nixpkgs/modules/services/networking/dhcpcd.nix
Peter Simons 7a69733704 Added 'networking.dhcpcd.denyInterfaces' to extend the list of network
interfaces black-listed for dhcpcd via configuration.nix. I use this option to
disable DHCP for "veth*" interfaces, which are created by LXC for use inside of
virtual machines.

svn path=/nixos/trunk/; revision=34018
2012-05-08 11:46:01 +00:00

121 lines
3.7 KiB
Nix

{ config, pkgs, ... }:
with pkgs.lib;
let
inherit (pkgs) dhcpcd;
# Don't start dhclient on explicitly configured interfaces or on
# interfaces that are part of a bridge.
ignoredInterfaces =
map (i: i.name) (filter (i: i ? ipAddress && i.ipAddress != "" ) config.networking.interfaces)
++ concatLists (attrValues (mapAttrs (n: v: v.interfaces) config.networking.bridges))
++ config.networking.dhcpcd.denyInterfaces;
# Config file adapted from the one that ships with dhcpcd.
dhcpcdConf = pkgs.writeText "dhcpcd.conf"
''
# Inform the DHCP server of our hostname for DDNS.
hostname
# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes, ntp_servers, interface_mtu
# A ServerID is required by RFC2131.
require dhcp_server_identifier
# A hook script is provided to lookup the hostname if not set by
# the DHCP server, but it should not be run by default.
nohook lookup-hostname
# Ignore peth* devices; on Xen, they're renamed physical
# Ethernet cards used for bridging. Likewise for vif* and tap*
# (Xen) and virbr* and vnet* (libvirt).
denyinterfaces ${toString ignoredInterfaces} peth* vif* tap* tun* virbr* vnet* vboxnet*
'';
# Hook for emitting ip-up/ip-down events.
exitHook = pkgs.writeText "dhcpcd.exit-hook"
''
#exec >> /var/log/dhcpcd 2>&1
#set -x
params="IFACE=$interface REASON=$reason"
# only works when interface is wireless and wpa_supplicant has a control socket
# but we allow it to fail silently
${optionalString config.networking.wireless.enable ''
params+=" $(${pkgs.wpa_supplicant}/sbin/wpa_cli -i$interface status 2>/dev/null | grep ssid | sed 's|^b|B|;s|ssid|SSID|' | xargs)"
''}
if [ "$reason" = BOUND -o "$reason" = REBOOT ]; then
# Restart ntpd. (The "ip-up" event below will trigger the
# restart.) We need to restart it to make sure that it will
# actually do something: if ntpd cannot resolve the server
# hostnames in its config file, then it will never do
# anything ever again ("couldn't resolve ..., giving up on
# it"), so we silently lose time synchronisation.
${config.system.build.upstart}/sbin/initctl stop ntpd
${config.system.build.upstart}/sbin/initctl emit -n ip-up $params
fi
if [ "$reason" = EXPIRE -o "$reason" = RELEASE -o "$reason" = NOCARRIER ] ; then
${config.system.build.upstart}/sbin/initctl emit -n ip-down $params
fi
'';
in
{
###### interface
options = {
networking.dhcpcd.denyInterfaces = mkOption {
default = [];
description = ''
Disable the DHCP client for any interface which's name matches
any of the shell glob patterns in this list. The purpose of
this option is blacklist virtual interfaces such as those
created by Xen, libvirt, LXC, etc.
'';
};
};
###### implementation
config = mkIf config.networking.useDHCP {
jobs.dhcpcd =
{ startOn = "started network-interfaces";
path = [ dhcpcd pkgs.nettools pkgs.openresolv ];
exec = "dhcpcd --config ${dhcpcdConf} --nobackground";
};
environment.systemPackages = [ dhcpcd ];
environment.etc =
[ { source = exitHook;
target = "dhcpcd.exit-hook";
}
];
powerManagement.resumeCommands =
''
# Tell dhcpcd to rebind its interfaces if it's running.
status="$(${config.system.build.upstart}/sbin/status dhcpcd)"
[[ "$status" =~ start/running ]] && ${dhcpcd}/sbin/dhcpcd --rebind
'';
};
}