/*
* $FreeBSD$
*
* Copyright (c) 2011-2013, 2015, 2019 Juniper Networks, Inc.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/ioccom.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mdioctl.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/vnode.h>
#include <security/mac_veriexec/mac_veriexec.h>
#include <security/mac_veriexec/mac_veriexec_internal.h>
#include "veriexec_ioctl.h"
/*
* We need a mutex while updating lists etc.
*/
extern struct mtx ve_mutex;
/*
* Handle the ioctl for the device
*/
static int
verifiedexecioctl(struct cdev *dev __unused, u_long cmd, caddr_t data,
int flags, struct thread *td)
{
struct nameidata nid;
struct vattr vattr;
struct verified_exec_label_params *lparams;
struct verified_exec_params *params;
int error = 0;
/*
* These commands are considered safe requests for anyone who has
* permission to access to device node.
*/
switch (cmd) {
case VERIEXEC_GETSTATE:
{
int *ip = (int *)data;
if (ip)
*ip = mac_veriexec_get_state();
else
error = EINVAL;
return (error);
}
break;
default:
break;
}
/*
* Anything beyond this point is considered dangerous, so we need to
* only allow processes that have kmem write privs to do them.
*
* MAC/veriexec will grant kmem write privs to "trusted" processes.
*/
error = priv_check(td, PRIV_KMEM_WRITE);
if (error)
return (error);
lparams = (struct verified_exec_label_params *)data;
if (cmd == VERIEXEC_LABEL_LOAD)
params = &lparams->params;
else
params = (struct verified_exec_params *)data;
switch (cmd) {
case VERIEXEC_ACTIVE:
mtx_lock(&ve_mutex);
if (mac_veriexec_in_state(VERIEXEC_STATE_LOADED))
mac_veriexec_set_state(VERIEXEC_STATE_ACTIVE);
else
error = EINVAL;
mtx_unlock(&ve_mutex);
break;
case VERIEXEC_DEBUG_ON:
mtx_lock(&ve_mutex);
{
int *ip = (int *)data;
mac_veriexec_debug++;
if (ip) {
if (*ip > 0)
mac_veriexec_debug = *ip;
*ip = mac_veriexec_debug;
}
}
mtx_unlock(&ve_mutex);
break;
case VERIEXEC_DEBUG_OFF:
mac_veriexec_debug = 0;
break;
case VERIEXEC_ENFORCE:
mtx_lock(&ve_mutex);
if (mac_veriexec_in_state(VERIEXEC_STATE_LOADED))
mac_veriexec_set_state(VERIEXEC_STATE_ACTIVE |
VERIEXEC_STATE_ENFORCE);
else
error = EINVAL;
mtx_unlock(&ve_mutex);
break;
case VERIEXEC_GETVERSION:
{
int *ip = (int *)data;
if (ip)
*ip = MAC_VERIEXEC_VERSION;
else
error = EINVAL;
}
break;
case VERIEXEC_LOCK:
mtx_lock(&ve_mutex);
mac_veriexec_set_state(VERIEXEC_STATE_LOCKED);
mtx_unlock(&ve_mutex);
break;
case VERIEXEC_LOAD:
if (prison0.pr_securelevel > 0)
return (EPERM); /* no updates when secure */
/* FALLTHROUGH */
case VERIEXEC_LABEL_LOAD:
case VERIEXEC_SIGNED_LOAD:
/*
* If we use a loader that will only use a
* digitally signed hash list - which it verifies.
* We can load fingerprints provided veriexec is not locked.
*/
if (prison0.pr_securelevel > 0 &&
!mac_veriexec_in_state(VERIEXEC_STATE_LOADED)) {
/*
* If securelevel has been raised and we
* do not have any fingerprints loaded,
* it would dangerous to do so now.
*/
return (EPERM);
}
if (mac_veriexec_in_state(VERIEXEC_STATE_LOCKED))
error = EPERM;
else {
size_t labellen = 0;
int flags = FREAD;
int override = (cmd != VERIEXEC_LOAD);
/*
* Get the attributes for the file name passed
* stash the file's device id and inode number
* along with it's fingerprint in a list for
* exec to use later.
*/
/*
* FreeBSD seems to copy the args to kernel space
*/
NDINIT(&nid, LOOKUP, FOLLOW, UIO_SYSSPACE,
params->file, td);
if ((error = vn_open(&nid, &flags, 0, NULL)) != 0)
return (error);
error = VOP_GETATTR(nid.ni_vp, &vattr, td->td_ucred);
if (error != 0) {
mac_veriexec_set_fingerprint_status(nid.ni_vp,
FINGERPRINT_INVALID);
VOP_UNLOCK(nid.ni_vp);
(void) vn_close(nid.ni_vp, FREAD, td->td_ucred,
td);
return (error);
}
if (override) {
/*
* If the file is on a "verified" filesystem
* someone may be playing games.
*/
if ((nid.ni_vp->v_mount->mnt_flag &
MNT_VERIFIED) != 0)
override = 0;
}
/*
* invalidate the node fingerprint status
* which will have been set in the vn_open
* and would always be FINGERPRINT_NOTFOUND
*/
mac_veriexec_set_fingerprint_status(nid.ni_vp,
FINGERPRINT_INVALID);
VOP_UNLOCK(nid.ni_vp);
(void) vn_close(nid.ni_vp, FREAD, td->td_ucred, td);
if (params->flags & VERIEXEC_LABEL)
labellen = strnlen(lparams->label,
sizeof(lparams->label) - 1) + 1;
mtx_lock(&ve_mutex);
error = mac_veriexec_metadata_add_file(
((params->flags & VERIEXEC_FILE) != 0),
vattr.va_fsid, vattr.va_fileid, vattr.va_gen,
params->fingerprint,
(params->flags & VERIEXEC_LABEL) ?
lparams->label : NULL, labellen,
params->flags, params->fp_type, override);
mac_veriexec_set_state(VERIEXEC_STATE_LOADED);
mtx_unlock(&ve_mutex);
}
break;
default:
error = ENODEV;
}
return (error);
}
struct cdevsw veriexec_cdevsw = {
.d_version = D_VERSION,
.d_ioctl = verifiedexecioctl,
.d_name = "veriexec",
};
static void
veriexec_drvinit(void *unused __unused)
{
make_dev(&veriexec_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "veriexec");
}
SYSINIT(veriexec, SI_SUB_PSEUDO, SI_ORDER_ANY, veriexec_drvinit, NULL);
MODULE_DEPEND(veriexec, mac_veriexec, 1, 1, 1);
