Merge pull request #695 from btm/btm/ipv6_mac

Fix detection of mac address on IPv6 only systems

5 files changed, 291 insertions, 144 deletions

diff --git a/lib/ohai/mixin/network_constants.rb b/lib/ohai/mixin/network_constants.rb
index 2b47a565..738ee546 100644
--- a/lib/ohai/mixin/network_constants.rb
+++ b/lib/ohai/mixin/network_constants.rb
@@ -1,6 +1,6 @@
 #
-# Author:: Serdar Sutay (<serdar@opscode.com>)
-# Copyright:: Copyright (c) 2014 Opscode, Inc.
+# Author:: Serdar Sutay (<serdar@chef.io>)
+# Copyright:: Copyright (c) 2014-2015 Chef Software, Inc.
 # License:: Apache License, Version 2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/lib/ohai/plugins/linux/network.rb b/lib/ohai/plugins/linux/network.rb
index 689001dc..0bc90ad1 100644
--- a/lib/ohai/plugins/linux/network.rb
+++ b/lib/ohai/plugins/linux/network.rb
@@ -138,6 +138,7 @@ Ohai.plugin(:Network) do
     end.compact.flatten
   end
 
+  # determine layer 1 details for the interface using ethtool
   def ethernet_layer_one(iface)
     return iface unless ethtool_binary = find_ethtool_binary
     keys = %w[ Speed Duplex Port Transceiver Auto-negotiation MDI-X ]
@@ -161,6 +162,7 @@ Ohai.plugin(:Network) do
     iface
   end
 
+  # determine link stats, vlans, queue length, and state for an interface using ip
   def link_statistics(iface, net_counters)
     so = shell_out("ip -d -s link")
     tmp_int = nil
@@ -251,7 +253,6 @@ Ohai.plugin(:Network) do
     end
   end
 
-
   def parse_ip_addr_link_line(cint, iface, line)
     if line =~ /link\/(\w+) ([\da-f\:]+) /
       iface[cint][:encapsulation] = linux_encaps_lookup($1)
@@ -293,7 +294,7 @@ Ohai.plugin(:Network) do
         iface[cint][:addresses][tmp_addr][:scope] = ($1.eql?("host") ? "Node" : $1.capitalize)
       end
 
-      # If we found we were an an alias interface, restore cint to its original value
+      # If we found we were an alias interface, restore cint to its original value
       cint = original_int unless original_int.nil?
     end
     cint
@@ -307,6 +308,71 @@ Ohai.plugin(:Network) do
     end
   end
 
+  # returns the macaddress for interface from a hash of interfaces (iface elsewhere in this file)
+  def get_mac_for_interface(interfaces, interface)
+    interfaces[interface][:addresses].select{|k,v| v["family"]=="lladdr"}.first.first unless interfaces[interface][:flags].include? "NOARP"
+  end
+
+  # returns the default route with the lowest metric (unspecified metric is 0)
+  def choose_default_route(routes)
+    default_route = routes.select do |r|
+      r[:destination] == "default"
+    end.sort do |x,y|
+      (x[:metric].nil? ? 0 : x[:metric].to_i) <=> (y[:metric].nil? ? 0 : y[:metric].to_i)
+    end.first
+  end
+
+  # ipv4/ipv6 routes are different enough that having a single algorithm to select the favored route for both creates unnecessary complexity
+  # this method attempts to deduce the route that is most important to the user, which is later used to deduce the favored values for {ip,mac,ip6}address
+  # we only consider routes that are default routes, or those routes that get us to the gateway for a default route
+  def favored_default_route(routes, iface, default_route, family)
+    routes.select do |r|
+      if family[:name] == "inet"
+        # selecting routes for ipv4
+        # using the source field when it's specified :
+        # 1) in the default route
+        # 2) in the route entry used to reach the default gateway
+        r[:src] and # it has a src field
+          iface[r[:dev]] and # the iface exists
+          iface[r[:dev]][:addresses].has_key? r[:src] and # the src ip is set on the node
+          iface[r[:dev]][:addresses][r[:src]][:scope].downcase != "link" and # this isn't a link level addresse
+          ( r[:destination] == "default" or
+            ( default_route[:via] and # the default route has a gateway
+              IPAddress(r[:destination]).include? IPAddress(default_route[:via]) # the route matches the gateway
+              )
+            )
+      elsif family[:name] == "inet6"
+        # selecting routes for ipv6
+        iface[r[:dev]] and # the iface exists
+          iface[r[:dev]][:state] == "up" and # the iface is up
+          ( r[:destination] == "default" or
+            ( default_route[:via] and # the default route has a gateway
+              IPAddress(r[:destination]).include? IPAddress(default_route[:via]) # the route matches the gateway
+              )
+            )
+      end
+    end.sort_by do |r|
+      # sorting the selected routes:
+      # - getting default routes first
+      # - then sort by metric
+      # - then by prefixlen
+      [
+       r[:destination] == "default" ? 0 : 1,
+       r[:metric].nil? ? 0 : r[:metric].to_i,
+       # for some reason IPAddress doesn't accept "::/0", it doesn't like prefix==0
+       # just a quick workaround: use 0 if IPAddress fails
+       begin
+         IPAddress( r[:destination] == "default" ? family[:default_route] : r[:destination] ).prefix
+       rescue
+         0
+       end
+      ]
+    end.first
+  end
+
+  # Both the network plugin and this plugin (linux/network) are run on linux. This plugin runs first.
+  # If the 'ip' binary is available, this plugin may set {ip,mac,ip6}address. The network plugin should not overwrite these.
+  # The older code section below that relies on the deprecated net-tools, e.g. netstat and ifconfig, provides less functionality.
   collect_data(:linux) do
     require 'ipaddr'
 
