Simple grouping by ifindex

lib/netlink/message.rb

@@ -60,12 +60,12 @@ module Netlink
     #   msg = Foo.new(:bar => 123)  # or ("bar" => 123)
     #   msg2 = Foo.new(msg)
     #   msg3 = Foo.new(:qux => 999) # error, no method "qux="
-    def initialize(h={})
+    def initialize(h=nil)
       if h.instance_of?(self.class)
         @attrs = h.to_hash.dup
       else
         @attrs = self.class::DEFAULTS.dup
-        h.each { |k,v| self[k] = v }
+        h.each { |k,v| self[k] = v } if h
       end
     end
     

lib/netlink/nlsocket.rb

@@ -109,14 +109,15 @@ module Netlink
     # are accepted.
     #
     # (Compare: rtnl_dump_filter_l in lib/libnetlink.c)
-    def receive_until_done(timeout=@timeout, junk_handler=nil, &blk) #:yields: type, flags, obj
+    def receive_until_done(expect_type=nil, timeout=@timeout, junk_handler=nil, &blk) #:yields: type, flags, obj
       res = []
       blk ||= lambda { |type, flags, obj| res << obj if obj }
-      junk_handler ||= lambda { |obj| warn "Discarding junk message #{obj}" } if $VERBOSE
+      junk_handler ||= lambda { |type, flags, seq, pid, obj|
+        warn "Discarding junk message (#{type}) #{obj}" } if $VERBOSE
       loop do
         receive_response(timeout) do |type, flags, seq, pid, obj|
           if pid != @pid || seq != @seq
-            junk_handler[obj] if junk_handler
+            junk_handler[type, flags, seq, pid, obj] if junk_handler
             next
           end
           case type
@@ -125,6 +126,10 @@ module Netlink
           when NLMSG_ERROR
             raise "Netlink Error received"
           end
+          if expect_type && type != expect_type
+            junk_handler[type, flags, seq, pid, obj] if junk_handler
+            next
+          end
           blk.call(type, flags, obj)
         end
       end

lib/netlink/rtsocket.rb

@@ -8,38 +8,74 @@ module Netlink
       super(opt.merge(:protocol => Netlink::NETLINK_ROUTE))
     end
 
-    # List links. Returns an array of Netlink::Link objects
-    def link_list(opt)
+    # List links (interfaces). Returns an array of Netlink::Link objects.
+    #   res = nl.link_list
+    #   p res
+    #   [#<Netlink::Link {:family=>0, :pad=>0, :type=>772, :index=>1,
+    #    :flags=>65609, :change=>0, :ifname=>"lo", :txqlen=>0, :operstate=>0,
+    #    :linkmode=>0, :mtu=>16436, :qdisc=>"noqueue", :map=>"...",
+    #    :address=>"\x00\x00\x00\x00\x00\x00", :broadcast=>"\x00\x00\x00\x00\x00\x00",
+    #    :stats=>#<struct Netlink::LinkStats rx_packets=22, ...>,
+    #    :stats64=>#<struct Netlink::LinkStats rx_packets=22, ...>}>, ...]
+    def links(opt=nil)
       send_request RTM_GETLINK, Link.new(opt),
                    NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST
-      receive_until_done
+      receive_until_done(RTM_NEWLINK)
     end
 
