{ config, lib, pkgs, ... }: with lib; let cfg = config.networking; interfaces = attrValues cfg.interfaces; hasVirtuals = any (i: i.virtual) interfaces; hasBonds = cfg.bonds != { }; interfaceOpts = { name, ... }: { options = { name = mkOption { example = "eth0"; type = types.str; description = "Name of the interface."; }; ipAddress = mkOption { default = null; example = "10.0.0.1"; type = types.nullOr (types.str); description = '' IP address of the interface. Leave empty to configure the interface using DHCP. ''; }; prefixLength = mkOption { default = null; example = 24; type = types.nullOr types.int; description = '' Subnet mask of the interface, specified as the number of bits in the prefix (24). ''; }; subnetMask = mkOption { default = ""; example = "255.255.255.0"; type = types.str; description = '' Subnet mask of the interface, specified as a bitmask. This is deprecated; use instead. ''; }; ipv6Address = mkOption { default = null; example = "2001:1470:fffd:2098::e006"; type = types.nullOr types.string; description = '' IPv6 address of the interface. Leave empty to configure the interface using NDP. ''; }; ipv6prefixLength = mkOption { default = 64; example = 64; type = types.int; description = '' Subnet mask of the interface, specified as the number of bits in the prefix (64). ''; }; macAddress = mkOption { default = null; example = "00:11:22:33:44:55"; type = types.nullOr (types.str); description = '' MAC address of the interface. Leave empty to use the default. ''; }; mtu = mkOption { default = null; example = 9000; type = types.nullOr types.int; description = '' MTU size for packets leaving the interface. Leave empty to use the default. ''; }; virtual = mkOption { default = false; type = types.bool; description = '' Whether this interface is virtual and should be created by tunctl. This is mainly useful for creating bridges between a host a virtual network such as VPN or a virtual machine. Defaults to tap device, unless interface contains "tun" in its name. ''; }; virtualOwner = mkOption { default = "root"; type = types.str; description = '' In case of a virtual device, the user who owns it. ''; }; proxyARP = mkOption { default = false; type = types.bool; description = '' Turn on proxy_arp for this device (and proxy_ndp for ipv6). This is mainly useful for creating pseudo-bridges between a real interface and a virtual network such as VPN or a virtual machine for interfaces that don't support real bridging (most wlan interfaces). As ARP proxying acts slightly above the link-layer, below-ip traffic isn't bridged, so things like DHCP won't work. The advantage above using NAT lies in the fact that no IP addresses are shared, so all hosts are reachable/routeable. WARNING: turns on ip-routing, so if you have multiple interfaces, you should think of the consequence and setup firewall rules to limit this. ''; }; }; config = { name = mkDefault name; }; }; in { ###### interface options = { networking.hostName = mkOption { default = "nixos"; description = '' The name of the machine. Leave it empty if you want to obtain it from a DHCP server (if using DHCP). ''; }; networking.enableIPv6 = mkOption { default = true; description = '' Whether to enable support for IPv6. ''; }; networking.defaultGateway = mkOption { default = ""; example = "131.211.84.1"; description = '' The default gateway. It can be left empty if it is auto-detected through DHCP. ''; }; networking.defaultGatewayWindowSize = mkOption { default = null; example = 524288; type = types.nullOr types.int; description = '' The window size of the default gateway. It limits maximal data bursts that TCP peers are allowed to send to us. ''; }; networking.nameservers = mkOption { default = []; example = ["130.161.158.4" "130.161.33.17"]; description = '' The list of nameservers. It can be left