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

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Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
/*-
* 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.
*
License and wording updates: NAI has authorized the removal of clause three from their BSD-style license. Also, s/NAI Labs/Network Associates Laboratories/.
2002-11-04 01:53:12 +00:00
* 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.
Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
*
* 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>
Redesign the externalization APIs from the MAC Framework to the MAC policy modules to improve robustness against C string bugs and vulnerabilities. Following these revisions, all string construction of labels for export to userspace (or elsewhere) is performed using the sbuf API, which prevents the consumer from having to perform laborious and intricate pointer and buffer checks. This substantially simplifies the externalization logic, both at the MAC Framework level, and in individual policies; this becomes especially useful when policies export more complex label data, such as with compartments in Biba and MLS. Bundled in here are some other minor fixes associated with externalization: including avoiding malloc while holding the process mutex in mac_lomac, and hence avoid a failure mode when printing labels during a downgrade operation due to the removal of the M_NOWAIT case. This has been running in the MAC development tree for about three weeks without problems. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-06-23 01:26:34 +00:00
#include <sys/sbuf.h>
Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
#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,
Redesign the externalization APIs from the MAC Framework to the MAC policy modules to improve robustness against C string bugs and vulnerabilities. Following these revisions, all string construction of labels for export to userspace (or elsewhere) is performed using the sbuf API, which prevents the consumer from having to perform laborious and intricate pointer and buffer checks. This substantially simplifies the externalization logic, both at the MAC Framework level, and in individual policies; this becomes especially useful when policies export more complex label data, such as with compartments in Biba and MLS. Bundled in here are some other minor fixes associated with externalization: including avoiding malloc while holding the process mutex in mac_lomac, and hence avoid a failure mode when printing labels during a downgrade operation due to the removal of the M_NOWAIT case. This has been running in the MAC development tree for about three weeks without problems. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-06-23 01:26:34 +00:00
struct sbuf *sb, int *claimed)
Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
{
if (strcmp(MAC_PARTITION_LABEL_NAME, element_name) != 0)
return (0);
(*claimed)++;
Redesign the externalization APIs from the MAC Framework to the MAC policy modules to improve robustness against C string bugs and vulnerabilities. Following these revisions, all string construction of labels for export to userspace (or elsewhere) is performed using the sbuf API, which prevents the consumer from having to perform laborious and intricate pointer and buffer checks. This substantially simplifies the externalization logic, both at the MAC Framework level, and in individual policies; this becomes especially useful when policies export more complex label data, such as with compartments in Biba and MLS. Bundled in here are some other minor fixes associated with externalization: including avoiding malloc while holding the process mutex in mac_lomac, and hence avoid a failure mode when printing labels during a downgrade operation due to the removal of the M_NOWAIT case. This has been running in the MAC development tree for about three weeks without problems. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-06-23 01:26:34 +00:00
if (sbuf_printf(sb, "%ld", SLOT(label)) == -1)
return (EINVAL);
else
return (0);
Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
}
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) {
/*
Change privilege model for mac_partition such that BSD superuser can change the partition once a partition has been set. This is required for correct operation of sendmail between partitions. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-11-03 00:53:03 +00:00
* 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.
Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
*/
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);
}
Update MAC modules for changes in arguments for exec MAC policy entry points to include an explicit execlabel. Approved by: re Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-11-08 18:04:36 +00:00
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);
}
Move to C99 sparse structure initialization for the mac_policy_ops structure definition, rather than using an operation vector we translate into the structure. Originally, we used a vector for two reasons: (1) We wanted to define the structure sparsely, which wasn't supported by the C compiler for structures. For a policy with five entry points, you don't want to have to stick in a few hundred NULL function pointers. (2) We thought it would improve ABI compatibility allowing modules to work with kernels that had a superset of the entry points defined in the module, even if the kernel had changed its entry point set. Both of these no longer apply: (1) C99 gives us a way to sparsely define a static structure. (2) The ABI problems existed anyway, due to enumeration numbers, argument changes, and semantic mismatches. Since the going rule for FreeBSD is that you really need your modules to pretty closely match your kernel, it's not worth the complexity. This submit eliminates the operation vector, dynamic allocation of the operation structure, copying of the vector to the structure, and redoes the vectors in each policy to direct structure definitions. One enourmous benefit of this change is that we now get decent type checking on policy entry point implementation arguments. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-30 18:48:51 +00:00
static struct mac_policy_ops mac_partition_ops =
Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
{
Move to C99 sparse structure initialization for the mac_policy_ops structure definition, rather than using an operation vector we translate into the structure. Originally, we used a vector for two reasons: (1) We wanted to define the structure sparsely, which wasn't supported by the C compiler for structures. For a policy with five entry points, you don't want to have to stick in a few hundred NULL function pointers. (2) We thought it would improve ABI compatibility allowing modules to work with kernels that had a superset of the entry points defined in the module, even if the kernel had changed its entry point set. Both of these no longer apply: (1) C99 gives us a way to sparsely define a static structure. (2) The ABI problems existed anyway, due to enumeration numbers, argument changes, and semantic mismatches. Since the going rule for FreeBSD is that you really need your modules to pretty closely match your kernel, it's not worth the complexity. This submit eliminates the operation vector, dynamic allocation of the operation structure, copying of the vector to the structure, and redoes the vectors in each policy to direct structure definitions. One enourmous benefit of this change is that we now get decent type checking on policy entry point implementation arguments. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-30 18:48:51 +00:00
.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,
Update MAC modules for changes in arguments for exec MAC policy entry points to include an explicit execlabel. Approved by: re Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-11-08 18:04:36 +00:00
.mpo_check_vnode_exec = mac_partition_check_vnode_exec,
Provide a simple sample labeled access control policy, mac_partition. This policy can be loaded dynamically, and assigns each process a partition number, as well as permitting processes to operate outside the partition. Processes contained in a partition can only "see" processes inside the same partition, so it's a little like jail. The partition of a user can be set using the label mechanisms in login.conf. This sample policy is a good starting point for developers wanting to learn about how to produce labeled policies, as it labels only one kernel object, the process credential. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2002-10-23 23:36:27 +00:00
};
Trim "trustedbsd_" from the front of the policy module "short names"; the vendor is only included in the long name currently, reducing verbosity when modules are registered and unregistered. Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-03-27 19:26:39 +00:00
MAC_POLICY_SET(&mac_partition_ops, mac_partition, "TrustedBSD MAC/Partition",
MPC_LOADTIME_FLAG_UNLOADOK, &partition_slot);
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