From ae27eafe4c08028d5c89cea528fd587a184f10dd Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Mon, 20 Feb 2012 01:17:53 +0000
Subject: [PATCH] * Added a module for dhcpcd, a DHCP client (not enabled by
 default   yet).  It's smaller than dhclient and has more features   (e.g.
 automatically detects link status changes, supports   openresolv, does
 IPv4LL, and supports IPv6 Router Advertisements).

svn path=/nixos/trunk/; revision=32413
---
 modules/services/networking/dhcpcd.nix | 92 ++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 modules/services/networking/dhcpcd.nix

diff --git a/modules/services/networking/dhcpcd.nix b/modules/services/networking/dhcpcd.nix
new file mode 100644
index 00000000000..ce0c08dda3a
--- /dev/null
+++ b/modules/services/networking/dhcpcd.nix
@@ -0,0 +1,92 @@
+{ 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));
+
+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.dhcpcd =
+      { startOn = "started network-interfaces";
+        stopOn = "stopping network-interfaces";
+
+        path = [ dhcpcd pkgs.nettools pkgs.openresolv ];
+
+        script =
+          ''
+            # Determine the interface on which to start dhcpcd.
+            interfaces=
+
+            for i in $(cd /sys/class/net && ls -d *); do
+                # Only run dhcpcd on interfaces of type ARPHRD_ETHER
+                # (1), i.e. Ethernet.  Ignore peth* devices; on Xen,
+                # they're renamed physical Ethernet cards used for
+                # bridging.  Likewise for vif* and tap* (Xen) and
+                # virbr* and vnet* (libvirt).
+                if [ "$(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 dhcpcd on $i"
+                        interfaces="$interfaces $i"
+                    fi
+                fi
+            done
+
+            if [ -z "$interfaces" ]; then
+                echo 'No interfaces on which to start dhcpcd!'
+                exit 1
+            fi
+
+            exec dhcpcd --nobackground --persistent $interfaces
+          '';
+      };
+
+    environment.systemPackages = [ dhcpcd ];
+
+    powerManagement.resumeCommands =
+      ''
+        ${config.system.build.upstart}/sbin/restart dhcpcd
+      '';
+
+    networking.interfaceMonitor.commands =
+      ''
+        if [ "$status" = up ]; then
+          ${config.system.build.upstart}/sbin/restart dhcpcd
+        fi
+      '';
+
+  };
+
+}