Right now this implements only 2 basic hooks:
- before the lxc control process is being launched
- after the lxc control process is terminated
the XML description of the domain is passed to the hook script stdin
/etc/libvirt/hook/lxc

* src/lxc/lxc_driver.c: implement synchronous script hooks for LXC
  at domain startup and end

Right now this implements only 2 basic hooks:
- before the qemu process is being launched
- after the qemu process is terminated
the XML description of the domain is passed to the hook script stdin
/etc/libvirt/hook/qemu

* src/qemu/qemu_driver.c: implement synchronous script hooks for QEmu
  at domain startup and end

It supports 3 kind of probing times, at daemon startup, when the
daemon reloads its drivers on SIGHUP and when the daemon exits

* daemon/libvirtd.c: daemon hooks for startup, reload and exit

This exports 3 basic routines:
  - virHookInitialize() initializing the hook support by looking for
    scripts availability
  - virHookPresent() used to test if there is a hook for a given driver
  - virHookCall() which actually calls a synchronous script hook with
    the needed parameters
Note that this doesn't expose any public API except for the locations
and arguments passed to the scripts

* src/Makefile.am: add the 2 new files
* src/util/hooks.h src/util/hooks.c: implements the 3 functions
* src/libvirt_private.syms: export the 3 symbols internally
* po/POTFILES.in: add src/util/hooks.c to translatables modules

* include/libvirt/virterror.h: add VIR_FROM_HOOK and VIR_ERR_HOOK_SCRIPT_FAILED
* src/util/virterror.c: associated strings

used to read the data from virExec stdout/err file descriptors

* src/util/util.c src/util/util.h: not static anymore and export it
* src/libvirt_private.syms: allow access internally

This flag is used in migration prepare step to send updated XML
definition of a guest.

Also ``virsh dumpxml --update-cpu [--inactive] guest'' command can be
used to see the updated CPU requirements.

Useful mainly for migration. cpuUpdate changes guest CPU requirements in
the following way:

- match == "strict" || match == "exact"
    - optional features which are supported by host CPU are changed into
      required features
    - optional features which are not supported by host CPU are disabled
    - all other features remain untouched
- match == "minimum"
    - match is changed into "exact"
    - optional features and all features not mentioned in guest CPU
      specification which are supported by host CPU become required
      features
    - other optional features are disabled
    - all other features remain untouched

This ensures that no feature will suddenly disappear from the guest
after migration.

When a domain is defined on host1, migrated to host2 and then migrated
back to host1, its current configuration would overwrite the libvirtd's
in-memory copy of persistent configuration of that domain. This is not
desired as we want to preserve the persistent configuration untouched.

This patch introduces new 'live' parameter to virDomainAssignDef.
Passing 'true' for 'live' means the configuration passed to
virDomainAssignDef describes a configuration of live instance of the
domain. This applies for saved domains which are being restored or for
incoming domains during migration.

All callers have been changed to pass the appropriate value.

* src/conf/nwfilter_conf.h: Indent cpp directives.
* src/conf/nwfilter_params.h: Likewise.
* src/datatypes.h: Likewise.
* src/nwfilter/nwfilter_driver.h: Likewise.
* src/nwfilter/nwfilter_ebiptables_driver.h: Likewise.
* src/nwfilter/nwfilter_gentech_driver.h: Likewise.

* Fixes per feedback from Dan and Daniel
* Added test datafiles
* Re-disabled JSON flags
* Added code to print the error policy attribute when generating XML
* Re-add empty tag

My prior patch forced an autogen.sh run, and I was surprised that the
suggested './autogen.sh' lost the fact that I had previously used
'./autogen.sh -C' for speed.

* autogen.sh: Use config.status, if present and there were no arguments.
Signed-off-by: NEric Blake <eblake@redhat.com>

Picks up fixes for gethostname compilation problems on mingw.

* .gnulib: Update to latest.
* build-aux/.gitignore: Regenerate.
* cfg.mk (local-checks-to-skip): Avoid new test not relevent to
libvirt.

This patch adds some example filters to libvirt. They are automatically
installed into the proper directory for libvirt to pick them up.

This patch adds support for L3/L4 filtering using iptables. This adds
support for 'tcp', 'udp', 'icmp', 'igmp', 'sctp' etc. filtering.