@@ -353,18 +419,15 @@ Ohai.plugin(:Network) do
 
         routes = parse_routes(family, iface)
 
-        # using a temporary var to hold the default route
-        # in case there are more than 1 default route, sort it by its metric
-        # and return the first one
-        # (metric value when unspecified is 0)
-        default_route = routes.select do |r|
-          r[:destination] == "default"
-        end.sort do |x,y|
-          (x[:metric].nil? ? 0 : x[:metric].to_i) <=> (y[:metric].nil? ? 0 : y[:metric].to_i)
-        end.first
+        default_route = choose_default_route(routes)
 
         if default_route.nil? or default_route.empty?
-          Ohai::Log.debug("Unable to determine default #{family[:name]} interface")
+          attribute_name == if family[:name] == "inet"
+                              "default_interface"
+                            else
+                              "default_#{family[:name]}_interface"
+                            end
+          Ohai::Log.debug("Unable to determine '#{attribute_name}' as no default routes were found for that interface family")
         else
           network["#{default_prefix}_interface"] = default_route[:dev]
           Ohai::Log.debug("#{default_prefix}_interface set to #{default_route[:dev]}")
@@ -373,52 +436,35 @@ Ohai.plugin(:Network) do
           network["#{default_prefix}_gateway"] = default_route[:via] ? default_route[:via] : family[:default_route].chomp("/0")
           Ohai::Log.debug("#{default_prefix}_gateway set to #{network["#{default_prefix}_gateway"]}")
 
+          # deduce the default route the user most likely cares about to pick {ip,mac,ip6}address below
+          favored_route = favored_default_route(routes, iface, default_route, family)
+
+          # FIXME: This entire block should go away, and the network plugin should be the sole source of {ip,ip6,mac}address
+
           # since we're at it, let's populate {ip,mac,ip6}address with the best values
-          # using the source field when it's specified :
-          # 1) in the default route
-          # 2) in the route entry used to reach the default gateway
-          route = routes.select do |r|
-            # selecting routes
-            r[:src] and # it has a src field
-              iface[r[:dev]] and # the iface exists
-              iface[r[:dev]][:addresses].has_key? r[:src] and # the src ip is set on the node
-              iface[r[:dev]][:addresses][r[:src]][:scope].downcase != "link" and # this isn't a link level addresse
-              ( r[:destination] == "default" or
-                ( default_route[:via] and # the default route has a gateway
-                  IPAddress(r[:destination]).include? IPAddress(default_route[:via]) # the route matches the gateway
-                  )
-                )
-          end.sort_by do |r|
-            # sorting the selected routes:
-            # - getting default routes first
-            # - then sort by metric
-            # - then by prefixlen
-            [
-             r[:destination] == "default" ? 0 : 1,
-             r[:metric].nil? ? 0 : r[:metric].to_i,
-             # for some reason IPAddress doesn't accept "::/0", it doesn't like prefix==0
-             # just a quick workaround: use 0 if IPAddress fails
-             begin
-               IPAddress( r[:destination] == "default" ? family[:default_route] : r[:destination] ).prefix
-             rescue
-               0
-             end
-            ]
-          end.first
-
-          unless route.nil? or route.empty?
+          # if we don't set these, the network plugin may set them afterwards
+          if favored_route && !favored_route.empty?
             if family[:name] == "inet"
-              ipaddress route[:src]
-              macaddress iface[route[:dev]][:addresses].select{|k,v| v["family"]=="lladdr"}.first.first unless iface[route[:dev]][:flags].include? "NOARP"
-            else
-              ip6address route[:src]
+              ipaddress favored_route[:src]
+              m = get_mac_for_interface(iface, favored_route[:dev])
+              Ohai::Log.debug("Overwriting macaddress #{macaddress} with #{m} from interface #{favored_route[:dev]}") if macaddress
+              macaddress m
+            elsif family[:name] == "inet6"
+              # this rarely does anything since we rarely have src for ipv6, so this usually falls back on the network plugin
+              ip6address favored_route[:src]
+              if macaddress
+                Ohai::Log.debug("Not setting macaddress from ipv6 interface #{favored_route[:dev]} because macaddress is already set")
+              else
+                macaddress get_mac_for_interface(iface, favored_route[:dev])
+              end
             end
+          else
+            Ohai::Log.debug("the linux/network plugin was unable to deduce the favored default route for family '#{family[:name]}' despite finding a default route, and is not setting ipaddress/ip6address/macaddress. the network plugin may provide fallbacks.")
+            Ohai::Log.debug("this potential default route was excluded: #{default_route}")
           end
         end
-      end
-
-    else
-
+      end # end families.each
+    else # ip binary not available, falling back to net-tools, e.g. route, ifconfig
       begin
         so = shell_out("route -n")
         route_result = so.stdout.split($/).grep( /^0.0.0.0/ )[0].split( /[ \t]+/ )
@@ -502,7 +548,7 @@ Ohai.plugin(:Network) do
           iface[$4][:arp][$1] = $2.downcase
         end
       end
-    end
+    end # end "ip else net-tools" block
 
