lib/libc/gen/sysctl.c

   1 /*      $NetBSD: sysctl.c,v 1.29 2006/02/24 19:33:09 drochner 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 1.29 2006/02/24 19:33:09 drochner 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 <errno.h>
  47 #include <paths.h>
  48 #include <stdio.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51 #include "extern.h"
  52
  53 #ifdef __weak_alias
  54 __weak_alias(sysctl,_sysctl)
  55 #endif
  56
  57 /*
  58  * handles requests off the user subtree
  59  */
  60 static int user_sysctl(const int *, u_int, void *, size_t *,
  61                         const void *, size_t);
  62
  63 /*
  64  * copies out individual nodes taking target version into account
  65  */
  66 static size_t __cvt_node_out(uint, const struct sysctlnode *, void **,
  67                              size_t *);
  68
  69 #include <stdlib.h>
  70
  71 int
  72 sysctl(name, namelen, oldp, oldlenp, newp, newlen)
  73         const int *name;
  74         unsigned int namelen;
  75         void *oldp;
  76         const void *newp;
  77         size_t *oldlenp, newlen;
  78 {
  79         size_t oldlen, savelen;
  80         int error;
  81
  82         if (name[0] != CTL_USER)
  83                 return (__sysctl(name, namelen, oldp, oldlenp,
  84                                  newp, newlen));
  85
  86         oldlen = (oldlenp == NULL) ? 0 : *oldlenp;
  87         savelen = oldlen;
  88         error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen);
  89
  90         if (error != 0) {
  91                 errno = error;
  92                 return (-1);
  93         }
  94
  95         if (oldlenp != NULL) {
  96                 *oldlenp = oldlen;
  97                 if (oldp != NULL && oldlen > savelen) {
  98                         errno = ENOMEM;
  99                         return (-1);
 100                 }
 101         }
 102
 103         return (0);
 104 }
 105
 106 static int
 107 user_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
 108         const int *name;
 109         unsigned int namelen;
 110         void *oldp;
 111         const void *newp;
 112         size_t *oldlenp, newlen;
 113 {
 114 #define _INT(s, n, v, d) {                                      \
 115         .sysctl_flags = CTLFLAG_IMMEDIATE|CTLFLAG_PERMANENT|    \
 116                         CTLTYPE_INT|SYSCTL_VERSION,             \
 117         sysc_init_field(_sysctl_size, sizeof(int)),             \
 118         .sysctl_name = (s),                                     \
 119         .sysctl_num = (n),                                      \
 120         .sysctl_un = { .scu_idata = (v), },                     \
 121         sysc_init_field(_sysctl_desc, (d)),                     \
 122         }
 123
 124         /*
 125          * the nodes under the "user" node
 126          */
 127         static const struct sysctlnode sysctl_usermib[] = {
 128 #if defined(lint)
 129                 /*
 130                  * lint doesn't like my initializers
 131                  */
 132                 0
 133 #else /* !lint */
 134                 {
 135                         .sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT|
 136                                 CTLTYPE_STRING,
 137                         sysc_init_field(_sysctl_size, sizeof(_PATH_STDPATH)),
 138                         .sysctl_name = "cs_path",
 139                         .sysctl_num = USER_CS_PATH,
 140                         /*
 141                          * XXX these nasty initializers (and the one in
 142                          * the _INT() macro) can go away once all ports
 143                          * are using gcc3, and become
 144                          *
 145                          *      .sysctl_data = _PATH_STDPATH,
 146                          *      .sysctl_desc = NULL,
 147                          */
 148                         .sysctl_un = { .scu_data = {
 149                                 sysc_init_field(_sud_data,
 150                                 __UNCONST(_PATH_STDPATH)),
 151                                 }, },
 152                         sysc_init_field(_sysctl_desc,
 153                                 "A value for the PATH environment variable "
 154                                 "that finds all the standard utilities"),
 155                 },
 156                 _INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX,
 157                      "The maximum ibase/obase values in the bc(1) utility"),
 158                 _INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX,
 159                      "The maximum array size in the bc(1) utility"),
 160                 _INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX,
 161                      "The maximum scale value in the bc(1) utility"),
 162                 _INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX,
 163                      "The maximum string length in the bc(1) utility"),
 164                 _INT("coll_weights_max", USER_COLL_WEIGHTS_MAX,
 165                      COLL_WEIGHTS_MAX, "The maximum number of weights that can "
 166                      "be assigned to any entry of the LC_COLLATE order keyword "
 167                      "in the locale definition file"),
