If a domain is explicitly configured with <seclabel type="none"/> we
correctly ensure that no labeling will be done by setting
norelabel=true. However, if no seclabel element is present in domain XML
and hypervisor is configured not to confine domains by default, we only
set type to "none" without turning off relabeling. Thus if such a domain
is being started, security driver wants to relabel resources with
default label, which doesn't make any sense.

Moreover, with SELinux security driver, the generated image label lacks
"s0" sensitivity, which causes setfilecon() fail with EINVAL in
enforcing mode.

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

Update the security drivers to use virReportError instead of
the virSecurityReportError custom macro
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Some security drivers require special options to be passed to
the mount system call. Add a security driver API for handling
this data.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

To allow the security drivers to apply different configuration
information per hypervisor, pass the virtualization driver name
into the security manager constructor.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

In case the caller specifies that confined guests are required but the
security driver turns out to be 'none', we should return an error since
this driver clearly cannot meet that requirement.  As a result of this
error, libvirtd fails to start when the host admin explicitly sets
confined guests are required but there is no security driver available.

Since security driver 'none' cannot create confined guests, we override
default confined setting so that hypervisor drivers do not thing they
should create confined guests.

Curently security labels can be of type 'dynamic' or 'static'.
If no security label is given, then 'dynamic' is assumed. The
current code takes advantage of this default, and avoids even
saving <seclabel> elements with type='dynamic' to disk. This
means if you temporarily change security driver, the guests
can all still start.

With the introduction of sVirt to LXC though, there needs to be
a new default of 'none' to allow unconfined LXC containers.

This patch introduces two new security label types

 - default:  the host configuration decides whether to run the
             guest with type 'none' or 'dynamic' at guest start
 - none:     the guest will run unconfined by security policy

The 'none' label type will obviously be undesirable for some
deployments, so a new qemu.conf option allows a host admin to
mandate confined guests. It is also possible to turn off default
confinement

  security_default_confined = 1|0  (default == 1)
  security_require_confined = 1|0  (default == 0)

* src/conf/domain_conf.c, src/conf/domain_conf.h: Add new
  seclabel types
* src/security/security_manager.c, src/security/security_manager.h:
  Set default sec label types
* src/security/security_selinux.c: Handle 'none' seclabel type
* src/qemu/qemu.conf, src/qemu/qemu_conf.c, src/qemu/qemu_conf.h,
  src/qemu/libvirtd_qemu.aug: New security config options
* src/qemu/qemu_driver.c: Tell security driver about default
  config

When sVirt is integrated with the LXC driver, it will be neccessary
to invoke the security driver APIs using only a virDomainDefPtr
since the lxc_container.c code has no virDomainObjPtr available.
Aside from two functions which want obj->pid, every bit of the
security driver code only touches obj->def. So we don't need to
pass a virDomainObjPtr into the security drivers, a virDomainDefPtr
is sufficient. Two functions also gain a 'pid_t pid' argument.

* src/qemu/qemu_driver.c, src/qemu/qemu_hotplug.c,
  src/qemu/qemu_migration.c, src/qemu/qemu_process.c,
  src/security/security_apparmor.c,
  src/security/security_dac.c,
  src/security/security_driver.h,
  src/security/security_manager.c,
  src/security/security_manager.h,
  src/security/security_nop.c,
  src/security/security_selinux.c,
  src/security/security_stack.c: Change all security APIs to use a
  virDomainDefPtr instead of virDomainObjPtr

The virSecurityManagerSetProcessFDLabel method was introduced
after a mis-understanding from a conversation about SELinux
socket labelling. The virSecurityManagerSetSocketLabel method
should have been used for all such scenarios.

* src/security/security_apparmor.c, src/security/security_apparmor.c,
  src/security/security_driver.h, src/security/security_manager.c,
  src/security/security_manager.h, src/security/security_selinux.c,
  src/security/security_stack.c: Remove SetProcessFDLabel driver

This API labels all sockets created until ClearSocketLabel is called in
a way that a vm can access them (i.e., they are labeled with svirt_t
based label in SELinux).

The APIs are designed to label a socket in a way that the libvirt daemon
itself is able to access it (i.e., in SELinux the label is virtd_t based
as opposed to svirt_* we use for labeling resources that need to be
accessed by a vm). The new name reflects this.

