add all files from Hong

handler/handler.go

@@ -0,0 +1,23 @@
+// Copyright 2018-present the CoreDHCP Authors. All rights reserved
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+package handler
+
+import (
+	"github.com/insomniacslk/dhcp/dhcpv4"
+	"github.com/insomniacslk/dhcp/dhcpv6"
+)
+
+// Handler6 is a function that is called on a given DHCPv6 packet.
+// It returns a DHCPv6 packet and a boolean.
+// If the boolean is true, this will be the last handler to be called.
+// The two input packets are the original request, and a response packet.
+// The response packet may or may not be modified by the function, and
+// the result will be returned by the handler.
+// If the returned boolean is true, the returned packet may be nil or
+// invalid, in which case no response will be sent.
+type Handler6 func(req, resp dhcpv6.DHCPv6) (dhcpv6.DHCPv6, bool)
+
+// Handler4 behaves like Handler6, but for DHCPv4 packets.
+type Handler4 func(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool)