freebsd-dev/sys/security/mac/mac_vfs.c

1071 lines
26 KiB
C
Raw Normal View History

/*-
* Copyright (c) 1999-2002, 2009 Robert N. M. Watson
* Copyright (c) 2001 Ilmar S. Habibulin
2005-01-30 12:38:47 +00:00
* Copyright (c) 2001-2005 McAfee, Inc.
* Copyright (c) 2005-2006 SPARTA, Inc.
* Copyright (c) 2008 Apple Inc.
* All rights reserved.
*
* This software was developed by Robert Watson and Ilmar Habibulin for the
* TrustedBSD Project.
*
2005-01-30 12:38:47 +00:00
* This software was developed for the FreeBSD Project in part by McAfee
* Research, the Security Research Division of McAfee, 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
When devfs cloning takes place, provide access to the credential of the process that caused the clone event to take place for the device driver creating the device. This allows cloned device drivers to adapt the device node based on security aspects of the process, such as the uid, gid, and MAC label. - Add a cred reference to struct cdev, so that when a device node is instantiated as a vnode, the cloning credential can be exposed to MAC. - Add make_dev_cred(), a version of make_dev() that additionally accepts the credential to stick in the struct cdev. Implement it and make_dev() in terms of a back-end make_dev_credv(). - Add a new event handler, dev_clone_cred, which can be registered to receive the credential instead of dev_clone, if desired. - Modify the MAC entry point mac_create_devfs_device() to accept an optional credential pointer (may be NULL), so that MAC policies can inspect and act on the label or other elements of the credential when initializing the skeleton device protections. - Modify tty_pty.c to register clone_dev_cred and invoke make_dev_cred(), so that the pty clone credential is exposed to the MAC Framework. While currently primarily focussed on MAC policies, this change is also a prerequisite for changes to allow ptys to be instantiated with the UID of the process looking up the pty. This requires further changes to the pty driver -- in particular, to immediately recycle pty nodes on last close so that the credential-related state can be recreated on next lookup. Submitted by: Andrew Reisse <andrew.reisse@sparta.com> Obtained from: TrustedBSD Project Sponsored by: SPAWAR, SPARTA MFC after: 1 week MFC note: Merge to 6.x, but not 5.x for ABI reasons
2005-07-14 10:22:09 +00:00
* N66001-04-C-6019 ("SEFOS").
*
* 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.
*/
2003-06-11 00:56:59 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/condvar.h>
#include <sys/extattr.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/sdt.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <fs/devfs/devfs.h>
#include <security/mac/mac_framework.h>
#include <security/mac/mac_internal.h>
#include <security/mac/mac_policy.h>
/*
* Warn about EA transactions only the first time they happen. No locking on
* this variable.
*/
static int ea_warn_once = 0;
static int mac_vnode_setlabel_extattr(struct ucred *cred,
struct vnode *vp, struct label *intlabel);
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
static struct label *
mac_devfs_label_alloc(void)
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
{
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
struct label *label;
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
label = mac_labelzone_alloc(M_WAITOK);
MAC_POLICY_PERFORM(devfs_init_label, label);
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
return (label);
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
}
void
mac_devfs_init(struct devfs_dirent *de)
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
{
if (mac_labeled & MPC_OBJECT_DEVFS)
de->de_label = mac_devfs_label_alloc();
else
de->de_label = NULL;
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
}
static struct label *
mac_mount_label_alloc(void)
{
struct label *label;
label = mac_labelzone_alloc(M_WAITOK);
MAC_POLICY_PERFORM(mount_init_label, label);
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
return (label);
}
void
mac_mount_init(struct mount *mp)
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
{
if (mac_labeled & MPC_OBJECT_MOUNT)
mp->mnt_label = mac_mount_label_alloc();
else
mp->mnt_label = NULL;
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
}
struct label *
mac_vnode_label_alloc(void)
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
{
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
struct label *label;
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
label = mac_labelzone_alloc(M_WAITOK);
MAC_POLICY_PERFORM(vnode_init_label, label);
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
return (label);
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
}
void
mac_vnode_init(struct vnode *vp)
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
{
if (mac_labeled & MPC_OBJECT_VNODE)
vp->v_label = mac_vnode_label_alloc();
else
vp->v_label = NULL;
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
}
static void
mac_devfs_label_free(struct label *label)
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
{
MAC_POLICY_PERFORM_NOSLEEP(devfs_destroy_label, label);
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
mac_labelzone_free(label);
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
}
void
mac_devfs_destroy(struct devfs_dirent *de)
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
{
if (de->de_label != NULL) {
mac_devfs_label_free(de->de_label);
de->de_label = NULL;
}
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
}
static void
mac_mount_label_free(struct label *label)
{
MAC_POLICY_PERFORM_NOSLEEP(mount_destroy_label, label);
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
mac_labelzone_free(label);
}
void
mac_mount_destroy(struct mount *mp)