Add a new security driver method for labelling an FD with
the process label, rather than the image label

* src/libvirt_private.syms, src/security/security_apparmor.c,
  src/security/security_dac.c, src/security/security_driver.h,
  src/security/security_manager.c, src/security/security_manager.h,
  src/security/security_selinux.c, src/security/security_stack.c:
  Add virSecurityManagerSetProcessFDLabel & impl

The virSecurityManagerSetFDLabel method is used to label
file descriptors associated with disk images. There will
shortly be a need to label other file descriptors in a
different way. So the current name is ambiguous. Rename
the method to virSecurityManagerSetImageFDLabel to clarify
its purpose

* src/libvirt_private.syms,
  src/qemu/qemu_migration.c, src/qemu/qemu_process.c,
  src/security/security_apparmor.c, src/security/security_dac.c,
  src/security/security_driver.h, src/security/security_manager.c,
  src/security/security_manager.h, src/security/security_selinux.c,
  src/security/security_stack.c: s/FDLabel/ImageFDLabel/

Regression introduced in commit d6623003 (v0.8.8) - using the
wrong sizeof operand meant that security manager private data
was overlaying the allowDiskFormatProbing member of struct
_virSecurityManager.  This reopens disk probing, which was
supposed to be prevented by the solution to CVE-2010-2238.

* src/security/security_manager.c
(virSecurityManagerGetPrivateData): Use correct offset.

A need was found to set the SELinux context label on an open fd (a
pipe, as a matter of fact). This patch adds a function to the security
driver API that will set the label on an open fd to secdef.label. For
all drivers other than the SELinux driver, it's a NOP. For the SElinux
driver, it calls fsetfilecon().

If the return is a failure, it only returns error up to the caller if
1) the desired label is different from the existing label, 2) the
destination fd is of a type that supports setting the selinux context,
and 3) selinux is in enforcing mode. Otherwise it will return
success. This follows the pattern of the existing function
SELinuxSetFilecon().

If the XML security model is NULL, it is assumed that the current
model will be used with dynamic labelling. The verify step is
meaningless and potentially crashes if dereferencing NULL

* src/security/security_manager.c: Skip NULL model on verify

The current security driver usage requires horrible code like

    if (driver->securityDriver &&
        driver->securityDriver->domainSetSecurityHostdevLabel &&
        driver->securityDriver->domainSetSecurityHostdevLabel(driver->securityDriver,
                                                              vm, hostdev) < 0)

This pair of checks for NULL clutters up the code, making the driver
calls 2 lines longer than they really need to be. The goal of the
patchset is to change the calling convention to simply

  if (virSecurityManagerSetHostdevLabel(driver->securityDriver,
                                        vm, hostdev) < 0)

The first check for 'driver->securityDriver' being NULL is removed
by introducing a 'no op' security driver that will always be present
if no real driver is enabled. This guarentees driver->securityDriver
!= NULL.

The second check for 'driver->securityDriver->domainSetSecurityHostdevLabel'
being non-NULL is hidden in a new abstraction called virSecurityManager.
This separates the driver callbacks, from main internal API. The addition
of a virSecurityManager object, that is separate from the virSecurityDriver
struct also allows for security drivers to carry state / configuration
information directly. Thus the DAC/Stack drivers from src/qemu which
used to pull config from 'struct qemud_driver' can now be moved into
the 'src/security' directory and store their config directly.

* src/qemu/qemu_conf.h, src/qemu/qemu_driver.c: Update to
  use new virSecurityManager APIs
* src/qemu/qemu_security_dac.c,  src/qemu/qemu_security_dac.h
  src/qemu/qemu_security_stacked.c, src/qemu/qemu_security_stacked.h:
  Move into src/security directory
* src/security/security_stack.c, src/security/security_stack.h,
  src/security/security_dac.c, src/security/security_dac.h: Generic
  versions of previous QEMU specific drivers
* src/security/security_apparmor.c, src/security/security_apparmor.h,
  src/security/security_driver.c, src/security/security_driver.h,
  src/security/security_selinux.c, src/security/security_selinux.h:
  Update to take virSecurityManagerPtr object as the first param
  in all callbacks
* src/security/security_nop.c, src/security/security_nop.h: Stub
  implementation of all security driver APIs.
* src/security/security_manager.h, src/security/security_manager.c:
  New internal API for invoking security drivers
* src/libvirt.c: Add missing debug for security APIs