sysctl.c revision 1.24 
1/*	$NetBSD: sysctl.c,v 1.24 2004/04/08 04:10:44 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
35static char sccsid[] = "@(#)sysctl.c	8.2 (Berkeley) 1/4/94";
36#else
37__RCSID("$NetBSD: sysctl.c,v 1.24 2004/04/08 04:10:44 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 */
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	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#else
182		_INT("posix2_c_bind", USER_POSIX2_C_BIND, 0,
183#endif
184		     "Whether the system's C-language development facilities "
185		     "support the C-Language Bindings Option"),
186#ifdef POSIX2_C_DEV
187		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 1,
188#else
189		_INT("posix2_c_dev", USER_POSIX2_C_DEV, 0,
190#endif
191		     "Whether the system supports the C-Language Development "
192		     "Utilities Option"),
193#ifdef POSIX2_CHAR_TERM
194		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1,
195#else
196		_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0,
197#endif
198		     "Whether the system supports at least one terminal type "
199		     "capable of all operations described in POSIX 1003.2"),
200#ifdef POSIX2_FORT_DEV
201		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1,
202#else
203		_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0,
204#endif
205		     "Whether the system supports the FORTRAN Development "
206		     "Utilities Option"),
207#ifdef POSIX2_FORT_RUN
208		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1,
209#else
210		_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0,
211#endif
212		     "Whether the system supports the FORTRAN Runtime "
213		     "Utilities Option"),
214#ifdef POSIX2_LOCALEDEF
215		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1,
216#else
217		_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0,
218#endif
219		     "Whether the system supports the creation of locales"),
220#ifdef POSIX2_SW_DEV
221		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1,
222#else
223		_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0,
224#endif
225		     "Whether the system supports the Software Development "
226		     "Utilities Option"),
227#ifdef POSIX2_UPE
228		_INT("posix2_upe", USER_POSIX2_UPE, 1,
229#else
230		_INT("posix2_upe", USER_POSIX2_UPE, 0,
231#endif
232		     "Whether the system supports the User Portability "
233		     "Utilities Option"),
234		_INT("stream_max", USER_STREAM_MAX, FOPEN_MAX,
235		     "The minimum maximum number of streams that a process "
236		     "may have open at any one time"),
237		_INT("tzname_max", USER_TZNAME_MAX, NAME_MAX,
238		     "The minimum maximum number of types supported for the "
239		     "name of a timezone"),
240		_INT("atexit_max", USER_ATEXIT_MAX, -1,
241		     "The maximum number of functions that may be registered "
242		     "with atexit(3)"),
243#endif /* !lint */
244	};
245#undef _INT
246
247	static const int clen = sizeof(sysctl_usermib) /
248		sizeof(sysctl_usermib[0]);
249
250	const struct sysctlnode *node;
251	int ni;
252	size_t l, sz;
253
254	/*
255	 * none of these nodes are writable and they're all terminal (for now)
256	 */
257	if (namelen != 1)
258		return (EINVAL);
259
260	l = *oldlenp;
261	if (name[0] == CTL_QUERY) {
262		uint v;
263		node = newp;
264		if (node == NULL) {
265			v = SYSCTL_VERS_0;
266			newlen = sizeof(struct sysctlnode);
267		}
268		else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_0 &&
269			 newlen == sizeof(struct sysctlnode0))
270			v = SYSCTL_VERS_0;
271		else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 &&
272			 newlen == sizeof(struct sysctlnode))
273			v = SYSCTL_VERS_1;
274		else
