1 /* $NetBSD: sysctl.c,v 1.35 2015/02/05 16:05:20 christos 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 1.35 2015/02/05 16:05:20 christos 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 <assert.h>
47 #include <errno.h>
48 #include <paths.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include "extern.h"
53
54 #ifdef __weak_alias
55 __weak_alias(sysctl,_sysctl)
56 #endif
57
58 /*
59 * handles requests off the user subtree
60 */
61 static int user_sysctl(const int *, u_int, void *, size_t *,
62 const void *, size_t);
63
64 /*
65 * copies out individual nodes taking target version into account
66 */
67 static size_t __cvt_node_out(uint, const struct sysctlnode *, void **,
68 size_t *);
69
70 #include <stdlib.h>
71
72 int
sysctl(const int * name,unsigned int namelen,void * oldp,size_t * oldlenp,const void * newp,size_t newlen)73 sysctl(const int *name, unsigned int namelen,
74 void *oldp, size_t *oldlenp,
75 const void *newp, size_t newlen)
76 {
77 size_t oldlen, savelen;
78 int error;
79
80 if (name[0] != CTL_USER)
81 return (__sysctl(name, namelen, oldp, oldlenp,
82 newp, newlen));
83
84 oldlen = (oldlenp == NULL) ? 0 : *oldlenp;
85 savelen = oldlen;
86 error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen);
87
88 if (error != 0) {
89 errno = error;
90 return (-1);
91 }
92
93 if (oldlenp != NULL) {
94 *oldlenp = oldlen;
95 if (oldp != NULL && oldlen > savelen) {
96 errno = ENOMEM;
97 return (-1);
98 }
99 }
100
101 return (0);
102 }
103
104 static int
user_sysctl(const int * name,unsigned int namelen,void * oldp,size_t * oldlenp,const void * newp,size_t newlen)105 user_sysctl(const int *name, unsigned int namelen,
106 void *oldp, size_t *oldlenp,
107 const void *newp, size_t newlen)
108 {
109 #define _INT(s, n, v, d) { \
110 .sysctl_flags = CTLFLAG_IMMEDIATE|CTLFLAG_PERMANENT| \
111 CTLTYPE_INT|SYSCTL_VERSION, \
112 .sysctl_size = sizeof(int), \
113 .sysctl_name = (s), \
114 .sysctl_num = (n), \
115 .sysctl_un.scu_idata = (v), \
116 .sysctl_desc = (d), \
117 }
118
119 /*
120 * the nodes under the "user" node
121 */
122 static const struct sysctlnode sysctl_usermib[] = {
123 #if defined(lint)
124 /*
125 * lint doesn't like my initializers
126 */
127 0
128 #else /* !lint */
129 {
130 .sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT|
131 CTLTYPE_STRING,
132 .sysctl_size = sizeof(_PATH_STDPATH),
133 .sysctl_name = "cs_path",
134 .sysctl_num = USER_CS_PATH,
135 .sysctl_data = __UNCONST(_PATH_STDPATH),
136 .sysctl_desc = __UNCONST(
137 "A value for the PATH environment variable "
138 "that finds all the standard utilities"),
139 },
140 _INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX,
141 "The maximum ibase/obase values in the bc(1) utility"),
142 _INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX,
143 "The maximum array size in the bc(1) utility"),
144 _INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX,
145 "The maximum scale value in the bc(1) utility"),
146 _INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX,
147 "The maximum string length in the bc(1) utility"),
148 _INT("coll_weights_max", USER_COLL_WEIGHTS_MAX,
149 COLL_WEIGHTS_MAX, "The maximum number of weights that can "
150 "be assigned to any entry of the LC_COLLATE order keyword "
151 "in the locale definition file"),
152 _INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX,
153 "The maximum number of expressions that can be nested "
154 "within parenthesis by the expr(1) utility"),
155 _INT("line_max", USER_LINE_MAX, LINE_MAX, "The maximum length "
