WIP: network module

nixos/modules/network.nix

@@ -0,0 +1,79 @@
+{ config, pkgs, lib, ... }:
+with lib;
+let
+  ipv4Regex =
+    let
+      compRegex = "(25[0-5]|(2[0-4]|10|1?[1-9])?[0-9])";
+    in
+    "(${compRegex}\\.){3}${compRegex}";
+
+  cidr4Regex = "${ipv4Regex}/(3[0-2]|[1-2]?[0-9])";
+in
+{
+  options = {
+    startOnBoot = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Whether to start this network on boot regardless if a VM is needing this network.";
+    };
+
+    namespace = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = "Linux network namespace under which this network is created. If not declared, it will create under hosts network namespace.";
+    };
+
+    type = mkOption {
+      type =types.enum [ "user" "nat" "natWANOnly" "routed" "routedWANOnly" "isolated" "bridge" ];
+      description = ''
+        Network types.
+        - "user" is qemu slirp user network, which can be shared across multiple VMs if needed
+        - "nat" is a NAT with an internal network, with a DHCP/DNS server, a domainsearch name and masqueraded access to the host's network
+        - "natWANOnly" just like nat but no access to the host itself, or other networks on the host, while allowing WAN access through the hosts default gateway
+        - "routed" is an internal network, with a DHCP/DNS server, a domainsearch name and routed inbound and outbound access to the host's network
+        - "routedWANOnly" just like routed, but no access to the host itself, or other networks on the host, while allowing WAN inbound and outbound access through the hosts default gateway
+        - "isolated" creates an internal network, a DHCP/DNS server, a domainsearch name with no access to host's network or WAN
+        - "bridge" is a bridge with another network or a host's network interface
+      '';
+    };
+
+    ipv4Range = mkOption {
+      type = types.strMatching cidr4Regex;
+      description = "IPv4 Range in x.x.x.x/y format to be assigned to the network.";
+    };
+
+    dhcp.enable = mkOption {
+      type = types.bool;
+      default = true;
+      description = "Whether to start a DHCP server within this network.";
+    };
+
+    dhcp.startAddress = mkOption {
+      type = types.strMatching ipv4Regex;
+      description = "Starting IP Address for DHCP clients.";
+    };
+
+    dhcp.endAddress = mkOption {
+      type = types.strMatching ipv4Regex;
+      description = "Ending IP Address for DHCP clients.";
+    };
+
+    dns.upstream = mkOption {
+      type = types.listOf (types.strMatching ipv4Regex);
+      default = [];
+      description = "List of IP Addresses of DNS servers to use as upstream DNS servers in the DHCP/DNS server. If left empty, it will use host's DNS servers";
+    };
+
+    dns.zonefiles = mkOption {
+      description = "Additional zonefiles to add for the DNS server";
+    };
+
+    routes.internal.add = mkOption {
+      description = "Additional routes to add on the internal network";
+    };
+
+    routes.host.add = mkOption {
+      description = "Addtional routes to add on the host's network namespace";
+    };
+  };
+}