Remove DHCPv6 stub implementations in unsupported plugins

These plugins don't support IPv6. With the new explicit plugin
registration, completely omitting the setup function for ipv6 in that
case is now possible.

Signed-off-by: Anatole Denis <anatole@unverle.fr>

plugins/netmask/plugin.go

@@ -13,7 +13,6 @@ import (
 	"github.com/coredhcp/coredhcp/logger"
 	"github.com/coredhcp/coredhcp/plugins"
 	"github.com/insomniacslk/dhcp/dhcpv4"
-	"github.com/insomniacslk/dhcp/dhcpv6"
 )
 
 var log = logger.GetLogger("plugins/netmask")
@@ -21,7 +20,6 @@ var log = logger.GetLogger("plugins/netmask")
 // Plugin wraps plugin registration information
 var Plugin = plugins.Plugin{
 	Name:   "netmask",
-	Setup6: setup6,
 	Setup4: setup4,
 }
 
@@ -29,12 +27,6 @@ var (
 	netmask net.IPMask
 )
 
-func setup6(args ...string) (handler.Handler6, error) {
-	// TODO setup function for IPv6
-	log.Warning("not implemented for IPv6")
-	return Handler6, nil
-}
-
 func setup4(args ...string) (handler.Handler4, error) {
 	log.Printf("loaded plugin for DHCPv4.")
 	if len(args) != 1 {
@@ -56,17 +48,12 @@ func setup4(args ...string) (handler.Handler4, error) {
 	return Handler4, nil
 }
 
-// Handler6 not implemented only IPv4
-func Handler6(req, resp dhcpv6.DHCPv6) (dhcpv6.DHCPv6, bool) {
-	// TODO add IPv6 netmask to the response
-	return resp, false
-}
-
 //Handler4 handles DHCPv4 packets for the netmask plugin
 func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
 	resp.Options.Update(dhcpv4.OptSubnetMask(netmask))
 	return resp, false
 }
+
 func checkValidNetmask(netmask net.IPMask) bool {
 	netmaskInt := binary.BigEndian.Uint32(netmask)
 	x := ^netmaskInt

plugins/router/plugin.go

@@ -12,7 +12,6 @@ import (
 	"github.com/coredhcp/coredhcp/logger"
 	"github.com/coredhcp/coredhcp/plugins"
 	"github.com/insomniacslk/dhcp/dhcpv4"
-	"github.com/insomniacslk/dhcp/dhcpv6"
 )
 
 var log = logger.GetLogger("plugins/router")
@@ -20,7 +19,6 @@ var log = logger.GetLogger("plugins/router")
 // Plugin wraps plugin registration information
 var Plugin = plugins.Plugin{
 	Name:   "router",
-	Setup6: setup6,
 	Setup4: setup4,
 }
 
@@ -28,12 +26,6 @@ var (
 	routers []net.IP
 )
 
-func setup6(args ...string) (handler.Handler6, error) {
-	// TODO setup function for IPv6
-	log.Warning("Not implemented for IPv6")
-	return Handler6, nil
-}
-
 func setup4(args ...string) (handler.Handler4, error) {
 	log.Printf("Loaded plugin for DHCPv4.")
 	if len(args) < 1 {
@@ -50,12 +42,6 @@ func setup4(args ...string) (handler.Handler4, error) {
 	return Handler4, nil
 }
 
-// Handler6 not implemented only IPv4
-func Handler6(req, resp dhcpv6.DHCPv6) (dhcpv6.DHCPv6, bool) {
-	// TODO add router IPv6 addresses to the response
-	return resp, false
-}
-
 //Handler4 handles DHCPv4 packets for the router plugin
 func Handler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
 	resp.Options.Update(dhcpv4.OptRouter(routers...))