action/network: Validate IP settings, show human-readable error

lib/vagrant/errors.rb

@@ -452,6 +452,10 @@ class NetworkDHCPAlreadyAttached < VagrantError
       error_key(:dhcp_already_attached, "vagrant.actions.vm.network")
     end
 
+    class NetworkInvalidAddress < VagrantError
+      error_key(:network_invalid_address)
+    end
+
     class NetworkNotFound < VagrantError
       error_key(:not_found, "vagrant.actions.vm.host_only_network")
     end

plugins/providers/virtualbox/action/network.rb

@@ -258,13 +258,27 @@ def hostonly_config(options)
           # Default IP is in the 20-bit private network block for DHCP based networks
           options[:ip] = "172.28.128.1" if options[:type] == :dhcp && !options[:ip]
 
-          ip = IPAddr.new(options[:ip])
-          if ip.ipv4?
-            options[:netmask] ||= "255.255.255.0"
+          begin
+            ip = IPAddr.new(options[:ip])
+            if ip.ipv4?
+              options[:netmask] ||= "255.255.255.0"
+            elsif ip.ipv6?
+              options[:netmask] ||= 64
+
+              # 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::NetworkInvalidAddress,
+                  options: options, error: e.message
+          end
 
+          if ip.ipv4?
             # Verify that a host-only network subnet would not collide
             # with a bridged networking interface.
             #
@@ -273,24 +287,16 @@ def hostonly_config(options)
             # traffic onto the real interface rather than the VirtualBox
             # interface.
             @env[:machine].provider.driver.read_bridged_interfaces.each do |interface|
-              that_netaddr = network_address(interface[:ip], interface[:netmask])
-              raise Vagrant::Errors::NetworkCollision if \
-                netaddr == that_netaddr && interface[:status] != "Down"
+              next if interface[:status] == "Down"
+              that_netaddr = IPAddr.new("#{interface[:ip]}/#{interface[:netmask]}")
+              raise Vagrant::Errors::NetworkCollision if netaddr.include? that_netaddr
             end
-          elsif ip.ipv6?
-            # Default subnet prefix length
-            options[:netmask] ||= 64
-
-            # 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 group appended by 1. Usually it is "x.x.x.1" for IPv4 and
           # "<prefix>::1" for IPv6
-          options[:adapter_ip] ||= (ip.mask(options[:netmask]) | 1).to_s
+          options[:adapter_ip] ||= (netaddr | 1).to_s
 
           dhcp_options = {}
           if options[:type] == :dhcp
@@ -299,7 +305,7 @@ def hostonly_config(options)
             # dhcp_ip: "192.168.22.66",
             # dhcp_lower: "192.168.22.67"
             # dhcp_upper: "192.168.22.126"
-            ip_range = ip.mask(options[:netmask]).to_range
+            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

templates/locales/en.yml

@@ -880,6 +880,11 @@ en:
         If the problem persists, please report a bug to the net-ssh project.
 
         %{message}
+      network_invalid_address: |-
+        Network settings specified in your Vagrantfile are invalid:
+
+        Network settings: %{options}
+        Error: %{error}
       network_type_not_supported: |-
         The %{type} network type is not supported for this box or guest.
       network_manager_not_installed: |-

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

@@ -167,4 +167,22 @@
       end
     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::NetworkInvalidAddress)
+      end
+    end
+  end
 end