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sysctl.c revision 1.28
      1 /*	$NetBSD: sysctl.c,v 1.28 2005/11/29 03:11:59 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
     35 static char sccsid[] = "@(#)sysctl.c	8.2 (Berkeley) 1/4/94";
     36 #else
     37 __RCSID("$NetBSD: sysctl.c,v 1.28 2005/11/29 03:11:59 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 <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(int *, u_int, void *, size_t *, const void *, size_t);
     61 
     62 /*
     63  * copies out individual nodes taking target version into account
     64  */
     65 static size_t __cvt_node_out(uint, const struct sysctlnode *, void **,
     66 			     size_t *);
     67 
     68 #include <stdlib.h>
     69 
     70 int
     71 sysctl(name, namelen, oldp, oldlenp, newp, newlen)
     72 	int *name;
     73 	unsigned int namelen;
     74 	void *oldp;
     75 	const void *newp;
     76 	size_t *oldlenp, newlen;
     77 {
     78 	size_t oldlen, savelen;
     79 	int error;
     80 
     81 	if (name[0] != CTL_USER)
     82 		return (__sysctl(name, namelen, oldp, oldlenp,
     83 				 __UNCONST(newp), newlen));
     84 
     85 	oldlen = (oldlenp == NULL) ? 0 : *oldlenp;
     86 	savelen = oldlen;
     87 	error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen);
     88 
     89 	if (error != 0) {
     90 		errno = error;
     91 		return (-1);
     92 	}
     93 
     94 	if (oldlenp != NULL) {
     95 		*oldlenp = oldlen;
     96 		if (oldp != NULL && oldlen > savelen) {
     97 			errno = ENOMEM;
     98 			return (-1);
     99 		}
    100 	}
    101 
    102 	return (0);
    103 }
    104 
    105 static int
    106 user_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
    107 	int *name;
    108 	unsigned int namelen;
    109 	void *oldp;
    110 	const void *newp;
    111 	size_t *oldlenp, newlen;
    112 {
    113 #define _INT(s, n, v, d) {					\
    114 	.sysctl_flags = CTLFLAG_IMMEDIATE|CTLFLAG_PERMANENT|	\
    115 			CTLTYPE_INT|SYSCTL_VERSION,		\
    116 	sysc_init_field(_sysctl_size, sizeof(int)),		\
    117 	.sysctl_name = (s),					\
    118 	.sysctl_num = (n),					\
    119 	.sysctl_un = { .scu_idata = (v), },			\
    120 	sysc_init_field(_sysctl_desc, (d)),			\
    121 	}
    122 
    123 	/*
    124 	 * the nodes under the "user" node
    125 	 */
    126 	static const struct sysctlnode sysctl_usermib[] = {
    127 #if defined(lint)
    128 		/*
    129 		 * lint doesn't like my initializers
    130 		 */
    131 		0
    132 #else /* !lint */
    133 		{
    134 			.sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT|
    135 				CTLTYPE_STRING,
    136 			sysc_init_field(_sysctl_size, sizeof(_PATH_STDPATH)),
    137 			.sysctl_name = "cs_path",
    138 			.sysctl_num = USER_CS_PATH,
    139 			/*
    140 			 * XXX these nasty initializers (and the one in
    141 			 * the _INT() macro) can go away once all ports
    142 			 * are using gcc3, and become
    143 			 *
    144 			 *	.sysctl_data = _PATH_STDPATH,
    145 			 *	.sysctl_desc = NULL,
    146 			 */
    147 			.sysctl_un = { .scu_data = {
    148 				sysc_init_field(_sud_data,
    149 				__UNCONST(_PATH_STDPATH)),
    150 				}, },
    151 			sysc_init_field(_sysctl_desc,
    152 				"A value for the PATH environment variable "
    153 				"that finds all the standard utilities"),
    154 		},
    155 		_INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX,
    156 		     "The maximum ibase/obase values in the bc(1) utility"),
    157 		_INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX,
    158 		     "The maximum array size in the bc(1) utility"),
    159 		_INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX,
    160 		     "The maximum scale value in the bc(1) utility"),
    161 		_INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX,
    162 		     "The maximum string length in the bc(1) utility"),
    163 		_INT("coll_weights_max", USER_COLL_WEIGHTS_MAX,
    164 		     COLL_WEIGHTS_MAX, "The maximum number of weights that can "
    165 		     "be assigned to any entry of the LC_COLLATE order keyword "
    166 		     "in the locale definition file"),
    167 		_INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX,
