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sysctl.c revision 1.32.2.1
      1 /*	$NetBSD: sysctl.c,v 1.32.2.1 2014/08/20 00:02:14 tls 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 1.32.2.1 2014/08/20 00:02:14 tls 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 #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 *)((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 
    364 static 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