     iface = ethernet_layer_one(iface)
     counters[:network][:interfaces] = net_counters
diff --git a/lib/ohai/plugins/network.rb b/lib/ohai/plugins/network.rb
index bc95a650..ac55f1b0 100644
--- a/lib/ohai/plugins/network.rb
+++ b/lib/ohai/plugins/network.rb
@@ -1,14 +1,14 @@
 #
-# Author:: Adam Jacob (<adam@opscode.com>)
-# Copyright:: Copyright (c) 2008 Opscode, Inc.
+# Author:: Adam Jacob (<adam@chef.io>)
+# Copyright:: Copyright (c) 2008-2015 Chef Software, Inc.
 # License:: Apache License, Version 2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
-# 
+#
 #     http://www.apache.org/licenses/LICENSE-2.0
-# 
+#
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -26,19 +26,21 @@ Ohai.plugin(:NetworkAddresses) do
 
   depends "network/interfaces"
 
+  # from interface data create array of hashes with ipaddress, scope, and iface
+  # sorted by scope, prefixlen and then ipaddress where longest prefixes first
   def sorted_ips(family = "inet")
-    raise "bad family #{family}" unless [ "inet", "inet6" ].include? family
+    fail "bad family #{family}" unless %w(inet inet6).include? family
 
-    # going to use that later to sort by scope
+    # priority of ipv6 link scopes to sort by later
     scope_prio = [ "global", "site", "link", "host", "node", nil ]
 
+    # grab ipaddress, scope, and iface for sorting later
     ipaddresses = []
-    # ipaddresses going to hold #{family} ipaddresses and their scope
     Mash[network['interfaces']].each do |iface, iface_v|
-      next if iface_v.nil? or not iface_v.has_key? 'addresses'
+      next if iface_v.nil? || !iface_v.has_key?('addresses')
       iface_v['addresses'].each do |addr, addr_v|
         next if addr_v.nil? or not addr_v.has_key? "family" or addr_v['family'] != family
-        ipaddresses <<  {
+        ipaddresses << {
           :ipaddress => addr_v["prefixlen"] ? IPAddress("#{addr}/#{addr_v["prefixlen"]}") : IPAddress("#{addr}/#{addr_v["netmask"]}"),
           :scope => addr_v["scope"].nil? ? nil : addr_v["scope"].downcase,
           :iface => iface
@@ -49,35 +51,35 @@ Ohai.plugin(:NetworkAddresses) do
     # sort ip addresses by scope, by prefixlen and then by ip address
     # 128 - prefixlen: longest prefixes first
     ipaddresses.sort_by do |v|
-      [ ( scope_prio.index(v[:scope]) or 999999 ),
+      [ ( scope_prio.index(v[:scope]) || 999999 ),
         128 - v[:ipaddress].prefix.to_i,
         ( family == "inet" ? v[:ipaddress].to_u32 : v[:ipaddress].to_u128 )
       ]
     end
   end
 
+  # finds ip address / interface for interface with default route based on
+  # passed in family.  returns [ipaddress, interface] uses 1st ip if no default
+  # route is found
   def find_ip(family = "inet")
-    ips=sorted_ips(family)
+    ips = sorted_ips(family)
 
-    # return if there isn't any #{family} address !
+    # return if there aren't any #{family} addresses!
     return [ nil, nil ] if ips.empty?
 
     # shortcuts to access default #{family} interface and gateway
     int_attr = Ohai::Mixin::NetworkConstants::FAMILIES[family] +"_interface"
     gw_attr = Ohai::Mixin::NetworkConstants::FAMILIES[family] + "_gateway"
 
-    # If we have a default interface that has addresses,
-    # populate the short-cut attributes ipaddress, ip6address and macaddress
     if network[int_attr]
-
       # working with the address(es) of the default network interface
       gw_if_ips = ips.select do |v|
         v[:iface] == network[int_attr]
       end
       if gw_if_ips.empty?
         Ohai::Log.warn("[#{family}] no ip address on #{network[int_attr]}")
-      elsif network[gw_attr] and
-          network["interfaces"][network[int_attr]] and
+      elsif network[gw_attr] &&
+          network["interfaces"][network[int_attr]] &&
           network["interfaces"][network[int_attr]]["addresses"]
         if [ "0.0.0.0", "::", /^fe80:/ ].any? { |pat| pat === network[gw_attr] }
           # link level default route
@@ -109,15 +111,16 @@ Ohai.plugin(:NetworkAddresses) do
     [ r[:ipaddress].to_s, r[:iface] ]
   end
 