 168                 _INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX,
 169                      "The maximum number of expressions that can be nested "
 170                      "within parenthesis by the expr(1) utility"),
 171                 _INT("line_max", USER_LINE_MAX, LINE_MAX, "The maximum length "
 172                      "in bytes of a text-processing utility's input line"),
 173                 _INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX, "The maximum "
 174                      "number of repeated occurrences of a regular expression "
 175                      "permitted when using interval notation"),
 176                 _INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION,
 177                      "The version of POSIX 1003.2 with which the system "
 178                      "attempts to comply"),
 179 #ifdef _POSIX2_C_BIND
 180                 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 1,
 181                      "Whether the system's C-language development facilities "
 182                      "support the C-Language Bindings Option"),
 183 #else
 184                 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 0,
 185                      "Whether the system's C-language development facilities "
 186                      "support the C-Language Bindings Option"),
 187 #endif
 188 #ifdef POSIX2_C_DEV
 189                 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 1,
 190                      "Whether the system supports the C-Language Development "
 191                      "Utilities Option"),
 192 #else
 193                 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 0,
 194                      "Whether the system supports the C-Language Development "
 195                      "Utilities Option"),
 196 #endif
 197 #ifdef POSIX2_CHAR_TERM
 198                 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1,
 199                      "Whether the system supports at least one terminal type "
 200                      "capable of all operations described in POSIX 1003.2"),
 201 #else
 202                 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0,
 203                      "Whether the system supports at least one terminal type "
 204                      "capable of all operations described in POSIX 1003.2"),
 205 #endif
 206 #ifdef POSIX2_FORT_DEV
 207                 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1,
 208                      "Whether the system supports the FORTRAN Development "
 209                      "Utilities Option"),
 210 #else
 211                 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0,
 212                      "Whether the system supports the FORTRAN Development "
 213                      "Utilities Option"),
 214 #endif
 215 #ifdef POSIX2_FORT_RUN
 216                 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1,
 217                      "Whether the system supports the FORTRAN Runtime "
 218                      "Utilities Option"),
 219 #else
 220                 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0,
 221                      "Whether the system supports the FORTRAN Runtime "
 222                      "Utilities Option"),
 223 #endif
 224 #ifdef POSIX2_LOCALEDEF
 225                 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1,
 226                      "Whether the system supports the creation of locales"),
 227 #else
 228                 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0,
 229                      "Whether the system supports the creation of locales"),
 230 #endif
 231 #ifdef POSIX2_SW_DEV
 232                 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1,
 233                      "Whether the system supports the Software Development "
 234                      "Utilities Option"),
 235 #else
 236                 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0,
 237                      "Whether the system supports the Software Development "
 238                      "Utilities Option"),
 239 #endif
 240 #ifdef POSIX2_UPE
 241                 _INT("posix2_upe", USER_POSIX2_UPE, 1,
 242                      "Whether the system supports the User Portability "
 243                      "Utilities Option"),
 244 #else
 245                 _INT("posix2_upe", USER_POSIX2_UPE, 0,
 246                      "Whether the system supports the User Portability "
 247                      "Utilities Option"),
 248 #endif
 249                 _INT("stream_max", USER_STREAM_MAX, FOPEN_MAX,
 250                      "The minimum maximum number of streams that a process "
 251                      "may have open at any one time"),
 252                 _INT("tzname_max", USER_TZNAME_MAX, NAME_MAX,
 253                      "The minimum maximum number of types supported for the "
 254                      "name of a timezone"),
 255                 _INT("atexit_max", USER_ATEXIT_MAX, -1,
 256                      "The maximum number of functions that may be registered "
 257                      "with atexit(3)"),
 258 #endif /* !lint */
 259         };
 260 #undef _INT
 261
 262         static const int clen = sizeof(sysctl_usermib) /
