Add functions for setting and restoring the label of input devices
to DAC and SELinux drivers.

https://bugzilla.redhat.com/show_bug.cgi?id=1231114

We have macros for both positive and negative string matching.
Therefore there is no need to use !STREQ or !STRNEQ. At the same
time as we are dropping this, new syntax-check rule is
introduced to make sure we won't introduce it again.
Signed-off-by: NIshmanpreet Kaur Khera <khera.ishman@gmail.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1124841

If running in session mode it may happen that we fail to set
correct SELinux label, but the image may still be readable to
the qemu process. Take this into account.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

We have plenty of callbacks in the driver. Some of these
callbacks require more than one argument to be passed. For that
we currently have a data type (struct) per each callback. Well,
so far for only one - SELinuxSCSICallbackData. But lets turn it
into more general name so it can be reused in other callbacks too
instead of each one introducing a new, duplicate data type.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The check is done in virSecuritySELinuxSetFilecon itself. There's
no need to check it again.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Remove unused variable, tag unused parameter and adjust return type.

introduced by 3f48345f

CC     security/libvirt_security_manager_la-security_selinux.lo
security/security_selinux.c: In function 'virSecuritySELinuxDomainSetDirLabel':
security/security_selinux.c:2520:5: error: return makes pointer from integer without a cast [-Werror]
security/security_selinux.c:2514:9: error: unused variable 'ret' [-Werror=unused-variable]
security/security_selinux.c:2509:59: error: unused parameter 'mgr' [-Werror=unused-parameter]

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

In virSecuritySELinuxSetSecurityChardevLabel() we are labelling unix
socket path, but accessing another structure of the union.  This does
not pose a problem currently as both paths are at the same offset, but
this should be fixed for the future.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1082521

Support for shared hostdev's was added in a number of commits, initially
starting with 'f2c1d9a8' and most recently commit id 'fd243fc4' to fix
issues with the initial implementation.  Missed in all those changes was
the need to mimic the virSELinux{Set|Restore}SecurityDiskLabel code to
handle the "shared" (or shareable) and readonly options when Setting
or Restoring the SELinux labels.

This patch will adjust the virSecuritySELinuxSetSecuritySCSILabel to not
use the virSecuritySELinuxSetSecurityHostdevLabelHelper in order to set
the label. Rather follow what the Disk code does by setting the label
differently based on whether shareable/readonly is set.  This patch will
also modify the virSecuritySELinuxRestoreSecuritySCSILabel to follow
the same logic as virSecuritySELinuxRestoreSecurityImageLabelInt and not
restore the label if shared/readonly

C guarantees that static variables are zero-initialized.  Some older
compilers (and also gcc -fno-zero-initialized-in-bss) create larger
binaries if you explicitly zero-initialize a static variable.

* src/conf/nwfilter_conf.c: Fix initialization.
* src/cpu/cpu_x86.c: Likewise.
* src/interface/interface_backend_netcf.c: Likewise.
* src/locking/lock_daemon.c: Likewise.
* src/locking/lock_driver_lockd.c: Likewise.
* src/locking/lock_driver_sanlock.c: Likewise.
* src/network/bridge_driver.c: Likewise.
* src/node_device/node_device_udev.c: Likewise.
* src/nwfilter/nwfilter_learnipaddr.c: Likewise.
* src/rpc/virnetserver.c: Likewise.
* src/security/security_selinux.c
(virSecuritySELinuxGenSecurityLabel): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1147057

The code for relabelling the TAP FD is there due to a race. When
libvirt creates a /dev/tapN device it's labeled as
'system_u:object_r:device_t:s0' by default. Later, when
udev/systemd reacts to this device, it's relabelled to the
expected label 'system_u:object_r:tun_tap_device_t:s0'. Hence, we
have a code that relabels the device, to cut the race down. For
more info see ae368ebf.

But the problem is, the relabel function is called on all TUN/TAP
devices. Yes, on /dev/net/tun too. This is however a special kind
of device - other processes uses it too. We shouldn't touch it's
label then.

