f-stack/freebsd/security/mac_partition/mac_partition.c

320 lines
8.2 KiB
C

/*-
* Copyright (c) 1999-2002, 2007-2008 Robert N. M. Watson
* Copyright (c) 2001-2002 Networks Associates Technology, Inc.
* Copyright (c) 2006 SPARTA, Inc.
* Copyright (c) 2008 Apple Inc.
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* 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 enhanced by SPARTA ISSO under SPAWAR contract
* N66001-04-C-6019 ("SEFOS").
*
* 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.
*
* $FreeBSD$
*/
/*
* Developed by the TrustedBSD Project.
*
* Experiment with a partition-like model.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <security/mac/mac_policy.h>
#include <security/mac_partition/mac_partition.h>
SYSCTL_DECL(_security_mac);
static SYSCTL_NODE(_security_mac, OID_AUTO, partition, CTLFLAG_RW, 0,
"TrustedBSD mac_partition policy controls");
static int partition_enabled = 1;
SYSCTL_INT(_security_mac_partition, OID_AUTO, enabled, CTLFLAG_RW,
&partition_enabled, 0, "Enforce partition policy");
static int partition_slot;
#define SLOT(l) mac_label_get((l), partition_slot)
#define SLOT_SET(l, v) mac_label_set((l), partition_slot, (v))
static int
partition_check(struct label *subject, struct label *object)
{
if (partition_enabled == 0)
return (0);
if (subject == NULL)
return (0);
if (SLOT(subject) == 0)
return (0);
/*
* If the object label hasn't been allocated, then it's effectively
* not in a partition, and we know the subject is as it has a label
* and it's not 0, so reject.
*/
if (object == NULL)
return (EPERM);
if (SLOT(subject) == SLOT(object))
return (0);
return (EPERM);
}
/*
* Object-specific entry points are sorted alphabetically by object type name
* and then by operation.
*/
static int
partition_cred_check_relabel(struct ucred *cred, struct label *newlabel)
{
int error;
error = 0;
/*
* Treat "0" as a no-op request because it reflects an unset
* partition label. If we ever want to support switching back to an
* unpartitioned state for a process, we'll need to differentiate the
* "not in a partition" and "no partition defined during internalize"
* conditions.
*/
if (SLOT(newlabel) != 0) {
/*
* Require BSD privilege in order to change the partition.
* Originally we also required that the process not be in a
* partition in the first place, but this didn't interact
* well with sendmail.
*/
error = priv_check_cred(cred, PRIV_MAC_PARTITION, 0);
}
return (error);
}
static int
partition_cred_check_visible(struct ucred *cr1, struct ucred *cr2)
{
int error;
error = partition_check(cr1->cr_label, cr2->cr_label);
return (error == 0 ? 0 : ESRCH);
}
static void
partition_cred_copy_label(struct label *src, struct label *dest)
{
if (src != NULL && dest != NULL)
SLOT_SET(dest, SLOT(src));
else if (dest != NULL)
SLOT_SET(dest, 0);
}
static void
partition_cred_create_init(struct ucred *cred)
{
SLOT_SET(cred->cr_label, 0);
}
static void
partition_cred_create_swapper(struct ucred *cred)
{
SLOT_SET(cred->cr_label, 0);
}
static void
partition_cred_destroy_label(struct label *label)
{
SLOT_SET(label, 0);
}
static int
partition_cred_externalize_label(struct label *label, char *element_name,
struct sbuf *sb, int *claimed)
{
if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0)
return (0);
(*claimed)++;
if (label != NULL) {
if (sbuf_printf(sb, "%jd", (intmax_t)SLOT(label)) == -1)
return (EINVAL);
} else {
if (sbuf_printf(sb, "0") == -1)
return (EINVAL);
}
return (0);
}
static void
partition_cred_init_label(struct label *label)
{
SLOT_SET(label, 0);
}
static int
partition_cred_internalize_label(struct label *label, char *element_name,
char *element_data, int *claimed)
{
if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0)
return (0);
(*claimed)++;
SLOT_SET(label, strtol(element_data, NULL, 10));
return (0);
}
static void
partition_cred_relabel(struct ucred *cred, struct label *newlabel)
{
if (newlabel != NULL && SLOT(newlabel) != 0)
SLOT_SET(cred->cr_label, SLOT(newlabel));
}
static int
partition_inpcb_check_visible(struct ucred *cred, struct inpcb *inp,
struct label *inplabel)
{
int error;
error = partition_check(cred->cr_label, inp->inp_cred->cr_label);
return (error ? ENOENT : 0);
}
static int
partition_proc_check_debug(struct ucred *cred, struct proc *p)
{
int error;
error = partition_check(cred->cr_label, p->p_ucred->cr_label);
return (error ? ESRCH : 0);
}
static int
partition_proc_check_sched(struct ucred *cred, struct proc *p)
{
int error;
error = partition_check(cred->cr_label, p->p_ucred->cr_label);
return (error ? ESRCH : 0);
}
static int
partition_proc_check_signal(struct ucred *cred, struct proc *p,
int signum)
{
int error;
error = partition_check(cred->cr_label, p->p_ucred->cr_label);
return (error ? ESRCH : 0);
}
static int
partition_socket_check_visible(struct ucred *cred, struct socket *so,
struct label *solabel)
{
int error;
error = partition_check(cred->cr_label, so->so_cred->cr_label);
return (error ? ENOENT : 0);
}
static int
partition_vnode_check_exec(struct ucred *cred, struct vnode *vp,
struct label *vplabel, struct image_params *imgp,
struct label *execlabel)
{
if (execlabel != NULL) {
/*
* We currently don't permit labels to be changed at
* exec-time as part of the partition model, so disallow
* non-NULL partition label changes in execlabel.
*/
if (SLOT(execlabel) != 0)
return (EINVAL);
}
return (0);
}
static struct mac_policy_ops partition_ops =
{
.mpo_cred_check_relabel = partition_cred_check_relabel,
.mpo_cred_check_visible = partition_cred_check_visible,
.mpo_cred_copy_label = partition_cred_copy_label,
.mpo_cred_create_init = partition_cred_create_init,
.mpo_cred_create_swapper = partition_cred_create_swapper,
.mpo_cred_destroy_label = partition_cred_destroy_label,
.mpo_cred_externalize_label = partition_cred_externalize_label,
.mpo_cred_init_label = partition_cred_init_label,
.mpo_cred_internalize_label = partition_cred_internalize_label,
.mpo_cred_relabel = partition_cred_relabel,
.mpo_inpcb_check_visible = partition_inpcb_check_visible,
.mpo_proc_check_debug = partition_proc_check_debug,
.mpo_proc_check_sched = partition_proc_check_sched,
.mpo_proc_check_signal = partition_proc_check_signal,
.mpo_socket_check_visible = partition_socket_check_visible,
.mpo_vnode_check_exec = partition_vnode_check_exec,
};
MAC_POLICY_SET(&partition_ops, mac_partition, "TrustedBSD MAC/Partition",
MPC_LOADTIME_FLAG_UNLOADOK, &partition_slot);