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
{
if (mp->mnt_label != NULL) {
mac_mount_label_free(mp->mnt_label);
mp->mnt_label = NULL;
}
}
void
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
mac_vnode_label_free(struct label *label)
{
MAC_POLICY_PERFORM_NOSLEEP(vnode_destroy_label, label);
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
mac_labelzone_free(label);
}
void
mac_vnode_destroy(struct vnode *vp)
{
if (vp->v_label != NULL) {
mac_vnode_label_free(vp->v_label);
vp->v_label = NULL;
}
}
void
mac_vnode_copy_label(struct label *src, struct label *dest)
{
MAC_POLICY_PERFORM_NOSLEEP(vnode_copy_label, src, dest);
}
int
mac_vnode_externalize_label(struct label *label, char *elements,
char *outbuf, size_t outbuflen)
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
{
int error;
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
MAC_POLICY_EXTERNALIZE(vnode, label, elements, outbuf, outbuflen);
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
return (error);
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
}
int
mac_vnode_internalize_label(struct label *label, char *string)
{
int error;
MAC_POLICY_INTERNALIZE(vnode, label, string);
return (error);
}
void
mac_devfs_update(struct mount *mp, struct devfs_dirent *de, struct vnode *vp)
{
MAC_POLICY_PERFORM_NOSLEEP(devfs_update, mp, de, de->de_label, vp,
Rework MAC Framework synchronization in a number of ways in order to improve performance: - Eliminate custom reference count and condition variable to monitor threads entering the framework, as this had both significant overhead and behaved badly in the face of contention. - Replace reference count with two locks: an rwlock and an sx lock, which will be read-acquired by threads entering the framework depending on whether a give policy entry point is permitted to sleep or not. - Replace previous mutex locking of the reference count for exclusive access with write acquiring of both the policy list sx and rw locks, which occurs only when policies are attached or detached. - Do a lockless read of the dynamic policy list head before acquiring any locks in order to reduce overhead when no dynamic policies are loaded; this a race we can afford to lose. - For every policy entry point invocation, decide whether sleeping is permitted, and if not, use a _NOSLEEP() variant of the composition macros, which will use the rwlock instead of the sxlock. In some cases, we decide which to use based on allocation flags passed to the MAC Framework entry point. As with the move to rwlocks/rmlocks in pfil, this may trigger witness warnings, but these should (generally) be false positives as all acquisition of the locks is for read with two very narrow exceptions for policy load/unload, and those code blocks should never acquire other locks. Sponsored by: Google, Inc. Obtained from: TrustedBSD Project Discussed with: csjp (idea, not specific patch)
2009-03-14 16:06:06 +00:00
vp->v_label);
}
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
void
mac_devfs_vnode_associate(struct mount *mp, struct devfs_dirent *de,
struct vnode *vp)
{
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
MAC_POLICY_PERFORM_NOSLEEP(devfs_vnode_associate, mp, mp->mnt_label,
de, de->de_label, vp, vp->v_label);
}
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
int
mac_vnode_associate_extattr(struct mount *mp, struct vnode *vp)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_associate_extattr");
MAC_POLICY_CHECK(vnode_associate_extattr, mp, mp->mnt_label, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp->v_label);
Clean up locking for the MAC Framework: (1) Accept that we're now going to use mutexes, so don't attempt to avoid treating them as mutexes. This cleans up locking accessor function names some. (2) Rename variables to _mtx, _cv, _count, simplifying the naming. (3) Add a new form of the _busy() primitive that conditionally makes the list busy: if there are entries on the list, bump the busy count. If there are no entries, don't bump the busy count. Return a boolean indicating whether or not the busy count was bumped. (4) Break mac_policy_list into two lists: one with the same name holding dynamic policies, and a new list, mac_static_policy_list, which holds policies loaded before mac_late and without the unload flag set. The static list may be accessed without holding the busy count, since it can't change at run-time. (5) In general, prefer making the list busy conditionally, meaning we pay only one mutex lock per entry point if all modules are on the static list, rather than two (since we don't have to lower the busy count when we're done with the framework). For systems running just Biba or MLS, this will halve the mutex accesses in the network stack, and may offer a substantial performance benefits. (6) Lay the groundwork for a dynamic-free kernel option which eliminates all locking associated with dynamically loaded or unloaded policies, for pre-configured systems requiring maximum performance but less run-time flexibility. These changes have been running for a few weeks on MAC development branch systems. Approved by: re (jhb) Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-05-07 17:49:24 +00:00
return (error);
}
void
mac_vnode_associate_singlelabel(struct mount *mp, struct vnode *vp)
{
MAC_POLICY_PERFORM_NOSLEEP(vnode_associate_singlelabel, mp,
mp->mnt_label, vp, vp->v_label);
}
/*
* Functions implementing extended-attribute backed labels for file systems
* that support it.
*
* Where possible, we use EA transactions to make writes to multiple
* attributes across difference policies mutually atomic. We allow work to
* continue on file systems not supporting EA transactions, but generate a
* printf warning.
