The counterpart to VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED.

https://bugzilla.redhat.com/show_bug.cgi?id=1206114

As qemu is now able to notify us about change of the channel state used
for communication with the guest agent we now can more precisely track
the state of the guest agent.

To allow notifying management apps this patch implements a new event
that will be triggered on changes of the guest agent state.

This new event will use typedParameters to expose what has been actually
updated and the reason is that we can in the future extend any tunable
values or add new tunable values. With typedParameters we don't have to
worry about creating some other events, we will just use this universal
event to inform user about updates.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

When the block job event was first added, it was for block pull,
where the active layer of the disk remains the same name.  It was
also in a day where we only cared about local files, and so we
always had a canonical absolute file name.  But two things have
changed since then: we now have network disks, where determining
a single absolute string does not really make sense; and we have
two-phase jobs (copy and active commit) where the name of the
active layer changes between the first event (ready, on the old
name) and second (complete, on the pivoted name).

Adam Litke reported that having an unstable string between events
makes life harder for clients.  Furthermore, all of our API that
operate on a particular disk of a domain accept multiple strings:
not only the absolute name of the active layer, but also the
destination device name (such as 'vda').  As this latter name is
stable, even for network sources, it serves as a better string
to supply in block job events.

But backwards-compatibility demands that we should not change the
name handed to users unless they explicitly request it.  Therefore,
this patch adds a new event, BLOCK_JOB_2 (alas, I couldn't think of
any nicer name - but at least Migrate2 and Migrate3 are precedent
for a number suffix).  We must double up on emitting both old-style
and new-style events according to what clients have registered for
(see also how IOError and IOErrorReason emits double events, but
there the difference was a larger struct rather than changed
meaning of one of the struct members).

Unfortunately, adding a new event isn't something that can easily
be broken into pieces, so the commit is rather large.

* include/libvirt/libvirt.h.in (virDomainEventID): Add a new id
for VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2.
(virConnectDomainEventBlockJobCallback): Document new semantics.
* src/conf/domain_event.c (_virDomainEventBlockJob): Rename field,
to ensure we catch all clients.
(virDomainEventBlockJobNew): Add parameter.
(virDomainEventBlockJobDispose)
(virDomainEventBlockJobNewFromObj)
(virDomainEventBlockJobNewFromDom)
(virDomainEventDispatchDefaultFunc): Adjust clients.
(virDomainEventBlockJob2NewFromObj)
(virDomainEventBlockJob2NewFromDom): New functions.
* src/conf/domain_event.h: Add new prototypes.
* src/libvirt_private.syms (domain_event.h): Export new functions.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Generate two
different events.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Likewise.
* src/remote/remote_protocol.x
(remote_domain_event_block_job_2_msg): New struct.
(REMOTE_PROC_DOMAIN_EVENT_BLOCK_JOB_2): New RPC.
* src/remote/remote_driver.c
(remoteDomainBuildEventBlockJob2): New handler.
(remoteEvents): Register new event.
* daemon/remote.c (remoteRelayDomainEventBlockJob2): New handler.
(domainEventCallbacks): Register new event.
* tools/virsh-domain.c (vshEventCallbacks): Likewise.
(vshEventBlockJobPrint): Adjust client.
* src/remote_protocol-structs: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

Create qemu monitor events as a distinct class to normal domain
events, because they will be filtered differently.  For ease of
review, the logic for filtering by event name is saved for a later
patch.

* src/conf/domain_event.c (virDomainQemuMonitorEventClass): New
class.
(virDomainEventsOnceInit): Register it.
(virDomainQemuMonitorEventDispose, virDomainQemuMonitorEventNew)
(virDomainQemuMonitorEventDispatchFunc)
(virDomainQemuMonitorEventStateRegisterID): New functions.
* src/conf/domain_event.h (virDomainQemuMonitorEventNew)
(virDomainQemuMonitorEventStateRegisterID): New prototypes.
* src/libvirt_private.syms (conf/domain_conf.h): Export them.

