provider/virtualbox: Refactor host-only network settings

plugins/providers/virtualbox/action/network.rb

@@ -261,16 +261,26 @@ def hostonly_config(options)
 
           begin
             ip = IPAddr.new(options[:ip])
-          rescue IPAddr::InvalidAddressError => e
-            raise Vagrant::Errors::NetworkAddressInvalid, :ip => options[:ip], :error_msg => e.message
-          end
+            if ip.ipv4?
+              options[:netmask] ||= "255.255.255.0"
+            elsif ip.ipv6?
+              options[:netmask] ||= 64
 
-          if ip.ipv4?
-            options[:netmask] ||= "255.255.255.0"
+              # Append a 6 to the end of the type
+              options[:type] = "#{options[:type]}6".to_sym
+            else
+              raise IPAddr::AddressFamilyError, 'unknown address family'
+            end
 
             # Calculate our network address for the given IP/netmask
-            netaddr  = network_address(options[:ip], options[:netmask])
+            netaddr = IPAddr.new("#{options[:ip]}/#{options[:netmask]}")
+          rescue IPAddr::Error => e
+            raise Vagrant::Errors::NetworkAddressInvalid,
+              address: options[:ip], mask: options[:netmask],
+              error: e.message
+          end
 
+          if ip.ipv4?
             # Verify that a host-only network subnet would not collide
             # with a bridged networking interface.
             #
@@ -287,44 +297,24 @@ def hostonly_config(options)
                   interface_name: interface[:name]
               end
             end
-
-            # Split the IP address into its components
-            ip_parts = netaddr.split(".").map { |i| i.to_i }
-
-            # Calculate the adapter IP, which we assume is the IP ".1" at
-            # the end usually.
-            adapter_ip    = ip_parts.dup
-            adapter_ip[3] += 1
-            options[:adapter_ip] ||= adapter_ip.join(".")
-          elsif ip.ipv6?
-            # Default subnet prefix length
-            options[:netmask] ||= 64
-
-            # Set adapter IP to <prefix>::1
-            options[:adapter_ip] ||= (ip.mask(options[:netmask].to_i) | 1).to_s
-
-            # Append a 6 to the end of the type
-            options[:type] = "#{options[:type]}6".to_sym
-          else
-            raise "BUG: Unknown IP type: #{ip.inspect}"
           end
 
+          # Calculate the adapter IP which is the network address with
+          # the final bit + 1. Usually it is "x.x.x.1" for IPv4 and
+          # "<prefix>::1" for IPv6
+          options[:adapter_ip] ||= (netaddr | 1).to_s
+
           dhcp_options = {}
           if options[:type] == :dhcp
-            # Calculate the DHCP server IP, which is the network address
-            # with the final octet + 2. So "172.28.0.0" turns into "172.28.0.2"
-            dhcp_ip    = ip_parts.dup
-            dhcp_ip[3] += 2
-            dhcp_options[:dhcp_ip] = options[:dhcp_ip] || dhcp_ip.join(".")
-
-            # Calculate the lower and upper bound for the DHCP server
-            dhcp_lower    = ip_parts.dup
-            dhcp_lower[3] += 3
-            dhcp_options[:dhcp_lower] = options[:dhcp_lower] || dhcp_lower.join(".")
-
-            dhcp_upper    = ip_parts.dup
-            dhcp_upper[3] = 254
-            dhcp_options[:dhcp_upper] = options[:dhcp_upper] || dhcp_upper.join(".")
+            # Calculate the DHCP server IP and lower & upper bound
+            # Example: for "192.168.22.64/26" network range those are:
+            # dhcp_ip: "192.168.22.66",
+            # dhcp_lower: "192.168.22.67"
+            # dhcp_upper: "192.168.22.126"
+            ip_range = netaddr.to_range
+            dhcp_options[:dhcp_ip] = options[:dhcp_ip] || (ip_range.first | 2).to_s
+            dhcp_options[:dhcp_lower] = options[:dhcp_lower] || (ip_range.first | 3).to_s
+            dhcp_options[:dhcp_upper] = options[:dhcp_upper] || (ip_range.last(2).first).to_s
           end
 
           return {

templates/locales/en.yml

@@ -972,10 +972,13 @@ en:
       network_type_not_supported: |-
         The %{type} network type is not supported for this box or guest.
       network_address_invalid: |-
-        The IP address '%{ip}' is not valid. Please review the error message
-        below to help resolve the issue:
+        Network settings specified in your Vagrantfile define an invalid
+        IP address. Please review the error message below and update your
+        Vagrantfile network settings:
 
-          %{error_msg}
+          Address: %{address}
+          Netmask: %{mask}
+          Error: %{error}
       network_manager_not_installed: |-
         Vagrant was instructed to configure the %{device} network device to
         be managed by NetworkManager. However, the configured guest VM does

test/unit/plugins/providers/virtualbox/action/network_test.rb

@@ -182,6 +182,24 @@
     end
   end
 
+  context 'with invalid settings' do
+    [
+      { ip: 'foo'},
+      { ip: '1.2.3'},
+      { ip: 'dead::beef::'},
+      { ip: '172.28.128.3', netmask: 64},
+      { ip: '172.28.128.3', netmask: 'ffff:ffff::'},
+      { ip: 'dead:beef::', netmask: 'foo:bar::'},
+      { ip: 'dead:beef::', netmask: '255.255.255.0'}
+    ].each do |args|
+      it 'raises an exception' do
+        machine.config.vm.network 'private_network', **args
+        expect { subject.call(env) }.
+          to raise_error(Vagrant::Errors::NetworkAddressInvalid)
+      end
+    end
+  end
+
   describe "#hostonly_find_matching_network" do
     let(:ip){ "192.168.55.2" }
     let(:config){ {ip: ip, netmask: "255.255.255.0"} }