/*-
* Copyright (c) 1999-2002, 2009, 2019 Robert N. M. Watson
* Copyright (c) 2001 Ilmar S. Habibulin
* Copyright (c) 2001-2004 Networks Associates Technology, Inc.
* Copyright (c) 2006 SPARTA, Inc.
* Copyright (c) 2008 Apple Inc.
* All rights reserved.
*
* This software was developed by Robert Watson and Ilmar Habibulin for the
* TrustedBSD Project.
*
* This software was enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS").
*
* 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.
*
* This software was developed at the University of Cambridge Computer
* Laboratory with support from a grant from Google, Inc.
*
* 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/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mac.h>
#include <sys/priv.h>
#include <sys/sbuf.h>
#include <sys/sdt.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <net/bpfdesc.h>
#include <net/if.h>
#include <net/if_var.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
/*
* XXXRW: struct ifnet locking is incomplete in the network code, so we use
* our own global mutex for struct ifnet. Non-ideal, but should help in the
* SMP environment.
*
* This lock is acquired only if a loaded policy is using ifnet labeling.
* This should not ever change during a MAC policy check, itself, but could
* change during setup/return from a check, so we have to condition unlock on
* previous lock.
*/
struct mtx mac_ifnet_mtx;
MTX_SYSINIT(mac_ifnet_mtx, &mac_ifnet_mtx, "mac_ifnet", MTX_DEF);
/*
* Retrieve the label associated with an mbuf by searching for the tag.
* Depending on the value of mac_labelmbufs, it's possible that a label will
* not be present, in which case NULL is returned. Policies must handle the
* possibility of an mbuf not having label storage if they do not enforce
* early loading.
*/
struct label *
mac_mbuf_to_label(struct mbuf *m)
{
struct m_tag *tag;
struct label *label;
if (m == NULL)
return (NULL);
tag = m_tag_find(m, PACKET_TAG_MACLABEL, NULL);
if (tag == NULL)
return (NULL);
label = (struct label *)(tag+1);
return (label);
}
static struct label *
mac_bpfdesc_label_alloc(void)
{
struct label *label;
label = mac_labelzone_alloc(M_WAITOK);
MAC_POLICY_PERFORM(bpfdesc_init_label, label);
return (label);
}
void
mac_bpfdesc_init(struct bpf_d *d)
{
if (mac_labeled & MPC_OBJECT_BPFDESC)
d->bd_label = mac_bpfdesc_label_alloc();
else
d->bd_label = NULL;
}
static struct label *
mac_ifnet_label_alloc(void)
{
struct label *label;
label = mac_labelzone_alloc(M_WAITOK);
MAC_POLICY_PERFORM(ifnet_init_label, label);
return (label);
}
void
mac_ifnet_init(struct ifnet *ifp)
{
if (mac_labeled & MPC_OBJECT_IFNET)
if_setmaclabel(ifp, mac_ifnet_label_alloc());
else
if_setmaclabel(ifp, NULL);
}
int
mac_mbuf_tag_init(struct m_tag *tag, int flag)
{
struct label *label;
int error;
label = (struct label *) (tag + 1);
mac_init_label(label);
if (flag & M_WAITOK)
MAC_POLICY_CHECK(mbuf_init_label, label, flag);
else
MAC_POLICY_CHECK_NOSLEEP(mbuf_init_label, label, flag);
if (error) {
MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
mac_destroy_label(label);
}
return (error);
}
int
mac_mbuf_init(struct mbuf *m, int flag)
{
struct m_tag *tag;
int error;
M_ASSERTPKTHDR(m);
if (mac_labeled & MPC_OBJECT_MBUF) {
tag = m_tag_get(PACKET_TAG_MACLABEL, sizeof(struct label),
flag);
if (tag == NULL)
return (ENOMEM);
error = mac_mbuf_tag_init(tag, flag);
if (error) {
m_tag_free(tag);
return (error);
}
m_tag_prepend(m, tag);
}
return (0);
}
static void
mac_bpfdesc_label_free(struct label *label)
{
MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_destroy_label, label);
mac_labelzone_free(label);
}
void
mac_bpfdesc_destroy(struct bpf_d *d)
{
if (d->bd_label != NULL) {
mac_bpfdesc_label_free(d->bd_label);
d->bd_label = NULL;
}
}
static void
mac_ifnet_label_free(struct label *label)
{
MAC_POLICY_PERFORM_NOSLEEP(ifnet_destroy_label, label);
mac_labelzone_free(label);
}
void
mac_ifnet_destroy(struct ifnet *ifp)
{
struct label *label = if_getmaclabel(ifp);
if (label != NULL) {
mac_ifnet_label_free(label);
if_setmaclabel(ifp, NULL);
}
}
void
mac_mbuf_tag_destroy(struct m_tag *tag)
{
struct label *label;
label = (struct label *)(tag+1);
MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label);
mac_destroy_label(label);
}
/*
* mac_mbuf_tag_copy is called when an mbuf header is duplicated, in which
* case the labels must also be duplicated.
