3 files changed, 55 insertions, 4 deletions
diff --git a/nixos/modules/system/activation/activation-script.nix b/nixos/modules/system/activation/activation-script.nix
index dd2ce1894ae6..72dd9b94a94e 100644
--- a/nixos/modules/system/activation/activation-script.nix
+++ b/nixos/modules/system/activation/activation-script.nix
@@ -95,6 +95,18 @@ in
 
     };
 
+    environment.usrbinenv = mkOption {
+      default = "${pkgs.coreutils}/bin/env";
+      example = literalExample ''
+        "''${pkgs.busybox}/bin/env"
+      '';
+      type = types.nullOr types.path;
+      visible = false;
+      description = ''
+        The env(1) executable that is linked system-wide to
+        <literal>/usr/bin/env</literal>.
+      '';
+    };
   };
 
 
@@ -129,11 +141,15 @@ in
         mkdir -m 0555 -p /var/empty
       '';
 
-    system.activationScripts.usrbinenv =
-      ''
+    system.activationScripts.usrbinenv = if config.environment.usrbinenv != null
+      then ''
         mkdir -m 0755 -p /usr/bin
-        ln -sfn ${pkgs.coreutils}/bin/env /usr/bin/.env.tmp
+        ln -sfn ${config.environment.usrbinenv} /usr/bin/.env.tmp
         mv /usr/bin/.env.tmp /usr/bin/env # atomically replace /usr/bin/env
+      ''
+      else ''
+        rm -f /usr/bin/env
+        rmdir --ignore-fail-on-non-empty /usr/bin /usr
       '';
 
     system.activationScripts.tmpfs =
diff --git a/nixos/modules/system/boot/networkd.nix b/nixos/modules/system/boot/networkd.nix
index 34eea9af83b1..ab7485500261 100644
--- a/nixos/modules/system/boot/networkd.nix
+++ b/nixos/modules/system/boot/networkd.nix
@@ -93,11 +93,13 @@ let
 
   checkNetwork = checkUnitConfig "Network" [
     (assertOnlyFields [
-      "Description" "DHCP" "DHCPServer" "IPv4LL" "IPv4LLRoute"
+      "Description" "DHCP" "DHCPServer" "IPForward" "IPMasquerade" "IPv4LL" "IPv4LLRoute"
       "LLMNR" "Domains" "Bridge" "Bond"
     ])
     (assertValueOneOf "DHCP" ["both" "none" "v4" "v6"])
     (assertValueOneOf "DHCPServer" boolValues)
+    (assertValueOneOf "IPForward" ["yes" "no" "ipv4" "ipv6"])
+    (assertValueOneOf "IPMasquerade" boolValues)
     (assertValueOneOf "IPv4LL" boolValues)
     (assertValueOneOf "IPv4LLRoute" boolValues)
     (assertValueOneOf "LLMNR" boolValues)
@@ -129,6 +131,16 @@ let
     (assertValueOneOf "RequestBroadcast" boolValues)
   ];
 
+  checkDhcpServer = checkUnitConfig "DHCPServer" [
+    (assertOnlyFields [
+      "PoolOffset" "PoolSize" "DefaultLeaseTimeSec" "MaxLeaseTimeSec"
+      "EmitDNS" "DNS" "EmitNTP" "NTP" "EmitTimezone" "Timezone"
+    ])
+    (assertValueOneOf "EmitDNS" boolValues)
+    (assertValueOneOf "EmitNTP" boolValues)
+    (assertValueOneOf "EmitTimezone" boolValues)
+  ];
+
   commonNetworkOptions = {
 
     enable = mkOption {
@@ -341,6 +353,18 @@ let
       '';
     };
 
+    dhcpServerConfig = mkOption {
+      default = {};
+      example = { PoolOffset = 50; EmitDNS = false; };
+      type = types.addCheck (types.attrsOf unitOption) checkDhcpServer;
+      description = ''
+        Each attribute in this set specifies an option in the
+        <literal>[DHCPServer]</literal> section of the unit.  See
+        <citerefentry><refentrytitle>systemd.network</refentrytitle>
+        <manvolnum>5</manvolnum></citerefentry> for details.
+      '';
+    };
+
     name = mkOption {
       type = types.nullOr types.str;
       default = null;
@@ -566,6 +590,11 @@ let
             ${attrsToSection def.dhcpConfig}
 
           ''}
+          ${optionalString (def.dhcpServerConfig != { }) ''
+            [DHCPServer]
+            ${attrsToSection def.dhcpServerConfig}
+
+          ''}
           ${flip concatMapStrings def.addresses (x: ''
             [Address]
             ${attrsToSection x.addressConfig}
diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix
index 211e0423216e..c5ee95f4c9a4 100644
--- a/nixos/modules/system/boot/systemd.nix
+++ b/nixos/modules/system/boot/systemd.nix
@@ -61,6 +61,8 @@ let
       "systemd-user-sessions.service"
       "dbus-org.freedesktop.login1.service"
       "dbus-org.freedesktop.machine1.service"
+      "org.freedesktop.login1.busname"
+      "org.freedesktop.machine1.busname"
       "user@.service"
 
       # Journal.
@@ -147,10 +149,14 @@ let
       "systemd-tmpfiles-setup-dev.service"
 
       # Misc.
+      "org.freedesktop.systemd1.busname"
       "systemd-sysctl.service"
       "dbus-org.freedesktop.timedate1.service"
       "dbus-org.freedesktop.locale1.service"
       "dbus-org.freedesktop.hostname1.service"
+      "org.freedesktop.timedate1.busname"
+      "org.freedesktop.locale1.busname"
+      "org.freedesktop.hostname1.busname"
       "systemd-timedated.service"
       "systemd-localed.service"
       "systemd-hostnamed.service"