156 "in bytes of a text-processing utility's input line"),
157 _INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX, "The maximum "
158 "number of repeated occurrences of a regular expression "
159 "permitted when using interval notation"),
160 _INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION,
161 "The version of POSIX 1003.2 with which the system "
162 "attempts to comply"),
163 #ifdef _POSIX2_C_BIND
164 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 1,
165 "Whether the system's C-language development facilities "
166 "support the C-Language Bindings Option"),
167 #else
168 _INT("posix2_c_bind", USER_POSIX2_C_BIND, 0,
169 "Whether the system's C-language development facilities "
170 "support the C-Language Bindings Option"),
171 #endif
172 #ifdef POSIX2_C_DEV
173 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 1,
174 "Whether the system supports the C-Language Development "
175 "Utilities Option"),
176 #else
177 _INT("posix2_c_dev", USER_POSIX2_C_DEV, 0,
178 "Whether the system supports the C-Language Development "
179 "Utilities Option"),
180 #endif
181 #ifdef POSIX2_CHAR_TERM
182 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1,
183 "Whether the system supports at least one terminal type "
184 "capable of all operations described in POSIX 1003.2"),
185 #else
186 _INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0,
187 "Whether the system supports at least one terminal type "
188 "capable of all operations described in POSIX 1003.2"),
189 #endif
190 #ifdef POSIX2_FORT_DEV
191 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1,
192 "Whether the system supports the FORTRAN Development "
193 "Utilities Option"),
194 #else
195 _INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0,
196 "Whether the system supports the FORTRAN Development "
197 "Utilities Option"),
198 #endif
199 #ifdef POSIX2_FORT_RUN
200 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1,
201 "Whether the system supports the FORTRAN Runtime "
202 "Utilities Option"),
203 #else
204 _INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0,
205 "Whether the system supports the FORTRAN Runtime "
206 "Utilities Option"),
207 #endif
208 #ifdef POSIX2_LOCALEDEF
209 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1,
210 "Whether the system supports the creation of locales"),
211 #else
212 _INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0,
213 "Whether the system supports the creation of locales"),
214 #endif
215 #ifdef POSIX2_SW_DEV
216 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1,
217 "Whether the system supports the Software Development "
218 "Utilities Option"),
219 #else
220 _INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0,
221 "Whether the system supports the Software Development "
222 "Utilities Option"),
223 #endif
224 #ifdef POSIX2_UPE
225 _INT("posix2_upe", USER_POSIX2_UPE, 1,
226 "Whether the system supports the User Portability "
227 "Utilities Option"),
228 #else
229 _INT("posix2_upe", USER_POSIX2_UPE, 0,
230 "Whether the system supports the User Portability "
231 "Utilities Option"),
232 #endif
233 _INT("stream_max", USER_STREAM_MAX, FOPEN_MAX,
234 "The minimum maximum number of streams that a process "
235 "may have open at any one time"),
236 _INT("tzname_max", USER_TZNAME_MAX, NAME_MAX,
237 "The minimum maximum number of types supported for the "
238 "name of a timezone"),
239 _INT("atexit_max", USER_ATEXIT_MAX, -1,
240 "The maximum number of functions that may be registered "