As mentioned in the introduction, a .c file provided by this patch
is #include'd into a .c file. This will need work, but should be alright
for review.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch adds IPv6 support for the ebtables layer. Since the parser
etc. are all parameterized, it was fairly easy to add this...
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

Add support for Qemu to have firewall rules applied and removed on VM
startup and shutdown respectively. This  patch also provides support for
the updating of a filter that causes all VMs that reference the filter
to have their ebtables/iptables rules updated.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch implements the core driver and provides
- management functionality for managing the filter XMLs
- compiling the internal filter representation into ebtables rules
- applying ebtables rules on a network (tap,macvtap) interface
- tearing down ebtables rules that were applied on behalf of an
interface
- updating of filters while VMs are running and causing the firewalls to
be rebuilt
- other bits and pieces
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch adds XML processing for the network filter schema
and extends the domain XML processing to parse the top level
referenced filter along with potentially provided parameters
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>
Signed-off-by: NGerhard Stenzel <gerhard.stenzel@de.ibm.com>

This patch adds virsh support for the five new CLI commands to manage
network filters.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch adds the definition of the wire format for RPC calls
and implementation of the RPC client & server code
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch adds the implementation of the public API for the network
filtering (ACL) extensions to libvirt.c .
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch adds the internal API extensions for network filtering (ACL) support.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch adds extensions to libvirt's public API necessary for
controlling the new functionality from remote for example.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

This patch adds recursive locks necessary due to the processing of
network filter XML that can reference other network filters, including
references that cause looks. Loops in the XML are prevented but their
detection requires recursive locks.
Signed-off-by: NStefan Berger <stefanb@us.ibm.com>

* Add types to switch; the switch is only exectuted for known types because of a preceding conditional, so this fix is merely to placate the compiler.

To find out where the net type 'direct' needs to be handled I introduced
the 'enum virDomainNetType' in the virDomainNetDef structure and let the
compiler tell me where the case statement is missing. Then I added the
unhandled device statement to the UML driver.

* src/conf/domain_conf.h: change _virDomainNetDef type from int to
  virDomainNetType enum
* src/conf/domain_conf.c src/lxc/lxc_driver.c src/qemu/qemu_conf.c
  src/uml/uml_conf.c: make sure all enum cases are properly handled
  in switches

In the documentation mention that the direct device support is there
since libvirt 0.7.7. A Linux kernel 2.6.34 is required for macvtap to be
available as standard device.

Use the new virDomainUpdateDeviceFlags API to allow the VNC password
to be changed on the fly

* src/internal.h: Define STREQ_NULLABLE() which is like STREQ()
  but does not crash if either argument is NULL, and treats two
  NULLs as equal.
* src/libvirt_private.syms: Export virDomainGraphicsTypeToString
* src/qemu/qemu_driver.c: Support VNC password change on a live
  machine
* src/qemu/qemu_monitor.c: Disable crazy debugging info. Treat a
  NULL password as "" (empty string), allowing passwords to be
  disabled in the monitor

Expand the parser for the standalone <device> XML format to
allow inclusion of the <graphics> device type

* src/conf/domain_conf.h: Add virDomainGraphicsDef to
  the virDomainDeviceDef struct
* src/conf/domain_conf.c: Wire up parser for virDomainGraphicsDef
  to virDomainDeviceDefParse method

Support the new virDomainUpdateDeviceFlags API in virsh by adding
a new 'update-device' command. In the future this should be augmented
with an explicit 'change-disk' command for media change to make it
end user discoverable, as attach-disk is.

* tools/virsh.c: Add 'update-device' command

To allow the new virDomainUpdateDeviceFlags() API to be universally
used with all drivers, this patch adds an impl to all the current
drivers which support CDROM or Floppy disk media change via the
current virDomainAttachDeviceFlags API

* src/qemu/qemu_driver.c, src/vbox/vbox_tmpl.c,
  src/xen/proxy_internal.c, src/xen/xen_driver.c,
  src/xen/xend_internal.c: Implement media change via the
  virDomainUpdateDeviceFlags API
* src/xen/xen_driver.h, src/xen/xen_hypervisor.c,
  src/xen/xen_inotify.c, src/xen/xm_internal.c,
  src/xen/xs_internal.c: Stubs for Xen driver entry points

This defines the wire format for the new virDomainUpdateDeviceFlags()
API, and implements the server & client side of the marshalling code.

