How to determine remote IP address in ActionWebService API's

Hello all!

I trying to create XMLRPC service with ActionWebService plugin and
Rails 2.0.2. I use conventional layered based API.

This is my controller:
class RpcController < ApplicationController
skip_before_filter :verify_authenticity_token
web_service_dispatching_mode :layered
web_service :user, UserRpcService.new
end

And service:
class UserRpcService < ActionWebService::Base
web_service_api UserRpcAPI
def auth(login, passwd)
user = User::find(:first, :conditions => {:login => login, :passwd
=> passwd})
raise UserAuthException, “Auth failed” unless user.instance_of?
(User)
true
end
end

In method UserRpcService.auth i need to know from which remote IP this
RPC call is come (for logging or restrictions etc.).