* src/util/bridge.c, src/util/bridge.h: Add virNetDevGetMAC

The MTU management APIs are useful to other code inside libvirt,
so should be exposed as non-static APIs.

* src/util/bridge.c, src/util/bridge.h: Expose virNetDevSetMTU,
  virNetDevSetMTUFromDevice & virNetDevGetMTU

* src/util/bridge.c, src/util/bridge.h: s/int/bool/ in
  virNetDevSetOnline and virNetDevBridgeSetSTP

The existing brXXX APIs in src/util/bridge.h are renamed to
follow one of three different conventions

 - virNetDevXXX       - operations for any type of interface
 - virNetDevBridgeXXX - operations for bridge interfaces
 - virNetDevTapXXX    - operations for tap interfaces

* src/util/bridge.h, src/util/bridge.c: Rename all APIs
* src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/qemu/qemu_command.c, src/uml/uml_conf.c,
  src/uml/uml_driver.c: Update for API renaming

The bridge management APIs in src/util/bridge.c require a brControl
object to be passed around. This holds the file descriptor for the
control socket. This extra object complicates use of the API for
only a minor efficiency gain, which is in turn entirely offset by
the need to fork/exec the brctl command for STP configuration.

This patch removes the 'brControl' object entirely, instead opening
the control socket & closing it again within the scope of each method.

The parameter names for the APIs are also made to consistently use
'brname' for bridge device name, and 'ifname' for an interface
device name. Finally annotations are added for non-NULL parameters
and return check validation

* src/util/bridge.c, src/util/bridge.h: Remove brControl object
  and update API parameter names & annotations.
* src/lxc/lxc_driver.c, src/network/bridge_driver.c,
  src/uml/uml_conf.h, src/uml/uml_conf.c, src/uml/uml_driver.c,
  src/qemu/qemu_command.c, src/qemu/qemu_conf.h,
  src/qemu/qemu_driver.c: Remove reference to 'brControl' object

This refactors the TAP creation code out of brAddTap into a new
function brCreateTap to allow it to be used on its own. I have also
changed ifSetInterfaceMac to brSetInterfaceMac and exported it since
it is will be needed by code outside of util/bridge.c in the next
patch.

 AUTHORS                 |    1 +
 src/libvirt_bridge.syms |    2 +
 src/util/bridge.c       |  116 +++++++++++++++++++++++++++++++----------------
 src/util/bridge.h       |    9 ++++
 4 files changed, 89 insertions(+), 39 deletions(-)

An upcoming patch has a use for a tap device to be created that
doesn't need to be actually put into the "up" state, and keeping it
"down" keeps the output of ifconfig from being unnecessarily cluttered
(ifconfig won't show down interfaces unless you add "-a").

bridge.[ch]: add "up" as an arg to brAddTap()
uml_conf.c, qemu_command.c: add "up" (set to "true") to brAddTap() call.

brSetInetAddress can only set a single IP address on the bridge, and
uses a method (ioctl(SIOCSETIFADDR)) that only works for IPv4. Replace
it and brSetInetNetmask with a single function that uses the external
"ip addr add" command to add an address/prefix to the interface - this
supports IPv6, and allows adding multiple addresses to the interface.

Although it isn't currently used in the code, we also add a
brDelInetAddress for completeness' sake.

Also, while we're modifying bridge.c, we change brSetForwardDelay and
brSetEnableSTP to use the new virCommand API rather than the
deprecated virRun, and also log an error message in bridge_driver.c if
either of those fail (previously the failure would be completely
silent).

Instead of storing the IP address string in virNetwork related
structs, store the parsed virSocketAddr. This will make it
easier to add IPv6 support in the future, by letting driver
code directly check what address family is present

* src/conf/network_conf.c, src/conf/network_conf.h,
  src/network/bridge_driver.c: Convert to use virSocketAddr
  in virNetwork, instead of char *.
* src/util/bridge.c, src/util/bridge.h,
  src/util/dnsmasq.c, src/util/dnsmasq.h,
  src/util/iptables.c, src/util/iptables.h: Convert to
  take a virSocketAddr instead of char * for any IP
  address parameters
* src/util/network.h: Add macros to determine if an address
  is set, and what address family is set.

The  inet_pton and inet_ntop functions are obsolete, replaced
by getaddrinfo+getnameinfo with the AI_NUMERICHOST flag set.
These can be accessed via the virSocket APIs.

The bridge.c code had methods for fetching the IP address of
a bridge which used inet_ntop. Aside from the use of inet_ntop
these methods are broken, because a NIC can have multiple
addresses and this only returns one address. Since the methods
are never used, just remove them.

* src/conf/network_conf.c, src/nwfilter/nwfilter_learnipaddr.c:
  Replace inet_pton and inet_ntop with virSocket APIs
* src/util/bridge.c, src/util/bridge.h: Remove unused methods
  which called inet_ntop.