Ideally, there would an API in SELinux that would label just the
passed FD and not the underlying path. That way, we wouldn't need
to care as we would be not labeling /dev/net/tun but the FD
passed to the domain. Unfortunately, there's no such API so we
have to workaround until then.
Tested-by: NRichard W.M. Jones <rjones@redhat.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The check for ISCSI devices was missing a check of subsys type, which
meant we could skip labelling of other host devices as well. This fixes
USB hotplug on F21

https://bugzilla.redhat.com/show_bug.cgi?id=1145968

https://bugzilla.redhat.com/show_bug.cgi?id=1141879

A long time ago I've implemented support for so called multiqueue
net.  The idea was to let guest network traffic be processed by
multiple host CPUs and thus increasing performance. However, this
behavior is enabled by QEMU via special ioctl() iterated over the
all tap FDs passed in by libvirt. Unfortunately, SELinux comes in
and disallows the ioctl() call because the /dev/net/tun has label
system_u:object_r:tun_tap_device_t:s0 and 'attach_queue' ioctl()
is not allowed on tun_tap_device_t type. So after discussion with
a SELinux developer we've decided that the FDs passed to the QEMU
should be labelled with svirt_t type and SELinux policy will
allow the ioctl(). Therefore I've made a patch
(cf976d9d) that does exactly this. The patch
was fixed then by a4431931 and
b635b7a1. However, things are not
that easy - even though the API to label FD is called
(fsetfilecon_raw) the underlying file is labelled too! So
effectively we are mangling /dev/net/tun label. Yes, that broke
dozen of other application from openvpn, or boxes, to qemu
running other domains.

The best solution would be if SELinux provides a way to label an
FD only, which could be then labeled when passed to the qemu.
However that's a long path to go and we should fix this
regression AQAP. So I went to talk to the SELinux developer again
and we agreed on temporary solution that:

1) All the three patches are reverted
2) SELinux temporarily allows 'attach_queue' on the
tun_tap_device_t
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

I've noticed two problem with the automatically created NVRAM varstore
file. The first, even though I run qemu as root:root for some reason I
get Permission denied when trying to open the _VARS.fd file. The
problem is, the upper directory misses execute permissions, which in
combination with us dropping some capabilities result in EPERM.

The next thing is, that if I switch SELinux to enforcing mode, I get
another EPERM because the vars file is not labeled correctly. It is
passed to qemu as disk and hence should be labelled as disk. QEMU may
write to it eventually, so this is different to kernel or initrd.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

After a4431931 the TAP FDs ale labeled with image label instead
of the process label. On the other hand, the commit was
incomplete as a few lines above, there's still old check for the
process label presence while it should be check for the image
label instead.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

QEMU now supports UEFI with the following command line:

  -drive file=/usr/share/OVMF/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on \
  -drive file=/usr/share/OVMF/OVMF_VARS.fd,if=pflash,format=raw,unit=1 \

where the first line reflects <loader> and the second one <nvram>.
Moreover, these two lines obsolete the -bios argument.

Note that UEFI is unusable without ACPI. This is handled properly now.
Among with this extension, the variable file is expected to be
writable and hence we need security drivers to label it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Acked-by: NLaszlo Ersek <lersek@redhat.com>

For security type='none' libvirt according to the docs should not
generate seclabel be it for selinux or any model. So, skip the
reservation of labels when type is none.
Signed-off-by: NShivaprasad G Bhat <sbhat@linux.vnet.ibm.com>

The cleanup in commit cf976d9d used secdef->label to label the tap
FDs, but that is not possible since it's process-only label (svirt_t)
and not a object label (e.g. svirt_image_t).  Starting a domain failed
with EPERM, but simply using secdef->imagelabel instead of
secdef->label fixes it.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1095636

When starting up the domain the domain's NICs are allocated. As of
1f24f682 (v1.0.6) we are able to use multiqueue feature on virtio
NICs. It breaks network processing into multiple queues which can be
processed in parallel by different host CPUs. The queues are, however,
created by opening /dev/net/tun several times. Unfortunately, only the
first FD in the row is labelled so when turning the multiqueue feature
on in the guest, qemu will get AVC denial. Make sure we label all the
FDs needed.

Moreover, the default label of /dev/net/tun doesn't allow
attaching a queue:

    type=AVC msg=audit(1399622478.790:893): avc:  denied  { attach_queue }
    for  pid=7585 comm="qemu-kvm"
    scontext=system_u:system_r:svirt_t:s0:c638,c877
    tcontext=system_u:system_r:virtd_t:s0-s0:c0.c1023
    tclass=tun_socket

And as suggested by SELinux maintainers, the tun FD should be labeled
as svirt_t. Therefore, we don't need to adjust any range (as done
previously by Guannan in ae368ebf) rather set the seclabel of the
domain directly.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Create the structures and API's to hold and manage the iSCSI host device.
This extends the 'scsi_host' definitions added in commit id '5c811dce'.
A future patch will add the XML parsing, but that code requires some
infrastructure to be in place first in order to handle the differences
between a 'scsi_host' and an 'iSCSI host' device.

