xref: /netbsd-src/lib/libc/gen/sysctl.c (revision 33cd1faa348fe1cb7947ea59b0556b9bad76cee9)
1 /*	$NetBSD: sysctl.c,v 1.23 2004/03/26 22:54:42 he 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 1.23 2004/03/26 22:54:42 he 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, NULL),
153 		},
154 		_INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX, NULL),
155 		_INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX, NULL),
156 		_INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX, NULL),
157 		_INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX, NULL),
158 		_INT("coll_weights_max", USER_COLL_WEIGHTS_MAX,
159 		     COLL_WEIGHTS_MAX, NULL),
160 		_INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX, NULL),
161 		_INT("line_max", USER_LINE_MAX, LINE_MAX, NULL),
162 		_INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX, NULL),
163 		_INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION, NULL),
164 #ifdef POSIX2_C_BIND
165 		_INT("posix2_c_bind", USER_POSIX2_C_BIND, 1, NULL),
166 #else
167 		_INT("posix2_c_bind", USER_POSIX2_C_BIND, 0, NULL),
168 #endif
169 #ifdef POSIX2_C_DEV
170 		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 1, NULL),
171 #else
172 		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 0, NULL),
173 #endif
174 #ifdef POSIX2_CHAR_TERM
175 		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1, NULL),
176 #else
177 		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0, NULL),
178 #endif
179 #ifdef POSIX2_FORT_DEV
180 		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1, NULL),
181 #else
182 		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0, NULL),
183 #endif
184 #ifdef POSIX2_FORT_RUN
185 		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1, NULL),
186 #else
187 		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0, NULL),
188 #endif
189 #ifdef POSIX2_LOCALEDEF
190 		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1, NULL),
191 #else
192 		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0, NULL),
193 #endif
194 #ifdef POSIX2_SW_DEV
195 		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1, NULL),
196 #else
197 		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0, NULL),
198 #endif
199 #ifdef POSIX2_UPE
200 		_INT("posix2_upe", USER_POSIX2_UPE, 1, NULL),
201 #else
202 		_INT("posix2_upe", USER_POSIX2_UPE, 0, NULL),
203 #endif
204 		_INT("stream_max", USER_STREAM_MAX, FOPEN_MAX, NULL),
205 		_INT("tzname_max", USER_TZNAME_MAX, NAME_MAX, NULL),
206 		_INT("atexit_max", USER_ATEXIT_MAX, -1, NULL),
207 #endif /* !lint */
208 	};
209 #undef _INT
210 
211 	static const int clen = sizeof(sysctl_usermib) /
212 		sizeof(sysctl_usermib[0]);
213 
214 	const struct sysctlnode *node;
215 	int ni;
216 	size_t l, sz;
217 
218 	/*
219 	 * none of these nodes are writable and they're all terminal (for now)
220 	 */
221 	if (namelen != 1)
222 		return (EINVAL);
223 
224 	l = *oldlenp;
225 	if (name[0] == CTL_QUERY) {
226 		uint v;
227 		node = newp;
228 		if (node == NULL) {
229 			v = SYSCTL_VERS_0;
230 			newlen = sizeof(struct sysctlnode);
231 		}
232 		else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_0 &&
233 			 newlen == sizeof(struct sysctlnode0))
234 			v = SYSCTL_VERS_0;
235 		else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 &&
236 			 newlen == sizeof(struct sysctlnode))
237 			v = SYSCTL_VERS_1;
238 		else
239 			return (EINVAL);
240 
241 		sz = 0;
242 		for (ni = 0; ni < clen; ni++)
243 			sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l);
244 		*oldlenp = sz;
