freebsd-dev/sys/kern/kern_xxx.c
Robert Watson 4f7d1876d5 Introduce a new lock, hostname_mtx, and use it to synchronize access
to global hostname and domainname variables.  Where necessary, copy
to or from a stack-local buffer before performing copyin() or
copyout().  A few uses, such as in cd9660 and daemon_saver, remain
under-synchronized and will require further updates.

Correct a bug in which a failed copyin() of domainname would leave
domainname potentially corrupted.

MFC after:	3 weeks
2008-07-05 13:10:10 +00:00

291 lines
6.6 KiB
C

/*-
* Copyright (c) 1982, 1986, 1989, 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.
* 4. 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.
*
* @(#)kern_xxx.c 8.2 (Berkeley) 11/14/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/utsname.h>
#if defined(COMPAT_43)
#ifndef _SYS_SYSPROTO_H_
struct gethostname_args {
char *hostname;
u_int len;
};
#endif
/* ARGSUSED */
int
ogethostname(td, uap)
struct thread *td;
struct gethostname_args *uap;
{
int name[2];
int error;
size_t len = uap->len;
name[0] = CTL_KERN;
name[1] = KERN_HOSTNAME;
mtx_lock(&Giant);
error = userland_sysctl(td, name, 2, uap->hostname, &len,
1, 0, 0, 0, 0);
mtx_unlock(&Giant);
return(error);
}
#ifndef _SYS_SYSPROTO_H_
struct sethostname_args {
char *hostname;
u_int len;
};
#endif
/* ARGSUSED */
int
osethostname(td, uap)
struct thread *td;
register struct sethostname_args *uap;
{
int name[2];
int error;
name[0] = CTL_KERN;
name[1] = KERN_HOSTNAME;
mtx_lock(&Giant);
error = userland_sysctl(td, name, 2, 0, 0, 0, uap->hostname,
uap->len, 0, 0);
mtx_unlock(&Giant);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct ogethostid_args {
int dummy;
};
#endif
/* ARGSUSED */
int
ogethostid(td, uap)
struct thread *td;
struct ogethostid_args *uap;
{
*(long *)(td->td_retval) = hostid;
return (0);
}
#endif /* COMPAT_43 */
#ifdef COMPAT_43
#ifndef _SYS_SYSPROTO_H_
struct osethostid_args {
long hostid;
};
#endif
/* ARGSUSED */
int
osethostid(td, uap)
struct thread *td;
struct osethostid_args *uap;
{
int error;
error = priv_check(td, PRIV_SETHOSTID);
if (error)
return (error);
mtx_lock(&Giant);
hostid = uap->hostid;
mtx_unlock(&Giant);
return (0);
}
int
oquota(td, uap)
struct thread *td;
struct oquota_args *uap;
{
return (ENOSYS);
}
#endif /* COMPAT_43 */
/*
* This is the FreeBSD-1.1 compatable uname(2) interface. These days it is
* done in libc as a wrapper around a bunch of sysctl's. This must maintain
* the old 1.1 binary ABI.
*/
#if SYS_NMLN != 32
#error "FreeBSD-1.1 uname syscall has been broken"
#endif
#ifndef _SYS_SYSPROTO_H_
struct uname_args {
struct utsname *name;
};
#endif
/* ARGSUSED */
int
uname(td, uap)
struct thread *td;
struct uname_args *uap;
{
int name[2], error;
size_t len;
char *s, *us;
name[0] = CTL_KERN;
name[1] = KERN_OSTYPE;
len = sizeof (uap->name->sysname);
mtx_lock(&Giant);
error = userland_sysctl(td, name, 2, uap->name->sysname, &len,
1, 0, 0, 0, 0);
if (error)
goto done2;
subyte( uap->name->sysname + sizeof(uap->name->sysname) - 1, 0);
name[1] = KERN_HOSTNAME;
len = sizeof uap->name->nodename;
error = userland_sysctl(td, name, 2, uap->name->nodename, &len,
1, 0, 0, 0, 0);
if (error)
goto done2;
subyte( uap->name->nodename + sizeof(uap->name->nodename) - 1, 0);
name[1] = KERN_OSRELEASE;
len = sizeof uap->name->release;
error = userland_sysctl(td, name, 2, uap->name->release, &len,
1, 0, 0, 0, 0);
if (error)
goto done2;
subyte( uap->name->release + sizeof(uap->name->release) - 1, 0);
/*
name = KERN_VERSION;
len = sizeof uap->name->version;
error = userland_sysctl(td, name, 2, uap->name->version, &len,
1, 0, 0, 0, 0);
if (error)
goto done2;
subyte( uap->name->version + sizeof(uap->name->version) - 1, 0);
*/
/*
* this stupid hackery to make the version field look like FreeBSD 1.1
*/
for(s = version; *s && *s != '#'; s++);
for(us = uap->name->version; *s && *s != ':'; s++) {
error = subyte( us++, *s);
if (error)
goto done2;
}
error = subyte( us++, 0);
if (error)
goto done2;
name[0] = CTL_HW;
name[1] = HW_MACHINE;
len = sizeof uap->name->machine;
error = userland_sysctl(td, name, 2, uap->name->machine, &len,
1, 0, 0, 0, 0);
if (error)
goto done2;
subyte( uap->name->machine + sizeof(uap->name->machine) - 1, 0);
done2:
mtx_unlock(&Giant);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct getdomainname_args {
char *domainname;
int len;
};
#endif
/* ARGSUSED */
int
getdomainname(td, uap)
struct thread *td;
struct getdomainname_args *uap;
{
char tmpdomainname[MAXHOSTNAMELEN];
int domainnamelen;
mtx_lock(&hostname_mtx);
bcopy(domainname, tmpdomainname, sizeof(tmpdomainname));
mtx_unlock(&hostname_mtx);
domainnamelen = strlen(tmpdomainname) + 1;
if ((u_int)uap->len > domainnamelen)
uap->len = domainnamelen;
return (copyout(tmpdomainname, uap->domainname, uap->len));
}
#ifndef _SYS_SYSPROTO_H_
struct setdomainname_args {
char *domainname;
int len;
};
#endif
/* ARGSUSED */
int
setdomainname(td, uap)
struct thread *td;
struct setdomainname_args *uap;
{
char tmpdomainname[MAXHOSTNAMELEN];
int error, domainnamelen;
error = priv_check(td, PRIV_SETDOMAINNAME);
if (error)
return (error);
if ((u_int)uap->len > sizeof(tmpdomainname) - 1)
return (EINVAL);
domainnamelen = uap->len;
error = copyin(uap->domainname, tmpdomainname, uap->len);
if (error == 0) {
tmpdomainname[domainnamelen] = 0;
mtx_lock(&hostname_mtx);
bcopy(tmpdomainname, domainname, sizeof(domainname));
mtx_unlock(&hostname_mtx);
}
return (error);
}