Split virDomainHostdevSubsysSCSI further. In preparation for having
either SCSI or iSCSI data, create a union in virDomainHostdevSubsysSCSI
to contain just a virDomainHostdevSubsysSCSIHost to describe the
'scsi_host' host device

Create a separate typedef for the hostdev union data describing SCSI
Then adjust the code to use the new pointer

Create a separate typedef for the hostdev union data describing PCI.
Then adjust the code to use the new pointer

Create a separate typedef for the hostdev union data describing USB.
Then adjust the code to use the new pointer

Similarly to the previous commit, boolean variables should not start
with 'no-' prefix.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

This negation in names of boolean variables is driving me insane. The
code is much more readable if we drop the 'no-' prefix. Well, at least
for me.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Refactor the code and reuse it to implement the functionality.

Refactor the existing code to allow re-using it for the per-image label
restore too.

In the future we might need to track state of individual images. Move
the readonly and shared flags to the virStorageSource struct so that we
can keep them in a per-image basis.

I'm going to add functions that will deal with individual image files
rather than whole disks. Rename the security function to make room for
the new one.

I'm going to add functions that will deal with individual image files
rather than whole disks. Rename the security function to make room for
the new one.

Also remove one spurious ATTRIBUTE_UNUSED guarding the @migrated
argument.

The image labels are stored in the virStorageSource struct. Convert the
virDomainDiskDefGetSecurityLabelDef helper not to use the full disk def
and move it appropriately.

A network disk might actually be backed by local storage. Also the path
iterator actually handles networked disks well now so remove the code
that skips the labelling in dac and selinux security driver.

This fixes startup of a domain with:
<seclabel type='none' model='dac'/>
on a host with selinux and dac drivers and
security_default_confined = 0

https://bugzilla.redhat.com/show_bug.cgi?id=1105939
https://bugzilla.redhat.com/show_bug.cgi?id=1102611

As part of the work on backing chains, I'm finding that it would
be easier to directly manipulate chains of pointers (adding a
snapshot merely adjusts pointers to form the correct list) rather
than copy data from one struct to another.  This patch converts
domain disk source to be a pointer.

In this patch, the pointer is ALWAYS allocated (thanks in part to
the previous patch forwarding all disk def allocation through a
common point), and all other changse are just mechanical fallout of
the new type; there should be no functional change.  It is possible
that we may want to leave the pointer NULL for a cdrom with no
medium in a later patch, but as that requires a closer audit of the
source to ensure we don't fault on a null dereference, I didn't do
it here.

* src/conf/domain_conf.h (_virDomainDiskDef): Change type of src.
* src/conf/domain_conf.c: Adjust all clients.
* src/security/security_selinux.c: Likewise.
* src/qemu/qemu_domain.c: Likewise.
* src/qemu/qemu_command.c: Likewise.
* src/qemu/qemu_conf.c: Likewise.
* src/qemu/qemu_process.c: Likewise.
* src/qemu/qemu_migration.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
* src/lxc/lxc_controller.c: Likewise.
* tests/securityselinuxlabeltest.c: Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Switch over to storing of the backing chain as a recursive
virStorageSource structure.

This is a string based move. Currently the first element will be present
twice in the backing chain as currently the retrieval function stores
the parent in the newly detected chain. This will be fixed later.

Fix minor typos in source comments
Signed-off-by: NEric Blake <eblake@redhat.com>

The code in virstoragefile.c is getting more complex as I
consolidate backing chain handling code.  But for the setuid
virt-login-shell, we don't need to crawl backing chains.  It's
easier to audit things for setuid security if there are fewer
files involved, so this patch moves the one function that
virFileOpen() was actually relying on to also live in virfile.c.

* src/util/virstoragefile.c (virStorageFileIsSharedFS)
(virStorageFileIsSharedFSType): Move...
* src/util/virfile.c (virFileIsSharedFS, virFileIsSharedFSType):
...to here, and rename.
(virFileOpenAs): Update caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetFileconHelper)
(virSecuritySELinuxSetSecurityAllLabel)
(virSecuritySELinuxRestoreSecurityImageLabelInt): Likewise.
* src/security/security_dac.c
(virSecurityDACRestoreSecurityImageLabelInt): Likewise.
* src/qemu/qemu_driver.c (qemuOpenFileAs): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/util/virstoragefile.h: Adjust declarations.
* src/util/virfile.h: Likewise.
* src/libvirt_private.syms (virfile.h, virstoragefile.h): Move
symbols as appropriate.
Signed-off-by: NEric Blake <eblake@redhat.com>

A continuation of the migration of disk details to virstoragefile.
This patch moves a single enum, but converting the name has quite
a bit of fallout.