241 "with atexit(3)"),
242 #endif /* !lint */
243 };
244 #undef _INT
245
246 static const int clen = sizeof(sysctl_usermib) /
247 sizeof(sysctl_usermib[0]);
248
249 const struct sysctlnode *node;
250 int ni;
251 size_t l, sz;
252
253 /*
254 * none of these nodes are writable and they're all terminal (for now)
255 */
256 if (namelen != 1)
257 return (EINVAL);
258
259 l = *oldlenp;
260 if (name[0] == CTL_QUERY) {
261 uint v;
262 node = newp;
263 if (node == NULL)
264 return (EINVAL);
265 else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 &&
266 newlen == sizeof(struct sysctlnode))
267 v = SYSCTL_VERS_1;
268 else
269 return (EINVAL);
270
271 sz = 0;
272 for (ni = 0; ni < clen; ni++)
273 sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l);
274 *oldlenp = sz;
275 return (0);
276 }
277
278 if (name[0] == CTL_DESCRIBE) {
279 /*
280 * XXX make sure this is larger than the largest
281 * "user" description
282 */
283 char buf[192];
284 struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp;
285 size_t d;
286
287 node = newp;
288 if (node != NULL &&
289 (SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 ||
290 newlen != sizeof(struct sysctlnode)))
291 return (EINVAL);
292
293 sz = 0;
294 for (ni = 0; ni < clen; ni++) {
295 memset(&buf[0], 0, sizeof(buf));
296 if (node != NULL &&
297 node->sysctl_num != sysctl_usermib[ni].sysctl_num)
298 continue;
299 d1->descr_num = sysctl_usermib[ni].sysctl_num;
300 d1->descr_ver = sysctl_usermib[ni].sysctl_ver;
301 if (sysctl_usermib[ni].sysctl_desc == NULL)
302 d1->descr_len = 1;
303 else {
304 size_t dlen;
305 (void)strlcpy(d1->descr_str,
306 sysctl_usermib[ni].sysctl_desc,
307 sizeof(buf) - sizeof(*d1));
308 dlen = strlen(d1->descr_str) + 1;
309 _DIAGASSERT(__type_fit(uint32_t, dlen));
310 d1->descr_len = (uint32_t)dlen;
311 }
312 d = (size_t)__sysc_desc_adv(NULL, d1->descr_len);
313 if (d2 != NULL)
314 memcpy(d2, d1, d);
315 sz += d;
316 d2 = (struct sysctldesc *)(void *)((char *)d2 + d);
317 if (node != NULL)
318 break;
319 }
320 *oldlenp = sz;
321 if (sz == 0 && node != NULL)
322 return (ENOENT);
323 return (0);
324
325 }
326
327 /*
328 * none of these nodes are writable
329 */
330 if (newp != NULL || newlen != 0)
331 return (EPERM);
332
333 node = &sysctl_usermib[0];
334 for (ni = 0; ni < clen; ni++)
335 if (name[0] == node[ni].sysctl_num)
336 break;
337 if (ni == clen)
338 return (EOPNOTSUPP);
339
340 node = &node[ni];
341 if (node->sysctl_flags & CTLFLAG_IMMEDIATE) {
342 switch (SYSCTL_TYPE(node->sysctl_flags)) {
343 case CTLTYPE_INT:
344 newp = &node->sysctl_idata;
345 break;
346 case CTLTYPE_QUAD:
347 newp = &node->sysctl_qdata;
348 break;
349 default:
350 return (EINVAL);
351 }
352 }
353 else
354 newp = node->sysctl_data;
355
356 l = MIN(l, node->sysctl_size);
357 if (oldp != NULL)
358 memcpy(oldp, newp, l);
359 *oldlenp = node->sysctl_size;
360
361 return (0);
362 }
363
364 static size_t
__cvt_node_out(uint v,const struct sysctlnode * n,void ** o,size_t * l)365 __cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l)
366 {
367 const void *src = n;
368 size_t sz;
369
370 switch (v) {
371 #if (SYSCTL_VERSION != SYSCTL_VERS_1)
372 #error __cvt_node_out: no support for SYSCTL_VERSION
373 #endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */
374
375 case SYSCTL_VERSION:
376 sz = sizeof(struct sysctlnode);
377 break;
378
379 default:
380 sz = 0;
381 break;
382 }
383
384 if (sz > 0 && *o != NULL && *l >= sz) {
385 memcpy(*o, src, sz);
386 *o = sz + (caddr_t)*o;
387 *l -= sz;
388 }
389
390 return(sz);
391 }
392