275			return (EINVAL);
276
277		sz = 0;
278		for (ni = 0; ni < clen; ni++)
279			sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l);
280		*oldlenp = sz;
281		return (0);
282	}
283
284	if (name[0] == CTL_DESCRIBE) {
285		/*
286		 * XXX make sure this is larger than the largest
287		 * "user" description
288		 */
289		char buf[192];
290		struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp;
291		size_t d;
292
293		node = newp;
294		if (node != NULL &&
295		    (SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 ||
296		     newlen != sizeof(struct sysctlnode)))
297			return (EINVAL);
298
299		sz = 0;
300		for (ni = 0; ni < clen; ni++) {
301			memset(&buf[0], 0, sizeof(buf));
302			if (node != NULL &&
303			    node->sysctl_num != sysctl_usermib[ni].sysctl_num)
304				continue;
305			d1->descr_num = sysctl_usermib[ni].sysctl_num;
306			d1->descr_ver = sysctl_usermib[ni].sysctl_ver;
307			if (sysctl_usermib[ni].sysctl_desc == NULL)
308				d1->descr_len = 1;
309			else {
310				strncpy(d1->descr_str,
311					sysctl_usermib[ni].sysctl_desc,
312					sizeof(buf) - sizeof(*d1));
313				buf[sizeof(buf) - 1] = '\0';
314				d1->descr_len = strlen(d1->descr_str) + 1;
315			}
316			d = (size_t)__sysc_desc_adv(NULL, d1->descr_len);
317			if (d2 != NULL)
318				memcpy(d2, d1, d);
319			sz += d;
320			if (node != NULL)
321				break;
322		}
323		*oldlenp = sz;
324		if (sz == 0 && node != NULL)
325			return (ENOENT);
326		return (0);
327
328	}
329
330	/*
331	 * none of these nodes are writable
332	 */
333	if (newp != NULL || newlen != 0)
334		return (EPERM);
335
336	node = &sysctl_usermib[0];
337	for (ni = 0; ni	< clen; ni++)
338		if (name[0] == node[ni].sysctl_num)
339			break;
340	if (ni == clen)
341		return (EOPNOTSUPP);
342
343	node = &node[ni];
344	if (node->sysctl_flags & CTLFLAG_IMMEDIATE) {
345		switch (SYSCTL_TYPE(node->sysctl_flags)) {
346		case CTLTYPE_INT:
347			newp = &node->sysctl_idata;
348			break;
349		case CTLTYPE_QUAD:
350			newp = &node->sysctl_qdata;
351			break;
352		default:
353			return (EINVAL);
354		}
355	}
356	else
357		newp = node->sysctl_data;
358
359	l = MIN(l, node->sysctl_size);
360	if (oldp != NULL)
361		memcpy(oldp, newp, l);
362	*oldlenp = node->sysctl_size;
363
364	return (0);
365}
366
367static size_t
368__cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l)
369{
370	struct sysctlnode0 node0;
371	const void *src = n;
372	size_t sz;
373
374	switch (v) {
375	    case SYSCTL_VERS_0:
376		memset(&node0, 0, sizeof(node0));
377		node0.sysctl0_flags = n->sysctl_flags;
378		node0.sysctl0_num = n->sysctl_num;
379		node0.sysctl0_size = n->sysctl_size;
380		memcpy(node0.sysctl0_name, n->sysctl_name, SYSCTL_NAMELEN);
381		node0.sysctl0_csize = n->sysctl_csize;
382		node0.sysctl0_clen = n->sysctl_clen;
383		node0.sysctl0_child = NULL;
384		node0.sysctl0_alias = n->sysctl_alias;
385		node0.sysctl0_idata = n->sysctl_idata;
386		node0.sysctl0_qdata = n->sysctl_qdata;
387		node0.sysctl0_data = n->sysctl_data;
388		node0.sysctl0_func = NULL;
389		node0.sysctl0_parent = NULL;
390		node0.sysctl0_ver = n->sysctl_ver;
391		node0.sysctl0_flags &= ~SYSCTL_VERS_MASK;
392		node0.sysctl0_flags |= SYSCTL_VERS_0;
393		src = &node0;
394		sz = sizeof(node0);
395		break;
396
397#if (SYSCTL_VERSION != SYSCTL_VERS_1)
398#error __cvt_node_out: no support for SYSCTL_VERSION
399#endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */
400
401	case SYSCTL_VERSION:
402		sz = sizeof(struct sysctlnode);
403		break;
404	default:
405		sz = 0;
406		break;
407	}
408
409	if (sz > 0 && *o != NULL && *l >= sz) {
410		memcpy(*o, src, sz);
411		*o = sz + (caddr_t)*o;
412		*l -= sz;
413	}
414
415	return(sz);
416}
417