We are currently able to work only with non-translated SELinux
contexts, but we are using functions that work with translated
contexts throughout the code.  This patch swaps all SELinux context
translation relative calls with their raw sisters to avoid parsing
problems.

The problems can be experienced with mcstrans for example.  The
difference is that if you have translations enabled (yum install
mcstrans; service mcstrans start), fgetfilecon_raw() will get you
something like 'system_u:object_r:virt_image_t:s0', whereas
fgetfilecon() will return 'system_u:object_r:virt_image_t:SystemLow'
that we cannot parse.

I was trying to confirm that the _raw variants were here since the dawn of
time, but the only thing I see now is that it was imported together in
the upstream repo [1] from svn, so before 2008.

Thanks Laurent Bigonville for finding this out.

[1] http://oss.tresys.com/git/selinux.git

All USB device lookup functions emit an error when they cannot find the
requested device. With this patch, their caller can choose if a missing
device is an error or normal condition.

This allows the user to control labelling of each character device
separately (the default is to inherit from the VM).
Signed-off-by: NRichard W.M. Jones <rjones@redhat.com>

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Currently the dynamic label generation code will create labels
with a sensitivity of s0, and a category pair in the range
0-1023. This is fine when running a standard MCS policy because
libvirtd will run with a label

  system_u:system_r:virtd_t:s0-s0:c0.c1023

With custom policies though, it is possible for libvirtd to have
a different sensitivity, or category range. For example

  system_u:system_r:virtd_t:s2-s3:c512.c1023

In this case we must assign the VM a sensitivity matching the
current lower sensitivity value, and categories in the range
512-1023
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The code to refactor sec label handling accidentally changed the
SELinux driver to use the 'domain_context' when generating the
image label instead of the 'file_context'
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

These changes make the security drivers able to find and handle the
correct security label information when more than one label is
available. They also update the DAC driver to be used as an usual
security driver.
Signed-off-by: NMarcelo Cerri <mhcerri@linux.vnet.ibm.com>

This patch updates the structures that store information about each
domain and each hypervisor to support multiple security labels and
drivers. It also updates all the remaining code to use the new fields.
Signed-off-by: NMarcelo Cerri <mhcerri@linux.vnet.ibm.com>

This is a fix for the object label generation. It uses a new flag for
virSecuritySELinuxGenNewContext that specifies whether the context is
for an object. If so the context role remains unchanged.
Without this fix it is not possible to start domains with image file or
block device backed storage when selinux is enabled.
Signed-off-by: NViktor Mihajlovski <mihajlov@linux.vnet.ibm.com>

The code for picking a MCS label is about to get significantly
more complicated, so it deserves to be in a standlone method,
instead of a switch/case body.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When generating an SELinux context for a VM from the template
"system_u:system_r:svirt_t:s0", copy the role + user from the
current process instead of the template context. So if the
current process is

   unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

then the VM context ends up as

  unconfined_u:unconfined_r:svirt_t:s0:c386,c703

instead of

   system_u:system_r:svirt_t:s0:c177,c424

Ideally the /etc/selinux/targeted/contexts/virtual_domain_context
file would have just shown the 'svirt_t' type, and not the full
context, but that can't be changed now for compatibility reasons.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The virSecuritySELinuxGenNewContext method was not reporting any
errors, leaving it up to the caller to report a generic error.
In addition it could potentially trigger a strdup(NULL) in an
OOM scenario. Move all error reporting into the
virSecuritySELinuxGenNewContext method where accurate info
can be provided
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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

Instead of using an O(n) efficiency linked list for storing
MCS labels, use a hash table. Instead of having the list
be global, put it in the SELinux driver private data struct
to ensure uniqueness across different instances of the driver.
This also ensures thread safety when multiple hypervisor
drivers are used in the same libvirtd process
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When adding MCS labels, OOM was not being handled correctly.
In addition when reserving an existing label, no check was
made to see if it was already reserved
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The function names in the SELinux driver all start with
SELinux or 'mcs' as a prefix. Sanitize this so that they
all use 'virSecuritySELinux' as the prefix
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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

Most versions of libselinux do not contain the function
selinux_lxc_contexts_path() that the security driver
recently started using for LXC. We must add a conditional
check for it in configure and then disable the LXC security
driver for builds where libselinux lacks this function.

