From d399ca8d71f010fd881347f1aeb0287c3932bddc Mon Sep 17 00:00:00 2001
From: wanyaoqi <wanyaoqi@yunionyun.com>
Date: Mon, 24 Jun 2019 20:28:00 +0800
Subject: [PATCH] make dhcp server port optional

---
 pkg/baremetal/pxe/pxe.go                    |  6 +-
 pkg/hostman/hostinfo/hostdhcp/dhcpserver.go | 22 ++++--
 pkg/util/dhcp/server.go                     | 84 ++++++++++-----------
 3 files changed, 57 insertions(+), 55 deletions(-)

diff --git a/pkg/baremetal/pxe/pxe.go b/pkg/baremetal/pxe/pxe.go
index dbd0e0a4b8..8b0ea0f5ad 100644
--- a/pkg/baremetal/pxe/pxe.go
+++ b/pkg/baremetal/pxe/pxe.go
@@ -128,11 +128,7 @@ func (s *Server) Serve() error {
 		return err
 	}
 
-	if s.DHCPPort != 67 {
-		return fmt.Errorf("DHCP listen port %d is not support", s.DHCPPort)
-	}
-
-	dhcpSrv, _, err := dhcp.NewDHCPServer2(s.ListenIface, dhcp.PORT_67)
+	dhcpSrv, _, err := dhcp.NewDHCPServer2(s.ListenIface, uint16(s.DHCPPort))
 	if err != nil {
 		return err
 	}
diff --git a/pkg/hostman/hostinfo/hostdhcp/dhcpserver.go b/pkg/hostman/hostinfo/hostdhcp/dhcpserver.go
index 91a228a0aa..9012b9995a 100644
--- a/pkg/hostman/hostinfo/hostdhcp/dhcpserver.go
+++ b/pkg/hostman/hostinfo/hostdhcp/dhcpserver.go
@@ -31,6 +31,8 @@ import (
 	"yunion.io/x/onecloud/pkg/util/netutils2"
 )
 
+const DHCP_RELAY_SERVER_PORT = 68
+
 type SGuestDHCPServer struct {
 	server *dhcp.DHCPServer
 	relay  *SDHCPRelay
@@ -45,21 +47,25 @@ func NewGuestDHCPServer(iface string, relay []string) (*SGuestDHCPServer, error)
 		guestdhcp = new(SGuestDHCPServer)
 	)
 
-	if options.HostOptions.DhcpServerPort != 67 {
-		return nil, fmt.Errorf("DHCP server listen port %d is not support", options.HostOptions.DhcpServerPort)
-	}
-
-	// port 67 for dhcp server, 68 for dhcp relay server
-	guestdhcp.server, guestdhcp.conn, err = dhcp.NewDHCPServer2(iface, dhcp.PORT_67_AND_68)
-	if err != nil {
-		return nil, err
+	if len(relay) > 0 && len(relay) != 2 {
+		return nil, fmt.Errorf("Wrong dhcp relay address")
 	}
 
 	if len(relay) == 2 {
+		// port 67 for dhcp server, 68 for dhcp relay server
+		guestdhcp.server, guestdhcp.conn, err = dhcp.NewDHCPServerWithRelay(iface, uint16(options.HostOptions.DhcpServerPort), DHCP_RELAY_SERVER_PORT)
+		if err != nil {
+			return nil, err
+		}
 		guestdhcp.relay, err = NewDHCPRelay(guestdhcp.conn, relay, iface)
 		if err != nil {
 			return nil, err
 		}
+	} else {
+		guestdhcp.server, guestdhcp.conn, err = dhcp.NewDHCPServer2(iface, uint16(options.HostOptions.DhcpServerPort))
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	guestdhcp.iface = iface
diff --git a/pkg/util/dhcp/server.go b/pkg/util/dhcp/server.go
index d234e108d5..7907df2b93 100644
--- a/pkg/util/dhcp/server.go
+++ b/pkg/util/dhcp/server.go
@@ -23,44 +23,6 @@ import (
 	"yunion.io/x/log"
 )
 
