process " 229 "may have open at any one time"), 230 _INT("tzname_max", USER_TZNAME_MAX, NAME_MAX, 231 "The minimum maximum number of types supported for the " 232 "name of a timezone"), 233 _INT("atexit_max", USER_ATEXIT_MAX, -1, 234 "The maximum number of functions that may be registered " 235 "with atexit(3)"), 236 }; 237 #undef _INT 238 239 static const int clen = sizeof(sysctl_usermib) / 240 sizeof(sysctl_usermib[0]); 241 242 const struct sysctlnode *node; 243 int ni; 244 size_t l, sz; 245 246 /* 247 * none of these nodes are writable and they're all terminal (for now) 248 */ 249 if (namelen != 1) 250 return (EINVAL); 251 252 l = *oldlenp; 253 if (name[0] == CTL_QUERY) { 254 uint v; 255 node = newp; 256 if (node == NULL) 257 return (EINVAL); 258 else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 && 259 newlen == sizeof(struct sysctlnode)) 260 v = SYSCTL_VERS_1; 261 else 262 return (EINVAL); 263 264 sz = 0; 265 for (ni = 0; ni < clen; ni++) 266 sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l); 267 *oldlenp = sz; 268 return (0); 269 } 270 271 if (name[0] == CTL_DESCRIBE) { 272 /* 273 * XXX make sure this is larger than the largest 274 * "user" description 275 */ 276 char buf[192]; 277 struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp; 278 size_t d; 279 280 node = newp; 281 if (node != NULL && 282 (SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 || 283 newlen != sizeof(struct sysctlnode))) 284 return (EINVAL); 285 286 sz = 0; 287 for (ni = 0; ni < clen; ni++) { 288 memset(&buf[0], 0, sizeof(buf)); 289 if (node != NULL && 290 node->sysctl_num != sysctl_usermib[ni].sysctl_num) 291 continue; 292 d1->descr_num = sysctl_usermib[ni].sysctl_num; 293 d1->descr_ver = sysctl_usermib[ni].sysctl_ver; 294 if (sysctl_usermib[ni].sysctl_desc == NULL) 295 d1->descr_len = 1; 296 else { 297 size_t dlen; 298 (void)strlcpy(d1->descr_str, 299 sysctl_usermib[ni].sysctl_desc, 300 sizeof(buf) - sizeof(*d1)); 301 dlen = strlen(d1->descr_str) + 1; 302 _DIAGASSERT(__type_fit(uint32_t, dlen)); 303 d1->descr_len = (uint32_t)dlen; 304 } 305 d = (size_t)__sysc_desc_len(d1->descr_len); 306 if (d2 != NULL) 307 memcpy(d2, d1, d); 308 sz += d; 309 d2 = (void *)((char *)(void *)d2 + d); 310 if (node != NULL) 311 break; 312 } 313 *oldlenp = sz; 314 if (sz == 0 && node != NULL) 315 return (ENOENT); 316 return (0); 317 318 } 319 320 /* 321 * none of these nodes are writable 322 */ 323 if (newp != NULL || newlen != 0) 324 return (EPERM); 325 326 node = &sysctl_usermib[0]; 327 for (ni = 0; ni < clen; ni++) 328 if (name[0] == node[ni].sysctl_num) 329 break; 330 if (ni == clen) 331 return (EOPNOTSUPP); 332 333 node = &node[ni]; 334 if (node->sysctl_flags & CTLFLAG_IMMEDIATE) { 335 switch (SYSCTL_TYPE(node->sysctl_flags)) { 336 case CTLTYPE_INT: 337 newp = &node->sysctl_idata; 338 break; 339 case CTLTYPE_QUAD: 340 newp = &node->sysctl_qdata; 341 break; 342 default: 343 return (EINVAL); 344 } 345 } 346 else 347 newp = node->sysctl_data; 348 349 l = MIN(l, node->sysctl_size); 350 if (oldp != NULL) 351 memcpy(oldp, newp, l); 352 *oldlenp = node->sysctl_size; 353 354 return (0); 355 } 356 357 static size_t 358 __cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l) 359 { 360 const void *src = n; 361 size_t sz; 362 363 switch (v) { 364 #if (SYSCTL_VERSION != SYSCTL_VERS_1) 365 #error __cvt_node_out: no support for SYSCTL_VERSION 366 #endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */ 367 368 case SYSCTL_VERSION: 369 sz = sizeof(struct sysctlnode); 370 break; 371 372 default: 373 sz = 0; 374 break; 375 } 376 377 if (sz > 0 && *o != NULL && *l >= sz) { 378 memcpy(*o, src, sz); 379 *o = sz + (caddr_t)*o; 380 *l -= sz; 381 } 382 383 return(sz); 384 } 385
Indexes created Fri Sep 26 08:10:20 GMT 2025