+  # select mac address of first interface with family of lladdr
   def find_mac_from_iface(iface)
-    r = network["interfaces"][iface]["addresses"].select{|k,v| v["family"]=="lladdr"}
-    r.nil? or r.first.nil? ? nil : r.first.first
+    r = network["interfaces"][iface]["addresses"].select{|k,v| v["family"] == "lladdr"}
+    r.nil? || r.first.nil? ? nil : r.first.first
   end
 
+  # address_to_match: String
+  # ipaddress: IPAddress
+  # iface: String
   def network_contains_address(address_to_match, ipaddress, iface)
-    # address_to_match: String
-    # ipaddress: IPAddress
-    # iface: String
     if peer = network["interfaces"][iface]["addresses"][ipaddress.to_s][:peer]
       IPAddress(peer) == IPAddress(address_to_match)
     else
@@ -125,11 +128,10 @@ Ohai.plugin(:NetworkAddresses) do
     end
   end
 
-  # ipaddress, ip6address and macaddress can be set by the #{os}::network plugin
-  # atm it is expected macaddress is set at the same time than ipaddress
-  # if ipaddress is set and macaddress is nil, that means the interface
-  # ipaddress is bound to has the NOARP flag
-
+  # ipaddress, ip6address and macaddress are set for each interface by the
+  # #{os}::network plugin. atm it is expected macaddress is set at the same
+  # time as ipaddress. if ipaddress is set and macaddress is nil, that means
+  # the interface ipaddress is bound to has the NOARP flag
   collect_data do
     results = {}
 
@@ -138,39 +140,44 @@ Ohai.plugin(:NetworkAddresses) do
     counters Mash.new unless counters
     counters[:network] = Mash.new unless counters[:network]
 
-    # inet family is treated before inet6
+    # inet family is processed before inet6 to give ipv4 precedence
     Ohai::Mixin::NetworkConstants::FAMILIES.keys.sort.each do |family|
       r = {}
-      ( r["ip"], r["iface"] ) = find_ip(family)
+      # find the ip/interface with the default route for this family
+      (r["ip"], r["iface"]) = find_ip(family)
       r["mac"] = find_mac_from_iface(r["iface"]) unless r["iface"].nil?
       # don't overwrite attributes if they've already been set by the "#{os}::network" plugin
-      if family == "inet" and ipaddress.nil?
+      if (family == "inet") && ipaddress.nil?
         if r["ip"].nil?
           Ohai::Log.warn("unable to detect ipaddress")
-          # i don't issue this warning if r["ip"] exists and r["mac"].nil?
-          # as it could be a valid setup with a NOARP default_interface
-          Ohai::Log.warn("unable to detect macaddress")
         else
           ipaddress r["ip"]
-          macaddress r["mac"]
         end
-      elsif family == "inet6" and ip6address.nil?
+      elsif (family == "inet6") && ip6address.nil?
         if r["ip"].nil?
           Ohai::Log.debug("unable to detect ip6address")
         else
           ip6address r["ip"]
-          if r["mac"] and macaddress.nil? and ipaddress.nil?
-            Ohai::Log.debug("macaddress set to #{r["mac"]} from the ipv6 setup")
-            macaddress r["mac"]
-          end
         end
       end
+
+      # set the macaddress [only if we haven't already]. this allows the #{os}::network plugin to set macaddress
+      # otherwise we set macaddress on a first-found basis (and we started with ipv4)
+      if macaddress.nil?
+        if r["mac"]
+          Ohai::Log.debug("setting macaddress to '#{r["mac"]}' from interface '#{r["iface"]}' for family '#{family}'")
+          macaddress r["mac"]
+        else
+          Ohai::Log.debug("unable to detect macaddress for family '#{family}'")
+        end
+      end
+
       results[family] = r
     end
 
-    if results["inet"]["iface"] and results["inet6"]["iface"] and
-        results["inet"]["iface"] != results["inet6"]["iface"]
-      Ohai::Log.debug("ipaddress and ip6address are set from different interfaces (#{results["inet"]["iface"]} & #{results["inet6"]["iface"]}), macaddress has been set using the ipaddress interface")
+    if results["inet"]["iface"] && results["inet6"]["iface"] &&
+        (results["inet"]["iface"] != results["inet6"]["iface"])
+      Ohai::Log.debug("ipaddress and ip6address are set from different interfaces (#{results["inet"]["iface"]} & #{results["inet6"]["iface"]})")
     end
   end
 end
diff --git a/spec/unit/plugins/linux/network_spec.rb b/spec/unit/plugins/linux/network_spec.rb
index de5a89ce..ab9387ef 100644
--- a/spec/unit/plugins/linux/network_spec.rb
+++ b/spec/unit/plugins/linux/network_spec.rb
@@ -1,7 +1,7 @@
 #
 #  Author:: Caleb Tennis <caleb.tennis@gmail.com>
 #  Author:: Chris Read <chris.read@gmail.com>
-#  Copyright:: Copyright (c) 2011 Opscode, Inc.
+#  Copyright:: Copyright (c) 2011-2015 Chef Software, Inc.
 #  License:: Apache License, Version 2.0
 #
 #  Licensed under the Apache License, Version 2.0 (the "License");
@@ -663,7 +663,14 @@ Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
         expect(plugin['network']['interfaces']['eth0.11']['routes']).to include Mash.new( :destination => "default", :via => "1111:2222:3333:4444::1", :metric => "1024", :family => "inet6")
       end
 