* configure.ac: Check for selinux_lxc_contexts_path
* src/security/security_selinux.c: Disable LXC security
  if selinux_lxc_contexts_path() is missing

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>

The SELinux policy for LXC uses a different configuration file
than the traditional svirt one. Thus we need to load
/etc/selinux/targeted/contexts/lxc_contexts which contains
something like this:

 process = "system_u:system_r:svirt_lxc_net_t:s0"
 file = "system_u:object_r:svirt_lxc_file_t:s0"
 content = "system_u:object_r:virt_var_lib_t:s0"

cleverly designed to be parsable by virConfPtr
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the SELinux driver stores its state in a set of global
variables. This switches it to use a private data struct instead.
This will enable different instances to have their own 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>

Return statements with parameter enclosed in parentheses were modified
and parentheses were removed. The whole change was scripted, here is how:

List of files was obtained using this command:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' |             \
grep -e '\.[ch]$' -e '\.py$'

Found files were modified with this command:
sed -i -e                                                                 \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'

Then checked for nonsense.

The whole command looks like this:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' |             \
grep -e '\.[ch]$' -e '\.py$' | xargs sed -i -e                            \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'

This eliminates the warning message reported in:

 https://bugzilla.redhat.com/show_bug.cgi?id=624447

It was caused by a failure to open an image file that is not
accessible by root (the uid libvirtd is running as) because it's on a
root-squash NFS share, owned by a different user, with permissions of
660 (or maybe 600).

The solution is to use virFileOpenAs() rather than open(). The
codepath that generates the error is during qemuSetupDiskCGroup(), but
the actual open() is in a lower-level generic function called from
many places (virDomainDiskDefForeachPath), so some other pieces of the
code were touched just to add dummy (or possibly useful) uid and gid
arguments.

Eliminating this warning message has the nice side effect that the
requested operation may even succeed (which in this case isn't
necessary, but shouldn't hurt anything either).

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

The old virRandom() API was not generating good random numbers.
Replace it with a new API virRandomBits which instead of being
told the upper limit, gets told the number of bits of randomness
required.

* src/util/virrandom.c, src/util/virrandom.h: Add virRandomBits,
  and move virRandomInitialize
* src/util/util.h, src/util/util.c: Delete virRandom and
  virRandomInitialize
* src/libvirt.c, src/security/security_selinux.c,
  src/test/test_driver.c, src/util/iohelper.c: Update for
  changes from virRandom to virRandomBits
* src/storage/storage_backend_iscsi.c: Remove bogus call
  to virRandomInitialize & convert to virRandomBits

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

This wires up the XML changes in the previous patch to let SELinux
labeling honor user overrides, as well as affecting the live XML
configuration in one case where the user didn't specify anything
in the offline XML.

I noticed that the logs contained messages like this:

2011-12-05 23:32:40.382+0000: 26569: warning : SELinuxRestoreSecurityFileLabel:533 : cannot lookup default selinux label for /nfs/libvirt/images/dom.img

for all my domain images living on NFS.  But if we would just remember
that on domain creation that we were unable to set a SELinux label (due to
NFSv3 lacking labels, or NFSv4 not being configured to expose attributes),
then we could avoid wasting the time trying to clear the label on
domain shutdown.  This in turn is one less point of NFS failure,
especially since there have been documented cases of virDomainDestroy
hanging during an attempted operation on a failed NFS connection.

* src/security/security_selinux.c (SELinuxSetFilecon): Move guts...
(SELinuxSetFileconHelper): ...to new function.
(SELinuxSetFileconOptional): New function.
(SELinuxSetSecurityFileLabel): Honor override label, and remember
if labeling failed.
(SELinuxRestoreSecurityImageLabelInt): Skip relabeling based on
override.

Network disks don't have paths to be resolved or files to be checked
for ownership. ee3efc41 checked this
for some image label functions, but was partially reverted in a
refactor.  This finishes adding the check to each security driver's
set and restore label methods for images.
Signed-off-by: NJosh Durgin <josh.durgin@dreamhost.com>

While Xen only has a single paravirt console, UML, and
QEMU both support multiple paravirt consoles. The LXC
driver can also be trivially made to support multiple
consoles. This patch extends the XML to allow multiple
<console> elements in the XML. It also makes the UML
and QEMU drivers support this config.

