(FACT-3171) Fix Link-local unicast range

RFC4291 define the Link-local unicast range as fe80::/10, not fe80::/16.
As a consequence some Link-local unicast addresses where not correctly
filtered, e.g. fe87::.

While here, add a "working" example with an actual global IPv6 address
from the 2001:0DB8::/32 range reserved for documentation (RFC3849).

Author: smortex

lib/facter/util/resolvers/networking/networking.rb

@@ -65,7 +65,7 @@ def find_valid_binding(bindings)
           end
 
           IPV4_LINK_LOCAL_ADDR = IPAddr.new('169.254.0.0/16').freeze # RFC5735
-          IPV6_LINK_LOCAL_ADDR = IPAddr.new('fe80::/16').freeze # RFC4291
+          IPV6_LINK_LOCAL_ADDR = IPAddr.new('fe80::/10').freeze # RFC4291
 
           def ignored_ip_address(addr)
             return true if addr.empty?

spec/facter/util/resolvers/networking/networking_spec.rb

@@ -233,7 +233,7 @@
       expect(networking_facts).to include(expected)
     end
 
-    context 'when there is a global ip address' do
+    context 'when there is a link-local ip address' do
       let(:networking_facts) do
         {
           interfaces:
@@ -251,10 +251,40 @@
 
       it 'expands the correct binding' do
         expected = {
-          ip6: 'fe87::1',
+          ip6: '::1',
+          netmask6: 'ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff',
+          network6: '::1',
+          scope6: 'host'
+        }
+
+        networking_helper.expand_main_bindings(networking_facts)
+
+        expect(networking_facts[:interfaces]['lo0']).to include(expected)
+      end
+    end
+
+    context 'when there is a global ip address' do
+      let(:networking_facts) do
+        {
+          interfaces:
+            { 'lo0' =>
+              { mtu: 16_384,
+                bindings6:
+                  [{ address: '::1',
+                     netmask: 'ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff',
+                     network: '::1' },
+                   { address: '2001:0DB8::1',
+                     netmask: 'ffff:ffff:ffff:ffff::',
+                     network: '2001:0DB8::' }] } }
+        }
+      end
+
+      it 'expands the correct binding' do
+        expected = {
+          ip6: '2001:0DB8::1',
           netmask6: 'ffff:ffff:ffff:ffff::',
-          network6: 'fe87::',
-          scope6: 'link'
+          network6: '2001:0DB8::',
+          scope6: 'global'
         }
 
         networking_helper.expand_main_bindings(networking_facts)