-      describe "when there isn't a source field in route entries " do
+      describe "when there isn't a source field in route entries and no ipv6 default routes" do
+        let(:linux_ip_route_inet6) {
+'fe80::/64 dev eth0  proto kernel  metric 256
+fe80::/64 dev eth0.11  proto kernel  metric 256
+1111:2222:3333:4444::/64 dev eth0.11  metric 1024  expires 86023sec
+'
+        }
+
         before(:each) do
           plugin.run
         end
@@ -798,7 +805,7 @@ default via 1111:2222:3333:4444::ffff dev eth0.11  metric 1023 src 1111:2222:333
         end
       end
 
-      describe "when there's a source field in a local route entry " do
+      describe "when there's a source field in a local route entry but it isnt in the default route" do
         let(:linux_ip_route) {
 '10.116.201.0/24 dev eth0  proto kernel  src 10.116.201.76
 192.168.5.0/24 dev eth0  proto kernel  src 192.168.5.1
@@ -828,18 +835,34 @@ default via 1111:2222:3333:4444::1 dev eth0.11  metric 1024
           expect(plugin['ipaddress']).to eq("10.116.201.76")
         end
 
+        # without a source address on the default route we cannot pick the an ipv6 address from the interface
+        # In the future an RFC6724 compliant process should choose ip6address in the network plugin
+        it "does not set ip6address" do
+          plugin.run
+          expect(plugin['ip6address']).to eq(nil)
+        end
+
+        context "with only ipv6 routes" do
+          let(:linux_ip_route) { '' }
+
+          it "sets macaddress to the mac address of the ip6 default interface" do
+            expect(plugin['macaddress']).to eq("00:AA:BB:CC:DD:EE")
+          end
+        end
+
         describe "when about to set macaddress" do
           it "sets macaddress" do
             plugin.run
             expect(plugin['macaddress']).to eq("12:31:3D:02:BE:A2")
           end
 
-          describe "when then interface has the NOARP flag" do
+          context "when then ipv4 interface has the NOARP flag and no ipv6 routes exist" do
             let(:linux_ip_route) {
 '10.118.19.1 dev tun0 proto kernel  src 10.118.19.39
 default via 172.16.19.1 dev tun0
 '
             }
+            let(:linux_ip_route_inet6) { '' }
 
             it "completes the run" do
               expect(Ohai::Log).not_to receive(:debug).with(/Plugin linux::network threw exception/)
@@ -853,11 +876,6 @@ default via 172.16.19.1 dev tun0
             end
           end
         end
-
-        it "sets ip6address" do
-          plugin.run
-          expect(plugin['ip6address']).to eq("1111:2222:3333:4444::3")
-        end
       end
 
       describe "with a link level default route" do
@@ -950,6 +968,9 @@ fe80::/64 dev eth0.11  proto kernel  metric 256
     inet6 2001:44b8:4160:8f00:a00:27ff:fe13:eacd/64 scope global dynamic
        valid_lft 6128sec preferred_lft 2526sec
 '}
+        # We don't have the corresponding ipv6 data for these tests
+        let(:linux_ip_route_inet6) { '' }
+        let(:linux_ip_inet6_neighbor_show) { '' }
 
         before(:each) do
           allow(plugin).to receive(:is_openvz?).and_return true
diff --git a/spec/unit/plugins/network_spec.rb b/spec/unit/plugins/network_spec.rb
index 03ea6b81..5b426334 100644
--- a/spec/unit/plugins/network_spec.rb
+++ b/spec/unit/plugins/network_spec.rb
@@ -26,8 +26,8 @@ def it_doesnt_fail
   end
 end
 