*/
void
mac_mbuf_tag_copy(struct m_tag *src, struct m_tag *dest)
{
struct label *src_label, *dest_label;
src_label = (struct label *)(src+1);
dest_label = (struct label *)(dest+1);
/*
* mac_mbuf_tag_init() is called on the target tag in m_tag_copy(),
* so we don't need to call it here.
*/
MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
}
void
mac_mbuf_copy(struct mbuf *m_from, struct mbuf *m_to)
{
struct label *src_label, *dest_label;
if (mac_policy_count == 0)
return;
src_label = mac_mbuf_to_label(m_from);
dest_label = mac_mbuf_to_label(m_to);
MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label);
}
static void
mac_ifnet_copy_label(struct label *src, struct label *dest)
{
MAC_POLICY_PERFORM_NOSLEEP(ifnet_copy_label, src, dest);
}
static int
mac_ifnet_externalize_label(struct label *label, char *elements,
char *outbuf, size_t outbuflen)
{
int error;
MAC_POLICY_EXTERNALIZE(ifnet, label, elements, outbuf, outbuflen);
return (error);
}
static int
mac_ifnet_internalize_label(struct label *label, char *string)
{
int error;
MAC_POLICY_INTERNALIZE(ifnet, label, string);
return (error);
}
void
mac_ifnet_create(struct ifnet *ifp)
{
int locked;
if (mac_policy_count == 0)
return;
MAC_IFNET_LOCK(ifp, locked);
MAC_POLICY_PERFORM_NOSLEEP(ifnet_create, ifp, if_getmaclabel(ifp));
MAC_IFNET_UNLOCK(ifp, locked);
}
void
mac_bpfdesc_create(struct ucred *cred, struct bpf_d *d)
{
MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create, cred, d, d->bd_label);
}
void
mac_bpfdesc_create_mbuf(struct bpf_d *d, struct mbuf *m)
{
struct label *label;
/* Assume reader lock is enough. */
BPFD_LOCK_ASSERT(d);
if (mac_policy_count == 0)
return;
label = mac_mbuf_to_label(m);
MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create_mbuf, d, d->bd_label, m,
label);
}
void
mac_ifnet_create_mbuf_impl(struct ifnet *ifp, struct mbuf *m)
{
struct label *label;
int locked;
label = mac_mbuf_to_label(m);
MAC_IFNET_LOCK(ifp, locked);
MAC_POLICY_PERFORM_NOSLEEP(ifnet_create_mbuf, ifp, if_getmaclabel(ifp), m,
label);
MAC_IFNET_UNLOCK(ifp, locked);
}
MAC_CHECK_PROBE_DEFINE2(bpfdesc_check_receive, "struct bpf_d *",
"struct ifnet *");
int
mac_bpfdesc_check_receive(struct bpf_d *d, struct ifnet *ifp)
{
int error, locked;
/* Assume reader lock is enough. */
BPFD_LOCK_ASSERT(d);
if (mac_policy_count == 0)
return (0);
MAC_IFNET_LOCK(ifp, locked);
MAC_POLICY_CHECK_NOSLEEP(bpfdesc_check_receive, d, d->bd_label, ifp,
if_getmaclabel(ifp));
MAC_CHECK_PROBE2(bpfdesc_check_receive, error, d, ifp);
MAC_IFNET_UNLOCK(ifp, locked);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(ifnet_check_transmit, "struct ifnet *",