*/
int
mac_vnode_create_extattr(struct ucred *cred, struct mount *mp,
struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_create_extattr");
ASSERT_VOP_LOCKED(vp, "mac_vnode_create_extattr");
error = VOP_OPENEXTATTR(vp, cred, curthread);
if (error == EOPNOTSUPP) {
if (ea_warn_once == 0) {
printf("Warning: transactions not supported "
"in EA write.\n");
ea_warn_once = 1;
}
} else if (error)
return (error);
MAC_POLICY_CHECK(vnode_create_extattr, cred, mp, mp->mnt_label, dvp,
dvp->v_label, vp, vp->v_label, cnp);
if (error) {
VOP_CLOSEEXTATTR(vp, 0, NOCRED, curthread);
return (error);
}
error = VOP_CLOSEEXTATTR(vp, 1, NOCRED, curthread);
if (error == EOPNOTSUPP)
error = 0;
return (error);
}
static int
mac_vnode_setlabel_extattr(struct ucred *cred, struct vnode *vp,
struct label *intlabel)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_setlabel_extattr");
error = VOP_OPENEXTATTR(vp, cred, curthread);
if (error == EOPNOTSUPP) {
if (ea_warn_once == 0) {
printf("Warning: transactions not supported "
"in EA write.\n");
ea_warn_once = 1;
}
} else if (error)
return (error);
MAC_POLICY_CHECK(vnode_setlabel_extattr, cred, vp, vp->v_label,
intlabel);
if (error) {
VOP_CLOSEEXTATTR(vp, 0, NOCRED, curthread);
return (error);
}
error = VOP_CLOSEEXTATTR(vp, 1, NOCRED, curthread);
if (error == EOPNOTSUPP)
error = 0;
return (error);
}
void
mac_vnode_execve_transition(struct ucred *old, struct ucred *new,
struct vnode *vp, struct label *interpvplabel, struct image_params *imgp)
{
ASSERT_VOP_LOCKED(vp, "mac_vnode_execve_transition");
MAC_POLICY_PERFORM(vnode_execve_transition, old, new, vp,
vp->v_label, interpvplabel, imgp, imgp->execlabel);
}
int
mac_vnode_execve_will_transition(struct ucred *old, struct vnode *vp,
struct label *interpvplabel, struct image_params *imgp)
{
int result;
ASSERT_VOP_LOCKED(vp, "mac_vnode_execve_will_transition");
result = 0;
Rework MAC Framework synchronization in a number of ways in order to improve performance: - Eliminate custom reference count and condition variable to monitor threads entering the framework, as this had both significant overhead and behaved badly in the face of contention. - Replace reference count with two locks: an rwlock and an sx lock, which will be read-acquired by threads entering the framework depending on whether a give policy entry point is permitted to sleep or not. - Replace previous mutex locking of the reference count for exclusive access with write acquiring of both the policy list sx and rw locks, which occurs only when policies are attached or detached. - Do a lockless read of the dynamic policy list head before acquiring any locks in order to reduce overhead when no dynamic policies are loaded; this a race we can afford to lose. - For every policy entry point invocation, decide whether sleeping is permitted, and if not, use a _NOSLEEP() variant of the composition macros, which will use the rwlock instead of the sxlock. In some cases, we decide which to use based on allocation flags passed to the MAC Framework entry point. As with the move to rwlocks/rmlocks in pfil, this may trigger witness warnings, but these should (generally) be false positives as all acquisition of the locks is for read with two very narrow exceptions for policy load/unload, and those code blocks should never acquire other locks. Sponsored by: Google, Inc. Obtained from: TrustedBSD Project Discussed with: csjp (idea, not specific patch)
2009-03-14 16:06:06 +00:00
/* No sleeping since the process lock will be held by the caller. */
MAC_POLICY_BOOLEAN_NOSLEEP(vnode_execve_will_transition, ||, old, vp,
Rework MAC Framework synchronization in a number of ways in order to improve performance: - Eliminate custom reference count and condition variable to monitor threads entering the framework, as this had both significant overhead and behaved badly in the face of contention. - Replace reference count with two locks: an rwlock and an sx lock, which will be read-acquired by threads entering the framework depending on whether a give policy entry point is permitted to sleep or not. - Replace previous mutex locking of the reference count for exclusive access with write acquiring of both the policy list sx and rw locks, which occurs only when policies are attached or detached. - Do a lockless read of the dynamic policy list head before acquiring any locks in order to reduce overhead when no dynamic policies are loaded; this a race we can afford to lose. - For every policy entry point invocation, decide whether sleeping is permitted, and if not, use a _NOSLEEP() variant of the composition macros, which will use the rwlock instead of the sxlock. In some cases, we decide which to use based on allocation flags passed to the MAC Framework entry point. As with the move to rwlocks/rmlocks in pfil, this may trigger witness warnings, but these should (generally) be false positives as all acquisition of the locks is for read with two very narrow exceptions for policy load/unload, and those code blocks should never acquire other locks. Sponsored by: Google, Inc. Obtained from: TrustedBSD Project Discussed with: csjp (idea, not specific patch)
2009-03-14 16:06:06 +00:00
vp->v_label, interpvplabel, imgp, imgp->execlabel);
return (result);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_access, "struct ucred *",
"struct vnode *", "accmode_t");
int
