nixpkgs/modules/services/networking/dhclient.nix
Eelco Dolstra c4780a8953 * dhcp 4.1 requires IPv6 support.
svn path=/nixos/branches/modular-nixos/; revision=16450
2009-07-24 00:31:22 +00:00

111 lines
3 KiB
Nix

{pkgs, config, ...}:
let
inherit (pkgs.lib) mkOption mkIf mergeEnableOption mergeListOption;
inherit (pkgs) nettools dhcp lib;
# Don't start dhclient on explicitly configured interfaces.
ignoredInterfaces = ["lo" "wmaster0"] ++
map (i: i.name) (lib.filter (i: i ? ipAddress) config.networking.interfaces);
stateDir = "/var/lib/dhcp"; # Don't use /var/state/dhcp; not FHS-compliant.
dhclientExitHooks = pkgs.writeText "dhclient-exit-hooks"
''
echo "$reason" >> /tmp/dhcp-exit
echo "$exit_status" >> /tmp/dhcp-exit
if test "$reason" = BOUND -o "$reason" = REBOOT; then
${pkgs.glibc}/sbin/nscd --invalidate hosts
# 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.
${pkgs.upstart}/sbin/initctl stop ntpd
${pkgs.upstart}/sbin/initctl emit ip-up
fi
if test "$reason" = EXPIRE -o "$reason" = RELEASE; then
${pkgs.upstart}/sbin/initctl emit ip-down
fi
'';
in
{
###### interface
options = {
networking.useDHCP = mkOption {
default = true;
merge = mergeEnableOption;
description = "
Whether to use DHCP to obtain an IP adress and other
configuration for all network interfaces that are not manually
configured.
";
};
};
###### implementation
config = mkIf config.networking.useDHCP {
jobs = pkgs.lib.singleton
{ name = "dhclient";
startOn = "network-interfaces/started";
stopOn = "network-interfaces/stop";
preStart =
''
# dhclient barfs if /proc/net/if_inet6 doesn't exist.
${config.system.sbin.modprobe}/sbin/modprobe ipv6 || true
'';
script =
''
# Determine the interface on which to start dhclient.
interfaces=
for i in $(cd /sys/class/net && ls -d *); do
if ! for j in ${toString ignoredInterfaces}; do echo $j; done | grep -F -x -q "$i"; then
echo "Running dhclient on $i"
interfaces="$interfaces $i"
fi
done
if test -z "$interfaces"; then
echo 'No interfaces on which to start dhclient!'
exit 1
fi
mkdir -m 755 -p ${stateDir}
exec ${dhcp}/sbin/dhclient -d $interfaces -e "PATH=$PATH" -lf ${stateDir}/dhclient.leases -sf ${dhcp}/sbin/dhclient-script
'';
};
environment.systemPackages = [dhcp];
environment.etc =
[ # Dhclient hooks for emitting ip-up/ip-down events.
{ source = dhclientExitHooks;
target = "dhclient-exit-hooks";
}
];
};
}