+# basic sanity check that is called in all describes below
 def it_populates_ipaddress_attributes
-
   source = caller[0]
 
   it "populates ipaddress, macaddress and ip6address" do
@@ -43,11 +43,11 @@ def it_populates_ipaddress_attributes
       raise
     end
   end
-
 end
 
 describe Ohai::System, "Network Plugin" do
 
+  # output of network plugins on particular platforms to mock plugin runs
   basic_data = {
     "freebsd" => {
       "network" => {
@@ -57,7 +57,9 @@ describe Ohai::System, "Network Plugin" do
             "number" => "0",
             "flags" => ["UP", "BROADCAST", "RUNNING", "SIMPLEX", "MULTICAST"],
             "addresses" => {
-              "00:00:24:c9:5e:b8" => {"family" => "lladdr"},
+              "00:00:24:c9:5e:b8" => {
+                "family" => "lladdr"
+              },
               "fe80::200:24ff:fec9:5eb8" => {
                 "family" => "inet6",
                 "zoneid" => "vr0",
@@ -80,7 +82,9 @@ describe Ohai::System, "Network Plugin" do
             "number" => "1",
             "flags" => ["UP", "BROADCAST", "RUNNING", "PROMISC", "SIMPLEX", "MULTICAST"],
             "addresses" => {
-              "00:00:24:c9:5e:b9" => {"family" => "lladdr"},
+              "00:00:24:c9:5e:b9" => {
+                "family" => "lladdr"
+              },
               "fe80::200:24ff:fec9:5eb9" => {
                 "family" => "inet6",
                 "zoneid" => "vr1",
@@ -94,7 +98,9 @@ describe Ohai::System, "Network Plugin" do
             "number" => "2",
             "flags" => ["UP", "BROADCAST", "RUNNING", "PROMISC", "SIMPLEX", "MULTICAST"],
             "addresses" => {
-              "00:00:24:c9:5e:ba" => {"family" => "lladdr"},
+              "00:00:24:c9:5e:ba" => {
+                "family" => "lladdr"
+              },
               "fe80::200:24ff:fec9:5eba" => {
                 "family" => "inet6",
                 "zoneid" => "vr2",
@@ -108,7 +114,9 @@ describe Ohai::System, "Network Plugin" do
             "number" => "3",
             "flags" => ["UP", "BROADCAST", "RUNNING", "PROMISC", "SIMPLEX", "MULTICAST"],
             "addresses" => {
-              "00:00:24:c9:5e:bb" => {"family" => "lladdr"},
+              "00:00:24:c9:5e:bb" => {
+                "family" => "lladdr"
+              },
               "fe80::200:24ff:fec9:5ebb" => {
                 "family" => "inet6",
                 "zoneid" => "vr3",
@@ -128,8 +136,14 @@ describe Ohai::System, "Network Plugin" do
             "number" => "0",
             "flags" => ["UP", "LOOPBACK", "RUNNING", "MULTICAST"],
             "addresses" => {
-              "127.0.0.1" => {"family" => "inet", "netmask" => "255.0.0.0"},
-              "::1" => {"family" => "inet6", "prefixlen" => "128"},
+              "127.0.0.1" => {
+                "family" => "inet",
+                "netmask" => "255.0.0.0"
+              },
+              "::1" => {
+                "family" => "inet6",
+                "prefixlen" => "128"
+              },
               "fe80::1" => {
                 "family" => "inet6",
                 "zoneid" => "lo0",
@@ -143,13 +157,18 @@ describe Ohai::System, "Network Plugin" do
             "number" => "0",
             "flags" => ["LEARNING", "DISCOVER", "AUTOEDGE", "AUTOPTP"],
             "addresses" => {
-              "02:20:6f:d2:c4:00" => {"family"=>"lladdr"},
+              "02:20:6f:d2:c4:00" => {
+                "family"=>"lladdr"
+              },
               "192.168.2.1" => {
                 "family" => "inet",
                 "netmask" => "255.255.255.0",
                 "broadcast" => "192.168.2.255"
               },
-              "2001:470:d:cb4::1" => {"family" => "inet6", "prefixlen" => "64"},
+              "2001:470:d:cb4::1" => {
+                "family" => "inet6",
+                "prefixlen" => "64"
+              },
               "fe80::cafe:babe:dead:beef" => {
                 "family" => "inet6",
                 "zoneid" => "bridge0",
@@ -183,12 +202,14 @@ describe Ohai::System, "Network Plugin" do
           }
         },
         "default_gateway" => "76.91.0.1",
-        "default_interface" => "vr0"
+        "default_interface" => "vr0",
+        "default_inet6_gateway" => "2001:470:d:cb4::2",
+        "default_inet6_interface" => "bridge0"
       }
     },
     "linux" => {
       "network" => {
-        # pp Hash[node['network']] from  shef to get the network data
+        # pp Hash[node['network']] from chef-shell to get the network data
         # have just removed the neighbour and route entries by hand
         "interfaces" => {
           "lo" => {
@@ -207,7 +228,8 @@ describe Ohai::System, "Network Plugin" do
               }
             },
             "mtu" => "16436",
-            "encapsulation" => "Loopback"
+            "encapsulation" => "Loopback",
+            "state" => "unknown"
           },
           "eth0" => {
             "flags" => ["BROADCAST", "MULTICAST", "UP"],
@@ -218,7 +240,9 @@ describe Ohai::System, "Network Plugin" do
                 "prefixlen" => "64",
                 "family" => "inet6"
               },
-              "00:16:3E:2F:36:79" => {"family" => "lladdr"},
+              "00:16:3E:2F:36:79" => {
+                "family" => "lladdr"
+              },
               "192.168.66.33" => {
                 "scope" => "Global",
                 "netmask" => "255.255.255.0",
@@ -229,7 +253,8 @@ describe Ohai::System, "Network Plugin" do
               "3ffe:1111:2222::33" => {
                 "prefixlen" => "48",
                 "family" => "inet6",
-                "scope" => "Global"
+                "scope" => "Global",
+                "state" => "up"
               }
             },
             "mtu" => "1500",
@@ -245,7 +270,9 @@ describe Ohai::System, "Network Plugin" do
                 "prefixlen" => "64",
                 "family" => "inet6"
               },
-              "00:16:3E:2F:36:80" => {"family" => "lladdr"},
+              "00:16:3E:2F:36:80" => {
+                "family" => "lladdr"
+              },
               "192.168.99.11" => {
                 "scope" => "Global",
                 "netmask" => "255.255.255.0",
@@ -301,14 +328,14 @@ describe Ohai::System, "Network Plugin" do
     }
   }
 
