sysctl.c revision 1.22 
1/*	$NetBSD: sysctl.c,v 1.22 2004/03/26 12:53:58 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
35static char sccsid[] = "@(#)sysctl.c	8.2 (Berkeley) 1/4/94";
36#else
37__RCSID("$NetBSD: sysctl.c,v 1.22 2004/03/26 12:53:58 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 */
60static 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 */
65static size_t __cvt_node_out(uint, const struct sysctlnode *, void **,
66			     size_t *);
67
68#include <stdlib.h>
69
70int
71sysctl(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
107static int
108user_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	._sysctl_size = { .__sysc_ustr = { .__sysc_sdatum = sizeof(int), }, },\
119	.sysctl_name = (s),					\
120	.sysctl_num = (n),					\
121	.sysctl_un = { .scu_idata = (v), },			\
122	._sysctl_desc = { .__sysc_ustr = { .__sysc_sdatum = (d), }, }, }
123
124	/*
125	 * the nodes under the "user" node
126	 */
127	static const struct sysctlnode sysctl_usermib[] = {
128#if defined(lint)
129		/*
130		 * lint doesn't like my initializers
131		 */
132		0
133#else /* !lint */
134		{
135			.sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT|
136				CTLTYPE_STRING,
137			._sysctl_size = { .__sysc_ustr = { .__sysc_sdatum = sizeof(_PATH_STDPATH), }, },
138			.sysctl_name = "cs_path",
139			.sysctl_num = USER_CS_PATH,
140			/*
141			 * XXX these nasty initializers (and the one in
142			 * the _INT() macro) can go away once all ports
143			 * are using gcc3, and become
144			 *
145			 *	.sysctl_data = _PATH_STDPATH,
146			 *	.sysctl_desc = NULL,
147			 */
148			.sysctl_un = { .scu_data = { ._sud_data =
149				{ .__sysc_ustr = { .__sysc_sdatum =
150				_PATH_STDPATH, }, }, }, },
151			._sysctl_desc = { .__sysc_ustr = { .__sysc_sdatum =
152				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
327static 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