/* $NetBSD: sysctl.c,v 1.38 2021/03/30 15:31:51 rillig Exp $ */
/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)sysctl.c 8.2 (Berkeley) 1/4/94";
#else
__RCSID("$NetBSD: sysctl.c,v 1.38 2021/03/30 15:31:51 rillig Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/param.h>
#define __COMPAT_SYSCTL
#include <sys/sysctl.h>
#include <assert.h>
#include <errno.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "extern.h"
#ifdef __weak_alias
__weak_alias(sysctl,_sysctl)
#endif
/*
* handles requests off the user subtree
*/
static int user_sysctl(const int *, u_int, void *, size_t *,
const void *, size_t);
/*
* copies out individual nodes taking target version into account
*/
static size_t __cvt_node_out(uint, const struct sysctlnode *, void **,
size_t *);
#include <stdlib.h>
int
sysctl(const int *name, unsigned int namelen,
void *oldp, size_t *oldlenp,
const void *newp, size_t newlen)
{
size_t oldlen, savelen;
int error;
if (name[0] != CTL_USER)
return (__sysctl(name, namelen, oldp, oldlenp,
newp, newlen));
oldlen = (oldlenp == NULL) ? 0 : *oldlenp;
savelen = oldlen;
error = user_sysctl(name + 1, namelen - 1, oldp, &oldlen, newp, newlen);
if (error != 0) {
errno = error;
return (-1);
}
if (oldlenp != NULL) {
*oldlenp = oldlen;
if (oldp != NULL && oldlen > savelen) {
errno = ENOMEM;
return (-1);
}
}
return (0);
}
static int
user_sysctl(const int *name, unsigned int namelen,
void *oldp, size_t *oldlenp,
const void *newp, size_t newlen)
{
#define _INT(s, n, v, d) { \
.sysctl_flags = CTLFLAG_IMMEDIATE|CTLFLAG_PERMANENT| \
CTLTYPE_INT|SYSCTL_VERSION, \
.sysctl_size = sizeof(int), \
.sysctl_name = (s), \
.sysctl_num = (n), \
.sysctl_un.scu_idata = (v), \
.sysctl_desc = (d), \
}
/*
* the nodes under the "user" node
*/
static const struct sysctlnode sysctl_usermib[] = {
{
.sysctl_flags = SYSCTL_VERSION|CTLFLAG_PERMANENT|
CTLTYPE_STRING,
.sysctl_size = sizeof(_PATH_STDPATH),
.sysctl_name = "cs_path",
.sysctl_num = USER_CS_PATH,
.sysctl_data = __UNCONST(_PATH_STDPATH),
.sysctl_desc = __UNCONST(
"A value for the PATH environment variable "
"that finds all the standard utilities"),
},
_INT("bc_base_max", USER_BC_BASE_MAX, BC_BASE_MAX,
"The maximum ibase/obase values in the bc(1) utility"),
_INT("bc_dim_max", USER_BC_DIM_MAX, BC_DIM_MAX,
"The maximum array size in the bc(1) utility"),
_INT("bc_scale_max", USER_BC_SCALE_MAX, BC_SCALE_MAX,
"The maximum scale value in the bc(1) utility"),
_INT("bc_string_max", USER_BC_STRING_MAX, BC_STRING_MAX,
"The maximum string length in the bc(1) utility"),
_INT("coll_weights_max", USER_COLL_WEIGHTS_MAX,
COLL_WEIGHTS_MAX, "The maximum number of weights that can "
"be assigned to any entry of the LC_COLLATE order keyword "
"in the locale definition file"),
_INT("expr_nest_max", USER_EXPR_NEST_MAX, EXPR_NEST_MAX,
"The maximum number of expressions that can be nested "
"within parenthesis by the expr(1) utility"),
_INT("line_max", USER_LINE_MAX, LINE_MAX, "The maximum length "
"in bytes of a text-processing utility's input line"),
_INT("re_dup_max", USER_RE_DUP_MAX, RE_DUP_MAX, "The maximum "
"number of repeated occurrences of a regular expression "
"permitted when using interval notation"),
_INT("posix2_version", USER_POSIX2_VERSION, _POSIX2_VERSION,
"The version of POSIX 1003.2 with which the system "
"attempts to comply"),
#ifdef _POSIX2_C_BIND
_INT("posix2_c_bind", USER_POSIX2_C_BIND, 1,
"Whether the system's C-language development facilities "
"support the C-Language Bindings Option"),
#else
_INT("posix2_c_bind", USER_POSIX2_C_BIND, 0,
"Whether the system's C-language development facilities "
"support the C-Language Bindings Option"),
#endif
#ifdef POSIX2_C_DEV
_INT("posix2_c_dev", USER_POSIX2_C_DEV, 1,
"Whether the system supports the C-Language Development "
"Utilities Option"),
#else
_INT("posix2_c_dev", USER_POSIX2_C_DEV, 0,
"Whether the system supports the C-Language Development "
"Utilities Option"),
#endif
#ifdef POSIX2_CHAR_TERM
_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 1,
"Whether the system supports at least one terminal type "
"capable of all operations described in POSIX 1003.2"),
#else
_INT("posix2_char_term", USER_POSIX2_CHAR_TERM, 0,
"Whether the system supports at least one terminal type "
"capable of all operations described in POSIX 1003.2"),
#endif
#ifdef POSIX2_FORT_DEV
_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 1,
"Whether the system supports the FORTRAN Development "
