dnsmasq: add support for set: and tag: pairs

dnsmasq: add support for set: and tag: pairs

On my network, I have a variety of machines and appliances, some of which need different configuration issues than the default options.

For example:

config host
	option name 'client'
	option mac '00:01:02:03:04:05'
	option ip '192.168.1.20'
	option tag 'acme'

config tag acme
	option force '1'
	list dhcp_option 'option:router,192.168.1.253'
	list dhcp_option 'option:domain-name,acme.com'
	list dhcp_option 'option:domain-search,acme.com,redfish-solutions.com'

which allows me to override the default router for my client's host, as well as its domain-name, and its domain-search.

this causes the following config lines:

dhcp-host=00:01:02:03:04:05,set:acme,192.168.1.20,client
dhcp-option-force=tag:acme,option:router,192.168.1.253
dhcp-option-force=tag:acme,option:domain-name,acme.com
dhcp-option-force=tag:acme,option:domain-search:acme.com,redfish-solutions.com

This could be useful elsewhere, for instance, if you have an IP CCTV that you don't want to have a default-route, etc.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@31815 3c298f89-4303-0410-b956-a3cf2f4a3e73