Revert "Merge pull request #3182 from wkennington/master.ipv6"

This reverts commit b23fd6585481a42937e105d5fce630a549900e86, reversing
changes made to 43654cba2c280ce17b81db44993d1c1bcae3a9c6.

nixos/doc/manual/configuration/ipv4-config.xml

···
 follows:
 
 <programlisting>
-networking.interfaces.eth0.ip4 = [ { address = "192.168.1.2"; prefixLength = 24; } ];
+networking.interfaces.eth0 = { ipAddress = "192.168.1.2"; prefixLength = 24; };
 </programlisting>
 
+(The network prefix can also be specified using the option
+<literal>subnetMask</literal>,
+e.g. <literal>"255.255.255.0"</literal>, but this is deprecated.)
 Typically you’ll also want to set a default gateway and set of name
 servers:
 

nixos/lib/build-vms.nix

···
             let
               interfacesNumbered = zipTwoLists config.virtualisation.vlans (range 1 255);
               interfaces = flip map interfacesNumbered ({ first, second }:
-                nameValuePair "eth${toString second}" { ip4 =
-                  [ { address = "192.168.${toString first}.${toString m.second}";
-                      prefixLength = 24;
-                  } ];
-                }
+                nameValuePair "eth${toString second}"
+                  { ipAddress = "192.168.${toString first}.${toString m.second}";
+                    subnetMask = "255.255.255.0";
+                  });
             in
             { key = "ip-address";
               config =
···
                   networking.interfaces = listToAttrs interfaces;
 
                   networking.primaryIPAddress =
-                    optionalString (interfaces != []) (head (head interfaces).value.ip4).address;
+                    optionalString (interfaces != []) (head interfaces).value.ipAddress;
 
                   # Put the IP addresses of all VMs in this machine's
                   # /etc/hosts file.  If a machine has multiple

nixos/modules/programs/virtualbox.nix

···
         '';
     };
 
-  networking.interfaces.vboxnet0.ip4 = [ { address = "192.168.56.1"; prefixLength = 24; } ];
+  networking.interfaces.vboxnet0 = { ipAddress = "192.168.56.1"; prefixLength = 24; };
 }

nixos/modules/services/networking/dhcpcd.nix

···
   # Don't start dhcpcd on explicitly configured interfaces or on
   # interfaces that are part of a bridge, bond or sit device.
   ignoredInterfaces =
-    map (i: i.name) (filter (i: i.ip4 != [ ] || i.ipAddress != null) (attrValues config.networking.interfaces))
+    map (i: i.name) (filter (i: i.ipAddress != null) (attrValues config.networking.interfaces))
     ++ mapAttrsToList (i: _: i) config.networking.sits
     ++ concatLists (attrValues (mapAttrs (n: v: v.interfaces) config.networking.bridges))
     ++ concatLists (attrValues (mapAttrs (n: v: v.interfaces) config.networking.bonds))

nixos/modules/tasks/network-interfaces.nix

···
   hasSits = cfg.sits != { };
   hasBonds = cfg.bonds != { };
 
-  addrOpts = v:
-    assert v == 4 || v == 6;
-    {
-      address = mkOption {
-        type = types.str;
-        description = ''
-          IPv${toString v} address of the interface.  Leave empty to configure the
-          interface using DHCP.
-        '';
-      };
-
-      prefixLength = mkOption {
-        type = types.addCheck types.int (n: n >= 0 && n <= (if v == 4 then 32 else 128));
-        description = ''
-          Subnet mask of the interface, specified as the number of
-          bits in the prefix (<literal>${if v == 4 then "24" else "64"}</literal>).
-        '';
-      };
-    };
-
   interfaceOpts = { name, ... }: {
 
     options = {
···
         description = "Name of the interface.";
       };
 
