freebsd-dev/sys/security/mac_partition/mac_partition.c

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/*-
* Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
* Copyright (c) 2001, 2002 Networks Associates Technology, 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.
*
* 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/types.h>
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/mac.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <fs/devfs/devfs.h>
#include <net/bpfdesc.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_var.h>
#include <vm/vm.h>
#include <sys/mac_policy.h>
#include <security/mac_partition/mac_partition.h>
SYSCTL_DECL(_security_mac);
SYSCTL_NODE(_security_mac, OID_AUTO, partition, CTLFLAG_RW, 0,
"TrustedBSD mac_partition policy controls");
static int mac_partition_enabled = 1;
SYSCTL_INT(_security_mac_partition, OID_AUTO, enabled, CTLFLAG_RW,
&mac_partition_enabled, 0, "Enforce partition policy");
static int partition_slot;
#define SLOT(l) (LABEL_TO_SLOT((l), partition_slot).l_long)
static void
mac_partition_init(struct mac_policy_conf *conf)
{
}
static void
mac_partition_init_label(struct label *label)
{
SLOT(label) = 0;
}
static void
mac_partition_destroy_label(struct label *label)
{
SLOT(label) = 0;
}
static int
mac_partition_externalize_label(struct label *label, char *element_name,
char *element_data, size_t size, size_t *len, int *claimed)
{
if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0)
return (0);
(*claimed)++;
*len = snprintf(element_data, size, "%ld", SLOT(label));
return (0);
}
static int
mac_partition_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(label) = strtol(element_data, NULL, 10);
return (0);
}
static void
mac_partition_create_cred(struct ucred *cred_parent, struct ucred *cred_child)
{
SLOT(&cred_child->cr_label) = SLOT(&cred_parent->cr_label);
}
static void
mac_partition_create_proc0(struct ucred *cred)
{
SLOT(&cred->cr_label) = 0;
}
static void
mac_partition_create_proc1(struct ucred *cred)
{
SLOT(&cred->cr_label) = 0;
}
static void
mac_partition_relabel_cred(struct ucred *cred, struct label *newlabel)
{
if (SLOT(newlabel) != 0)
SLOT(&cred->cr_label) = SLOT(newlabel);
}
static int
label_on_label(struct label *subject, struct label *object)
{
if (mac_partition_enabled == 0)
return (0);
if (SLOT(subject) == 0)
return (0);
if (SLOT(subject) == SLOT(object))
return (0);
return (EPERM);
}
static int
mac_partition_check_cred_relabel(struct ucred *cred, struct label *newlabel)
{
int error;
error = 0;
/* Treat "0" as a no-op request. */
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 = suser_cred(cred, 0);
}
return (error);
}
static int
mac_partition_check_cred_visible(struct ucred *u1, struct ucred *u2)
{
int error;
error = label_on_label(&u1->cr_label, &u2->cr_label);
return (error == 0 ? 0 : ESRCH);
}
static int
mac_partition_check_proc_debug(struct ucred *cred, struct proc *proc)
{
int error;
error = label_on_label(&cred->cr_label, &proc->p_ucred->cr_label);
return (error ? ESRCH : 0);
}
static int
mac_partition_check_proc_sched(struct ucred *cred, struct proc *proc)
{
int error;
error = label_on_label(&cred->cr_label, &proc->p_ucred->cr_label);
return (error ? ESRCH : 0);
}
static int
mac_partition_check_proc_signal(struct ucred *cred, struct proc *proc,
int signum)
{
int error;
error = label_on_label(&cred->cr_label, &proc->p_ucred->cr_label);
return (error ? ESRCH : 0);
}
static int
mac_partition_check_socket_visible(struct ucred *cred, struct socket *socket,
struct label *socketlabel)
{
int error;
error = label_on_label(&cred->cr_label, socketlabel);
return (error ? ENOENT : 0);
}
static int
mac_partition_check_vnode_exec(struct ucred *cred, struct vnode *vp,
struct label *label, 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 mac_partition_ops =
{
.mpo_init = mac_partition_init,
.mpo_init_cred_label = mac_partition_init_label,
.mpo_destroy_cred_label = mac_partition_destroy_label,
.mpo_externalize_cred_label = mac_partition_externalize_label,
.mpo_internalize_cred_label = mac_partition_internalize_label,
.mpo_create_cred = mac_partition_create_cred,
.mpo_create_proc0 = mac_partition_create_proc0,
.mpo_create_proc1 = mac_partition_create_proc1,
.mpo_relabel_cred = mac_partition_relabel_cred,
.mpo_check_cred_relabel = mac_partition_check_cred_relabel,
.mpo_check_cred_visible = mac_partition_check_cred_visible,
.mpo_check_proc_debug = mac_partition_check_proc_debug,
.mpo_check_proc_sched = mac_partition_check_proc_sched,
.mpo_check_proc_signal = mac_partition_check_proc_signal,
.mpo_check_socket_visible = mac_partition_check_socket_visible,
.mpo_check_vnode_exec = mac_partition_check_vnode_exec,
};
MAC_POLICY_SET(&mac_partition_ops, trustedbsd_mac_partition,
"TrustedBSD MAC/Partition", MPC_LOADTIME_FLAG_UNLOADOK, &partition_slot);