Change any variable names with Usb, Pci or Scsi to use
USB, PCI and SCSI since they are abbreviations.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Auditing all callers of virCommandRun and virCommandWait that
passed a non-NULL pointer for exit status turned up some
interesting observations. Many callers were merely passing
a pointer to avoid the overall command dying, but without
caring what the exit status was - but these callers would
be better off treating a child death by signal as an abnormal
exit. Other callers were actually acting on the status, but
not all of them remembered to filter by WIFEXITED and convert
with WEXITSTATUS; depending on the platform, this can result
in a status being reported as 256 times too big. And among
those that correctly parse the output, it gets rather verbose.
Finally, there were the callers that explicitly checked that
the status was 0, and gave their own message, but with fewer
details than what virCommand gives for free.
So the best idea is to move the complexity out of callers and
into virCommand - by default, we return the actual exit status
already cleaned through WEXITSTATUS and treat signals as a
failed command; but the few callers that care can ask for raw
status and act on it themselves.
* src/util/vircommand.h (virCommandRawStatus): New prototype.
* src/libvirt_private.syms (util/command.h): Export it.
* docs/internals/command.html.in: Document it.
* src/util/vircommand.c (virCommandRawStatus): New function.
(virCommandWait): Adjust semantics.
* tests/commandtest.c (test1): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Adjust callers.
* src/access/viraccessdriverpolkit.c (virAccessDriverPolkitCheck):
Likewise.
* src/fdstream.c (virFDStreamCloseInt): Likewise.
* src/lxc/lxc_process.c (virLXCProcessStart): Likewise.
* src/qemu/qemu_command.c (qemuCreateInBridgePortWithHelper):
Likewise.
* src/xen/xen_driver.c (xenUnifiedXendProbe): Simplify.
* tests/reconnect.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* src/bhyve/bhyve_process.c (virBhyveProcessStart)
(virBhyveProcessStop): Don't overwrite virCommand error.
* src/libvirt.c (virConnectAuthGainPolkit): Likewise.
* src/openvz/openvz_driver.c (openvzDomainGetBarrierLimit)
(openvzDomainSetBarrierLimit): Likewise.
* src/util/virebtables.c (virEbTablesOnceInit): Likewise.
* src/util/viriptables.c (virIpTablesOnceInit): Likewise.
* src/util/virnetdevveth.c (virNetDevVethCreate): Fix debug
message.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Add comment.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSINodeUpdate): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Right now, a caller waiting for a child process either requires
the child to have status 0, or must use WIFEXITED() and friends
itself. But in many cases, we want the middle ground of treating
fatal signals as an error, and directly accessing the normal exit
value without having to use WEXITSTATUS(), in order to easily
detect an expected non-zero exit status. This adds the middle
ground to the low-level virProcessWait; the next patch will add
it to virCommand.
* src/util/virprocess.h (virProcessWait): Alter signature.
* src/util/virprocess.c (virProcessWait): Add parameter.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/vircommand.c (virCommandWait): Likewise.
* src/util/virfile.c (virFileAccessibleAs): Likewise.
* src/lxc/lxc_container.c (lxcContainerHasReboot)
(lxcContainerAvailable): Likewise.
* daemon/libvirtd.c (daemonForkIntoBackground): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/testutils.c (virtTestCaptureProgramOutput): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
This function is needed for user namespaces, where we need to chmod()
the cgroup to the initial uid/gid such that systemd is allowed to
use the cgroup.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virDomainGetRootFilesystem method can be generalized to allow
any filesystem path to be obtained.
While doing this, start a new test case for purpose of testing various
helper methods in the domain_conf.{c,h} files, such as this one.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virCgroupXXX APIs' return value must be checked for
being less than 0, not equal to 0.
An VIR_ERR_OPERATION_INVALID error must also be raised
when the VM is not running to prevent a crash on NULL
priv->cgroup field.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Destroying a suspended domain needs special action.
We cannot simply terminate all process because they are frozen.
Do deal with that we send them SIGKILL and thaw them.
Upon wakeup the process sees the pending signal and dies immediately.
Signed-off-by: Richard Weinberger <richard@nod.at>
There might be some use cases, where user wants to prepare the host or
its environment prior to starting a network and do some cleanup after
the network has been shut down. Consider all the functionality that
libvirt doesn't currently have as an example what a hook script can
possibly do.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Rewrite multiple hotunplug functions to to use the
virProcessRunInMountNamespace helper. This avoids
risk of a malicious guest replacing /dev with an absolute
symlink, tricking the driver into changing the host OS
filesystem.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Rewrite lxcDomainAttachDeviceHostdevMiscLive function
to use the virProcessRunInMountNamespace helper. This avoids
risk of a malicious guest replacing /dev with a absolute
symlink, tricking the driver into changing the host OS
filesystem.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Rewrite lxcDomainAttachDeviceHostdevStorageLive function
to use the virProcessRunInMountNamespace helper. This avoids
risk of a malicious guest replacing /dev with a absolute
symlink, tricking the driver into changing the host OS
filesystem.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Rewrite lxcDomainAttachDeviceHostdevSubsysUSBLive function
to use the virProcessRunInMountNamespace helper. This avoids
risk of a malicious guest replacing /dev with a absolute
symlink, tricking the driver into changing the host OS
filesystem.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Rewrite lxcDomainAttachDeviceDiskLive function to use the
virProcessRunInMountNamespace helper. This avoids risk of
a malicious guest replacing /dev with a absolute symlink,
tricking the driver into changing the host OS filesystem.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Use helper virProcessRunInMountNamespace in lxcDomainShutdownFlags and
lxcDomainReboot. Otherwise, a malicious guest could use symlinks
to force the host to manipulate the wrong file in the host's namespace.