mac_vnode_check_access(struct ucred *cred, struct vnode *vp, accmode_t accmode)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_access");
MAC_POLICY_CHECK(vnode_check_access, cred, vp, vp->v_label, accmode);
MAC_CHECK_PROBE3(vnode_check_access, error, cred, vp, accmode);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(vnode_check_chdir, "struct ucred *",
"struct vnode *");
int
mac_vnode_check_chdir(struct ucred *cred, struct vnode *dvp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_chdir");
MAC_POLICY_CHECK(vnode_check_chdir, cred, dvp, dvp->v_label);
MAC_CHECK_PROBE2(vnode_check_chdir, error, cred, dvp);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(vnode_check_chroot, "struct ucred *",
"struct vnode *");
int
mac_vnode_check_chroot(struct ucred *cred, struct vnode *dvp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_chroot");
MAC_POLICY_CHECK(vnode_check_chroot, cred, dvp, dvp->v_label);
MAC_CHECK_PROBE2(vnode_check_chroot, error, cred, dvp);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_create, "struct ucred *",
"struct vnode *", "struct componentname *", "struct vattr *");
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
int
mac_vnode_check_create(struct ucred *cred, struct vnode *dvp,
struct componentname *cnp, struct vattr *vap)
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_create");
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
MAC_POLICY_CHECK(vnode_check_create, cred, dvp, dvp->v_label, cnp,
vap);
MAC_CHECK_PROBE4(vnode_check_create, error, cred, dvp, cnp, vap);
return (error);
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_deleteacl, "struct ucred *",
"struct vnode *", "acl_type_t");
int
mac_vnode_check_deleteacl(struct ucred *cred, struct vnode *vp,
acl_type_t type)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_deleteacl");
MAC_POLICY_CHECK(vnode_check_deleteacl, cred, vp, vp->v_label, type);
MAC_CHECK_PROBE3(vnode_check_deleteacl, error, cred, vp, type);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_deleteextattr, "struct ucred *",
"struct vnode *", "int", "const char *");
int
mac_vnode_check_deleteextattr(struct ucred *cred, struct vnode *vp,
int attrnamespace, const char *name)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_deleteextattr");
MAC_POLICY_CHECK(vnode_check_deleteextattr, cred, vp, vp->v_label,
attrnamespace, name);
MAC_CHECK_PROBE4(vnode_check_deleteextattr, error, cred, vp,
attrnamespace, name);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_exec, "struct ucred *", "struct vnode *",
"struct image_params *");
int
mac_vnode_check_exec(struct ucred *cred, struct vnode *vp,
struct image_params *imgp)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_exec");
MAC_POLICY_CHECK(vnode_check_exec, cred, vp, vp->v_label, imgp,
imgp->execlabel);
MAC_CHECK_PROBE3(vnode_check_exec, error, cred, vp, imgp);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_getacl, "struct ucred *",
"struct vnode *", "acl_type_t");
int
mac_vnode_check_getacl(struct ucred *cred, struct vnode *vp, acl_type_t type)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_getacl");
MAC_POLICY_CHECK(vnode_check_getacl, cred, vp, vp->v_label, type);
MAC_CHECK_PROBE3(vnode_check_getacl, error, cred, vp, type);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_getextattr, "struct ucred *",
"struct vnode *", "int", "const char *");
int
mac_vnode_check_getextattr(struct ucred *cred, struct vnode *vp,
int attrnamespace, const char *name)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_getextattr");
MAC_POLICY_CHECK(vnode_check_getextattr, cred, vp, vp->v_label,
attrnamespace, name);
MAC_CHECK_PROBE4(vnode_check_getextattr, error, cred, vp,
attrnamespace, name);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_link, "struct ucred *", "struct vnode *",
"struct vnode *", "struct componentname *");
int
mac_vnode_check_link(struct ucred *cred, struct vnode *dvp,
struct vnode *vp, struct componentname *cnp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_link");
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_link");
MAC_POLICY_CHECK(vnode_check_link, cred, dvp, dvp->v_label, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp->v_label, cnp);
MAC_CHECK_PROBE4(vnode_check_link, error, cred, dvp, vp, cnp);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_listextattr, "struct ucred *",
"struct vnode *", "int");
int
mac_vnode_check_listextattr(struct ucred *cred, struct vnode *vp,
int attrnamespace)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_listextattr");
MAC_POLICY_CHECK(vnode_check_listextattr, cred, vp, vp->v_label,
attrnamespace);
MAC_CHECK_PROBE3(vnode_check_listextattr, error, cred, vp,
attrnamespace);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_lookup, "struct ucred *",
"struct vnode *", "struct componentname *");
int
mac_vnode_check_lookup(struct ucred *cred, struct vnode *dvp,
struct componentname *cnp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_lookup");
MAC_POLICY_CHECK(vnode_check_lookup, cred, dvp, dvp->v_label, cnp);
MAC_CHECK_PROBE3(vnode_check_lookup, error, cred, dvp, cnp);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_mmap, "struct ucred *", "struct vnode *",
"int", "int");
int
mac_vnode_check_mmap(struct ucred *cred, struct vnode *vp, int prot,
int flags)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_mmap");
MAC_POLICY_CHECK(vnode_check_mmap, cred, vp, vp->v_label, prot, flags);
MAC_CHECK_PROBE4(vnode_check_mmap, error, cred, vp, prot, flags);