empty if it is auto-detected through DHCP. ''; }; networking.domain = mkOption { default = ""; example = "home"; description = '' The domain. It can be left empty if it is auto-detected through DHCP. ''; }; networking.useHostResolvConf = mkOption { type = types.bool; default = false; description = '' In containers, whether to use the resolv.conf supplied by the host. ''; }; networking.localCommands = mkOption { default = ""; example = "text=anything; echo You can put $text here."; description = '' Shell commands to be executed at the end of the network-setup systemd service. Note that if you are using DHCP to obtain the network configuration, interfaces may not be fully configured yet. ''; }; networking.interfaces = mkOption { default = {}; example = { eth0 = { ipAddress = "131.211.84.78"; subnetMask = "255.255.255.128"; }; }; description = '' The configuration for each network interface. If is true, then every interface not listed here will be configured using DHCP. ''; type = types.loaOf types.optionSet; options = [ interfaceOpts ]; }; networking.bridges = mkOption { default = { }; example = { br0.interfaces = [ "eth0" "eth1" ]; br1.interfaces = [ "eth2" "wlan0" ]; }; description = '' This option allows you to define Ethernet bridge devices that connect physical networks together. The value of this option is an attribute set. Each attribute specifies a bridge, with the attribute name specifying the name of the bridge's network interface. ''; type = types.attrsOf types.optionSet; options = { interfaces = mkOption { example = [ "eth0" "eth1" ]; type = types.listOf types.string; description = "The physical network interfaces connected by the bridge."; }; }; }; networking.bonds = mkOption { default = { }; example = { bond0 = { interfaces = [ "eth0" "wlan0" ]; miimon = 100; mode = "active-backup"; }; fatpipe.interfaces = [ "enp4s0f0" "enp4s0f1" "enp5s0f0" "enp5s0f1" ]; }; description = '' This option allows you to define bond devices that aggregate multiple, underlying networking interfaces together. The value of this option is an attribute set. Each attribute specifies a bond, with the attribute name specifying the name of the bond's network interface ''; type = types.attrsOf types.optionSet; options = { interfaces = mkOption { example = [ "enp4s0f0" "enp4s0f1" "wlan0" ]; type = types.listOf types.string; description = "The interfaces to bond together"; }; miimon = mkOption { default = null; example = 100; type = types.nullOr types.int; description = '' Miimon is the number of millisecond in between each round of polling by the device driver for failed links. By default polling is not enabled and the driver is trusted to properly detect and handle failure scenarios. ''; }; mode = mkOption { default = null; example = "active-backup"; type = types.nullOr types.string; description = '' The mode which the bond will be running. The default mode for the bonding driver is balance-rr, optimizing for throughput. More information about valid modes can be found at https://www.kernel.org/doc/Documentation/networking/bonding.txt ''; }; }; }; networking.vlans = mkOption { default = { }; example = { vlan0 = { id = 3; interface = "enp3s0"; }; vlan1 = { id = 1; interface = "wlan0"; }; }; description = '' This option allows you to define vlan devices that tag packets on top of a physical interface. The value of this option is an attribute set. Each attribute specifies a vlan, with the name specifying the name of the vlan interface. ''; type = types.attrsOf types.optionSet; options = { id = mkOption { example = 1; type = types.int; description = "The vlan identifier"; }; interface = mkOption { example = "enp4s0"; type = types.string; description = "The interface the vlan will transmit packets through."; }; }; }; networking.useDHCP = mkOption { type = types.bool; default = true; description = '' Whether to use DHCP to obtain an IP address and other configuration for all network interfaces that are not manually configured. ''; }; }; ###### implementation config = { boot.kernelModules = [ ] ++ optional cfg.enableIPv6 "ipv6" ++ optional hasVirtuals "tun" ++ optional hasBonds "bonding"; boot.extraModprobeConfig = # This setting is intentional as it prevents default bond devices # from being created. optionalString hasBonds "options bonding max_bonds=0"; environment.systemPackages = [ pkgs.host pkgs.iproute pkgs.iputils pkgs.nettools pkgs.wirelesstools pkgs.iw pkgs.rfkill pkgs.openresolv ] ++ optional (cfg.bridges != {}) pkgs.bridge_utils ++ optional hasVirtuals pkgs.tunctl ++ optional cfg.enableIPv6 pkgs.ndisc6; security.setuidPrograms = [ "ping" "ping6" ]; systemd.targets."network-interfaces" = { description = "All Network Interfaces"; wantedBy = [ "network.target" ]; unitConfig.X-StopOnReconfiguration = true; }; systemd.services = let networkSetup = { description = "Networking Setup"; after = [ "network-interfaces.target" ]; before = [ "network.target" ]; wantedBy = [ "network.target" ]; unitConfig.ConditionCapability = "CAP_NET_ADMIN"; path = [ pkgs.iproute ]; serviceConfig.Type = "oneshot"; serviceConfig.RemainAfterExit = true; script = '' # Set the static DNS configuration, if given. ${pkgs.openresolv}/sbin/resolvconf -m 1 -a static < /proc/sys/net/ipv6/conf/all/disable_ipv6 fi ''} # Set the default gateway. ${optionalString (cfg.defaultGateway != "") '' # FIXME: get rid of "|| true" (necessary to make it idempotent). ip route add default via "${cfg.defaultGateway}" ${ optionalString (cfg.defaultGatewayWindowSize != null) "window ${cfg.defaultGatewayWindowSize}"} || true ''} # Turn on forwarding if any interface has enabled proxy_arp. ${optionalString (any (i: i.proxyARP) interfaces) '' echo 1 > /proc/sys/net/ipv4/ip_forward ''} # Run any user-specified commands. ${cfg.localCommands} ''; }; # For each interface , create a job ‘-cfg.service" # that performs static configuration. It has a "wants" # dependency on ‘.service’, which is supposed to create # the interface and need not exist (i.e. for hardware # interfaces). It has a binds-to dependency on the actual # network device, so it only gets started after the interface # has appeared, and it's stopped when the interface # disappears. configureInterface = i: nameValuePair "${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 { description = "Configuration of ${i.name}"; wantedBy = [ "network-interfaces.target" ]; bindsTo = [ "sys-subsystem-net-devices-${i.name}.device" ]; after = [ "sys-subsystem-net-devices-${i.name}.device" ]; serviceConfig.Type = "oneshot"; serviceConfig.RemainAfterExit = true; path = [ pkgs.iproute pkgs.gawk ]; script = '' echo "bringing up interface..." ip link set "${i.name}" up '' + optionalString (i.macAddress != null) '' echo "setting MAC address to ${i.macAddress}..." ip link set "${i.name}" address "${i.macAddress}" '' + optionalString (i.mtu != null) '' echo "setting MTU to ${toString i.mtu}..." ip link set "${i.name}" mtu "${toString i.mtu}" '' + optionalString (i.ipAddress != null) '' cur=$(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 '' + optionalString (staticIPv6) '' # 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 (i.ipAddress != null || staticIPv6) '' if [ restart_network_setup = true ]; then # Ensure that the default gateway remains set. # (Flushing this interface may have removed it.) ${config.systemd.package}/bin/systemctl try-restart --no-block network-setup.service fi ${config.systemd.package}/bin/systemctl start ip-up.target '' + optionalString i.proxyARP '' echo 1 > /proc/sys/net/ipv4/conf/${i.name}/proxy_arp '' + optionalString (i.proxyARP && cfg.enableIPv6) '' echo 1 > /proc/sys/net/ipv6/conf/${i.name}/proxy_ndp ''; }); createTunDevice = i: nameValuePair "${i.name}" { description = "Virtual Network Interface ${i.name}"; requires = [ "dev-net-tun.device" ]; after = [ "dev-net-tun.device" ]; wantedBy = [ "network.target" ]; requiredBy = [ "sys-subsystem-net-devices-${i.name}.device" ]; serviceConfig = { Type = "oneshot"; RemainAfterExit = true; ExecStart = "${pkgs.tunctl}/bin/tunctl -t '${i.name}' -u '${i.virtualOwner}'"; ExecStop = "${pkgs.tunctl}/bin/tunctl -d '${i.name}'"; }; }; createBridgeDevice = n: v: let deps = map (i: "sys-subsystem-net-devices-${i}.device") v.interfaces; in { description = "Bridge Interface ${n}"; wantedBy = [ "network.target" "sys-subsystem-net-devices-${n}.device" ]; bindsTo = deps; after = deps; serviceConfig.Type = "oneshot"; serviceConfig.RemainAfterExit = true; path = [ pkgs.bridge_utils pkgs.iproute ]; script = '' # Remove Dead Interfaces ip link show "${n}" >/dev/null 2>&1 && ip link delete "${n}" brctl addbr "${n}" # Set bridge's hello time to 0 to avoid startup delays. brctl setfd "${n}" 0 ${flip concatMapStrings v.interfaces (i: '' brctl addif "${n}" "${i}" ip link set "${i}" up ip addr flush dev "${i}" echo "bringing up network device ${n}..." ip link set "${n}" up '')} # !!! Should delete (brctl delif) any interfaces that # no longer belong to the bridge. ''; postStop = '' ip link set "${n}" down brctl delbr "${n}" ''; }; createBondDevice = n: v: let deps = map (i: "sys-subsystem-net-devices-${i}.device") v.interfaces; in { description = "Bond Interface ${n}"; wantedBy = [ "network.target" "sys-subsystem-net-devices-${n}.device" ]; bindsTo = deps; after = deps; serviceConfig.Type = "oneshot"; serviceConfig.RemainAfterExit = true; path = [ pkgs.ifenslave pkgs.iproute ]; script = '' # Remove Dead Interfaces ip link show "${n}" >/dev/null 2>&1 && ip link delete "${n}" ip link add "${n}" type bond # !!! There must be a better way to wait for the interface while [ ! -d /sys/class/net/${n} ]; do sleep 0.1; done; # Set the miimon and mode options ${optionalString (v.miimon != null) "echo ${toString v.miimon} > /sys/class/net/${n}/bonding/miimon"} ${optionalString (v.mode != null) "echo \"${v.mode}\" > /sys/class/net/${n}/bonding/mode"} # Bring up the bridge and enslave the specified interfaces ip link set "${n}" up ${flip concatMapStrings v.interfaces (i: '' ifenslave "${n}" "${i}" '')} ''; postStop = '' ip link set "${n}" down ifenslave -d "${n}" ip link delete "${n}" ''; }; createVlanDevice = n: v: let deps = [ "sys-subsystem-net-devices-${v.interface}.device" ]; in { description = "Vlan Interface ${n}"; wantedBy = [ "network.target" "sys-subsystem-net-devices-${n}.device" ]; bindsTo = deps; after = deps; serviceConfig.Type = "oneshot"; serviceConfig.RemainAfterExit = true; path = [ pkgs.iproute ]; script = '' # Remove Dead Interfaces ip link show "${n}" >/dev/null 2>&1 && ip link delete "${n}" ip link add link "${v.interface}" "${n}" type vlan id "${toString v.id}" ip link set "${n}" up ''; postStop = '' ip link delete "${n}" ''; }; in listToAttrs ( map configureInterface interfaces ++ map createTunDevice (filter (i: i.virtual) interfaces)) // mapAttrs createBridgeDevice cfg.bridges // mapAttrs createBondDevice cfg.bonds // mapAttrs createVlanDevice cfg.vlans // { "network-setup" = networkSetup; }; # Set the host and domain names in the activation script. Don't # clear it if it's not configured in the NixOS configuration, # since it may have been set by dhcpcd in the meantime. system.activationScripts.hostname = optionalString (config.networking.hostName != "") '' hostname "${config.networking.hostName}" ''; system.activationScripts.domain = optionalString (config.networking.domain != "") '' domainname "${config.networking.domain}" ''; services.udev.extraRules = '' KERNEL=="tun", TAG+="systemd" ''; }; }