Commit 57ddcc23 (v0.9.11) introduced the pmwakeup event, with
an optional 'reason' field reserved for possible future expansion.
But it failed to wire the field through RPC, so even if we do
add a reason in the future, we will be unable to get it back
to the user.

Worse, commit 7ba5defb (v1.0.0) repeated the same mistake with
the pmsuspend_disk event.

As long as we are adding new RPC calls, we might as well fix
the events to actually match the signature so that we don't have
to add yet another RPC in the future if we do decide to start
using the reason field.

* src/remote/remote_protocol.x
(remote_domain_event_callback_pmwakeup_msg)
(remote_domain_event_callback_pmsuspend_msg)
(remote_domain_event_callback_pmsuspend_disk_msg): Add reason
field.
* daemon/remote.c (remoteRelayDomainEventPMWakeup)
(remoteRelayDomainEventPMSuspend)
(remoteRelayDomainEventPMSuspendDisk): Pass reason to client.
* src/conf/domain_event.h (virDomainEventPMWakeupNewFromDom)
(virDomainEventPMSuspendNewFromDom)
(virDomainEventPMSuspendDiskNewFromDom): Require additional
parameter.
* src/conf/domain_event.c (virDomainEventPMClass): New class.
(virDomainEventPMDispose): New function.
(virDomainEventPMWakeupNew*, virDomainEventPMSuspendNew*)
(virDomainEventPMSuspendDiskNew*)
(virDomainEventDispatchDefaultFunc): Use new class.
* src/remote/remote_driver.c (remoteDomainBuildEvent*PM*): Pass
reason through.
* src/remote_protocol-structs: Regenerate.
Signed-off-by: NEric Blake <eblake@redhat.com>

We want to convert over to server-side events, even for older
APIs.  To do that, the client side of the remote driver wants
to distinguish between legacy virConnectDomainEventRegister and
normal virConnectDomainEventRegisterAny, while knowing the
client callbackID and the server's serverID for both types of
registration.  The client also needs to probe whether the
server supports server-side filtering.  However, for ease of
review, we don't actually use the new RPCs until a later patch.

* src/conf/object_event_private.h (virObjectEventStateCallbackID):
Add parameter.
* src/conf/object_event.c (virObjectEventCallbackListAddID)
(virObjectEventStateRegisterID): Separate legacy from callbackID.
(virObjectEventStateCallbackID): Pass through parameter.
(virObjectEventCallbackLookup): Let legacy and global domain
lifecycle events share a common remoteID.
* src/conf/network_event.c (virNetworkEventStateRegisterID):
Update caller.
* src/conf/domain_event.c (virDomainEventStateRegister)
(virDomainEventStateRegisterID, virDomainEventStateDeregister):
Likewise.
(virDomainEventStateRegisterClient)
(virDomainEventStateCallbackID): Implement new functions.
* src/conf/domain_event.h (virDomainEventStateRegisterClient)
(virDomainEventStateCallbackID): New prototypes.
* src/remote/remote_driver.c (private_data): Add field.
(doRemoteOpen): Probe server feature.
(remoteConnectDomainEventRegister)
(remoteConnectDomainEventRegisterAny): Use new function.
Signed-off-by: NEric Blake <eblake@redhat.com>

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: NEric Blake <eblake@redhat.com>

Ever since ACL filtering was added in commit 76397360 (v1.1.1), a
user could still use event registration to obtain access to a
domain that they could not normally access via virDomainLookup*
or virConnectListAllDomains and friends.  We already have the
framework in the RPC generator for creating the filter, and
previous cleanup patches got us to the point that we can now
wire the filter through the entire object event stack.

