xref: /netbsd-src/lib/libc/gen/sysctl.c (revision 21e37cc72a480a47828990a439cde7ac9ffaf0c6)
1 /*	$NetBSD: sysctl.c,v 1.26 2004/04/25 05:47:52 atatat 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 1.26 2004/04/25 05:47:52 atatat 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 				strncpy(d1->descr_str,
321 					sysctl_usermib[ni].sysctl_desc,
322 					sizeof(buf) - sizeof(*d1));
323 				buf[sizeof(buf) - 1] = '\0';
324 				d1->descr_len = strlen(d1->descr_str) + 1;
325 			}
326 			d = (size_t)__sysc_desc_adv(NULL, d1->descr_len);
327 			if (d2 != NULL)
328 				memcpy(d2, d1, d);
329 			sz += d;
330 			if (node != NULL)
331 				break;
332 		}
333 		*oldlenp = sz;
334 		if (sz == 0 && node != NULL)
335 			return (ENOENT);
336 		return (0);
337 
338 	}
339 
340 	/*
341 	 * none of these nodes are writable
342 	 */
343 	if (newp != NULL || newlen != 0)
344 		return (EPERM);
345 
346 	node = &sysctl_usermib[0];
347 	for (ni = 0; ni	< clen; ni++)
348 		if (name[0] == node[ni].sysctl_num)
349 			break;
350 	if (ni == clen)
351 		return (EOPNOTSUPP);
352 
353 	node = &node[ni];
354 	if (node->sysctl_flags & CTLFLAG_IMMEDIATE) {
355 		switch (SYSCTL_TYPE(node->sysctl_flags)) {
356 		case CTLTYPE_INT:
357 			newp = &node->sysctl_idata;
358 			break;
359 		case CTLTYPE_QUAD:
360 			newp = &node->sysctl_qdata;
361 			break;
362 		default:
363 			return (EINVAL);
364 		}
365 	}
366 	else
367 		newp = node->sysctl_data;
368 
369 	l = MIN(l, node->sysctl_size);
370 	if (oldp != NULL)
371 		memcpy(oldp, newp, l);
372 	*oldlenp = node->sysctl_size;
373 
374 	return (0);
375 }
376 
377 static size_t
378 __cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l)
379 {
380 	const void *src = n;
381 	size_t sz;
382 
383 	switch (v) {
384 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
385 #error __cvt_node_out: no support for SYSCTL_VERSION
386 #endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */
387 
388 	case SYSCTL_VERSION:
389 		sz = sizeof(struct sysctlnode);
390 		break;
391 
392 	default:
393 		sz = 0;
394 		break;
395 	}
396 
397 	if (sz > 0 && *o != NULL && *l >= sz) {
398 		memcpy(*o, src, sz);
399 		*o = sz + (caddr_t)*o;
400 		*l -= sz;
401 	}
402 
403 	return(sz);
404 }
405