nixpkgs/modules/services/networking/dhcpcd.nix
Eelco Dolstra 326891443c * dhcpcd: Don't use the "persistent" option. With it, dhcpcd won't
delete routes and addresses when it quits.  This causes those routes
  and addresses to stick around forever, since dhcpcd won't delete
  them when it runs next (even if it acquires a new lease on the same
  interface).  This is bad; in particular the stale (default) routes
  can break networking.

  The downside to removing "persistent" is that you should never ever
  do "stop dhcpcd" on a remote machine configured by dhcpcd.

svn path=/nixos/trunk/; revision=33388
2012-03-23 21:00:32 +00:00

94 lines
2.9 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 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 ${toString ignoredInterfaces} peth* vif* tap* tun* virbr* vnet* vboxnet*
'';
# Hook for emitting ip-up/ip-down events.
exitHook = pkgs.writeText "dhcpcd.exit-hook"
''
#exec >> /var/log/dhcpcd 2>&1
#set -x
if [ "$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
${config.system.build.upstart}/sbin/initctl emit -n ip-up IFACE=$interface
fi
if [ "$reason" = EXPIRE -o "$reason" = RELEASE ]; then
${config.system.build.upstart}/sbin/initctl emit -n ip-down IFACE=$interface
fi
'';
in
{
###### 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
'';
};
}