A Linux software bridge will assume the MAC address of the enslaved
interface with the numerically lowest MAC addr. When the bridge
changes MAC address there is a period of network blackout, so a
change should be avoided. The kernel gives TAP devices a completely
random MAC address. Occassionally the random TAP device MAC is lower
than that of the physical interface (eth0, eth1etc) that is enslaved,
causing the bridge to change its MAC.

This change sets an explicit MAC address for all TAP devices created
using the configured MAC from the XML, but with the high byte set
to 0xFE. This should ensure TAP device MACs are higher than any
physical interface MAC.

* src/qemu/qemu_conf.c, src/uml/uml_conf.c: Pass in a MAC addr
  for the TAP device with high byte set to 0xFE
* src/util/bridge.c, src/util/bridge.h: Set a MAC when creating
  the TAP device to override random MAC

* global: patch created by running:
for f in $(git ls-files '*.[ch]') ; do
    cppi $f > $f.t && mv $f.t $f
done

* src/bridge.c, src/bridge.h, src/buf.c, src/buf.h, src/cgroup.c,
  src/cgroup.h, src/conf.c, src/conf.h, src/event.c, src/event.h,
  src/hash.c, src/hash.h, src/hostusb.c, src/hostusb.h,
  src/iptables.c, src/iptables.h, src/logging.c, src/logging.h,
  src/memory.c, src/memory.h, src/pci.c, src/pci.h, src/qparams.c,
  src/qparams.h, src/stats_linux.c, src/stats_linux.h,
  src/threads-pthread.c, src/threads-pthread.h, src/threads-win32.c,
  src/threads-win32.h, src/threads.c, src/threads.h, src/util.c,
  src/util.h, src/uuid.c, src/uuid.h, src/virterror.c,
  src/virterror_internal.h, src/xml.c, src/xml.h: Move all files
  into src/util/
* daemon/Makefile.am: Add -Isrc/util/ to build flags
* src/Makefile.am: Add -Isrc/util/ to build flags and update for
  moved files
* src/libvirt_private.syms: Export cgroup APIs since they're now
  in util rather than linking directly to drivers
* src/xen/xs_internal.c: Disable bogus virEventRemoveHandle call
  when built under PROXY
* proxy/Makefile.am: Update for changed file locations. Remove
  bogus build of event.c
* tools/Makefile.am, tests/Makefile.am: Add -Isrc/util/ to build flags

* configure.in: Enable internal WITH_BRIDGE support not just for LXC or
QEMU, but also for --with-network.  Russell Haering reported that
compilation failed when configured with --without-lxc --without-qemu.
Details: http://thread.gmane.org/gmane.comp.emulators.libvirt/11928
* src/bridge.h: Use #if WITH_BRIDGE, rather than currently-equivalent
"#if defined(WITH_QEMU) || defined(WITH_LXC)"

IFF_VNET_HDR is a tun/tap flag that allows you to send and receive
large (i.e. GSO) packets and packets with partial checksums. Setting
the flag means that every packet is proceeded by the same header which
virtio uses to communicate GSO/csum metadata.

By enabling this flag on the tap fds we create, we greatly increase
the achievable throughput with virtio_net.

However, we need to be careful to only set the flag when a) QEMU has
support for this ABI and b) the value of the flag is queryable using
the TUNGETIFF ioctl.

It's nearly five months since kvm-74 - the first KVM release with this
feature - was released. Up until now, we've not added libvirt support
because there is no clean way to detect support for this in QEMU at
runtime. A brief attempt to add a "info capabilities" monitor command
to QEMU floundered. Perfect is the enemy of good enough. Probing the
KVM version will suffice for now.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>

Done with these commands:
git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* vim:(.|\n)*,\n,'

git grep -l Local.variab|xargs \
  perl -0x3b -pi -e 's,\n+/\*\n \* Local variables:\n(.|\n)*,\n,'

Use <config.h>, not "config.h", per autoconf documentation.
* Makefile.cfg (local-checks-to-skip) [sc_require_config_h]: Enable.
* .x-sc_require_config_h: New file, to list exempted files.
* Makefile.am (EXTRA_DIST): Add .x-sc_require_config_h.

	* src/bridge.c, src/bridge.h, src/qemu_conf.c, src/qemu_conf.h,
	  src/qemu_driver.c, src/qemu_driver.h, src/test.c: Disable more
	  of qemu if configured --without-qemu.

  stylesheet
* docs/*: regenerated
* src/bridge.c src/bridge.h src/buf.c src/iptables.c src/libvirt.c
  src/qemu_driver.c src/qemu_driver.h src/uuid.c src/uuid.h: cleanup,
  addd comments, made functions static and fixe a few bugs
Daniel

        * configure.in: add --disable-bridge-params, check
        for libsysfs and various kernel headers

        * bridge.[ch]: add code for managing bridges

        * qemud/Makefile.am: add bridge.[ch] and link against
        libsysfs if enabled.

        * qemud/conf.c: add support for bridge config.

        * qemud/internal.h: add various bridging bits

        * qemud/qemud.c: implement qemudStartNetworkDaemon()
        and qemudShutdownNetworkDaemon().