return (error);
}
void
mac_vnode_check_mmap_downgrade(struct ucred *cred, struct vnode *vp,
int *prot)
{
int result = *prot;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_mmap_downgrade");
MAC_POLICY_PERFORM(vnode_check_mmap_downgrade, cred, vp, vp->v_label,
&result);
*prot = result;
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_mprotect, "struct ucred *",
"struct vnode *", "int");
int
mac_vnode_check_mprotect(struct ucred *cred, struct vnode *vp, int prot)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_mprotect");
MAC_POLICY_CHECK(vnode_check_mprotect, cred, vp, vp->v_label, prot);
MAC_CHECK_PROBE3(vnode_check_mprotect, error, cred, vp, prot);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_open, "struct ucred *", "struct vnode *",
"accmode_t");
int
mac_vnode_check_open(struct ucred *cred, struct vnode *vp, accmode_t accmode)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_open");
MAC_POLICY_CHECK(vnode_check_open, cred, vp, vp->v_label, accmode);
MAC_CHECK_PROBE3(vnode_check_open, error, cred, vp, accmode);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_poll, "struct ucred *", "struct ucred *",
"struct vnode *");
int
mac_vnode_check_poll(struct ucred *active_cred, struct ucred *file_cred,
struct vnode *vp)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_poll");
MAC_POLICY_CHECK(vnode_check_poll, active_cred, file_cred, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp->v_label);
MAC_CHECK_PROBE3(vnode_check_poll, error, active_cred, file_cred,
vp);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_read, "struct ucred *", "struct ucred *",
"struct vnode *");
int
mac_vnode_check_read(struct ucred *active_cred, struct ucred *file_cred,
struct vnode *vp)
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
{
int error;
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_read");
Move MAC label storage for mbufs into m_tags from the m_pkthdr structure, returning some additional room in the first mbuf in a chain, and avoiding feature-specific contents in the mbuf header. To do this: - Modify mbuf_to_label() to extract the tag, returning NULL if not found. - Introduce mac_init_mbuf_tag() which does most of the work mac_init_mbuf() used to do, except on an m_tag rather than an mbuf. - Scale back mac_init_mbuf() to perform m_tag allocation and invoke mac_init_mbuf_tag(). - Replace mac_destroy_mbuf() with mac_destroy_mbuf_tag(), since m_tag's are now GC'd deep in the m_tag/mbuf code rather than at a higher level when mbufs are directly free()'d. - Add mac_copy_mbuf_tag() to support m_copy_pkthdr() and related notions. - Generally change all references to mbuf labels so that they use mbuf_to_label() rather than &mbuf->m_pkthdr.label. This required no changes in the MAC policies (yay!). - Tweak mbuf release routines to not call mac_destroy_mbuf(), tag destruction takes care of it for us now. - Remove MAC magic from m_copy_pkthdr() and m_move_pkthdr() -- the existing m_tag support does all this for us. Note that we can no longer just zero the m_tag list on the target mbuf, rather, we have to delete the chain because m_tag's will already be hung off freshly allocated mbuf's. - Tweak m_tag copying routines so that if we're copying a MAC m_tag, we don't do a binary copy, rather, we initialize the new storage and do a deep copy of the label. - Remove use of MAC_FLAG_INITIALIZED in a few bizarre places having to do with mbuf header copies previously. - When an mbuf is copied in ip_input(), we no longer need to explicitly copy the label because it will get handled by the m_tag code now. - No longer any weird handling of MAC labels in if_loop.c during header copies. - Add MPC_LOADTIME_FLAG_LABELMBUFS flag to Biba, MLS, mac_test. In mac_test, handle the label==NULL case, since it can be dynamically loaded. In order to improve performance with this change, introduce the notion of "lazy MAC label allocation" -- only allocate m_tag storage for MAC labels if we're running with a policy that uses MAC labels on mbufs. Policies declare this intent by setting the MPC_LOADTIME_FLAG_LABELMBUFS flag in their load-time flags field during declaration. Note: this opens up the possibility of post-boot policy modules getting back NULL slot entries even though they have policy invariants of non-NULL slot entries, as the policy might have been loaded after the mbuf was allocated, leaving the mbuf without label storage. Policies that cannot handle this case must be declared as NOTLATE, or must be modified. - mac_labelmbufs holds the current cumulative status as to whether any policies require mbuf labeling or not. This is updated whenever the active policy set changes by the function mac_policy_updateflags(). The function iterates the list and checks whether any have the flag set. Write access to this variable is protected by the policy list; read access is currently not protected for performance reasons. This might change if it causes problems. - Add MAC_POLICY_LIST_ASSERT_EXCLUSIVE() to permit the flags update function to assert appropriate locks. - This makes allocation in mac_init_mbuf() conditional on the flag. Reviewed by: sam Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-04-14 20:39:06 +00:00
MAC_POLICY_CHECK(vnode_check_read, active_cred, file_cred, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp->v_label);
MAC_CHECK_PROBE3(vnode_check_read, error, active_cred, file_cred,