-  describe "with linux" do
+  describe "on linux" do
     before(:each) do
       @plugin = get_plugin("network")
       @plugin["network"] = basic_data["linux"]["network"]
     end
 
     describe "when the linux::network plugin hasn't set any of {ip,ip6,mac}address attributes" do
-      describe "simple setup" do
+      describe "simple network setup" do
         it_populates_ipaddress_attributes
 
         it "detects {ip,ip6,mac}address" do
@@ -363,10 +390,9 @@ describe Ohai::System, "Network Plugin" do
             expect(@plugin["ip6address"]).to eq("3ffe:1111:3333::1")
           end
 
-          it "doesn't set macaddress, ipv4 setup is valid and has precedence over ipv6" do
-            expect(Ohai::Log).not_to receive(:warn).with(/^unable to detect macaddress/)
+          it "sets macaddress to the ipv6 interface because it hadn't set one for ipv4 first" do
             @plugin.run
-            expect(@plugin["macaddress"]).to be_nil
+            expect(@plugin["macaddress"]).to eq("00:16:3E:2F:36:80")
           end
 
           it "informs about this setup" do
@@ -393,10 +419,11 @@ describe Ohai::System, "Network Plugin" do
             expect(@plugin["macaddress"]).to eq("00:16:3E:2F:36:80")
             expect(@plugin["ip6address"]).to eq("3ffe:1111:3333::1")
           end
-          
+
           it "warns about this conflict" do
             expect(Ohai::Log).to receive(:debug).with(/^\[inet\] no ipaddress\/mask on eth1/).once
             expect(Ohai::Log).to receive(:debug).with(/^\[inet6\] no ipaddress\/mask on eth1/).once
+            allow(Ohai::Log).to receive(:debug)
             @plugin.run
           end
         end
@@ -434,9 +461,9 @@ describe Ohai::System, "Network Plugin" do
 
           it "warns about this conflict" do
             expect(Ohai::Log).to receive(:warn).with(/^unable to detect ipaddress/).once
-            expect(Ohai::Log).to receive(:warn).with(/^unable to detect macaddress/).once
             expect(Ohai::Log).to receive(:warn).with(/^\[inet\] no ip address on eth0/).once
             expect(Ohai::Log).to receive(:debug).with(/^unable to detect ip6address/).once
+            expect(Ohai::Log).to receive(:debug).with(/^unable to detect macaddress/).twice # for each family
             expect(Ohai::Log).to receive(:warn).with(/^\[inet6\] no ip address on eth0/).once
             @plugin.run
           end
@@ -465,7 +492,7 @@ describe Ohai::System, "Network Plugin" do
 
           it "should warn about it" do
             expect(Ohai::Log).to receive(:warn).with(/^unable to detect ipaddress/).once
-            expect(Ohai::Log).to receive(:warn).with(/^unable to detect macaddress/).once
+            expect(Ohai::Log).to receive(:debug).with(/^unable to detect macaddress/).twice # for each family
             expect(Ohai::Log).to receive(:debug).with(/^unable to detect ip6address/).once
             @plugin.run
           end
@@ -769,7 +796,9 @@ describe Ohai::System, "Network Plugin" do
 
         it "warns about not being able to set {ip,mac}address (ipv4)" do
           expect(Ohai::Log).to receive(:warn).with(/^unable to detect ipaddress/).once
-          expect(Ohai::Log).to receive(:warn).with(/^unable to detect macaddress/).once
+          expect(Ohai::Log).to receive(:debug).with(/^unable to detect macaddress/) # for ipv4
+          expect(Ohai::Log).to receive(:debug).with(/^setting macaddress to/) # for ipv6
+          expect(Ohai::Log).to receive(:debug).with(/^\[inet6\] Using default interface eth0 and default gateway/) # for ipv6
           @plugin.run
         end
 
@@ -781,14 +810,46 @@ describe Ohai::System, "Network Plugin" do
         end
 
         it "informs about macaddress being set using the ipv6 setup" do
-          expect(Ohai::Log).to receive(:debug).with(/^macaddress set to 00:16:3E:2F:36:79 from the ipv6 setup/).once
+          expect(Ohai::Log).to receive(:debug).with(/^setting macaddress to '00:16:3E:2F:36:79'/)
           allow(Ohai::Log).to receive(:debug)
           @plugin.run
         end
       end
 
