Webservice - get client ip address

Hi
I have the following problem in my application I have
in the controller:

class XmlrpcController < ApplicationController
web_service_dispatching_mode :layered
wsdl_service_name ‘weblogUpdates.ping’
web_service_scaffold :invoke
web_service :weblogUpdates, WeblogUpdates.new
end

in the api definition file:

class WeblogUpdatesApi < ActionWebService::API::Base
inflect_names false

api_method :ping, :expects => [{:sitename=>:string},

{:url=>:string}], :returns => [XmlrpcStructs::PingInfo]
end

class WeblogUpdates < ActionWebService::Base
web_service_api WeblogUpdatesApi
def ping(sitename, url)
# a logic here

return XmlrpcStructs::PingInfo.new(:flerror => flerror, :message
=> message)
end
end

Everything works here
Now in my ping method I would like to use a request object
How can I pass a request from the controller to ping method
in WeblogUpdates class

I’m new to ruby on rails
If I posted this to the wrong group sorry and please direct me to the
right one

Thanks
simon