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sysctl.c revision 1.27
      1 /*	$NetBSD: sysctl.c,v 1.27 2004/09/07 13:20:39 jrf 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 1.27 2004/09/07 13:20:39 jrf 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 		/* LINTED will fix when sysctl interface gets corrected */
     83 		/* XXX when will that be? */
     84 		return (__sysctl(name, namelen, oldp, oldlenp,
     85 				 (void *)newp, newlen));
     86 
     87 	oldlen = (oldlenp == NULL) ? 0 : *oldlenp;
     88 	savelen = oldlen;
     89 	error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen);
     90 
     91 	if (error != 0) {
     92 		errno = error;
     93 		return (-1);
     94 	}
     95 
     96 	if (oldlenp != NULL) {
     97 		*oldlenp = oldlen;
     98 		if (oldp != NULL && oldlen > savelen) {
     99 			errno = ENOMEM;
    100 			return (-1);
    101 		}
    102 	}
    103 
    104 	return (0);
    105 }
    106 
    107 static int
    108 user_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
    109 	int *name;
    110 	unsigned int namelen;
    111 	void *oldp;
    112 	const void *newp;
    113 	size_t *oldlenp, newlen;
    114 {
    115 #define _INT(s, n, v, d) {					\
    116 	.sysctl_flags = CTLFLAG_IMMEDIATE|CTLFLAG_PERMANENT|	\
    117 			CTLTYPE_INT|SYSCTL_VERSION,		\
    118 	sysc_init_field(_sysctl_size, sizeof(int)),		\
    119 	.sysctl_name = (s),					\
    120 	.sysctl_num = (n),					\
    121 	.sysctl_un = { .scu_idata = (v), },			\
    122 	sysc_init_field(_sysctl_desc, (d)),			\
    123 	}
    124 
    125 	/*
    126 	 * the nodes under the "user" node
    127 	 */
    128 	static const struct sysctlnode sysctl_usermib[] = {
    129 #if defined(lint)
    130 		/*
    131 		 * lint doesn't like my initializers
    132 		 */
    133 		0
    134 #else /* !lint */
    135 		{
    136 			.sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT|
    137 				CTLTYPE_STRING,
    138 			sysc_init_field(_sysctl_size, sizeof(_PATH_STDPATH)),
    139 			.sysctl_name = "cs_path",
    140 			.sysctl_num = USER_CS_PATH,
    141 			/*
    142 			 * XXX these nasty initializers (and the one in
    143 			 * the _INT() macro) can go away once all ports
    144 			 * are using gcc3, and become
    145 			 *
    146 			 *	.sysctl_data = _PATH_STDPATH,
    147 			 *	.sysctl_desc = NULL,
    148 			 */
    149 			.sysctl_un = { .scu_data = {
    150 				sysc_init_field(_sud_data, _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 }
    404