245 		return (0);
246 	}
247 
248 	if (name[0] == CTL_DESCRIBE) {
249 		char buf[128];
250 		struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp;
251 		size_t d;
252 
253 		node = newp;
254 		if (node != NULL &&
255 		    (SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 ||
256 		     newlen != sizeof(struct sysctlnode)))
257 			return (EINVAL);
258 
259 		sz = 0;
260 		for (ni = 0; ni < clen; ni++) {
261 			memset(&buf[0], 0, sizeof(buf));
262 			if (node != NULL &&
263 			    node->sysctl_num != sysctl_usermib[ni].sysctl_num)
264 				continue;
265 			d1->descr_num = sysctl_usermib[ni].sysctl_num;
266 			d1->descr_ver = sysctl_usermib[ni].sysctl_ver;
267 			if (sysctl_usermib[ni].sysctl_desc == NULL)
268 				d1->descr_len = 1;
269 			else {
270 				strncpy(d1->descr_str,
271 					sysctl_usermib[ni].sysctl_desc,
272 					sizeof(buf) - sizeof(*d1));
273 				buf[sizeof(buf) - 1] = '\0';
274 				d1->descr_len = strlen(d1->descr_str) + 1;
275 			}
276 			d = (size_t)__sysc_desc_adv(NULL, d1->descr_len);
277 			if (d2 != NULL)
278 				memcpy(d2, d1, d);
279 			sz += d;
280 			if (node != NULL)
281 				break;
282 		}
283 		*oldlenp = sz;
284 		if (sz == 0 && node != NULL)
285 			return (ENOENT);
286 		return (0);
287 
288 	}
289 
290 	/*
291 	 * none of these nodes are writable
292 	 */
293 	if (newp != NULL || newlen != 0)
294 		return (EPERM);
295 
296 	node = &sysctl_usermib[0];
297 	for (ni = 0; ni	< clen; ni++)
298 		if (name[0] == node[ni].sysctl_num)
299 			break;
300 	if (ni == clen)
301 		return (EOPNOTSUPP);
302 
303 	node = &node[ni];
304 	if (node->sysctl_flags & CTLFLAG_IMMEDIATE) {
305 		switch (SYSCTL_TYPE(node->sysctl_flags)) {
306 		case CTLTYPE_INT:
307 			newp = &node->sysctl_idata;
308 			break;
309 		case CTLTYPE_QUAD:
310 			newp = &node->sysctl_qdata;
311 			break;
312 		default:
313 			return (EINVAL);
314 		}
315 	}
316 	else
317 		newp = node->sysctl_data;
318 
319 	l = MIN(l, node->sysctl_size);
320 	if (oldp != NULL)
321 		memcpy(oldp, newp, l);
322 	*oldlenp = node->sysctl_size;
323 
324 	return (0);
325 }
326 
327 static size_t
328 __cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l)
329 {
330 	struct sysctlnode0 node0;
331 	const void *src = n;
332 	size_t sz;
333 
334 	switch (v) {
335 	    case SYSCTL_VERS_0:
336 		memset(&node0, 0, sizeof(node0));
337 		node0.sysctl0_flags = n->sysctl_flags;
338 		node0.sysctl0_num = n->sysctl_num;
339 		node0.sysctl0_size = n->sysctl_size;
340 		memcpy(node0.sysctl0_name, n->sysctl_name, SYSCTL_NAMELEN);
341 		node0.sysctl0_csize = n->sysctl_csize;
342 		node0.sysctl0_clen = n->sysctl_clen;
343 		node0.sysctl0_child = NULL;
344 		node0.sysctl0_alias = n->sysctl_alias;
345 		node0.sysctl0_idata = n->sysctl_idata;
346 		node0.sysctl0_qdata = n->sysctl_qdata;
347 		node0.sysctl0_data = n->sysctl_data;
348 		node0.sysctl0_func = NULL;
349 		node0.sysctl0_parent = NULL;
350 		node0.sysctl0_ver = n->sysctl_ver;
351 		node0.sysctl0_flags &= ~SYSCTL_VERS_MASK;
352 		node0.sysctl0_flags |= SYSCTL_VERS_0;
353 		src = &node0;
354 		sz = sizeof(node0);
355 		break;
356 
357 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
358 #error __cvt_node_out: no support for SYSCTL_VERSION
359 #endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */
360 
361 	case SYSCTL_VERSION:
362 		sz = sizeof(struct sysctlnode);
363 		break;
364 	default:
365 		sz = 0;
366 		break;
367 	}
368 
369 	if (sz > 0 && *o != NULL && *l >= sz) {
370 		memcpy(*o, src, sz);
371 		*o = sz + (caddr_t)*o;
372 		*l -= sz;
373 	}
374 
375 	return(sz);
376 }
377