"struct mbuf *");
int
mac_ifnet_check_transmit_impl(struct ifnet *ifp, struct mbuf *m)
{
struct label *label;
int error, locked;
M_ASSERTPKTHDR(m);
label = mac_mbuf_to_label(m);
MAC_IFNET_LOCK(ifp, locked);
MAC_POLICY_CHECK_NOSLEEP(ifnet_check_transmit, ifp, if_getmaclabel(ifp), m,
label);
MAC_CHECK_PROBE2(ifnet_check_transmit, error, ifp, m);
MAC_IFNET_UNLOCK(ifp, locked);
return (error);
}
int
mac_ifnet_ioctl_get(struct ucred *cred, struct ifreq *ifr,
struct ifnet *ifp)
{
char *elements, *buffer;
struct label *intlabel;
struct mac mac;
int error, locked;
if (!(mac_labeled & MPC_OBJECT_IFNET))
return (EINVAL);
error = copyin(ifr_data_get_ptr(ifr), &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL);
if (error) {
free(elements, M_MACTEMP);
return (error);
}
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO);
intlabel = mac_ifnet_label_alloc();
MAC_IFNET_LOCK(ifp, locked);
mac_ifnet_copy_label(if_getmaclabel(ifp), intlabel);
MAC_IFNET_UNLOCK(ifp, locked);
error = mac_ifnet_externalize_label(intlabel, elements, buffer,
mac.m_buflen);
mac_ifnet_label_free(intlabel);
if (error == 0)
error = copyout(buffer, mac.m_string, strlen(buffer)+1);
free(buffer, M_MACTEMP);
free(elements, M_MACTEMP);
return (error);
}
int
mac_ifnet_ioctl_set(struct ucred *cred, struct ifreq *ifr, struct ifnet *ifp)
{
struct label *intlabel;
struct mac mac;
char *buffer;
int error, locked;
if (!(mac_labeled & MPC_OBJECT_IFNET))
return (EINVAL);
error = copyin(ifr_data_get_ptr(ifr), &mac, sizeof(mac));
if (error)
return (error);
error = mac_check_structmac_consistent(&mac);
if (error)
return (error);
buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
if (error) {
free(buffer, M_MACTEMP);
return (error);
}
intlabel = mac_ifnet_label_alloc();
error = mac_ifnet_internalize_label(intlabel, buffer);
free(buffer, M_MACTEMP);
if (error) {
mac_ifnet_label_free(intlabel);
return (error);
}
/*
* XXX: Note that this is a redundant privilege check, since policies
* impose this check themselves if required by the policy
* Eventually, this should go away.
*/
error = priv_check_cred(cred, PRIV_NET_SETIFMAC);
if (error) {
mac_ifnet_label_free(intlabel);
return (error);
}
MAC_IFNET_LOCK(ifp, locked);
MAC_POLICY_CHECK_NOSLEEP(ifnet_check_relabel, cred, ifp,
if_getmaclabel(ifp), intlabel);
if (error) {
MAC_IFNET_UNLOCK(ifp, locked);
mac_ifnet_label_free(intlabel);
return (error);
}
MAC_POLICY_PERFORM_NOSLEEP(ifnet_relabel, cred, ifp, if_getmaclabel(ifp),
intlabel);
MAC_IFNET_UNLOCK(ifp, locked);
mac_ifnet_label_free(intlabel);
return (0);
}