-      ip4 = mkOption {
-        default = [ ];
-        example = [
-          { address = "10.0.0.1"; prefixLength = 16; }
-          { address = "192.168.1.1"; prefixLength = 24; }
-        ];
-        type = types.listOf types.optionSet;
-        options = addrOpts 4;
-        description = ''
-          List of IPv4 addresses that will be statically assigned to the interface.
-        '';
-      };
-
-      ip6 = mkOption {
-        default = [ ];
-        example = [
-          { address = "fdfd:b3f0:482::1"; prefixLength = 48; }
-          { address = "2001:1470:fffd:2098::e006"; prefixLength = 64; }
-        ];
-        type = types.listOf types.optionSet;
-        options = addrOpts 6;
-        description = ''
-          List of IPv6 addresses that will be statically assigned to the interface.
-        '';
-      };
-
       ipAddress = mkOption {
         default = null;
         example = "10.0.0.1";
-        type = types.nullOr types.str;
+        type = types.nullOr (types.str);
         description = ''
           IP address of the interface.  Leave empty to configure the
           interface using DHCP.
···
       };
 
       subnetMask = mkOption {
-        default = null;
+        default = "";
+        example = "255.255.255.0";
+        type = types.str;
         description = ''
-          Defunct, supply the prefix length instead.
+          Subnet mask of the interface, specified as a bitmask.
+          This is deprecated; use <option>prefixLength</option>
+          instead.
         '';
       };
 
       ipv6Address = mkOption {
         default = null;
         example = "2001:1470:fffd:2098::e006";
-        type = types.nullOr types.str;
+        type = types.nullOr types.string;
         description = ''
           IPv6 address of the interface.  Leave empty to configure the
           interface using NDP.
···
     networking.interfaces = mkOption {
       default = {};
       example =
-        { eth0.ip4 = [ {
-            address = "131.211.84.78";
-            prefixLength = 25;
-          } ];
+        { eth0 = {
+            ipAddress = "131.211.84.78";
+            subnetMask = "255.255.255.128";
+          };
         };
       description = ''
         The configuration for each network interface.  If
···
 
   config = {
 
-    assertions =
-      flip map interfaces (i: {
-        assertion = i.subnetMask == null;
-        message = "The networking.interfaces.${i.name}.subnetMask option is defunct. Use prefixLength instead.";
-      });
-
     boot.kernelModules = [ ]
       ++ optional cfg.enableIPv6 "ipv6"
       ++ optional hasVirtuals "tun"
···
         # network device, so it only gets started after the interface
         # has appeared, and it's stopped when the interface
         # disappears.
-        configureInterface = i:
-          let
-            ips = i.ip4 ++ optionals cfg.enableIPv6 i.ip6
-              ++ optional (i.ipAddress != null) {
-                ipAddress = i.ipAddress;
-                prefixLength = i.prefixLength;
-              } ++ optional (cfg.enableIPv6 && i.ipv6Address != null) {
-                ipAddress = i.ipv6Address;
-                prefixLength = i.ipv6PrefixLength;
-              };
+        configureInterface = i: nameValuePair "${i.name}-cfg"
+          (let mask =
+                if i.prefixLength != null then toString i.prefixLength else
+                if i.subnetMask != "" then i.subnetMask else "32";
+               staticIPv6 = cfg.enableIPv6 && i.ipv6Address != null;
           in
-          nameValuePair "${i.name}-cfg"
           { description = "Configuration of ${i.name}";
             wantedBy = [ "network-interfaces.target" ];
             bindsTo = [ "sys-subsystem-net-devices-${i.name}.device" ];
···
                   echo "setting MTU to ${toString i.mtu}..."
                   ip link set "${i.name}" mtu "${toString i.mtu}"
                 ''
-
-              # Ip Setup
-              +
+              + optionalString (i.ipAddress != null)
                 ''
-                  curIps=$(ip -o a show dev "${i.name}" | awk '{print $4}')
-                  # Only do an add if it's necessary.  This is
+                  cur=$(ip -4 -o a show dev "${i.name}" | awk '{print $4}')
+                  # Only do a flush/add if it's necessary.  This is
                   # useful when the Nix store is accessed via this
                   # interface (e.g. in a QEMU VM test).
+                  if [ "$cur" != "${i.ipAddress}/${mask}" ]; then
+                    echo "configuring interface..."
+                    ip -4 addr flush dev "${i.name}"
+                    ip -4 addr add "${i.ipAddress}/${mask}" dev "${i.name}"
+                    restart_network_setup=true
+                  else
+                    echo "skipping configuring interface"
+                  fi
                 ''
-              + flip concatMapStrings (ips) (ip:
-                let
-                  address = "${ip.address}/${toString ip.prefixLength}";
-                in
+              + optionalString (staticIPv6)
                 ''
-                  echo "checking ip ${address}..."
-                  if ! echo "$curIps" | grep "${address}" >/dev/null 2>&1; then
-                    if out=$(ip addr add "${address}" dev "${i.name}" 2>&1); then
-                      echo "added ip ${address}..."
-                      restart_network_setup=true
-                    elif ! echo "$out" | grep "File exists" >/dev/null 2>&1; then
-                      echo "failed to add ${address}"
-                      exit 1
-                    fi
+                  # Only do a flush/add if it's necessary.  This is
+                  # useful when the Nix store is accessed via this
+                  # interface (e.g. in a QEMU VM test).
+                  if ! ip -6 -o a show dev "${i.name}" | grep "${i.ipv6Address}/${toString i.ipv6prefixLength}"; then
+                    echo "configuring interface..."
+                    ip -6 addr flush dev "${i.name}"
+                    ip -6 addr add "${i.ipv6Address}/${toString i.ipv6prefixLength}" dev "${i.name}"
+                    restart_network_setup=true
+                  else
+                    echo "skipping configuring interface"
                   fi
-                '')
-              + optionalString (ips != [ ])
+                ''
+              + optionalString (i.ipAddress != null || staticIPv6)
                 ''
                   if [ restart_network_setup = true ]; then
                     # Ensure that the default gateway remains set.
···
                 ''
                   echo 1 > /proc/sys/net/ipv6/conf/${i.name}/proxy_ndp
                 '';
-            preStop =
-              ''
-                echo "releasing configured ip's..."
-              ''
-              + flip concatMapStrings (ips) (ip:
-                let
-                  address = "${ip.address}/${toString ip.prefixLength}";
-                in
-                ''
-                  echo -n "Deleting ${address}..."
-                  ip addr del "${address}" dev "${i.name}" >/dev/null 2>&1 || echo -n " Failed"
-                  echo ""
-                '');
-          };
+          });
 