+    # Return a Hash of Netlink::Link objects keyed by interface index, which
+    # is what the 'routes' and 'addrs' objects point to.
+    def links_by_index(opt=nil)
+      res = {}
+      links(opt).each { |obj| res[obj.index] = obj }
+      res
+    end
+      
     # List routes. Returns an array of Netlink::Route objects
     #   res = nl.routes(:family => Socket::AF_INET)
-    #   #=> [..., ...]
-    def route_list(opt)
+    #   p res
+    #   [#<Netlink::Route {:family=>2, :dst_len=>32, :src_len=>0, :tos=>0,
+    #    :table=>255, :protocol=>2, :scope=>253, :type=>3, :flags=>0, :table2=>255,
+    #    :dst=>#<IPAddr: IPv4:127.255.255.255/255.255.255.255>,
+    #    :prefsrc=>#<IPAddr: IPv4:127.0.0.1/255.255.255.255>, :oif=>1}>, ...]
+    #
+    # Note that not all attributes will always be present. In particular,
+    # a defaultroute (dst_len=0) misses out the dst address completely:
+    #
+    #   [#<Netlink::Route {:family=>2, :dst_len=>0, :src_len=>0, :tos=>0,
+    #    :table=>254, :protocol=>4, :scope=>0, :type=>1, :flags=>0, :table2=>254,
+    #    :gateway=>#<IPAddr: IPv4:10.69.255.253/255.255.255.255>, :oif=>2}>, ...]
+    def routes(opt=nil)
       send_request RTM_GETROUTE, Route.new(opt),
                    NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST
-      receive_until_done
+      receive_until_done(RTM_NEWROUTE)
+    end
+    
+    # Return routes as a hash of {index=>[route,route], index=>[route,route]}
+    def routes_by_oif(opt=nil)
+      res = routes(opt).group_by { |obj| obj.oif }
+      res.default = [].freeze
+      res
     end
 
-    def addr_list(opt)
+    # List addresses. Return an array of Netlink::Addr objects.
+    # You will need to use the 'index' to cross reference to the interface.
+    #   res = nl.addrs(:family => Socket::AF_INET)
+    #   p res
+    #   [#<Netlink::Addr {:family=>2, :prefixlen=>8, :flags=>128, :scope=>254,
+    #    :index=>1, :address=>#<IPAddr: IPv4:127.0.0.1/255.255.255.255>,
+    #    :local=>#<IPAddr: IPv4:127.0.0.1/255.255.255.255>, :label=>"lo"}>, ...]
+    def addrs(opt=nil)
       send_request RTM_GETADDR, Addr.new(opt),
                    NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST
-      receive_until_done
+      receive_until_done(RTM_NEWADDR)
     end
 
-    # Add a route
-    #    nl.add_route(:family => Socket::AF_INET, ...)
-    def route_add(r)
-      send_request RTM_NEWROUTE, Route.new(r)
-      # Do we get any success/fail?
-    end
-
-    # Delete a route
-    def route_delete(r)
-      send_request RTM_DELROUTE, Route.new(r)
+    # Return addresses as a hash of {index=>[addr,addr], index=>[addr,addr]}
+    def addrs_by_index(opt=nil)
+      res = addrs(opt).group_by { |obj| obj.index }
+      res.default = [].freeze
+      res
     end
   end
 end
@@ -47,10 +83,23 @@ end
 if __FILE__ == $0
   require 'pp'
   nl = Netlink::RTSocket.new
-  puts "*** routes ***"
-  pp nl.route_list(:family => Socket::AF_INET)
-  puts "*** links ***"
-  pp nl.link_list(:family => Socket::AF_INET)
-  puts "*** addrs ***"
-  pp nl.addr_list(:family => Socket::AF_INET)
+  #puts "*** routes ***"
+  #pp nl.routes(:family => Socket::AF_INET)
+  #puts "*** links ***"
+  #pp nl.links(:family => Socket::AF_INET)
+  #puts "*** addrs ***"
+  #pp nl.addrs(:family => Socket::AF_INET)
+  links = nl.links
+  addrs = nl.addrs_by_index(:family=>Socket::AF_UNSPEC)
+  routes = nl.routes_by_oif(:family=>Socket::AF_UNSPEC)
+  links.each do |link|
+    puts "#{link.ifname}"
+    addrs[link.index].each do |addr|
+      puts "  family=#{addr.family} #{addr.address}/#{addr.prefixlen} label=#{addr.label}"
+    end
+    routes[link.index].each do |route|
+      #p route
+      puts "  >> family=#{route.family} #{route.dst}/#{route.dst_len} gw=#{route.gateway}"
+    end
+  end
 end