/* $NetBSD: linux_sysctl.c,v 1.48 2023/07/10 02:31:55 christos Exp $ */

/* $NetBSD: linux_sysctl.c,v 1.48 2023/07/10 02:31:55 christos Exp $ */

/*-
* Copyright (c) 2003, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Brown.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

/*
* sysctl system call.
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_sysctl.c,v 1.48 2023/07/10 02:31:55 christos Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <sys/sched.h>
#include <sys/syscallargs.h>
#include <sys/ktrace.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>

#include <compat/linux/linux_syscallargs.h>
#include <compat/linux/common/linux_sysctl.h>
#include <compat/linux/common/linux_exec.h>
#include <compat/linux/common/linux_machdep.h>

char linux_sysname[128] = "Linux";
char linux_release[128] = "6.3.10";
char linux_version[128] = "#1 SMP PREEMPT_DYNAMIC Wed Jun 28 18:34:30 UTC 2023";

struct sysctlnode linux_sysctl_root = {
.sysctl_flags = SYSCTL_VERSION|
CTLFLAG_ROOT|CTLTYPE_NODE|CTLFLAG_READWRITE,
.sysctl_num = 0,
.sysctl_name = "(linux_root)",
.sysctl_size = sizeof(struct sysctlnode),
};

extern int linux_enabled;

/*
* We need an additional sysctllog here since each log can only
* deal with a single root node.
*/

static struct sysctllog *linux_clog;

void
linux_sysctl_fini(void)
{

sysctl_teardown(&linux_clog);
sysctl_free(&linux_sysctl_root);
}

#if !defined(__aarch64__)

SYSCTL_SETUP(linux_sysctl_setup, "linux emulation sysctls")
{
const struct sysctlnode *node = &linux_sysctl_root;

sysctl_createv(&linux_clog, 0, &node, &node,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "kern", NULL,
NULL, 0, NULL, 0,
LINUX_CTL_KERN, CTL_EOL);
sysctl_createv(&linux_clog, 0, &node, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRING, "ostype", NULL,
NULL, 0, linux_sysname, sizeof(linux_sysname),
LINUX_KERN_OSTYPE, CTL_EOL);
sysctl_createv(&linux_clog, 0, &node, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRING, "osrelease", NULL,
NULL, 0, linux_release, sizeof(linux_release),
LINUX_KERN_OSRELEASE, CTL_EOL);
sysctl_createv(&linux_clog, 0, &node, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRING, "version", NULL,
NULL, 0, linux_version, sizeof(linux_version),
LINUX_KERN_VERSION, CTL_EOL);

sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "linux",
SYSCTL_DESCR("Linux emulation settings"),
NULL, 0, NULL, 0,
CTL_EMUL, EMUL_LINUX, CTL_EOL);

sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "kern",
SYSCTL_DESCR("Linux kernel emulation settings"),
NULL, 0, NULL, 0,
CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_STRING, "ostype",
SYSCTL_DESCR("Linux operating system type"),
NULL, 0, linux_sysname, sizeof(linux_sysname),
CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
EMUL_LINUX_KERN_OSTYPE, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_STRING, "osrelease",
SYSCTL_DESCR("Linux operating system release"),
NULL, 0, linux_release, sizeof(linux_release),
CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
EMUL_LINUX_KERN_OSRELEASE, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_STRING, "osversion",
SYSCTL_DESCR("Linux operating system revision"),
NULL, 0, linux_version, sizeof(linux_version),
CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
EMUL_LINUX_KERN_VERSION, CTL_EOL);

sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_READWRITE,
CTLTYPE_INT, "enabled",
SYSCTL_DESCR("Linux compat enabled."),
linux_sysctl_enable, 0, &linux_enabled, 0,
CTL_EMUL, EMUL_LINUX, CTL_CREATE, CTL_EOL);

linux_sysctl_root.sysctl_flags &= ~CTLFLAG_READWRITE;
}

/*
* linux sysctl system call
*/
int
linux_sys___sysctl(struct lwp *l, const struct linux_sys___sysctl_args *uap, register_t *retval)
{
struct linux___sysctl ls;
int error, nerror, name[CTL_MAXNAME];
size_t savelen = 0, oldlen = 0;

/*
* get linux args structure
*/
if ((error = copyin(SCARG(uap, lsp), &ls, sizeof(ls))))
return error;

/*
* get oldlen
*/
oldlen = 0;
if (ls.oldlenp != NULL) {
error = copyin(ls.oldlenp, &oldlen, sizeof(oldlen));
if (error)
return (error);
}
savelen = oldlen;

/*
* top-level sysctl names may or may not be non-terminal, but
* we don't care
*/
if (ls.nlen > CTL_MAXNAME || ls.nlen < 1)
return (ENOTDIR);
error = copyin(ls.name, &name, ls.nlen * sizeof(int));
if (error)
return (error);

ktrmib(name, ls.nlen);

/*
* dispatch request into linux sysctl tree
*/
sysctl_lock(ls.newval != NULL);
error = sysctl_dispatch(&name[0], ls.nlen,
ls.oldval, &oldlen,
ls.newval, ls.newlen,
&name[0], l, &linux_sysctl_root);
sysctl_unlock();

/*
* reset caller's oldlen, even if we got an error
*/
if (ls.oldlenp) {
nerror = copyout(&oldlen, ls.oldlenp, sizeof(oldlen));
if (error == 0)
error = nerror;
}

/*
* if the only problem is that we weren't given enough space,
* that's an ENOMEM error
*/
if (error == 0 && ls.oldval != NULL && savelen < oldlen)
error = ENOMEM;

return (error);
}
#endif