+      describe "ipv6 only with ipv4 loopback" do
+        before do
+          @plugin["network"]["default_gateway"] = nil
+          @plugin["network"]["default_interface"] = nil
+          @plugin["network"]["interfaces"].each do |i,iv|
+            next if i == 'lo'
+            iv["addresses"].delete_if{|k,kv| kv["family"] == "inet" }
+          end
+        end
+
+        it_doesnt_fail
+
+        it "can't detect ipaddress" do
+          allow(Ohai::Log).to receive(:warn)
+          @plugin.run
+          expect(@plugin["ipaddress"]).to eq("127.0.0.1")
+        end
+
+        it "sets {ip6,mac}address" do
+          allow(Ohai::Log).to receive(:warn)
+          @plugin.run
+          expect(@plugin["ip6address"]).to eq("3ffe:1111:2222::33")
+          expect(@plugin["macaddress"]).to eq("00:16:3E:2F:36:79")
+        end
+
+        it "informs about macaddress being set using the ipv6 setup" do
+          expect(Ohai::Log).to receive(:debug).with(/^setting macaddress to '00:16:3E:2F:36:79'/)
+          allow(Ohai::Log).to receive(:debug)
+          @plugin.run
+        end
+      end
     end
 
+    # specs using network plugin data for each mocked OS (freebsd,linux,windows)
     basic_data.keys.sort.each do |os|
       describe "the #{os}::network has already set some of the {ip,mac,ip6}address attributes" do
         before(:each) do
@@ -801,13 +862,16 @@ describe Ohai::System, "Network Plugin" do
             @plugin["macaddress"] = "00:AA:BB:CC:DD:EE"
             @expected_results = {
               "freebsd" => {
-                "ip6address" => "::1"
+                "ip6address" => "2001:470:d:cb4::1",
+                "macaddress" => "02:20:6f:d2:c4:00"
               },
               "linux" => {
-                "ip6address" => "3ffe:1111:2222::33"
+                "ip6address" => "3ffe:1111:2222::33",
+                "macaddress" => "00:16:3E:2F:36:79"
               },
               "windows" => {
-                "ip6address" => "fe80::698d:3e37:7950:b28c"
+                "ip6address" => "fe80::698d:3e37:7950:b28c",
+                "macaddress" => "00:AA:BB:CC:DD:EE"
               }
             }
           end
@@ -870,6 +934,17 @@ describe Ohai::System, "Network Plugin" do
                 end
               end
               @plugin["ip6address"] = "3ffe:8888:9999::1"
+              @expected_results = {
+                "freebsd" => {
+                  "macaddress" => "02:20:6f:d2:c4:00"
+                },
+                "linux" => {
+                  "macaddress" => "00:16:3E:2F:36:79"
+                },
+                "windows" => {
+                  "macaddress" => "52:54:44:66:66:02"
+                }
+              }
             end
 
             it_doesnt_fail
@@ -880,15 +955,14 @@ describe Ohai::System, "Network Plugin" do
               expect(@plugin["ipaddress"]).to be_nil
             end
 
-            it "can't detect macaddress either" do
+            it "takes the macaddress from ipv6" do
               allow(Ohai::Log).to receive(:warn)
               @plugin.run
-              expect(@plugin["macaddress"]).to be_nil
+              expect(@plugin["macaddress"]).to eq(@expected_results[os]["macaddress"])
             end
 
-            it "warns about not being able to set {ip,mac}address" do
+            it "warns about not being able to set ipaddress" do
               expect(Ohai::Log).to receive(:warn).with(/^unable to detect ipaddress/).once
-              expect(Ohai::Log).to receive(:warn).with(/^unable to detect macaddress/).once
               @plugin.run
             end
 
@@ -923,10 +997,10 @@ describe Ohai::System, "Network Plugin" do
 
             it_populates_ipaddress_attributes
 
-            it "detects ipaddress and overwrite macaddress" do
+            it "detects ipaddress and does not overwrite macaddress" do
               @plugin.run
               expect(@plugin["ipaddress"]).to eq(@expected_results[os]["ipaddress"])
-              expect(@plugin["macaddress"]).to eq(@expected_results[os]["macaddress"])
+              expect(@plugin["macaddress"]).to eq(@plugin["macaddress"])
             end
 
             it "doesn't overwrite ip6address" do
@@ -990,10 +1064,9 @@ describe Ohai::System, "Network Plugin" do
 
           it_doesnt_fail
 
-          it "doesn't overwrite {ip,mac,ip6}address" do
+          it "doesn't overwrite {ip,ip6}address" do
             @plugin.run
             expect(@plugin["ipaddress"]).to eq("10.11.12.13")
-            expect(@plugin["macaddress"]).to eq(nil)
             expect(@plugin["ip6address"]).to eq("3ffe:8888:9999::1")
           end
         end