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nixpkgs/modules/services/networking/dhclient.nix
Eelco Dolstra 116306c8dc * Restart ntpd when we get a new DHCP lease. Without this, if ntpd
previously failed to resolve the NTP server hostnames in its config
  file, it will happily sit in a loop forever doing nothing.

svn path=/nixos/branches/modular-nixos/; revision=15830
2009-06-02 19:42:31 +00:00

135 lines
3.5 KiB
Nix

{pkgs, config, ...}:
###### interface
let
inherit (pkgs.lib) mkOption
mergeEnableOption mergeListOption;
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.
";
};
interfaces = mkOption {
default = [];
merge = mergeListOption;
example = [
{ name = "eth0";
ipAddress = "131.211.84.78";
subnetMask = "255.255.255.128";
}
];
description = "
The configuration for each network interface. If
<option>networking.useDHCP</option> is true, then each interface
not listed here will be configured using DHCP.
";
};
};
};
in
###### implementation
let
ifEnable = arg:
if config.networking.useDHCP then arg
else if builtins.isList arg then []
else if builtins.isAttrs arg then {}
else null;
inherit (pkgs) nettools dhcp lib;
# Don't start dhclient on explicitly configured interfaces.
ignoredInterfaces = ["lo"] ++
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
${pkgs.upstart}/sbin/initctl emit ip-down
fi
'';
in
{
require = [
#../upstart-jobs/default.nix
options
];
services.extraJobs = ifEnable [{
name = "dhclient";
extraPath = [dhcp];
job = ''
description "DHCP client"
start on network-interfaces/started
stop on network-interfaces/stop
env PATH_DHCLIENT_SCRIPT=${dhcp}/sbin/dhclient-script
script
export PATH=${nettools}/sbin:$PATH
# 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
end script
'';
}];
environment.etc = ifEnable
[ # Dhclient hooks for emitting ip-up/ip-down events.
{ source = dhclientExitHooks;
target = "dhclient-exit-hooks";
}
];
}