vp);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(vnode_check_readdir, "struct ucred *",
"struct vnode *");
int
mac_vnode_check_readdir(struct ucred *cred, struct vnode *dvp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_readdir");
MAC_POLICY_CHECK(vnode_check_readdir, cred, dvp, dvp->v_label);
MAC_CHECK_PROBE2(vnode_check_readdir, error, cred, dvp);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(vnode_check_readlink, "struct ucred *",
"struct vnode *");
int
mac_vnode_check_readlink(struct ucred *cred, struct vnode *vp)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_readlink");
MAC_POLICY_CHECK(vnode_check_readlink, cred, vp, vp->v_label);
MAC_CHECK_PROBE2(vnode_check_readlink, error, cred, vp);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_relabel, "struct ucred *",
"struct vnode *", "struct label *");
static int
mac_vnode_check_relabel(struct ucred *cred, struct vnode *vp,
struct label *newlabel)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_relabel");
MAC_POLICY_CHECK(vnode_check_relabel, cred, vp, vp->v_label, newlabel);
MAC_CHECK_PROBE3(vnode_check_relabel, error, cred, vp, newlabel);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_rename_from, "struct ucred *",
"struct vnode *", "struct vnode *", "struct componentname *");
int
mac_vnode_check_rename_from(struct ucred *cred, struct vnode *dvp,
struct vnode *vp, struct componentname *cnp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_rename_from");
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_rename_from");
MAC_POLICY_CHECK(vnode_check_rename_from, cred, dvp, dvp->v_label, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp->v_label, cnp);
MAC_CHECK_PROBE4(vnode_check_rename_from, error, cred, dvp, vp, cnp);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_rename_to, "struct ucred *",
"struct vnode *", "struct vnode *", "struct componentname *");
int
mac_vnode_check_rename_to(struct ucred *cred, struct vnode *dvp,
struct vnode *vp, int samedir, struct componentname *cnp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_rename_to");
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_rename_to");
MAC_POLICY_CHECK(vnode_check_rename_to, cred, dvp, dvp->v_label, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp != NULL ? vp->v_label : NULL, samedir, cnp);
MAC_CHECK_PROBE4(vnode_check_rename_to, error, cred, dvp, vp, cnp);
return (error);
}
MAC_CHECK_PROBE_DEFINE2(vnode_check_revoke, "struct ucred *",
"struct vnode *");
int
mac_vnode_check_revoke(struct ucred *cred, struct vnode *vp)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_revoke");
MAC_POLICY_CHECK(vnode_check_revoke, cred, vp, vp->v_label);
MAC_CHECK_PROBE2(vnode_check_revoke, error, cred, vp);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_setacl, "struct ucred *",
"struct vnode *", "acl_type_t", "struct acl *");
int
mac_vnode_check_setacl(struct ucred *cred, struct vnode *vp, acl_type_t type,
struct acl *acl)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_setacl");
MAC_POLICY_CHECK(vnode_check_setacl, cred, vp, vp->v_label, type, acl);
MAC_CHECK_PROBE4(vnode_check_setacl, error, cred, vp, type, acl);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_setextattr, "struct ucred *",
"struct vnode *", "int", "const char *");
int
mac_vnode_check_setextattr(struct ucred *cred, struct vnode *vp,
int attrnamespace, const char *name)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_setextattr");
MAC_POLICY_CHECK(vnode_check_setextattr, cred, vp, vp->v_label,
attrnamespace, name);
MAC_CHECK_PROBE4(vnode_check_setextattr, error, cred, vp,
attrnamespace, name);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_setflags, "struct ucred *",
"struct vnode *", "u_long");
int
mac_vnode_check_setflags(struct ucred *cred, struct vnode *vp, u_long flags)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_setflags");
MAC_POLICY_CHECK(vnode_check_setflags, cred, vp, vp->v_label, flags);
MAC_CHECK_PROBE3(vnode_check_setflags, error, cred, vp, flags);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_setmode, "struct ucred *",
"struct vnode *", "mode_t");
int
mac_vnode_check_setmode(struct ucred *cred, struct vnode *vp, mode_t mode)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_setmode");
MAC_POLICY_CHECK(vnode_check_setmode, cred, vp, vp->v_label, mode);
MAC_CHECK_PROBE3(vnode_check_setmode, error, cred, vp, mode);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_setowner, "struct ucred *",
"struct vnode *", "uid_t", "gid_t");
int
mac_vnode_check_setowner(struct ucred *cred, struct vnode *vp, uid_t uid,
gid_t gid)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_setowner");
MAC_POLICY_CHECK(vnode_check_setowner, cred, vp, vp->v_label, uid, gid);
MAC_CHECK_PROBE4(vnode_check_setowner, error, cred, vp, uid, gid);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_setutimes, "struct ucred *",
"struct vnode *", "struct timespec *", "struct timespec *");
int
mac_vnode_check_setutimes(struct ucred *cred, struct vnode *vp,
struct timespec atime, struct timespec mtime)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_setutimes");
MAC_POLICY_CHECK(vnode_check_setutimes, cred, vp, vp->v_label, atime,
mtime);
MAC_CHECK_PROBE4(vnode_check_setutimes, error, cred, vp, &atime,
&mtime);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_stat, "struct ucred *", "struct ucred *",