         createTunDevice = i: nameValuePair "${i.name}"
           { description = "Virtual Network Interface ${i.name}";

nixos/tests/bittorrent.nix

···
   miniupnpdConf = nodes: pkgs.writeText "miniupnpd.conf"
     ''
       ext_ifname=eth1
-      listening_ip=${(head nodes.router.config.networking.interfaces.eth2.ip4).address}/24
+      listening_ip=${nodes.router.config.networking.interfaces.eth2.ipAddress}/24
       allow 1024-65535 192.168.2.0/24 1024-65535
     '';
 
···
         { environment.systemPackages = [ pkgs.transmission ];
           virtualisation.vlans = [ 2 ];
           networking.defaultGateway =
-            (head nodes.router.config.networking.interfaces.eth2.ip4).address;
+            nodes.router.config.networking.interfaces.eth2.ipAddress;
           networking.firewall.enable = false;
         };
 
···
       # Create the torrent.
       $tracker->succeed("mkdir /tmp/data");
       $tracker->succeed("cp ${file} /tmp/data/test.tar.bz2");
-      $tracker->succeed("transmission-create /tmp/data/test.tar.bz2 -t http://${(head nodes.tracker.config.networking.interfaces.eth1.ip4).address}:6969/announce -o /tmp/test.torrent");
+      $tracker->succeed("transmission-create /tmp/data/test.tar.bz2 -t http://${nodes.tracker.config.networking.interfaces.eth1.ipAddress}:6969/announce -o /tmp/test.torrent");
       $tracker->succeed("chmod 644 /tmp/test.torrent");
 
       # Start the tracker.  !!! use a less crappy tracker

nixos/tests/nat.nix

···
         { virtualisation.vlans = [ 1 ];
           networking.firewall.allowPing = true;
           networking.defaultGateway =
-            (head nodes.router.config.networking.interfaces.eth2.ip4).address;
+            nodes.router.config.networking.interfaces.eth2.ipAddress;
         };
 
       router =