* src/conf/domain_conf.h (virDomainDiskType): Move...
* src/util/virstoragefile.h (virStorageType): ...and rename.
* src/bhyve/bhyve_command.c (bhyveBuildDiskArgStr)
(virBhyveProcessBuildLoadCmd): Update clients.
* src/conf/domain_conf.c (virDomainDiskSourceDefParse)
(virDomainDiskDefParseXML, virDomainDiskSourceDefFormatInternal)
(virDomainDiskDefFormat, virDomainDiskGetActualType)
(virDomainDiskDefForeachPath, virDomainDiskSourceIsBlockType):
Likewise.
* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Likewise.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefParseXML)
(virDomainSnapshotAlignDisks, virDomainSnapshotDiskDefFormat):
Likewise.
* src/esx/esx_driver.c (esxAutodetectSCSIControllerModel)
(esxDomainDefineXML): Likewise.
* src/locking/domain_lock.c (virDomainLockManagerAddDisk):
Likewise.
* src/lxc/lxc_controller.c
(virLXCControllerSetupLoopDeviceDisk)
(virLXCControllerSetupNBDDeviceDisk)
(virLXCControllerSetupLoopDevices, virLXCControllerSetupDisk):
Likewise.
* src/parallels/parallels_driver.c (parallelsGetHddInfo):
Likewise.
* src/phyp/phyp_driver.c (phypDiskType): Likewise.
* src/qemu/qemu_command.c (qemuGetDriveSourceString)
(qemuDomainDiskGetSourceString, qemuBuildDriveStr)
(qemuBuildCommandLine, qemuParseCommandLineDisk)
(qemuParseCommandLine): Likewise.
* src/qemu/qemu_conf.c (qemuCheckSharedDevice)
(qemuTranslateDiskSourcePool)
(qemuTranslateSnapshotDiskSourcePool): Likewise.
* src/qemu/qemu_domain.c (qemuDomainDeviceDefPostParse)
(qemuDomainDetermineDiskChain): Likewise.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo)
(qemuDomainSnapshotPrepareDiskExternalBackingInactive)
(qemuDomainSnapshotPrepareDiskExternalBackingActive)
(qemuDomainSnapshotPrepareDiskExternalOverlayActive)
(qemuDomainSnapshotPrepareDiskExternalOverlayInactive)
(qemuDomainSnapshotPrepareDiskInternal)
(qemuDomainSnapshotPrepare)
(qemuDomainSnapshotCreateSingleDiskActive): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainChangeEjectableMedia):
Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/security/security_apparmor.c
(AppArmorRestoreSecurityImageLabel)
(AppArmorSetSecurityImageLabel): Likewise.
* src/security/security_dac.c (virSecurityDACSetSecurityImageLabel)
(virSecurityDACRestoreSecurityImageLabelInt)
(virSecurityDACSetSecurityAllLabel): Likewise.
* src/security/security_selinux.c
(virSecuritySELinuxRestoreSecurityImageLabelInt)
(virSecuritySELinuxSetSecurityImageLabel)
(virSecuritySELinuxSetSecurityAllLabel): Likewise.
* src/storage/storage_backend.c (virStorageFileBackendForType):
Likewise.
* src/storage/storage_backend_fs.c (virStorageFileBackendFile)
(virStorageFileBackendBlock): Likewise.
* src/storage/storage_backend_gluster.c
(virStorageFileBackendGluster): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc, vboxAttachDrives)
(vboxDomainAttachDeviceImpl, vboxDomainDetachDevice): Likewise.
* src/vmware/vmware_conf.c (vmwareVmxPath): Likewise.
* src/vmx/vmx.c (virVMXParseDisk, virVMXFormatDisk)
(virVMXFormatFloppy): Likewise.
* src/xenxs/xen_sxpr.c (xenParseSxprDisks, xenParseSxpr)
(xenFormatSxprDisk): Likewise.
* src/xenxs/xen_xm.c (xenParseXM, xenFormatXMDisk): Likewise.
* tests/securityselinuxlabeltest.c (testSELinuxLoadDef):
Likewise.
* src/libvirt_private.syms (domain_conf.h): Move symbols...
(virstoragefile.h): ...as appropriate.
Signed-off-by: NEric Blake <eblake@redhat.com>