freebsd-skq/sys/kern/kern_xxx.c
phk ca21a25f17 This Implements the mumbled about "Jail" feature.
This is a seriously beefed up chroot kind of thing.  The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.

For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact:  "real virtual servers".

Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.

Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.

It generally does what one would expect, but setting up a jail
still takes a little knowledge.

A few notes:

   I have no scripts for setting up a jail, don't ask me for them.

   The IP number should be an alias on one of the interfaces.

   mount a /proc in each jail, it will make ps more useable.

   /proc/<pid>/status tells the hostname of the prison for
   jailed processes.

   Quotas are only sensible if you have a mountpoint per prison.

   There are no privisions for stopping resource-hogging.

   Some "#ifdef INET" and similar may be missing (send patches!)

If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!

Tools, comments, patches & documentation most welcome.

Have fun...

Sponsored by:   http://www.rndassociates.com/
Run for almost a year by:       http://www.servetheweb.com/
1999-04-28 11:38:52 +00:00

257 lines
6.1 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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
* $Id: kern_xxx.c,v 1.29 1999/04/27 11:16:09 phk Exp $
*/
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/utsname.h>
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#ifndef _SYS_SYSPROTO_H_
struct gethostname_args {
char *hostname;
u_int len;
};
#endif
/* ARGSUSED */
int
ogethostname(p, uap)
struct proc *p;
struct gethostname_args *uap;
{
int name[2];
size_t len = uap->len;
name[0] = CTL_KERN;
name[1] = KERN_HOSTNAME;
return (userland_sysctl(p, name, 2, uap->hostname, &len,
1, 0, 0, 0));
}
#ifndef _SYS_SYSPROTO_H_
struct sethostname_args {
char *hostname;
u_int len;
};
#endif
/* ARGSUSED */
int
osethostname(p, uap)
struct proc *p;
register struct sethostname_args *uap;
{
int name[2];
int error;
name[0] = CTL_KERN;
name[1] = KERN_HOSTNAME;
if ((error = suser_xxx(0, p, PRISON_ROOT)))
return (error);
return (userland_sysctl(p, name, 2, 0, 0, 0,
uap->hostname, uap->len, 0));
}
#ifndef _SYS_SYSPROTO_H_
struct ogethostid_args {
int dummy;
};
#endif
/* ARGSUSED */
int
ogethostid(p, uap)
struct proc *p;
struct ogethostid_args *uap;
{
*(long *)(p->p_retval) = hostid;
return (0);
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
#ifdef COMPAT_43
#ifndef _SYS_SYSPROTO_H_
struct osethostid_args {
long hostid;
};
#endif
/* ARGSUSED */
int
osethostid(p, uap)
struct proc *p;
struct osethostid_args *uap;
{
int error;
if ((error = suser(p)))
return (error);
hostid = uap->hostid;
return (0);
}
int
oquota(p, uap)
struct proc *p;
struct oquota_args *uap;
{
return (ENOSYS);
}
#endif /* COMPAT_43 */
#ifndef _SYS_SYSPROTO_H_
struct uname_args {
struct utsname *name;
};
#endif
/* ARGSUSED */
int
uname(p, uap)
struct proc *p;
struct uname_args *uap;
{
int name[2], rtval;
size_t len;
char *s, *us;
name[0] = CTL_KERN;
name[1] = KERN_OSTYPE;
len = sizeof uap->name->sysname;
rtval = userland_sysctl(p, name, 2, uap->name->sysname, &len,
1, 0, 0, 0);
if( rtval) return rtval;
subyte( uap->name->sysname + sizeof(uap->name->sysname) - 1, 0);
name[1] = KERN_HOSTNAME;
len = sizeof uap->name->nodename;
rtval = userland_sysctl(p, name, 2, uap->name->nodename, &len,
1, 0, 0, 0);
if( rtval) return rtval;
subyte( uap->name->nodename + sizeof(uap->name->nodename) - 1, 0);
name[1] = KERN_OSRELEASE;
len = sizeof uap->name->release;
rtval = userland_sysctl(p, name, 2, uap->name->release, &len,
1, 0, 0, 0);
if( rtval) return rtval;
subyte( uap->name->release + sizeof(uap->name->release) - 1, 0);
/*
name = KERN_VERSION;
len = sizeof uap->name->version;
rtval = userland_sysctl(p, name, 2, uap->name->version, &len,
1, 0, 0, 0);
if( rtval) return rtval;
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++) {
rtval = subyte( us++, *s);
if( rtval)
return rtval;
}
rtval = subyte( us++, 0);
if( rtval)
return rtval;
name[0] = CTL_HW;
name[1] = HW_MACHINE;
len = sizeof uap->name->machine;
rtval = userland_sysctl(p, name, 2, uap->name->machine, &len,
1, 0, 0, 0);
if( rtval) return rtval;
subyte( uap->name->machine + sizeof(uap->name->machine) - 1, 0);
return 0;
}
#ifndef _SYS_SYSPROTO_H_
struct getdomainname_args {
char *domainname;
int len;
};
#endif
/* ARGSUSED */
int
getdomainname(p, uap)
struct proc *p;
struct getdomainname_args *uap;
{
int domainnamelen = strlen(domainname) + 1;
if ((u_int)uap->len > domainnamelen + 1)
uap->len = domainnamelen + 1;
return (copyout((caddr_t)domainname, (caddr_t)uap->domainname, uap->len));
}
#ifndef _SYS_SYSPROTO_H_
struct setdomainname_args {
char *domainname;
int len;
};
#endif
/* ARGSUSED */
int
setdomainname(p, uap)
struct proc *p;
struct setdomainname_args *uap;
{
int error, domainnamelen;
if ((error = suser(p)))
return (error);
if ((u_int)uap->len > sizeof (domainname) - 1)
return EINVAL;
domainnamelen = uap->len;
error = copyin((caddr_t)uap->domainname, domainname, uap->len);
domainname[domainnamelen] = 0;
return (error);
}