    168 		     "The maximum number of expressions that can be nested "
    169 		     "within parenthesis by the expr(1) utility"),
    170 		_INT("line_max", USER_LINE_MAX, LINE_MAX, "The maximum length "
    171 		     "in bytes of a text-processing utility's input line"),
    172 		_INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX, "The maximum "
    173 		     "number of repeated occurrences of a regular expression "
    174 		     "permitted when using interval notation"),
    175 		_INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION,
    176 		     "The version of POSIX 1003.2 with which the system "
    177 		     "attempts to comply"),
    178 #ifdef POSIX2_C_BIND
    179 		_INT("posix2_c_bind", USER_POSIX2_C_BIND, 1,
    180 		     "Whether the system's C-language development facilities "
    181 		     "support the C-Language Bindings Option"),
    182 #else
    183 		_INT("posix2_c_bind", USER_POSIX2_C_BIND, 0,
    184 		     "Whether the system's C-language development facilities "
    185 		     "support the C-Language Bindings Option"),
    186 #endif
    187 #ifdef POSIX2_C_DEV
    188 		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 1,
    189 		     "Whether the system supports the C-Language Development "
    190 		     "Utilities Option"),
    191 #else
    192 		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 0,
    193 		     "Whether the system supports the C-Language Development "
    194 		     "Utilities Option"),
    195 #endif
    196 #ifdef POSIX2_CHAR_TERM
    197 		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1,
    198 		     "Whether the system supports at least one terminal type "
    199 		     "capable of all operations described in POSIX 1003.2"),
    200 #else
    201 		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0,
    202 		     "Whether the system supports at least one terminal type "
    203 		     "capable of all operations described in POSIX 1003.2"),
    204 #endif
    205 #ifdef POSIX2_FORT_DEV
    206 		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1,
    207 		     "Whether the system supports the FORTRAN Development "
    208 		     "Utilities Option"),
    209 #else
    210 		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0,
    211 		     "Whether the system supports the FORTRAN Development "
    212 		     "Utilities Option"),
    213 #endif
    214 #ifdef POSIX2_FORT_RUN
    215 		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1,
    216 		     "Whether the system supports the FORTRAN Runtime "
    217 		     "Utilities Option"),
    218 #else
    219 		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0,
    220 		     "Whether the system supports the FORTRAN Runtime "
    221 		     "Utilities Option"),
    222 #endif
    223 #ifdef POSIX2_LOCALEDEF
    224 		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1,
    225 		     "Whether the system supports the creation of locales"),
    226 #else
    227 		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0,
    228 		     "Whether the system supports the creation of locales"),
    229 #endif
    230 #ifdef POSIX2_SW_DEV
    231 		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1,
    232 		     "Whether the system supports the Software Development "
    233 		     "Utilities Option"),
    234 #else
    235 		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0,
    236 		     "Whether the system supports the Software Development "
    237 		     "Utilities Option"),
    238 #endif
    239 #ifdef POSIX2_UPE
    240 		_INT("posix2_upe", USER_POSIX2_UPE, 1,
    241 		     "Whether the system supports the User Portability "
    242 		     "Utilities Option"),
    243 #else
    244 		_INT("posix2_upe", USER_POSIX2_UPE, 0,
    245 		     "Whether the system supports the User Portability "
    246 		     "Utilities Option"),
    247 #endif
    248 		_INT("stream_max", USER_STREAM_MAX, FOPEN_MAX,
    249 		     "The minimum maximum number of streams that a process "
    250 		     "may have open at any one time"),
    251 		_INT("tzname_max", USER_TZNAME_MAX, NAME_MAX,
    252 		     "The minimum maximum number of types supported for the "
    253 		     "name of a timezone"),
    254 		_INT("atexit_max", USER_ATEXIT_MAX, -1,