Idea by Dan Berrange, based on an initial report by Reco
<recoverym4n@gmail.com> at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=732394
Signed-off-by: Eric Blake <eblake@redhat.com>
The check for whether the cgroup devices ACL is available is
done quite late during LXC hotplug - in fact after the device
node is already created in the container in some cases. Better
to do it upfront so we fail immediately.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The LXC disk hotplug code was allowing block or character devices
to be given as disk. A disk is always a block device.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When detaching a USB device from an LXC guest we must remove
the device from the cgroup ACL. Unfortunately we were telling
the cgroup code to use the guest /dev path, not the host /dev
path, and the guest device node had already been unlinked.
This was, however, fortunate since the code passed &priv->cgroup
instead of priv->cgroup, so would have crash if the device node
were accessible.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
After hotplugging a USB device, the LXC driver forgot
to add the device def to the virDomainDefPtr.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The LXC code missed the 'usb' component out of the path
/dev/bus/usb/$BUSNUM/$DEVNUM, so it failed to actually
setup cgroups for the device. This was in fact lucky
because the call to virLXCSetupHostUsbDeviceCgroup
was also mistakenly passing '&priv->cgroup' instead of
just 'priv->cgroup'. So once the path is fixed, libvirtd
would then crash trying to access the bogus virCgroupPtr
pointer. This would have been a security issue, were it
not for the bogus path preventing the pointer reference
being reached.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The problem with VLAN is that the user still has to manually create the
vlan interface on the host. Then the generated configuration will use
it as a nerwork hostdev device. So the generated configurations of the
following two fragments are equivalent (see rhbz#1059637).
lxc.network.type = phys
lxc.network.link = eth0.5
lxc.network.type = vlan
lxc.network.link = eth0
lxc.network.vlan.id = 5
Some of the LXC configuration properties aren't migrated since they
would only cause problems in libvirt-lxc:
* lxc.network.ipv[46]: LXC driver doesn't setup IP address of guests,
see rhbz#1059624
* lxc.network.name, see rhbz#1059630
If no network configuration is provided, LXC only provides the loopback
interface. To match this, we need to use the privnet feature. LXC will
also define a 'none' network type in its 1.0.0 version that fits
libvirt LXC driver's default.
LXC rootfs can be either a directory or a block device or an image
file. The first two types have been implemented, but the image file is
still to be done since LXC auto-guesses the file format at mount time
and the LXC driver doesn't support the 'auto' format.
This function aims at converting LXC configuration into a libvirt
domain XML description to help users migrate from LXC to libvirt.
Here is an example of how the lxc configuration works:
virsh -c lxc:/// domxml-from-native lxc-tools /var/lib/lxc/migrate_test/config
It is possible that some parts couldn't be properly mapped into a
domain XML fragment, so users should carefully review the result
before creating the domain.
fstab files in lxc.mount lines will need to be merged into the
configuration file as lxc.mount.entry.
As we can't know the amount of memory of the host, we have to set a
default value for max_balloon that users will probably want to adjust.
https://bugzilla.redhat.com/show_bug.cgi?id=1058839
Commit f9f56340 for CVE-2014-0028 almost had the right idea - we
need to check the ACL rules to filter which events to send. But
it overlooked one thing: the event dispatch queue is running in
the main loop thread, and therefore does not normally have a
current virIdentityPtr. But filter checks can be based on current
identity, so when libvirtd.conf contains access_drivers=["polkit"],
we ended up rejecting access for EVERY event due to failure to
look up the current identity, even if it should have been allowed.
Furthermore, even for events that are triggered by API calls, it
is important to remember that the point of events is that they can
be copied across multiple connections, which may have separate
identities and permissions. So even if events were dispatched
from a context where we have an identity, we must change to the
correct identity of the connection that will be receiving the
event, rather than basing a decision on the context that triggered
the event, when deciding whether to filter an event to a
particular connection.
If there were an easy way to get from virConnectPtr to the
appropriate virIdentityPtr, then object_event.c could adjust the
identity prior to checking whether to dispatch an event. But
setting up that back-reference is a bit invasive. Instead, it
is easier to delay the filtering check until lower down the
stack, at the point where we have direct access to the RPC
client object that owns an identity. As such, this patch ends
up reverting a large portion of the framework of commit f9f56340.