"struct vnode *");
int
mac_vnode_check_stat(struct ucred *active_cred, struct ucred *file_cred,
struct vnode *vp)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_stat");
MAC_POLICY_CHECK(vnode_check_stat, active_cred, file_cred, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp->v_label);
MAC_CHECK_PROBE3(vnode_check_stat, error, active_cred, file_cred,
vp);
return (error);
}
MAC_CHECK_PROBE_DEFINE4(vnode_check_unlink, "struct ucred *",
"struct vnode *", "struct vnode *", "struct componentname *");
int
mac_vnode_check_unlink(struct ucred *cred, struct vnode *dvp,
struct vnode *vp, struct componentname *cnp)
{
int error;
ASSERT_VOP_LOCKED(dvp, "mac_vnode_check_unlink");
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_unlink");
MAC_POLICY_CHECK(vnode_check_unlink, cred, dvp, dvp->v_label, vp,
vp->v_label, cnp);
MAC_CHECK_PROBE4(vnode_check_unlink, error, cred, dvp, vp, cnp);
return (error);
}
MAC_CHECK_PROBE_DEFINE3(vnode_check_write, "struct ucred *",
"struct ucred *", "struct vnode *");
int
mac_vnode_check_write(struct ucred *active_cred, struct ucred *file_cred,
struct vnode *vp)
{
int error;
ASSERT_VOP_LOCKED(vp, "mac_vnode_check_write");
MAC_POLICY_CHECK(vnode_check_write, active_cred, file_cred, vp,
Modify the MAC Framework so that instead of embedding a (struct label) in various kernel objects to represent security data, we embed a (struct label *) pointer, which now references labels allocated using a UMA zone (mac_label.c). This allows the size and shape of struct label to be varied without changing the size and shape of these kernel objects, which become part of the frozen ABI with 5-STABLE. This opens the door for boot-time selection of the number of label slots, and hence changes to the bound on the number of simultaneous labeled policies at boot-time instead of compile-time. This also makes it easier to embed label references in new objects as required for locking/caching with fine-grained network stack locking, such as inpcb structures. This change also moves us further in the direction of hiding the structure of kernel objects from MAC policy modules, not to mention dramatically reducing the number of '&' symbols appearing in both the MAC Framework and MAC policy modules, and improving readability. While this results in minimal performance change with MAC enabled, it will observably shrink the size of a number of critical kernel data structures for the !MAC case, and should have a small (but measurable) performance benefit (i.e., struct vnode, struct socket) do to memory conservation and reduced cost of zeroing memory. NOTE: Users of MAC must recompile their kernel and all MAC modules as a result of this change. Because this is an API change, third party MAC modules will also need to be updated to make less use of the '&' symbol. Suggestions from: bmilekic Obtained from: TrustedBSD Project Sponsored by: DARPA, Network Associates Laboratories
2003-11-12 03:14:31 +00:00
vp->v_label);
MAC_CHECK_PROBE3(vnode_check_write, error, active_cred, file_cred,
vp);
return (error);
}
void
mac_vnode_relabel(struct ucred *cred, struct vnode *vp,
struct label *newlabel)
{
MAC_POLICY_PERFORM(vnode_relabel, cred, vp, vp->v_label, newlabel);
}
void
mac_mount_create(struct ucred *cred, struct mount *mp)
{
MAC_POLICY_PERFORM(mount_create, cred, mp, mp->mnt_label);
}
MAC_CHECK_PROBE_DEFINE2(mount_check_stat, "struct ucred *",
"struct mount *");
int
mac_mount_check_stat(struct ucred *cred, struct mount *mount)
{
int error;
MAC_POLICY_CHECK_NOSLEEP(mount_check_stat, cred, mount, mount->mnt_label);
MAC_CHECK_PROBE2(mount_check_stat, error, cred, mount);
return (error);
}
void
mac_devfs_create_device(struct ucred *cred, struct mount *mp,
When devfs cloning takes place, provide access to the credential of the process that caused the clone event to take place for the device driver creating the device. This allows cloned device drivers to adapt the device node based on security aspects of the process, such as the uid, gid, and MAC label. - Add a cred reference to struct cdev, so that when a device node is instantiated as a vnode, the cloning credential can be exposed to MAC. - Add make_dev_cred(), a version of make_dev() that additionally accepts the credential to stick in the struct cdev. Implement it and make_dev() in terms of a back-end make_dev_credv(). - Add a new event handler, dev_clone_cred, which can be registered to receive the credential instead of dev_clone, if desired. - Modify the MAC entry point mac_create_devfs_device() to accept an optional credential pointer (may be NULL), so that MAC policies can inspect and act on the label or other elements of the credential when initializing the skeleton device protections. - Modify tty_pty.c to register clone_dev_cred and invoke make_dev_cred(), so that the pty clone credential is exposed to the MAC Framework. While currently primarily focussed on MAC policies, this change is also a prerequisite for changes to allow ptys to be instantiated with the UID of the process looking up the pty. This requires further changes to the pty driver -- in particular, to immediately recycle pty nodes on last close so that the credential-related state can be recreated on next lookup. Submitted by: Andrew Reisse <andrew.reisse@sparta.com> Obtained from: TrustedBSD Project Sponsored by: SPAWAR, SPARTA MFC after: 1 week MFC note: Merge to 6.x, but not 5.x for ABI reasons