 263                 sizeof(sysctl_usermib[0]);
 264
 265         const struct sysctlnode *node;
 266         int ni;
 267         size_t l, sz;
 268
 269         /*
 270          * none of these nodes are writable and they're all terminal (for now)
 271          */
 272         if (namelen != 1)
 273                 return (EINVAL);
 274
 275         l = *oldlenp;
 276         if (name[0] == CTL_QUERY) {
 277                 uint v;
 278                 node = newp;
 279                 if (node == NULL)
 280                         return (EINVAL);
 281                 else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 &&
 282                          newlen == sizeof(struct sysctlnode))
 283                         v = SYSCTL_VERS_1;
 284                 else
 285                         return (EINVAL);
 286
 287                 sz = 0;
 288                 for (ni = 0; ni < clen; ni++)
 289                         sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l);
 290                 *oldlenp = sz;
 291                 return (0);
 292         }
 293
 294         if (name[0] == CTL_DESCRIBE) {
 295                 /*
 296                  * XXX make sure this is larger than the largest
 297                  * "user" description
 298                  */
 299                 char buf[192];
 300                 struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp;
 301                 size_t d;
 302
 303                 node = newp;
 304                 if (node != NULL &&
 305                     (SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 ||
 306                      newlen != sizeof(struct sysctlnode)))
 307                         return (EINVAL);
 308
 309                 sz = 0;
 310                 for (ni = 0; ni < clen; ni++) {
 311                         memset(&buf[0], 0, sizeof(buf));
 312                         if (node != NULL &&
 313                             node->sysctl_num != sysctl_usermib[ni].sysctl_num)
 314                                 continue;
 315                         d1->descr_num = sysctl_usermib[ni].sysctl_num;
 316                         d1->descr_ver = sysctl_usermib[ni].sysctl_ver;
 317                         if (sysctl_usermib[ni].sysctl_desc == NULL)
 318                                 d1->descr_len = 1;
 319                         else {
 320                                 (void)strlcpy(d1->descr_str,
 321                                         sysctl_usermib[ni].sysctl_desc,
 322                                         sizeof(buf) - sizeof(*d1));
 323                                 d1->descr_len = strlen(d1->descr_str) + 1;
 324                         }
 325                         d = (size_t)__sysc_desc_adv(NULL, d1->descr_len);
 326                         if (d2 != NULL)
 327                                 memcpy(d2, d1, d);
 328                         sz += d;
 329                         if (node != NULL)
 330                                 break;
 331                 }
 332                 *oldlenp = sz;
 333                 if (sz == 0 && node != NULL)
 334                         return (ENOENT);
 335                 return (0);
 336
 337         }
 338
 339         /*
 340          * none of these nodes are writable
 341          */
 342         if (newp != NULL || newlen != 0)
 343                 return (EPERM);
 344
 345         node = &sysctl_usermib[0];
 346         for (ni = 0; ni < clen; ni++)
 347                 if (name[0] == node[ni].sysctl_num)
 348                         break;
 349         if (ni == clen)
 350                 return (EOPNOTSUPP);
 351
 352         node = &node[ni];
 353         if (node->sysctl_flags & CTLFLAG_IMMEDIATE) {
 354                 switch (SYSCTL_TYPE(node->sysctl_flags)) {
 355                 case CTLTYPE_INT:
 356                         newp = &node->sysctl_idata;
 357                         break;
 358                 case CTLTYPE_QUAD:
 359                         newp = &node->sysctl_qdata;
 360                         break;
 361                 default:
 362                         return (EINVAL);
 363                 }
 364         }
 365         else
 366                 newp = node->sysctl_data;
 367
 368         l = MIN(l, node->sysctl_size);
 369         if (oldp != NULL)
 370                 memcpy(oldp, newp, l);
 371         *oldlenp = node->sysctl_size;
 372
 373         return (0);
 374 }
 375
 376 static size_t
 377 __cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l)
 378 {
 379         const void *src = n;
 380         size_t sz;
 381
 382         switch (v) {
 383 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
 384 #error __cvt_node_out: no support for SYSCTL_VERSION
 385 #endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */
 386
 387         case SYSCTL_VERSION:
 388                 sz = sizeof(struct sysctlnode);
 389                 break;
 390
 391         default:
 392                 sz = 0;
 393                 break;
 394         }
 395
 396         if (sz > 0 && *o != NULL && *l >= sz) {
 397                 memcpy(*o, src, sz);
 398                 *o = sz + (caddr_t)*o;
 399                 *l -= sz;
 400         }
 401
 402         return(sz);
 403 }