NetBSD/sys/kern/kern_xxx.c
elad 5f7169ccb1 First take at security model abstraction.
- Add a few scopes to the kernel: system, network, and machdep.

- Add a few more actions/sub-actions (requests), and start using them as
  opposed to the KAUTH_GENERIC_ISSUSER place-holders.

- Introduce a basic set of listeners that implement our "traditional"
  security model, called "bsd44". This is the default (and only) model we
  have at the moment.

- Update all relevant documentation.

- Add some code and docs to help folks who want to actually use this stuff:

  * There's a sample overlay model, sitting on-top of "bsd44", for
    fast experimenting with tweaking just a subset of an existing model.

    This is pretty cool because it's *really* straightforward to do stuff
    you had to use ugly hacks for until now...

  * And of course, documentation describing how to do the above for quick
    reference, including code samples.

All of these changes were tested for regressions using a Python-based
testsuite that will be (I hope) available soon via pkgsrc. Information
about the tests, and how to write new ones, can be found on:

	http://kauth.linbsd.org/kauthwiki

NOTE FOR DEVELOPERS: *PLEASE* don't add any code that does any of the
following:

  - Uses a KAUTH_GENERIC_ISSUSER kauth(9) request,
  - Checks 'securelevel' directly,
  - Checks a uid/gid directly.

(or if you feel you have to, contact me first)

This is still work in progress; It's far from being done, but now it'll
be a lot easier.

Relevant mailing list threads:

http://mail-index.netbsd.org/tech-security/2006/01/25/0011.html
http://mail-index.netbsd.org/tech-security/2006/03/24/0001.html
http://mail-index.netbsd.org/tech-security/2006/04/18/0000.html
http://mail-index.netbsd.org/tech-security/2006/05/15/0000.html
http://mail-index.netbsd.org/tech-security/2006/08/01/0000.html
http://mail-index.netbsd.org/tech-security/2006/08/25/0000.html

Many thanks to YAMAMOTO Takashi, Matt Thomas, and Christos Zoulas for help
stablizing kauth(9).

Full credit for the regression tests, making sure these changes didn't break
anything, goes to Matt Fleming and Jaime Fournier.

Happy birthday Randi! :)
2006-09-08 20:58:56 +00:00

169 lines
4.8 KiB
C

/* $NetBSD: kern_xxx.c,v 1.60 2006/09/08 20:58:57 elad Exp $ */
/*
* 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. 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 8.3 (Berkeley) 2/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_xxx.c,v 1.60 2006/09/08 20:58:57 elad Exp $");
#include "opt_syscall_debug.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/mount.h>
#include <sys/sa.h>
#include <sys/syscallargs.h>
#include <sys/kauth.h>
/* ARGSUSED */
int
sys_reboot(struct lwp *l, void *v, register_t *retval)
{
struct sys_reboot_args /* {
syscallarg(int) opt;
syscallarg(char *) bootstr;
} */ *uap = v;
int error;
char *bootstr, bs[128];
if ((error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_REBOOT,
0, NULL, NULL, NULL)) != 0)
return (error);
/*
* Only use the boot string if RB_STRING is set.
*/
if ((SCARG(uap, opt) & RB_STRING) &&
(error = copyinstr(SCARG(uap, bootstr), bs, sizeof(bs), 0)) == 0)
bootstr = bs;
else
bootstr = NULL;
/*
* Not all ports use the bootstr currently.
*/
cpu_reboot(SCARG(uap, opt), bootstr);
return (0);
}
#ifdef SYSCALL_DEBUG
#define SCDEBUG_CALLS 0x0001 /* show calls */
#define SCDEBUG_RETURNS 0x0002 /* show returns */
#define SCDEBUG_ALL 0x0004 /* even syscalls that are implemented */
#define SCDEBUG_SHOWARGS 0x0008 /* show arguments to calls */
#if 0
int scdebug = SCDEBUG_CALLS|SCDEBUG_RETURNS|SCDEBUG_SHOWARGS;
#else
int scdebug = SCDEBUG_CALLS|SCDEBUG_RETURNS|SCDEBUG_SHOWARGS|SCDEBUG_ALL;
#endif
void
scdebug_call(struct lwp *l, register_t code, register_t args[])
{
struct proc *p = l->l_proc;
const struct sysent *sy;
const struct emul *em;
int i;
if (!(scdebug & SCDEBUG_CALLS))
return;
em = p->p_emul;
sy = &em->e_sysent[code];
if (!(scdebug & SCDEBUG_ALL || code < 0
#ifndef __HAVE_MINIMAL_EMUL
|| code >= em->e_nsysent
#endif
|| sy->sy_call == sys_nosys))
return;
KERNEL_PROC_LOCK(l);
printf("proc %d (%s): %s num ", p->p_pid, p->p_comm, em->e_name);
if (code < 0
#ifndef __HAVE_MINIMAL_EMUL
|| code >= em->e_nsysent
#endif
)
printf("OUT OF RANGE (%ld)", (long)code);
else {
printf("%ld call: %s", (long)code, em->e_syscallnames[code]);
if (scdebug & SCDEBUG_SHOWARGS) {
printf("(");
for (i = 0; i < sy->sy_argsize/sizeof(register_t); i++)
printf("%s0x%lx", i == 0 ? "" : ", ",
(long)args[i]);
printf(")");
}
}
printf("\n");
KERNEL_PROC_UNLOCK(l);
}
void
scdebug_ret(struct lwp *l, register_t code, int error, register_t retval[])
{
struct proc *p = l->l_proc;
const struct sysent *sy;
const struct emul *em;
if (!(scdebug & SCDEBUG_RETURNS))
return;
em = p->p_emul;
sy = &em->e_sysent[code];
if (!(scdebug & SCDEBUG_ALL || code < 0
#ifndef __HAVE_MINIMAL_EMUL
|| code >= em->e_nsysent
#endif
|| sy->sy_call == sys_nosys))
return;
KERNEL_PROC_LOCK(l);
printf("proc %d (%s): %s num ", p->p_pid, p->p_comm, em->e_name);
if (code < 0
#ifndef __HAVE_MINIMAL_EMUL
|| code >= em->e_nsysent
#endif
)
printf("OUT OF RANGE (%ld)", (long)code);
else
printf("%ld ret: err = %d, rv = 0x%lx,0x%lx", (long)code,
error, (long)retval[0], (long)retval[1]);
printf("\n");
KERNEL_PROC_UNLOCK(l);
}
#endif /* SYSCALL_DEBUG */