-const (
-	PORT_67        = 67
-	PORT_67_AND_68 = 67 + 68
-)
-
-var UDP_BPF_PORT_MAP = map[uint16][]bpf.RawInstruction{
-	// ip and udp and dst port 67
-	PORT_67: {
-		{0x28, 0, 0, 0x0000000c},
-		{0x15, 0, 8, 0x00000800},
-		{0x30, 0, 0, 0x00000017},
-		{0x15, 0, 6, 0x00000011},
-		{0x28, 0, 0, 0x00000014},
-		{0x45, 4, 0, 0x00001fff},
-		{0xb1, 0, 0, 0x0000000e},
-		{0x48, 0, 0, 0x00000010},
-		{0x15, 0, 1, 0x00000043},
-		{0x6, 0, 0, 0x00040000},
-		{0x6, 0, 0, 0x00000000},
-	},
-	// ip and udp and dst port 67 and port 68
-	PORT_67_AND_68: {
-		{0x28, 0, 0, 0x0000000c},
-		{0x15, 0, 10, 0x00000800},
-		{0x30, 0, 0, 0x00000017},
-		{0x15, 0, 8, 0x00000011},
-		{0x28, 0, 0, 0x00000014},
-		{0x45, 6, 0, 0x00001fff},
-		{0xb1, 0, 0, 0x0000000e},
-		{0x48, 0, 0, 0x00000010},
-		{0x15, 0, 3, 0x00000043},
-		{0x48, 0, 0, 0x0000000e},
-		{0x15, 0, 1, 0x00000044},
-		{0x6, 0, 0, 0x00040000},
-		{0x6, 0, 0, 0x00000000},
-	},
-}
-
 type DHCPServer struct {
 	Address string
 	Port    int
@@ -74,10 +36,48 @@ func NewDHCPServer(address string, port int) *DHCPServer {
 	}
 }
 
-func NewDHCPServer2(iface string, portDesc uint16) (*DHCPServer, *Conn, error) {
-	bpf, ok := UDP_BPF_PORT_MAP[portDesc]
-	if !ok {
-		return nil, nil, fmt.Errorf("BPF not found %d", portDesc)
+func NewDHCPServer2(iface string, port uint16) (*DHCPServer, *Conn, error) {
+	bpf := []bpf.RawInstruction{ // ip and udp and dst port 67
+		{0x28, 0, 0, 0x0000000c},
+		{0x15, 0, 8, 0x00000800},
+		{0x30, 0, 0, 0x00000017},
+		{0x15, 0, 6, 0x00000011},
+		{0x28, 0, 0, 0x00000014},
+		{0x45, 4, 0, 0x00001fff},
+		{0xb1, 0, 0, 0x0000000e},
+		{0x48, 0, 0, 0x00000010},
+		{0x15, 0, 1, uint32(port)},
+		{0x6, 0, 0, 0x00040000},
+		{0x6, 0, 0, 0x00000000},
+	}
+	conn, err := NewSocketConn(iface, bpf)
+	if err != nil {
+		return nil, nil, err
+	}
+	return &DHCPServer{
+		conn: conn,
+	}, conn, nil
+}
+
+func NewDHCPServerWithRelay(iface string, dhcpServerPort, dhcpRelayPort uint16) (*DHCPServer, *Conn, error) {
+	// ip and udp and port 67 and port 68
+	bpf := []bpf.RawInstruction{
+		{0x28, 0, 0, 0x0000000c},
+		{0x15, 0, 13, 0x00000800},
+		{0x30, 0, 0, 0x00000017},
+		{0x15, 0, 11, 0x00000011},
+		{0x28, 0, 0, 0x00000014},
+		{0x45, 9, 0, 0x00001fff},
+		{0xb1, 0, 0, 0x0000000e},
+		{0x48, 0, 0, 0x0000000e},
+		{0x15, 0, 2, uint32(dhcpServerPort)},
+		{0x48, 0, 0, 0x00000010},
+		{0x15, 3, 4, uint32(dhcpRelayPort)},
+		{0x15, 0, 3, uint32(dhcpRelayPort)},
+		{0x48, 0, 0, 0x00000010},
+		{0x15, 0, 1, uint32(dhcpServerPort)},
+		{0x6, 0, 0, 0x00040000},
+		{0x6, 0, 0, 0x00000000},
 	}
 	conn, err := NewSocketConn(iface, bpf)
 	if err != nil {