freebsd-dev/sys/security/mac/mac_label.c
Robert Watson 0142affc77 Introduce accessor functions mac_label_get() and mac_label_set() to replace
LABEL_TO_SLOT() macro used by policy modules to query and set label data
in struct label.  Instead of using a union, store an intptr_t, simplifying
the API.

Update policies: in most cases this required only small tweaks to current
wrapper macros.  In two cases, a single wrapper macros had to be split into
separate get and set macros.

Move struct label definition from _label.h to mac_internal.h and remove
_label.h.  With this change, policies may now treat struct label * as
opaque, allowing us to change the layout of struct label without breaking
the policy module ABI.  For example, we could make the maximum number of
policies with labels modifiable at boot-time rather than just at
compile-time.

Obtained from:	TrustedBSD Project
2007-02-06 14:19:25 +00:00

152 lines
4.0 KiB
C

/*-
* Copyright (c) 2003-2004 Networks Associates Technology, Inc.
* Copyright (c) 2007 Robert N. M. Watson
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <vm/uma.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
/*
* zone_label is the UMA zone from which most labels are allocated. Label
* structures are initialized to zero bytes so that policies see a NULL/0
* slot on first use, even if the policy is loaded after the label is
* allocated for an object.
*/
static uma_zone_t zone_label;
static int mac_labelzone_ctor(void *mem, int size, void *arg, int flags);
static void mac_labelzone_dtor(void *mem, int size, void *arg);
void
mac_labelzone_init(void)
{
zone_label = uma_zcreate("MAC labels", sizeof(struct label),
mac_labelzone_ctor, mac_labelzone_dtor, NULL, NULL,
UMA_ALIGN_PTR, 0);
}
/*
* mac_init_label() and mac_destroy_label() are exported so that they can be
* used in mbuf tag initialization, where labels are not slab allocated from
* the zone_label zone.
*/
void
mac_init_label(struct label *label)
{
bzero(label, sizeof(*label));
label->l_flags = MAC_FLAG_INITIALIZED;
}
void
mac_destroy_label(struct label *label)
{
KASSERT(label->l_flags & MAC_FLAG_INITIALIZED,
("destroying uninitialized label"));
#ifdef DIAGNOSTIC
bzero(label, sizeof(*label));
#else
label->l_flags &= ~MAC_FLAG_INITIALIZED;
#endif
}
static int
mac_labelzone_ctor(void *mem, int size, void *arg, int flags)
{
struct label *label;
KASSERT(size == sizeof(*label), ("mac_labelzone_ctor: wrong size\n"));
label = mem;
mac_init_label(label);
return (0);
}
static void
mac_labelzone_dtor(void *mem, int size, void *arg)
{
struct label *label;
KASSERT(size == sizeof(*label), ("mac_labelzone_dtor: wrong size\n"));
label = mem;
mac_destroy_label(label);
}
struct label *
mac_labelzone_alloc(int flags)
{
return (uma_zalloc(zone_label, flags));
}
void
mac_labelzone_free(struct label *label)
{
uma_zfree(zone_label, label);
}
/*
* Functions used by policy modules to get and set label values.
*/
intptr_t
mac_label_get(struct label *l, int slot)
{
KASSERT(l != NULL, ("mac_label_get: NULL label"));
return (l->l_perpolicy[slot]);
}
void
mac_label_set(struct label *l, int slot, intptr_t v)
{
KASSERT(l != NULL, ("mac_label_set: NULL label"));
l->l_perpolicy[slot] = v;
}