"Utilities Option"),
#else
_INT("posix2_fort_dev", USER_POSIX2_FORT_DEV, 0,
"Whether the system supports the FORTRAN Development "
"Utilities Option"),
#endif
#ifdef POSIX2_FORT_RUN
_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 1,
"Whether the system supports the FORTRAN Runtime "
"Utilities Option"),
#else
_INT("posix2_fort_run", USER_POSIX2_FORT_RUN, 0,
"Whether the system supports the FORTRAN Runtime "
"Utilities Option"),
#endif
#ifdef POSIX2_LOCALEDEF
_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 1,
"Whether the system supports the creation of locales"),
#else
_INT("posix2_localedef", USER_POSIX2_LOCALEDEF, 0,
"Whether the system supports the creation of locales"),
#endif
#ifdef POSIX2_SW_DEV
_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 1,
"Whether the system supports the Software Development "
"Utilities Option"),
#else
_INT("posix2_sw_dev", USER_POSIX2_SW_DEV, 0,
"Whether the system supports the Software Development "
"Utilities Option"),
#endif
#ifdef POSIX2_UPE
_INT("posix2_upe", USER_POSIX2_UPE, 1,
"Whether the system supports the User Portability "
"Utilities Option"),
#else
_INT("posix2_upe", USER_POSIX2_UPE, 0,
"Whether the system supports the User Portability "
"Utilities Option"),
#endif
_INT("stream_max", USER_STREAM_MAX, FOPEN_MAX,
"The minimum maximum number of streams that a process "
"may have open at any one time"),
_INT("tzname_max", USER_TZNAME_MAX, NAME_MAX,
"The minimum maximum number of types supported for the "
"name of a timezone"),
_INT("atexit_max", USER_ATEXIT_MAX, -1,
"The maximum number of functions that may be registered "
"with atexit(3)"),
};
#undef _INT
static const int clen = sizeof(sysctl_usermib) /
sizeof(sysctl_usermib[0]);
const struct sysctlnode *node;
int ni;
size_t l, sz;
/*
* none of these nodes are writable and they're all terminal (for now)
*/
if (namelen != 1)
return (EINVAL);
l = *oldlenp;
if (name[0] == CTL_QUERY) {
uint v;
node = newp;
if (node == NULL)
return (EINVAL);
else if (SYSCTL_VERS(node->sysctl_flags) == SYSCTL_VERS_1 &&
newlen == sizeof(struct sysctlnode))
v = SYSCTL_VERS_1;
else
return (EINVAL);
sz = 0;
for (ni = 0; ni < clen; ni++)
sz += __cvt_node_out(v, &sysctl_usermib[ni], &oldp, &l);
*oldlenp = sz;
return (0);
}
if (name[0] == CTL_DESCRIBE) {
/*
* XXX make sure this is larger than the largest
* "user" description
*/
char buf[192];
struct sysctldesc *d1 = (void *)&buf[0], *d2 = oldp;
size_t d;
node = newp;
if (node != NULL &&
(SYSCTL_VERS(node->sysctl_flags) < SYSCTL_VERS_1 ||
newlen != sizeof(struct sysctlnode)))
return (EINVAL);
sz = 0;
for (ni = 0; ni < clen; ni++) {
memset(&buf[0], 0, sizeof(buf));
if (node != NULL &&
node->sysctl_num != sysctl_usermib[ni].sysctl_num)
continue;
d1->descr_num = sysctl_usermib[ni].sysctl_num;
d1->descr_ver = sysctl_usermib[ni].sysctl_ver;
if (sysctl_usermib[ni].sysctl_desc == NULL)
d1->descr_len = 1;
else {
size_t dlen;
(void)strlcpy(d1->descr_str,
sysctl_usermib[ni].sysctl_desc,
sizeof(buf) - sizeof(*d1));
dlen = strlen(d1->descr_str) + 1;
_DIAGASSERT(__type_fit(uint32_t, dlen));
d1->descr_len = (uint32_t)dlen;
}
d = (size_t)__sysc_desc_len(d1->descr_len);
if (d2 != NULL)
memcpy(d2, d1, d);
sz += d;
d2 = (void *)((char *)(void *)d2 + d);
if (node != NULL)
break;
}
*oldlenp = sz;
if (sz == 0 && node != NULL)
return (ENOENT);
return (0);
}
/*
* none of these nodes are writable
*/
if (newp != NULL || newlen != 0)
return (EPERM);
node = &sysctl_usermib[0];
for (ni = 0; ni < clen; ni++)
if (name[0] == node[ni].sysctl_num)
break;
if (ni == clen)
return (EOPNOTSUPP);
node = &node[ni];
if (node->sysctl_flags & CTLFLAG_IMMEDIATE) {
switch (SYSCTL_TYPE(node->sysctl_flags)) {
case CTLTYPE_INT:
newp = &node->sysctl_idata;
break;
case CTLTYPE_QUAD:
newp = &node->sysctl_qdata;
break;
default:
return (EINVAL);
}
}
else
newp = node->sysctl_data;
l = MIN(l, node->sysctl_size);
if (oldp != NULL)
memcpy(oldp, newp, l);
*oldlenp = node->sysctl_size;
return (0);
}
static size_t
__cvt_node_out(uint v, const struct sysctlnode *n, void **o, size_t *l)
{
const void *src = n;
size_t sz;
switch (v) {
#if (SYSCTL_VERSION != SYSCTL_VERS_1)
#error __cvt_node_out: no support for SYSCTL_VERSION
#endif /* (SYSCTL_VERSION != SYSCTL_VERS_1) */
case SYSCTL_VERSION:
sz = sizeof(struct sysctlnode);
break;
default:
sz = 0;
break;
}
if (sz > 0 && *o != NULL && *l >= sz) {
memcpy(*o, src, sz);
*o = sz + (caddr_t)*o;
*l -= sz;
}
return(sz);
}
