nixpkgs/nixos/modules/services/networking/dhclient.nix

112 lines
3.4 KiB
Nix

{ config, pkgs, ... }:
with pkgs.lib;
let
inherit (pkgs) nettools dhcp lib;
# Don't start dhclient on explicitly configured interfaces or on
# interfaces that are part of a bridge.
ignoredInterfaces =
map (i: i.name) (lib.filter (i: i ? ipAddress && i.ipAddress != "" ) config.networking.interfaces)
++ concatLists (attrValues (mapAttrs (n: v: v.interfaces) config.networking.bridges));
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
# 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
${config.system.build.upstart}/sbin/initctl emit -n ip-up
fi
if test "$reason" = EXPIRE -o "$reason" = RELEASE; then
${config.system.build.upstart}/sbin/initctl emit -n ip-down
fi
'';
in
{
###### implementation
config = mkIf config.networking.useDHCP {
# dhclient barfs if /proc/net/if_inet6 doesn't exist.
boot.kernelModules = [ "ipv6" ];
jobs.dhclient =
{ startOn = "started network-interfaces";
stopOn = "stopping network-interfaces";
path = [ dhcp ];
script =
''
# Determine the interface on which to start dhclient.
interfaces=
for i in $(cd /sys/class/net && ls -d *); do
# Only run dhclient on interfaces of type ARPHRD_ETHER
# (1), i.e. Ethernet. Ignore peth* devices; on Xen,
# they're renamed physical Ethernet cards used for
# bridging. Likewise for vif* and tap* (Xen) and
# virbr* and vnet* (libvirt).
if [ "$(cat /sys/class/net/$i/type)" = 1 ]; then
if ! for j in ${toString ignoredInterfaces}; do echo $j; done | grep -F -x -q "$i" &&
! echo "$i" | grep -x -q "peth.*\|vif.*\|tap.*\|virbr.*\|vnet.*";
then
echo "Running dhclient on $i"
interfaces="$interfaces $i"
fi
fi
done
if test -z "$interfaces"; then
echo 'No interfaces on which to start dhclient!'
exit 1
fi
mkdir -m 755 -p ${stateDir}
exec 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";
}
];
powerManagement.resumeCommands =
''
${config.system.build.upstart}/sbin/restart dhclient
'';
networking.interfaceMonitor.commands =
''
if [ "$status" = up ]; then
${config.system.build.upstart}/sbin/restart dhclient
fi
'';
};
}