We also have to teach 'make check' to special-case the fact that
the event registration filtering is done at the point of dispatch,
rather than the point of registration. Note that even though we
don't actually use virConnectDomainEventRegisterCheckACL (because
the RegisterAny variant is sufficient), we still generate the
function for the purposes of documenting that the filtering
takes place.
Also note that I did not entirely delete the notion of a filter
from object_event.c; I still plan on using that for my upcoming
patch series for qemu monitor events in libvirt-qemu.so. In
other words, while this patch changes ACL filtering to live in
remote.c and therefore we have no current client of the filtering
in object_event.c, the notion of filtering in object_event.c is
still useful down the road.
* src/check-aclrules.pl: Exempt event registration from having to
pass checkACL filter down call stack.
* daemon/remote.c (remoteRelayDomainEventCheckACL)
(remoteRelayNetworkEventCheckACL): New functions.
(remoteRelay*Event*): Use new functions.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Drop unused parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/domain_event.c (virDomainEventFilter): Delete unused
function.
* src/conf/network_event.c (virNetworkEventFilter): Likewise.
* src/libxl/libxl_driver.c: Adjust caller.
* src/lxc/lxc_driver.c: Likewise.
* src/network/bridge_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/remote/remote_driver.c: Likewise.
* src/test/test_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/vbox/vbox_tmpl.c: Likewise.
* src/xen/xen_driver.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Coverity complains about default: label in libxl_driver.c not be able
to be reached. It's by design for the code and since it's not necessary
in the code nor does it elicit any compiler/make check warnings - just
remove it rather than adding a coverity[dead_error_begin] tag.
While I'm at it, lxc_driver.c and nodeinfo.c have the same design, so I
removed the default labels and the existing coverity tags.
The NWFilter code has as a deadlock race condition between
the virNWFilter{Define,Undefine} APIs and starting of guest
VMs due to mis-matched lock ordering.
In the virNWFilter{Define,Undefine} codepaths the lock ordering
is
1. nwfilter driver lock
2. virt driver lock
3. nwfilter update lock
4. domain object lock
In the VM guest startup paths the lock ordering is
1. virt driver lock
2. domain object lock
3. nwfilter update lock
As can be seen the domain object and nwfilter update locks are
not acquired in a consistent order.
The fix used is to push the nwfilter update lock upto the top
level resulting in a lock ordering for virNWFilter{Define,Undefine}
of
1. nwfilter driver lock
2. nwfilter update lock
3. virt driver lock
4. domain object lock
and VM start using
1. nwfilter update lock
2. virt driver lock
3. domain object lock
This has the effect of serializing VM startup once again, even if
no nwfilters are applied to the guest. There is also the possibility
of deadlock due to a call graph loop via virNWFilterInstantiate
and virNWFilterInstantiateFilterLate.
These two problems mean the lock must be turned into a read/write
lock instead of a plain mutex at the same time. The lock is used to
serialize changes to the "driver->nwfilters" hash, so the write lock
only needs to be held by the define/undefine methods. All other
methods can rely on a read lock which allows good concurrency.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
I noticed that we allow virDomainGetVcpusFlags even for read-only
connections, but that with a flag, it can require guest agent
interaction. It is feasible that a malicious guest could
intentionally abuse the replies it sends over the guest agent
connection to possibly trigger a bug in libvirt's JSON parser,
or withhold an answer so as to prevent the use of the agent
in a later command such as a shutdown request. Although we
don't know of any such exploits now (and therefore don't mind
posting this patch publicly without trying to get a CVE assigned),
it is better to err on the side of caution and explicitly require
full access to any domain where the API requires guest interaction
to operate correctly.
I audited all commands that are marked as conditionally using a
guest agent. Note that at least virDomainFSTrim is documented
as needing a guest agent, but that such use is unconditional
depending on the hypervisor (so the existing domain:fs_trim ACL
should be sufficient there, rather than also requirng domain:write).
But when designing future APIs, such as the plans for obtaining
a domain's IP addresses, we should copy the approach of this patch
in making interaction with the guest be specified via a flag, and
use that flag to also require stricter access checks.
* src/libvirt.c (virDomainGetVcpusFlags): Forbid guest interaction
on read-only connection.
(virDomainShutdownFlags, virDomainReboot): Improve docs on agent
interaction.
* src/remote/remote_protocol.x
(REMOTE_PROC_DOMAIN_SNAPSHOT_CREATE_XML)
(REMOTE_PROC_DOMAIN_SET_VCPUS_FLAGS)
(REMOTE_PROC_DOMAIN_GET_VCPUS_FLAGS, REMOTE_PROC_DOMAIN_REBOOT)
(REMOTE_PROC_DOMAIN_SHUTDOWN_FLAGS): Require domain:write for any
conditional use of a guest agent.
* src/xen/xen_driver.c: Fix clients.
* src/libxl/libxl_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