* src/conf/domain_conf.c, src/conf/domain_conf.h: Allow
  multiple <console> devices
* src/lxc/lxc_driver.c, src/xen/xen_driver.c,
  src/xenxs/xen_sxpr.c, src/xenxs/xen_xm.c: Update for
  internal API changes
* src/security/security_selinux.c, src/security/virt-aa-helper.c:
  Only label consoles that aren't a copy of the serial device
* src/qemu/qemu_command.c, src/qemu/qemu_driver.c,
  src/qemu/qemu_process.c, src/uml/uml_conf.c,
  src/uml/uml_driver.c: Support multiple console devices
* tests/qemuxml2xmltest.c, tests/qemuxml2argvtest.c: Extra
  tests for multiple virtio consoles. Set QEMU_CAPS_CHARDEV
  for all console /channel tests
* tests/qemuxml2argvdata/qemuxml2argv-channel-virtio-auto.args,
  tests/qemuxml2argvdata/qemuxml2argv-channel-virtio.args
  tests/qemuxml2argvdata/qemuxml2argv-console-virtio.args: Update
  for correct chardev syntax
* tests/qemuxml2argvdata/qemuxml2argv-console-virtio-many.args,
  tests/qemuxml2argvdata/qemuxml2argv-console-virtio-many.xml: New
  test file

This patch fixes the regression with using named pipes for qemu serial
devices noted in:

  https://bugzilla.redhat.com/show_bug.cgi?id=740478

The problem was that, while new code in libvirt looks for a single
bidirectional fifo of the name given in the config, then relabels that
and continues without looking for / relabelling the two unidirectional
fifos named ${name}.in and ${name}.out, qemu looks in the opposite
order. So if the user had naively created all three fifos, libvirt
would relabel the bidirectional fifo to allow qemu access, but qemu
would attempt to use the two unidirectional fifos and fail (because it
didn't have proper permissions/rights).

This patch changes the order that libvirt looks for the fifos to match
what qemu does - first it looks for the dual fifos, then it looks for
the single bidirectional fifo. If it finds the dual unidirectional
fifos first, it labels/chowns them and ignores any possible
bidirectional fifo.

(Note commit d37c6a3a (which first appeared in libvirt-0.9.2) added
the code that checked for a bidirectional fifo. Prior to that commit,
bidirectional fifos for serial devices didn't work because libvirt
always required the ${name}.(in|out) fifos to exist, and qemu would
always prefer those.

Previous patch c9b37fee tried to deal with virt_use_nfs. But
setfilecon() returns EOPNOTSUPP on NFS so we need to move the
warning to else branch.

If we fail setting label on a file and this file is on NFS share,
it is wise to advise user to set virt_use_nfs selinux boolean
variable.

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.

In preparation for a future patch adding new virFile APIs.

* src/util/files.h, src/util/files.c: Move...
* src/util/virfile.h, src/util/virfile.c: ...here, and rename
functions to virFile prefix.  Macro names are intentionally
left alone.
* *.c: All '#include "files.h"' uses changed.
* src/Makefile.am (UTIL_SOURCES): Reflect rename.
* cfg.mk (exclude_file_name_regexp--sc_prohibit_close): Likewise.
* src/libvirt_private.syms: Likewise.
* docs/hacking.html.in: Likewise.
* HACKING: Regenerate.

When no <seclabel> is present in the XML, the virDomainSeclabelDef
struct is left as all zeros. Unfortunately, this means it gets setup
as type=dynamic, with relabel=no, which is an illegal combination.

Change the 'bool relabel' attribute in virDomainSeclabelDef to
the inverse 'bool norelabel' so that the default initialization
is sensible

* src/conf/domain_conf.c, src/conf/domain_conf.h,
  src/security/security_apparmor.c, src/security/security_selinux.c:
  Replace 'relabel' with 'norelabel'

Add a new attribute to the <seclabel> XML to allow resource
relabelling to be enabled with static label usage.

  <seclabel model='selinux' type='static' relabel='yes'>
    <label>system_u:system_r:svirt_t:s0:c392,c662</label>
  </seclabel>

* docs/schemas/domain.rng: Add relabel attribute
* src/conf/domain_conf.c, src/conf/domain_conf.h: Parse
  the 'relabel' attribute
* src/qemu/qemu_process.c: Unconditionally clear out the
  'imagelabel' attribute
* src/security/security_apparmor.c: Skip based on 'relabel'
  attribute instead of label type
* src/security/security_selinux.c: Skip based on 'relabel'
  attribute instead of label type and fill in <imagelabel>
  attribute if relabel is enabled.