* daemon/remote.c: Server side dispatch for virDomainUpdateDeviceFlags
* src/remote/remote_driver.c: Client side serialization for
  virDomainUpdateDeviceFlags
* src/remote/remote_protocol.x: Define wire format for
  virDomainUpdateDeviceFlags
* daemon/remote_dispatch_args.h, daemon/remote_dispatch_prototypes.h,
  daemon/remote_dispatch_table.h, src/remote/remote_protocol.c,
  src/remote/remote_protocol.h: Re-generate code

The current virDomainAttachDevice API can be (ab)used to change
the media of an existing CDROM/Floppy device. Going forward there
will be more devices that can be configured on the fly and overloading
virDomainAttachDevice for this is not too pleasant. This patch adds
a new virDomainUpdateDeviceFlags() explicitly just for modifying
existing devices.

* include/libvirt/libvirt.h.in: Add virDomainUpdateDeviceFlags
* src/driver.h: Internal API for virDomainUpdateDeviceFlags
* src/libvirt.c, src/libvirt_public.syms: Glue public API to
  driver API
* src/esx/esx_driver.c, src/lxc/lxc_driver.c, src/opennebula/one_driver.c,
  src/openvz/openvz_driver.c, src/phyp/phyp_driver.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, src/xenapi/xenapi_driver.c: Add
  stubs for new driver entry point

This introduces a new event type

   VIR_DOMAIN_EVENT_ID_GRAPHICS

The same event can be emitted in 3 scenarios

  typedef enum {
      VIR_DOMAIN_EVENT_GRAPHICS_CONNECT = 0,
      VIR_DOMAIN_EVENT_GRAPHICS_INITIALIZE,
      VIR_DOMAIN_EVENT_GRAPHICS_DISCONNECT,
  } virDomainEventGraphicsPhase;

Connect/disconnect are triggered at socket accept/close.
The initialize phase is immediately after the protocol
setup and authentication has completed. ie when the
client is authorized and about to start interacting with
the graphical desktop

This event comes with *a lot* of potential information

 - IP address, port & address family of client
 - IP address, port & address family of server
 - Authentication scheme (arbitrary string)
 - Authenticated subject identity. A subject may have
   multiple identities with some authentication schemes.
   For example, vencrypt+sasl results in a x509dname
   and saslUsername identities.

This results in a very complicated callback :-(

   typedef enum {
      VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_IPV4,
      VIR_DOMAIN_EVENT_GRAPHICS_ADDRESS_IPV6,
   } virDomainEventGraphicsAddressType;

   struct _virDomainEventGraphicsAddress {
       int family;
       const char *node;
       const char *service;
   };
   typedef struct _virDomainEventGraphicsAddress virDomainEventGraphicsAddress;
   typedef virDomainEventGraphicsAddress *virDomainEventGraphicsAddressPtr;

   struct _virDomainEventGraphicsSubject {
      int nidentity;
      struct {
          const char *type;
          const char *name;
      } *identities;
   };
   typedef struct _virDomainEventGraphicsSubject virDomainEventGraphicsSubject;
   typedef virDomainEventGraphicsSubject *virDomainEventGraphicsSubjectPtr;

   typedef void (*virConnectDomainEventGraphicsCallback)(virConnectPtr conn,
                                                         virDomainPtr dom,
                                                         int phase,
                                                         virDomainEventGraphicsAddressPtr local,
                                                         virDomainEventGraphicsAddressPtr remote,
                                                         const char *authScheme,
                                                         virDomainEventGraphicsSubjectPtr subject,
                                                         void *opaque);

The wire protocol is similarly complex

   struct remote_domain_event_graphics_address {
     int family;
     remote_nonnull_string node;
     remote_nonnull_string service;
   };

   const REMOTE_DOMAIN_EVENT_GRAPHICS_IDENTITY_MAX = 20;

   struct remote_domain_event_graphics_identity {
     remote_nonnull_string type;
     remote_nonnull_string name;
   };

   struct remote_domain_event_graphics_msg {
     remote_nonnull_domain dom;
     int phase;
     remote_domain_event_graphics_address local;
     remote_domain_event_graphics_address remote;
     remote_nonnull_string authScheme;
     remote_domain_event_graphics_identity subject<REMOTE_DOMAIN_EVENT_GRAPHICS_IDENTITY_MAX>;
   };

This is currently implemented in QEMU for the VNC graphics
protocol, but designed to be usable with SPICE graphics in
the future too.