Furthermore, whether or not domain:getattr is honored, use of
global events is a form of obtaining a list of networks, which
is covered by connect:search_domains added in a93cd08f (v1.1.0).
Ideally, we'd have a way to enforce connect:search_domains when
doing global registrations while omitting that check on a
per-domain registration.  But this patch just unconditionally
requires connect:search_domains, even when no list could be
obtained, based on the following observations:
1. Administrators are unlikely to grant domain:getattr for one
or all domains while still denying connect:search_domains - a
user that is able to manage domains will want to be able to
manage them efficiently, but efficient management includes being
able to list the domains they can access.  The idea of denying
connect:search_domains while still granting access to individual
domains is therefore not adding any real security, but just
serves as a layer of obscurity to annoy the end user.
2. In the current implementation, domain events are filtered
on the client; the server has no idea if a domain filter was
requested, and must therefore assume that all domain event
requests are global.  Even if we fix the RPC protocol to
allow for server-side filtering for newer client/server combos,
making the connect:serach_domains ACL check conditional on
whether the domain argument was NULL won't benefit older clients.
Therefore, we choose to document that connect:search_domains
is a pre-requisite to any domain event management.

Network events need the same treatment, with the obvious
change of using connect:search_networks and network:getattr.

* src/access/viraccessperm.h
(VIR_ACCESS_PERM_CONNECT_SEARCH_DOMAINS)
(VIR_ACCESS_PERM_CONNECT_SEARCH_NETWORKS): Document additional
effect of the permission.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Add new parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/object_event_private.h (virObjectEventStateRegisterID):
Likewise.
* src/conf/object_event.c (_virObjectEventCallback): Track a filter.
(virObjectEventDispatchMatchCallback): Use filter.
(virObjectEventCallbackListAddID): Register filter.
* src/conf/domain_event.c (virDomainEventFilter): New function.
(virDomainEventStateRegister, virDomainEventStateRegisterID):
Adjust callers.
* src/conf/network_event.c (virNetworkEventFilter): New function.
(virNetworkEventStateRegisterID): Adjust caller.
* src/remote/remote_protocol.x
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER)
(REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER_ANY)
(REMOTE_PROC_CONNECT_NETWORK_EVENT_REGISTER_ANY): Generate a
filter, and require connect:search_domains instead of weaker
connect:read.
* src/test/test_driver.c (testConnectDomainEventRegister)
(testConnectDomainEventRegisterAny)
(testConnectNetworkEventRegisterAny): Update callers.
* src/remote/remote_driver.c (remoteConnectDomainEventRegister)
(remoteConnectDomainEventRegisterAny): Likewise.
* src/xen/xen_driver.c (xenUnifiedConnectDomainEventRegister)
(xenUnifiedConnectDomainEventRegisterAny): Likewise.
* src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc): Likewise.
* src/libxl/libxl_driver.c (libxlConnectDomainEventRegister)
(libxlConnectDomainEventRegisterAny): Likewise.
* src/qemu/qemu_driver.c (qemuConnectDomainEventRegister)
(qemuConnectDomainEventRegisterAny): Likewise.
* src/uml/uml_driver.c (umlConnectDomainEventRegister)
(umlConnectDomainEventRegisterAny): Likewise.
* src/network/bridge_driver.c
(networkConnectNetworkEventRegisterAny): Likewise.
* src/lxc/lxc_driver.c (lxcConnectDomainEventRegister)
(lxcConnectDomainEventRegisterAny): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

Instead of having the object event code have to know about each
type of event and their dispatch functions, associate a dispatch
function with the object instance. The dispatch code can thus be
significantly simplified.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Each unique event ID will thus be composed by 1 byte for the namespace
and 1 byte for a namespace-specific ID. The namespace for domain event
needs to be 0 for compatibility reasons.

The virDomainEvent class is kept as it indicates what meta informations
are valid for the children classes. This may be useful in the future.

This aims at providing some consistency with other domain events

Added a parent class virObjectEvent for future event types

Keep virDomainEventStateRegisterID as a convenience wrapper around
this new function.

Keep the legacy Domain lifecycle event functions as is.

Leave virDomainEventRegister and its Deregister brother as these are
legacy functions only for domain lifecycle events.

The event queue will be generalized to hold events related
to any object type.

The event callbacks will be generalized to handle events
for any object type.

This patch adds support for SUSPEND_DISK event; both lifecycle and
separated.  The support is added for QEMU, machines are changed to
PMSUSPENDED, but as QEMU sends SHUTDOWN afterwards, the state changes
to shut-off.  This and much more needs to be done in order for libvirt
to work with transient devices, wake-ups etc.  This patch is not
aiming for that functionality.

