Currently, libvirtd will start a dnsmasq process for the virtual
network, but (aside from killing the dnsmasq process and replacing it),
there's no way to define tftp boot options.

This change introduces the appropriate tags to the dhcp configuration:

 <network>
   <name>default</name>
   <bridge name="virbr%d" />
   <forward/>
   <ip address="192.168.122.1" netmask="255.255.255.0">
     <tftp root="/var/lib/tftproot" />
     <dhcp>
       <range start="192.168.122.2" end="192.168.122.254" />
       <bootp file="pxeboot.img"/>
     </dhcp>
   </ip>
 </network>

When the attributes are present, these are passed to the
arguments to dnsmasq:

 dnsmasq [...] --enable-tftp --tftp-root /srv/tftp --dhcp-boot pxeboot.img
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^
                      from <tftp />                     from <bootp />

At present, only local tftp servers are supported (ie, dnsmasq runs as
the tftp server), but we could improve this in future by adding a
server= attribute.
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

2009-09-21  Paolo Bonzini  <pbonzini@redhat.com>
            Jeremy Kerr  <jk@ozlabs.org>

	* docs/formatnetwork.html.in: Document new tags.
	* docs/formatnetwork.html: Regenerate.
	* docs/schemas/network.rng: Update.
	* src/network_conf.c (virNetworkDefFree): Free new fields.
	(virNetworkDHCPRangeDefParseXML): Parse <bootp>.
	(virNetworkIPParseXML): New, parsing <dhcp> and <tftp>.
	(virNetworkDefParseXML): Use virNetworkIPParseXML instead of
	virNetworkDHCPRangeDefParseXML.
	(virNetworkDefFormat): Pretty print new fields.
	* src/network_conf.h (struct _virNetworkDef): Add netboot fields.
	* src/network_driver.c (networkBuildDnsmasqArgv): Add
	TFTP and BOOTP arguments.

	* tests/Makefile.am (EXTRA_DIST): Add networkschemadata.
	* tests/networkschematest: Look in networkschemadata.
	* tests/networkschemadata/netboot-network.xml: New.