* daemon/remote.c: Dispatch graphics events to client
* examples/domain-events/events-c/event-test.c: Watch for
  graphics events
* include/libvirt/libvirt.h.in: Define new graphics event ID
  and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Extend API to handle graphics events
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
  for VNC events and emit a libvirt graphics event
* src/remote/remote_driver.c: Receive and dispatch graphics
  events to application
* src/remote/remote_protocol.x: Wire protocol definition for
  graphics events
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for VNC_CONNECTED,
  VNC_INITIALIZED & VNC_DISCONNETED events from QEMU monitor

This introduces a new event type

   VIR_DOMAIN_EVENT_ID_IO_ERROR

This event includes the action that is about to be taken
as a result of the watchdog triggering

  typedef enum {
     VIR_DOMAIN_EVENT_IO_ERROR_NONE = 0,
     VIR_DOMAIN_EVENT_IO_ERROR_PAUSE,
     VIR_DOMAIN_EVENT_IO_ERROR_REPORT,
  } virDomainEventIOErrorAction;

In addition it has the source path of the disk that had the
error and its unique device alias. It does not include the
target device name (/dev/sda), since this would preclude
triggering IO errors from other file backed devices (eg
serial ports connected to a file)

Thus there is a new callback definition for this event type

typedef void (*virConnectDomainEventIOErrorCallback)(virConnectPtr conn,
                                                     virDomainPtr dom,
                                                     const char *srcPath,
                                                     const char *devAlias,
                                                     int action,
                                                     void *opaque);

This is currently wired up to the QEMU block IO error events

* daemon/remote.c: Dispatch IO error events to client
* examples/domain-events/events-c/event-test.c: Watch for
  IO error events
* include/libvirt/libvirt.h.in: Define new IO error event ID
  and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Extend API to handle IO error events
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
  for block IO errors and emit a libvirt IO error event
* src/remote/remote_driver.c: Receive and dispatch IO error
  events to application
* src/remote/remote_protocol.x: Wire protocol definition for
  IO error events
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for BLOCK_IO_ERROR event
  from QEMU monitor

This introduces a new event type

   VIR_DOMAIN_EVENT_ID_WATCHDOG

This event includes the action that is about to be taken
as a result of the watchdog triggering

 typedef enum {
     VIR_DOMAIN_EVENT_WATCHDOG_NONE = 0,
     VIR_DOMAIN_EVENT_WATCHDOG_PAUSE,
     VIR_DOMAIN_EVENT_WATCHDOG_RESET,
     VIR_DOMAIN_EVENT_WATCHDOG_POWEROFF,
     VIR_DOMAIN_EVENT_WATCHDOG_SHUTDOWN,
     VIR_DOMAIN_EVENT_WATCHDOG_DEBUG,
 } virDomainEventWatchdogAction;

Thus there is a new callback definition for this event type

 typedef void (*virConnectDomainEventWatchdogCallback)(virConnectPtr conn,
                                                       virDomainPtr dom,
                                                       int action,
                                                       void *opaque);

* daemon/remote.c: Dispatch watchdog events to client
* examples/domain-events/events-c/event-test.c: Watch for
  watchdog events
* include/libvirt/libvirt.h.in: Define new watchdg event ID
  and callback signature
* src/conf/domain_event.c, src/conf/domain_event.h,
  src/libvirt_private.syms: Extend API to handle watchdog events
* src/qemu/qemu_driver.c: Connect to the QEMU monitor event
  for watchdogs and emit a libvirt watchdog event
* src/remote/remote_driver.c: Receive and dispatch watchdog
  events to application
* src/remote/remote_protocol.x: Wire protocol definition for
  watchdog events
* src/qemu/qemu_monitor.c, src/qemu/qemu_monitor.h,
  src/qemu/qemu_monitor_json.c: Watch for WATCHDOG event
  from QEMU monitor