2005-07-14 10:22:09 +00:00
struct cdev *dev, struct devfs_dirent *de)
{
MAC_POLICY_PERFORM_NOSLEEP(devfs_create_device, cred, mp, dev, de,
Rework MAC Framework synchronization in a number of ways in order to improve performance: - Eliminate custom reference count and condition variable to monitor threads entering the framework, as this had both significant overhead and behaved badly in the face of contention. - Replace reference count with two locks: an rwlock and an sx lock, which will be read-acquired by threads entering the framework depending on whether a give policy entry point is permitted to sleep or not. - Replace previous mutex locking of the reference count for exclusive access with write acquiring of both the policy list sx and rw locks, which occurs only when policies are attached or detached. - Do a lockless read of the dynamic policy list head before acquiring any locks in order to reduce overhead when no dynamic policies are loaded; this a race we can afford to lose. - For every policy entry point invocation, decide whether sleeping is permitted, and if not, use a _NOSLEEP() variant of the composition macros, which will use the rwlock instead of the sxlock. In some cases, we decide which to use based on allocation flags passed to the MAC Framework entry point. As with the move to rwlocks/rmlocks in pfil, this may trigger witness warnings, but these should (generally) be false positives as all acquisition of the locks is for read with two very narrow exceptions for policy load/unload, and those code blocks should never acquire other locks. Sponsored by: Google, Inc. Obtained from: TrustedBSD Project Discussed with: csjp (idea, not specific patch)
2009-03-14 16:06:06 +00:00
de->de_label);
}
void
mac_devfs_create_symlink(struct ucred *cred, struct mount *mp,
struct devfs_dirent *dd, struct devfs_dirent *de)
{
MAC_POLICY_PERFORM_NOSLEEP(devfs_create_symlink, cred, mp, dd,
Rework MAC Framework synchronization in a number of ways in order to improve performance: - Eliminate custom reference count and condition variable to monitor threads entering the framework, as this had both significant overhead and behaved badly in the face of contention. - Replace reference count with two locks: an rwlock and an sx lock, which will be read-acquired by threads entering the framework depending on whether a give policy entry point is permitted to sleep or not. - Replace previous mutex locking of the reference count for exclusive access with write acquiring of both the policy list sx and rw locks, which occurs only when policies are attached or detached. - Do a lockless read of the dynamic policy list head before acquiring any locks in order to reduce overhead when no dynamic policies are loaded; this a race we can afford to lose. - For every policy entry point invocation, decide whether sleeping is permitted, and if not, use a _NOSLEEP() variant of the composition macros, which will use the rwlock instead of the sxlock. In some cases, we decide which to use based on allocation flags passed to the MAC Framework entry point. As with the move to rwlocks/rmlocks in pfil, this may trigger witness warnings, but these should (generally) be false positives as all acquisition of the locks is for read with two very narrow exceptions for policy load/unload, and those code blocks should never acquire other locks. Sponsored by: Google, Inc. Obtained from: TrustedBSD Project Discussed with: csjp (idea, not specific patch)
2009-03-14 16:06:06 +00:00
dd->de_label, de, de->de_label);
}
void
mac_devfs_create_directory(struct mount *mp, char *dirname, int dirnamelen,
struct devfs_dirent *de)
{
MAC_POLICY_PERFORM_NOSLEEP(devfs_create_directory, mp, dirname,
dirnamelen, de, de->de_label);
}
/*
* Implementation of VOP_SETLABEL() that relies on extended attributes to
* store label data. Can be referenced by filesystems supporting extended
* attributes.
*/
int
vop_stdsetlabel_ea(struct vop_setlabel_args *ap)
{
struct vnode *vp = ap->a_vp;
struct label *intlabel = ap->a_label;
int error;
ASSERT_VOP_LOCKED(vp, "vop_stdsetlabel_ea");
if ((vp->v_mount->mnt_flag & MNT_MULTILABEL) == 0)
return (EOPNOTSUPP);
error = mac_vnode_setlabel_extattr(ap->a_cred, vp, intlabel);
if (error)
return (error);
mac_vnode_relabel(ap->a_cred, vp, intlabel);
return (0);
}
int
vn_setlabel(struct vnode *vp, struct label *intlabel, struct ucred *cred)
{
int error;
if (vp->v_mount == NULL) {
/* printf("vn_setlabel: null v_mount\n"); */
if (vp->v_type != VNON)
printf("vn_setlabel: null v_mount with non-VNON\n");
return (EBADF);
}
if ((vp->v_mount->mnt_flag & MNT_MULTILABEL) == 0)
return (EOPNOTSUPP);
/*
* Multi-phase commit. First check the policies to confirm the
* change is OK. Then commit via the filesystem. Finally, update
* the actual vnode label.
*
* Question: maybe the filesystem should update the vnode at the end
* as part of VOP_SETLABEL()?
*/
error = mac_vnode_check_relabel(cred, vp, intlabel);
if (error)
return (error);
/*
* VADMIN provides the opportunity for the filesystem to make
* decisions about who is and is not able to modify labels and
* protections on files. This might not be right. We can't assume
* VOP_SETLABEL() will do it, because we might implement that as part
* of vop_stdsetlabel_ea().
*/
error = VOP_ACCESS(vp, VADMIN, cred, curthread);
if (error)
return (error);
error = VOP_SETLABEL(vp, intlabel, cred, curthread);
if (error)
return (error);
return (0);
}