routes.get

examples/route_hi.rb

@@ -22,3 +22,6 @@ pp rt.routes.list(:family=>Socket::AF_INET, :table=>Netlink::RT_TABLE_MAIN).to_a
 puts "\nDefault route is probably:"
 pp rt.routes.list(:family=>Socket::AF_INET, :table=>Netlink::RT_TABLE_MAIN).
   min_by { |route| route.dst_len }
+
+puts "\nTraffic to 192.168.1.1 goes out via:"
+puts rt.ifname(rt.routes.get(:dst=>"192.168.1.1").oif)

lib/netlink/nlsocket.rb

@@ -128,10 +128,10 @@ module Netlink
     # an exception if any error message is returned, or on timeout.
     #
     # (Compare: rtnl_talk in lib/libnetlink.c, with answer=NULL)
-    def cmd(type, msg, flags=NLM_F_REQUEST, timeout=@timeout, sockaddr=SOCKADDR_DEFAULT)
+    def cmd(type, msg, flags=NLM_F_REQUEST, resp_type=NLMSG_ERROR, timeout=@timeout, sockaddr=SOCKADDR_DEFAULT)
       send_request(type, msg, flags|NLM_F_ACK, sockaddr)
       receive_responses(true, timeout) do |type,msg|
-        return if type == NLMSG_ERROR
+        return msg if type == resp_type
         false
       end
     end

lib/netlink/route/route_handler.rb

@@ -139,6 +139,15 @@ module Netlink
         iproute_modify(RTM_DELROUTE, 0, opt)
       end
 
+      # Get route matching given criteria
+      def get(msg)
+        msg = RT.new(msg)
+        raise "Missing :dst" unless msg.dst
+        msg.iif = index(msg.iif) if msg.iif.is_a?(String)
+        msg.oif = index(msg.oif) if msg.oif.is_a?(String)
+        @rtsocket.cmd RTM_GETROUTE, msg, NLM_F_REQUEST, RTM_NEWROUTE
+      end
+      
       def iproute_modify(code, flags, msg) #:nodoc:
         msg = RT.new(msg)