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/

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

When the guest changes its memory balloon applications may want
to know what the new value is, without having to periodically
poll on XML / domain info. Introduce a "balloon change" event
to let apps see this

* include/libvirt/libvirt.h.in: Define the
  virConnectDomainEventBalloonChangeCallback callback
  and VIR_DOMAIN_EVENT_ID_BALLOON_CHANGE constant
* python/libvirt-override-virConnect.py,
  python/libvirt-override.c: Wire up helpers for new event
* daemon/remote.c: Helper for serializing balloon event
* examples/domain-events/events-c/event-test.c,
  examples/domain-events/events-python/event-test.py: Add
  example of balloon event usage
* src/conf/domain_event.c, src/conf/domain_event.h: Handling
  of balloon events
* src/remote/remote_driver.c: Add handler of balloon events
* src/remote/remote_protocol.x: Define wire protocol for
  balloon events
* src/remote_protocol-structs: Likewise.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When the last reference to a virConnectPtr is released by
libvirtd, it was possible for a deadlock to occur in the
virDomainEventState functions. The virDomainEventStatePtr
holds a reference on virConnectPtr for each registered
callback. When removing a callback, the virUnrefConnect
function is run. If this causes the last reference on the
virConnectPtr to be released, then virReleaseConnect can
be run, which in turns calls qemudClose. This function has
a call to virDomainEventStateDeregisterConn which is intended
to remove all callbacks associated with the virConnectPtr
instance. This will try to grab a lock on virDomainEventState
but this lock is already held. Deadlock ensues

Thread 1 (Thread 0x7fcbb526a840 (LWP 23185)):

Since each callback associated with a virConnectPtr holds a
reference on virConnectPtr, it is impossible for the qemudClose
method to be invoked while any callbacks are still registered.
Thus the call to virDomainEventStateDeregisterConn must in fact
be a no-op. Thus it is possible to just remove all trace of
virDomainEventStateDeregisterConn and avoid the deadlock.

* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Delete virDomainEventStateDeregisterConn
* src/libxl/libxl_driver.c, src/lxc/lxc_driver.c,
  src/qemu/qemu_driver.c, src/uml/uml_driver.c: Remove
  calls to virDomainEventStateDeregisterConn

This patch introduces a new event type for the QMP event
SUSPEND:

    VIR_DOMAIN_EVENT_ID_PMSUSPEND

The event doesn't take any data, but considering there might
be reason for wakeup in future, the callback definition is:

typedef void
(*virConnectDomainEventSuspendCallback)(virConnectPtr conn,
                                        virDomainPtr dom,
                                        int reason,
                                        void *opaque);

"reason" is unused currently, always passes "0".

This patch introduces a new event type for the QMP event
WAKEUP:

    VIR_DOMAIN_EVENT_ID_PMWAKEUP

The event doesn't take any data, but considering there might
be reason for wakeup in future, the callback definition is:

typedef void
(*virConnectDomainEventWakeupCallback)(virConnectPtr conn,
                                       virDomainPtr dom,
                                       int reason,
                                       void *opaque);

"reason" is unused currently, always passes "0".

This patch introduces a new event type for the QMP event
DEVICE_TRAY_MOVED, which occurs when the tray of a removable
disk is moved (i.e opened or closed):

    VIR_DOMAIN_EVENT_ID_TRAY_CHANGE

The event's data includes the device alias and the reason
for tray status' changing, which indicates why the tray
status was changed. Thus the callback definition for the event
is:

enum {
    VIR_DOMAIN_EVENT_TRAY_CHANGE_OPEN = 0,
    VIR_DOMAIN_EVENT_TRAY_CHANGE_CLOSE,

\#ifdef VIR_ENUM_SENTINELS
    VIR_DOMAIN_EVENT_TRAY_CHANGE_LAST
\#endif
} virDomainEventTrayChangeReason;

typedef void
(*virConnectDomainEventTrayChangeCallback)(virConnectPtr conn,
                                           virDomainPtr dom,
                                           const char *devAlias,
                                           int reason,
                                           void *opaque);

The lifetime of the virDomainEventState object is tied to
the lifetime of the driver, which in stateless drivers is
tied to the lifetime of the virConnectPtr.

