Merge pull request #13209 from swordqiu/feature/qj-support-dhcp-option-82

feature: support dhcp relay information option 82

pkg/baremetal/pxe/dhcp.go

@@ -88,6 +88,12 @@ func (h *DHCPHandler) ServeDHCP(pkt dhcp.Packet, _ *net.UDPAddr, _ *net.Interfac
 	if conf == nil {
 		return nil, nil, fmt.Errorf("Empty packet config")
 	}
+	// handle Option 82 relay information
+	// https://datatracker.ietf.org/doc/html/rfc3046
+	if relayInfo := pkt.GetOptionValue(dhcp.OptionRelayAgentInformation); relayInfo != nil {
+		// return relay information transparently
+		conf.RelayInfo = relayInfo
+	}
 	pkg, err := dhcp.MakeReplyPacket(pkt, conf)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "dhcp.MakeReplyPacket")

pkg/hostman/hostinfo/hostdhcp/dhcpserver.go

@@ -151,6 +151,10 @@ func (s *SGuestDHCPServer) getGuestConfig(guestDesc, guestNic jsonutils.JSONObje
 		}
 	}
 
+	if nicdesc.Mtu > 0 {
+		conf.MTU = uint16(nicdesc.Mtu)
+	}
+
 	conf.OsName, _ = guestDesc.GetString("os_name")
 	conf.LeaseTime = time.Duration(options.HostOptions.DhcpLeaseTime) * time.Second
 	conf.RenewalTime = time.Duration(options.HostOptions.DhcpRenewalTime) * time.Second

pkg/util/dhcp/helpers.go

@@ -47,6 +47,10 @@ type ResponseConfig struct {
 	DNSServers    []net.IP      // OptDNSServers
 	Routes        [][]string    // TODO: 249 for windows, 121 for linux
 	NTPServers    []net.IP      // OptNTPServers 42
+	MTU           uint16        // OptMTU 26
+
+	// Relay Info https://datatracker.ietf.org/doc/html/rfc3046
+	RelayInfo []byte
 
 	// TFTP config
 	BootServer string
@@ -62,6 +66,12 @@ func (conf ResponseConfig) GetHostname() string {
 	return hostname
 }
 
+func GetOptUint16(val uint16) []byte {
+	opts := []byte{0, 0}
+	binary.BigEndian.PutUint16(opts, val)
+	return opts
+}
+
 func GetOptIP(ip net.IP) []byte {
 	return []byte(ip.To4())
 }
@@ -154,6 +164,12 @@ func makeDHCPReplyPacket(req Packet, conf *ResponseConfig, msgType MessageType)
 	if len(conf.NTPServers) > 0 {
 		opts = append(opts, Option{OptionNetworkTimeProtocolServers, GetOptIPs(conf.NTPServers)})
 	}
+	if conf.MTU > 0 {
+		opts = append(opts, Option{OptionInterfaceMTU, GetOptUint16(conf.MTU)})
+	}
+	if conf.RelayInfo != nil {
+		opts = append(opts, Option{OptionRelayAgentInformation, conf.RelayInfo})
+	}
 	resp := ReplyPacket(req, msgType, conf.ServerIP, conf.ClientIP, conf.LeaseTime, opts)
 	if conf.BootServer != "" {
 		//resp.Options[OptOverload] = []byte{3}