Add an IpHelper utility module

2 files changed, 180 insertions, 0 deletions

diff --git a/lib/ohai/util/ip_helper.rb b/lib/ohai/util/ip_helper.rb
new file mode 100644
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+++ b/lib/ohai/util/ip_helper.rb
@@ -0,0 +1,52 @@
+#
+# Author:: Stafford Brunk (<stafford.brunk@gmail.com>)
+# 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.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+module Ohai
+  module Util
+    module IpHelper
+      # Corresponding to RFC 4193
+      IPV6_PRIVATE_ADDRESS_BLOCK = IPAddress('fc00::/7')
+
+      def private_address?(addr)
+        ip = IPAddress(addr)
+
+        if ip.respond_to? :private?
+          ip.private?
+        else
+          IPV6_PRIVATE_ADDRESS_BLOCK.include?(ip)
+        end
+      end
+      alias :unique_local_address? :private_address?
+
+      def public_address?(addr)
+        !private_address?(addr)
+      end
+
+      # The ipaddress gem doesn't implement loopback?
+      # for IPv4 addresses
+      # https://github.com/bluemonk/ipaddress/issues/25
+      def loopback?(addr)
+        ip = IPAddress(addr)
+
+        if ip.respond_to? :loopback?
+          ip.loopback?
+        else
+          IPAddress('127.0.0.0/8').include? ip
+        end
+      end
+    end
+  end
+end
diff --git a/spec/unit/util/ip_helper_spec.rb b/spec/unit/util/ip_helper_spec.rb
new file mode 100644
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+++ b/spec/unit/util/ip_helper_spec.rb
@@ -0,0 +1,128 @@
+#
+# Author:: Stafford Brunk (<stafford.brunk@gmail.com>)
+# 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.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require 'ipaddress'
+require 'spec_helper'
+require 'ohai/util/ip_helper'
+
+class IpHelperMock
+  include Ohai::Util::IpHelper
+end
+
+describe "Ohai::Util::IpHelper" do
+  let(:ip_helper) { IpHelperMock.new }
+
+  shared_examples 'ip address types' do
+    context 'with an IPv4 address' do
+      context 'that is private' do
+        let(:address) { '10.128.142.89' }
+
+        it 'identifies the address as private' do
+          expect(ip_helper.private_address?(address)).to be_truthy
+        end
+      end
+
+      context 'that is public' do
+        let(:address) { '74.125.224.72' }
+
+        it 'identifies the address as public' do
+          expect(ip_helper.private_address?(address)).to be_falsey
+        end
+      end
+    end
+
+    context 'with an IPv6 address' do
+      context 'that is an RFC 4193 unique local address' do
+        let(:address) { 'fdf8:f53b:82e4::53' }
+
+        it 'identifies the address as a unique local address' do
+          expect(ip_helper.private_address?(address)).to be_truthy
+        end
+      end
+
+      context 'that is a non RFC 4193 unique local address' do
+        let(:address) { 'FE80::0202:B3FF:FE1E:8329' }
+
+        it 'does not identify the address as a unique local address' do
+          expect(ip_helper.private_address?(address)).to be_falsey
+        end
+      end
+    end
+  end
+
+  describe 'private_address?' do
+    include_examples 'ip address types'
+  end 
+
+  describe 'unique_local_address?' do
+    include_examples 'ip address types'
+  end
+
+  describe 'public_address?' do
+    let(:address) { '10.128.142.89' }
+
+    before do
+      allow(ip_helper).to receive(:private_address?)
+    end
+
+    it 'should call #private_address?' do
+      expect(ip_helper).to receive(:private_address?)
+      ip_helper.public_address?(address)
+    end
+
+    it 'should return the inverse of #private_address?' do
+      expect(ip_helper.public_address?(address)).to equal !ip_helper.private_address?(address)
+    end
+  end
+
+  describe 'loopback?' do
+    context 'with an IPv4 address' do
+      context 'that is a loopback address' do
+        let(:address) { '127.0.0.1' }
+
+        it 'should identify the address as a loopback address' do
+          expect(ip_helper.loopback?(address)).to be_truthy
+        end
+      end
+
+      context 'that is not a loopback address' do
+        let(:address) { '1.2.3.4' }
+
+        it 'should not identify the address as a loopback address' do
+          expect(ip_helper.loopback?(address)).to be_falsey
+        end
+      end
+    end
+
+    context 'with an IPv6 address' do
+      context 'that is a loopback address' do
+        let(:address) { '0:0:0:0:0:0:0:1' }
+
+        it 'should identify the address as a loopback address' do
+          expect(ip_helper.loopback?(address)).to be_truthy
+        end
+      end
+
+      context 'that is not a loopback address' do
+        let(:address) { '2400:6180:0000:00D0:0000:0000:0009:7001' }
+
+        it 'should not identify the address as a loopback address' do
+          expect(ip_helper.loopback?(address)).to be_falsey
+        end
+      end
+    end
+  end
+end