/*-
* Copyright (c) 2004 Networks Associates Technology, Inc.
* Copyright (c) 2005 SPARTA, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* 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 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 AUTHOR 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.
*/
#include <kern/zalloc.h>
#include <security/_label.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <security/mac_internal.h>
ZONE_DEFINE_ID(ZONE_ID_MAC_LABEL, "MAC Labels", struct label,
ZC_READONLY | ZC_ZFREE_CLEARMEM);
/*
* Number of initial values matches logic in security/_label.h
*/
const struct label empty_label = {
.l_perpolicy[0 ... MAC_MAX_SLOTS - 1] = MAC_LABEL_NULL_SLOT,
};
static struct label *
label_alloc_noinit(int flags)
{
static_assert(MAC_NOWAIT == Z_NOWAIT);
return zalloc_ro(ZONE_ID_MAC_LABEL, Z_ZERO | (flags & MAC_NOWAIT));
}
struct label *
mac_labelzone_alloc(int flags)
{
struct label *label;
label = label_alloc_noinit(flags);
if (label) {
zalloc_ro_update_elem(ZONE_ID_MAC_LABEL, label, &empty_label);
}
return label;
}
struct label *
mac_labelzone_alloc_for_owner(struct label **labelp, int flags,
void (^extra_setup)(struct label *))
{
struct label *label;
if (labelp) {
struct label tmp_label = empty_label;
label = zalloc_ro(ZONE_ID_MAC_LABEL, Z_ZERO | (flags & MAC_NOWAIT));
tmp_label.l_owner = labelp;
zalloc_ro_update_elem(ZONE_ID_MAC_LABEL, label, &tmp_label);
} else {
label = mac_labelzone_alloc(flags);
}
if (label && extra_setup) {
extra_setup(label);
}
return label;
}
struct label *
mac_labelzone_alloc_owned(struct label **labelp, int flags,
void (^extra_setup)(struct label *))
{
struct label *label;
label = mac_labelzone_alloc_for_owner(labelp, flags, extra_setup);
if (labelp) {
*labelp = label;
}
return label;
}
void
mac_labelzone_free(struct label *label)
{
if (label == NULL) {
panic("Free of NULL MAC label");
}
zfree_ro(ZONE_ID_MAC_LABEL, label);
}
void
mac_labelzone_free_owned(struct label **labelp,
void (^extra_deinit)(struct label *))
{
struct label *label;
label = mac_label_verify(labelp);
if (label) {
if (extra_deinit) {
extra_deinit(label);
}
*labelp = NULL;
mac_labelzone_free(label);
}
}
__abortlike
static void
mac_label_verify_panic(struct label **labelp)
{
panic("label backref mismatch: labelp:%p label:%p l_owner:%p", labelp,
*labelp, (*labelp)->l_owner);
}
struct label *
mac_label_verify(struct label **labelp)
{
struct label *label = *labelp;
if (label != NULL) {
zone_require_ro(ZONE_ID_MAC_LABEL, sizeof(struct label), label);
if (__improbable(label->l_owner != labelp)) {
mac_label_verify_panic(labelp);
}
}
return label;
}
static intptr_t
mac_label_slot_encode(intptr_t p)
{
return p ?: MAC_LABEL_NULL_SLOT;
}
static intptr_t
mac_label_slot_decode(intptr_t p)
{
switch (p) {
case 0:
/* make sure 0 doesn't mean NULL and causes crashes */
return MAC_LABEL_NULL_SLOT;
case MAC_LABEL_NULL_SLOT:
return 0l;
default:
return p;
}
}
/*
* Functions used by policy modules to get and set label values.
*/
intptr_t
mac_label_get(struct label *label, int slot)
{
KASSERT(label != NULL, ("mac_label_get: NULL label"));
zone_require_ro(ZONE_ID_MAC_LABEL, sizeof(struct label), label);
return mac_label_slot_decode((intptr_t) label->l_perpolicy[slot]);
}
__abortlike
static void
panic_label_set_sentinel(void)
{
panic("cannot set mac label to ~0");
}
void
mac_label_set(struct label *label, int slot, intptr_t v)
{
KASSERT(label != NULL, ("mac_label_set: NULL label"));
#if DEVELOPMENT || DEBUG
/* can't modify a sealed label, see mac_cred_label_seal() */
assertf(label->l_owner != (struct label **)-1,
"mac_label_set(%p, %d, 0x%lx) is sealed",
label, slot, v);
#endif
if (v == MAC_LABEL_NULL_SLOT) {
panic_label_set_sentinel();
}
v = mac_label_slot_encode(v);
zalloc_ro_update_field(ZONE_ID_MAC_LABEL, label, l_perpolicy[slot], &v);
}