1/*	$NetBSD: sysctl.c,v 1.29 2006/02/24 19:33:09 drochner 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 1.29 2006/02/24 19:33:09 drochner 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(const int *, u_int, void *, size_t *,
61			const void *, size_t);
62
63/*
64 * copies out individual nodes taking target version into account
65 */
66static size_t __cvt_node_out(uint, const struct sysctlnode *, void **,
67			     size_t *);
68
69#include <stdlib.h>
70
71int
72sysctl(name, namelen, oldp, oldlenp, newp, newlen)
73	const int *name;
74	unsigned int namelen;
75	void *oldp;
76	const void *newp;
77	size_t *oldlenp, newlen;
78{
79	size_t oldlen, savelen;
80	int error;
81
82	if (name[0] != CTL_USER)
83		return (__sysctl(name, namelen, oldp, oldlenp,
84				 newp, newlen));
85
86	oldlen = (oldlenp == NULL) ? 0 : *oldlenp;
87	savelen = oldlen;
88	error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen);
89
90	if (error != 0) {
91		errno = error;
92		return (-1);
93	}
94
95	if (oldlenp != NULL) {
96		*oldlenp = oldlen;
97		if (oldp != NULL && oldlen > savelen) {
98			errno = ENOMEM;
99			return (-1);
100		}
101	}
102
103	return (0);
104}
105
106static int
107user_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
108	const int *name;
109	unsigned int namelen;
110	void *oldp;
111	const void *newp;
112	size_t *oldlenp, newlen;
113{
114#define _INT(s, n, v, d) {					\
115	.sysctl_flags = CTLFLAG_IMMEDIATE|CTLFLAG_PERMANENT|	\
116			CTLTYPE_INT|SYSCTL_VERSION,		\
117	sysc_init_field(_sysctl_size, sizeof(int)),		\
118	.sysctl_name = (s),					\
119	.sysctl_num = (n),					\
120	.sysctl_un = { .scu_idata = (v), },			\
121	sysc_init_field(_sysctl_desc, (d)),			\
122	}
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			sysc_init_field(_sysctl_size, 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 = {
149				sysc_init_field(_sud_data,
150				__UNCONST(_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
376static 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