    255 		     "The maximum number of functions that may be registered "
    256 		     "with atexit(3)"),
    257 #endif /* !lint */
    258 	};
    259 #undef _INT
    260 
    261 	static const int clen = sizeof(sysctl_usermib) /
    262 		sizeof(sysctl_usermib[0]);
    263 
    264 	const struct sysctlnode *node;
    265 	int ni;
    266 	size_t l, sz;
    267 
    268 	/*
    269 	 * none of these nodes are writable and they're all terminal (for now)
    270 	 */
    271 	if (namelen != 1)
    272 		return (EINVAL);
    273 
    274 	l = *oldlenp;
    275 	if (name[0] == CTL_QUERY) {
    276 		uint v;
    277 		node = newp;
    278 		if (node == NULL)
    279 			return (EINVAL);
    280 		else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 &&
    281 			 newlen == sizeof(struct sysctlnode))
    282 			v = SYSCTL_VERS_1;
    283 		else
    284 			return (EINVAL);
    285 
    286 		sz = 0;
    287 		for (ni = 0; ni < clen; ni++)
    288 			sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l);
    289 		*oldlenp = sz;
    290 		return (0);
    291 	}
    292 
    293 	if (name[0] == CTL_DESCRIBE) {
    294 		/*
    295 		 * XXX make sure this is larger than the largest
    296 		 * "user" description
    297 		 */
    298 		char buf[192];
    299 		struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp;
    300 		size_t d;
    301 
    302 		node = newp;
    303 		if (node != NULL &&
    304 		    (SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 ||
    305 		     newlen != sizeof(struct sysctlnode)))
    306 			return (EINVAL);
    307 
    308 		sz = 0;
    309 		for (ni = 0; ni < clen; ni++) {
    310 			memset(&buf[0], 0, sizeof(buf));
    311 			if (node != NULL &&
    312 			    node->sysctl_num != sysctl_usermib[ni].sysctl_num)
    313 				continue;
    314 			d1->descr_num = sysctl_usermib[ni].sysctl_num;
    315 			d1->descr_ver = sysctl_usermib[ni].sysctl_ver;
    316 			if (sysctl_usermib[ni].sysctl_desc == NULL)
    317 				d1->descr_len = 1;
    318 			else {
    319 				(void)strlcpy(d1->descr_str,
    320 					sysctl_usermib[ni].sysctl_desc,
    321 					sizeof(buf) - sizeof(*d1));
    322 				d1->descr_len = strlen(d1->descr_str) + 1;
    323 			}
    324 			d = (size_t)__sysc_desc_adv(NULL, d1->descr_len);
    325 			if (d2 != NULL)
    326 				memcpy(d2, d1, d);
    327 			sz += d;
    328 			if (node != NULL)
    329 				break;
    330 		}
    331 		*oldlenp = sz;
    332 		if (sz == 0 && node != NULL)
    333 			return (ENOENT);
    334 		return (0);
    335 
    336 	}
    337 
    338 	/*
    339 	 * none of these nodes are writable
    340 	 */
    341 	if (newp != NULL || newlen != 0)
    342 		return (EPERM);
    343 
    344 	node = &sysctl_usermib[0];
    345 	for (ni = 0; ni	< clen; ni++)
    346 		if (name[0] == node[ni].sysctl_num)
    347 			break;
    348 	if (ni == clen)
    349 		return (EOPNOTSUPP);
    350 
    351 	node = &node[ni];
    352 	if (node->sysctl_flags & CTLFLAG_IMMEDIATE) {
    353 		switch (SYSCTL_TYPE(node->sysctl_flags)) {
    354 		case CTLTYPE_INT:
    355 			newp = &node->sysctl_idata;
    356 			break;
    357 		case CTLTYPE_QUAD:
    358 			newp = &node->sysctl_qdata;
    359 			break;
    360 		default:
    361 			return (EINVAL);
    362 		}
    363 	}
    364 	else
    365 		newp = node->sysctl_data;
    366 
    367 	l = MIN(l, node->sysctl_size);
    368 	if (oldp != NULL)
    369 		memcpy(oldp, newp, l);
    370 	*oldlenp = node->sysctl_size;
    371 
    372 	return (0);
    373 }
    374 
    375 static size_t
    376 __cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l)
    377 {
    378 	const void *src = n;
    379 	size_t sz;
    380 
    381 	switch (v) {
    382 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
    383 #error __cvt_node_out: no support for SYSCTL_VERSION
    384 #endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */
    385 
    386 	case SYSCTL_VERSION:
    387 		sz = sizeof(struct sysctlnode);
    388 		break;
    389 
    390 	default:
    391 		sz = 0;
    392 		break;
    393 	}
    394 
    395 	if (sz > 0 && *o != NULL && *l >= sz) {
    396 		memcpy(*o, src, sz);
    397 		*o = sz + (caddr_t)*o;
    398 		*l -= sz;
    399 	}
    400 
    401 	return(sz);
    402 }
    403