add all files from Hong

plugins/searchdomains/plugin.go

@@ -0,0 +1,77 @@
+// 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 searchdomains
+
+// This is an searchdomains plugin that adds default DNS search domains.
+
+import (
+	"github.com/coredhcp/coredhcp/handler"
+	"github.com/coredhcp/coredhcp/logger"
+	"github.com/coredhcp/coredhcp/plugins"
+	"github.com/insomniacslk/dhcp/dhcpv4"
+	"github.com/insomniacslk/dhcp/dhcpv6"
+	"github.com/insomniacslk/dhcp/rfc1035label"
+)
+
+var log = logger.GetLogger("plugins/searchdomains")
+
+// Plugin wraps the default DNS search domain options.
+// Note that importing the plugin is not enough to use it: you have to
+// explicitly specify the intention to use it in the `config.yml` file, in the
+// plugins section. For searchdomains:
+//
+// server6:
+//   listen: '[::]547'
+//   - searchdomains: domain.a domain.b
+//   - server_id: LL aa:bb:cc:dd:ee:ff
+//   - file: "leases.txt"
+//
+var Plugin = plugins.Plugin{
+	Name:   "searchdomains",
+	Setup6: setup6,
+	Setup4: setup4,
+}
+
+// These are the DNS search domains that are set by the plugin.
+// Note that DHCPv4 and DHCPv6 options are totally independent.
+// If you need the same settings for both, you'll need to configure
+// this plugin once for the v4 and once for the v6 server.
+var v4SearchList []string
+var v6SearchList []string
+
+// copySlice creates a new copy of a string slice in memory.
+// This helps to ensure that downstream plugins can't corrupt
+// this plugin's configuration
+func copySlice(original []string) []string {
+	copied := make([]string, len(original))
+	copy(copied, original)
+	return copied
+}
+
+func setup6(args ...string) (handler.Handler6, error) {
+	v6SearchList = args
+	log.Printf("Registered domain search list (DHCPv6) %s", v6SearchList)
+	return domainSearchListHandler6, nil
+}
+
+func setup4(args ...string) (handler.Handler4, error) {
+	v4SearchList = args
+	log.Printf("Registered domain search list (DHCPv4) %s", v4SearchList)
+	return domainSearchListHandler4, nil
+}
+
+func domainSearchListHandler6(req, resp dhcpv6.DHCPv6) (dhcpv6.DHCPv6, bool) {
+	resp.UpdateOption(dhcpv6.OptDomainSearchList(&rfc1035label.Labels{
+		Labels: copySlice(v6SearchList),
+	}))
+	return resp, false
+}
+
+func domainSearchListHandler4(req, resp *dhcpv4.DHCPv4) (*dhcpv4.DHCPv4, bool) {
+	resp.UpdateOption(dhcpv4.OptDomainSearch(&rfc1035label.Labels{
+		Labels: copySlice(v4SearchList),
+	}))
+	return resp, false
+}