If we add & remove a timer when allocating/freeing the
virDomainEventState object, we can get a situation where
the timer still triggers once after virDomainEventState
has been freed. The timeout callback can't keep a ref
on the event state though, since that would be a circular
reference.

The trick is to only register the timer when a callback
is registered with the event state & remove the timer
when the callback is unregistered.

The demo for the bug is to run

  while true ; do date ; ../tools/virsh -q -c test:///default 'shutdown test; undefine test; dominfo test' ; done

prior to this fix, it will frequently hang and / or
crash, or corrupt memory

Currently all drivers using domain events need to provide a callback
for handling a timer to dispatch events in a clean stack. There is
no technical reason for dispatch to go via driver specific code. It
could trivially be dispatched directly from the domain event code,
thus removing tedious boilerplate code from all drivers

Also fix the libxl & xen drivers to pass 'true' when creating the
virDomainEventState, since they run inside the daemon & thus always
expect events to be present.

* src/conf/domain_event.c, src/conf/domain_event.h: Internalize
  dispatch of events from timer callback
* src/libxl/libxl_driver.c, src/lxc/lxc_driver.c,
  src/qemu/qemu_domain.c, src/qemu/qemu_driver.c,
  src/remote/remote_driver.c, src/test/test_driver.c,
  src/uml/uml_driver.c, src/vbox/vbox_tmpl.c,
  src/xen/xen_driver.c: Remove all timer dispatch functions

The virDomainEventCallbackList and virDomainEventQueue APIs are
now solely helpers used internally by virDomainEventState APIs.
Remove their decls from domain_event.h since no driver code should
need to use them any more.

* src/conf/domain_event.c: Make virDomainEventCallbackList and
  virDomainEventQueue APIs static & remove some unused APIs
* src/conf/domain_event.h, src/libvirt_private.syms: Remove
  virDomainEventCallbackList and virDomainEventQueue APIs

No caller of the domain events APIs should need to poke at the
struct internals. Thus they should all be removed from the
header file

* src/conf/domain_event.h: Remove struct definitions
* src/conf/domain_event.c: Add struct definitions

While virDomainEventState has APIs for managing removal of callbacks,
while locked, adding callbacks in the first place requires direct
access to the virDomainEventCallbackList structure. This is not
threadsafe since it is bypassing the virDomainEventState locks

* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Add APIs for managing callbacks
  via virDomainEventState.

When registering a callback for a particular event some callers
need to know how many callbacks already exist for that event.
While it is possible to ask for a count, this is not free from
race conditions when threaded. Thus the API for registering
callbacks should return the count of callbacks. Also rename
virDomainEventStateDeregisterAny to virDomainEventStateDeregisterID

* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Return count of callbacks when
  registering callbacks
* src/libxl/libxl_driver.c, src/libxl/libxl_driver.c,
  src/qemu/qemu_driver.c, src/remote/remote_driver.c,
  src/remote/remote_driver.c, src/uml/uml_driver.c,
  src/vbox/vbox_tmpl.c, src/xen/xen_driver.c: Update
  for change in APIs

If a disk source gets dropped because it is not accessible,
mgmt application might want to be informed about this. Therefore
we need to emit an event. The event presented in this patch
is however a bit superset of what written above. The reason is simple:
an intention to be easily expanded, e.g. on 'user ejected disk
in guest' events. Therefore, callback gets source string and disk alias
(which should be unique among a domain) and reason (an integer);

Currently, push & pop from event queue (both server & client side)
rely on lock from higher levels, e.g. on driver lock (qemu),
private_data (remote), ...; This alone is not sufficient as not
every function that interacts with this queue can/does lock,
esp. in client where we have a different approach, "passing
the buck".

Therefore we need a separate lock just to protect event queue.

For more info see:
https://bugzilla.redhat.com/show_bug.cgi?id=743817