server: add support specifying addresses to listen

Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>

4 files changed, 61 insertions, 35 deletions

diff --git a/config/bgp_configs.go b/config/bgp_configs.go
index c6a3e53e..4191bbd2 100644
--- a/config/bgp_configs.go
+++ b/config/bgp_configs.go
@@ -1448,6 +1448,8 @@ type Neighbor struct {
 type ListenConfig struct {
 	// original -> gobgp:port
 	Port int32 `mapstructure:"port"`
+	// original -> gobgp:local-address
+	LocalAddressList []string `mapstructure:"local-address-list"`
 }
 
 //struct for container gobgp:mpls-label-range
diff --git a/docs/sources/configuration.md b/docs/sources/configuration.md
index abe04d32..4866d950 100644
--- a/docs/sources/configuration.md
+++ b/docs/sources/configuration.md
@@ -22,6 +22,14 @@
     [global.mpls-label-range]
         min-label = 1000
         max-label = 2000
+    [global.listen-config]
+        # listen port (by default 179)
+        port = 1790
+        # to disable listening
+        # port = -1
+
+        # listen address list (by default "0.0.0.0" and "::")
+        local-address-list = ["192.168.10.1", "2001:db8::1"]
 
 [[rpki-servers]]
     [rpki-servers.config]
diff --git a/server/server.go b/server/server.go
index 25ccb9e5..a6d663a7 100644
--- a/server/server.go
+++ b/server/server.go
@@ -102,7 +102,7 @@ type BgpServer struct {
 	policy         *table.RoutingPolicy
 	broadcastReqs  []*GrpcRequest
 	broadcastMsgs  []broadcastMsg
-	listenerMap    map[string]*net.TCPListener
+	listeners      []*net.TCPListener
 	neighborMap    map[string]*Peer
 	globalRib      *table.TableManager
 	zclient        *zebra.Client
@@ -128,13 +128,21 @@ func NewBgpServer() *BgpServer {
 }
 
 // avoid mapped IPv6 address
-func listenAndAccept(proto string, port uint32, ch chan *net.TCPConn) (*net.TCPListener, error) {
-	service := ":" + strconv.Itoa(int(port))
-	addr, _ := net.ResolveTCPAddr(proto, service)
+func listenAndAccept(address string, port uint32, ch chan *net.TCPConn) (*net.TCPListener, error) {
+	proto := "tcp4"
+	if ip := net.ParseIP(address); ip == nil {
+		return nil, fmt.Errorf("can't listen on %s", address)
+	} else if strings.Contains(address, ":") {
+		address = fmt.Sprintf("[%s]", address)
+		proto = "tcp6"
+	}
+	addr, err := net.ResolveTCPAddr(proto, fmt.Sprintf("%s:%d", address, port))
+	if err != nil {
+		return nil, err
+	}
 
 	l, err := net.ListenTCP(proto, addr)
 	if err != nil {
-		log.Info(err)
 		return nil, err
 	}
 	go func() {
@@ -163,6 +171,18 @@ func (server *BgpServer) notify2watchers(typ watcherEventType, ev watcherEvent)
 	return nil
 }
 
+func (server *BgpServer) Listeners(addr string) []*net.TCPListener {
+	list := make([]*net.TCPListener, 0, len(server.listeners))
+	rhs := net.ParseIP(addr).To4() != nil
+	for _, l := range server.listeners {
+		lhs := net.ParseIP(l.Addr().String()).To4() != nil
+		if lhs == rhs {
+			list = append(list, l)
+		}
+	}
+	return list
+}
+
 func (server *BgpServer) Serve() {
 	var g config.Global
 	for {
@@ -256,27 +276,21 @@ func (server *BgpServer) Serve() {
 
 	rfs, _ := config.AfiSafis(g.AfiSafis).ToRfList()
 	server.globalRib = table.NewTableManager(rfs, g.MplsLabelRange.MinLabel, g.MplsLabelRange.MaxLabel)
-	server.listenerMap = make(map[string]*net.TCPListener)
+	server.listeners = make([]*net.TCPListener, 0, 2)
 	acceptCh := make(chan *net.TCPConn, 4096)
 	if g.ListenConfig.Port > 0 {
-		l4, err1 := listenAndAccept("tcp4", uint32(g.ListenConfig.Port), acceptCh)
-		server.listenerMap["tcp4"] = l4
-		l6, err2 := listenAndAccept("tcp6", uint32(g.ListenConfig.Port), acceptCh)
-		server.listenerMap["tcp6"] = l6
-		if err1 != nil && err2 != nil {
-			log.Fatal("can't listen either v4 and v6")
-			os.Exit(1)
+		list := []string{"0.0.0.0", "::"}
+		if len(g.ListenConfig.LocalAddressList) > 0 {
+			list = g.ListenConfig.LocalAddressList
 		}
-	}
-
-	listener := func(addr string) *net.TCPListener {
-		var l *net.TCPListener
-		if net.ParseIP(addr).To4() != nil {
-			l = server.listenerMap["tcp4"]
-		} else {
-			l = server.listenerMap["tcp6"]
+		for _, addr := range list {
+			l, err := listenAndAccept(addr, uint32(g.ListenConfig.Port), acceptCh)
+			if err != nil {
+				log.Fatal(err)
+				os.Exit(1)
+			}
+			server.listeners = append(server.listeners, l)
 		}
-		return l
 	}
 
 	server.fsmincomingCh = make(chan *FsmMsg, 4096)
@@ -393,7 +407,9 @@ func (server *BgpServer) Serve() {
 				continue
 			}
 			if g.ListenConfig.Port > 0 {
-				SetTcpMD5SigSockopts(listener(addr), addr, config.Config.AuthPassword)
+				for _, l := range server.Listeners(addr) {
+					SetTcpMD5SigSockopts(l, addr, config.Config.AuthPassword)
+				}
 			}
 			peer := NewPeer(g, config, server.globalRib, server.policy)
 			server.setPolicyByConfig(peer.ID(), config.ApplyPolicy)
@@ -416,7 +432,9 @@ func (server *BgpServer) Serve() {
 			server.broadcastPeerState(peer, bgp.BGP_FSM_IDLE)
 		case config := <-server.deletedPeerCh:
 			addr := config.Config.NeighborAddress
-			SetTcpMD5SigSockopts(listener(addr), addr, "")
+			for _, l := range server.Listeners(addr) {
+				SetTcpMD5SigSockopts(l, addr, "")
+			}
 			peer, found := server.neighborMap[addr]
 			if found {
 				log.Info("Delete a peer configuration for ", addr)
@@ -2118,15 +2136,6 @@ func (server *BgpServer) handleGrpcModNeighbor(grpcReq *GrpcRequest) (sMsgs []*S
 	if arg.Operation != api.Operation_ADD && !ok {
 		return nil, fmt.Errorf("not found neighbor %s", addr)
 	}
-	listener := func(addr net.IP) *net.TCPListener {
-		var l *net.TCPListener
-		if addr.To4() != nil {
-			l = server.listenerMap["tcp4"]
-		} else {
-			l = server.listenerMap["tcp6"]
-		}
-		return l
-	}
 
 	switch arg.Operation {
 	case api.Operation_ADD:
@@ -2136,7 +2145,9 @@ func (server *BgpServer) handleGrpcModNeighbor(grpcReq *GrpcRequest) (sMsgs []*S
 			log.Infof("Peer %s is added", addr)
 		}
 		if server.bgpConfig.Global.ListenConfig.Port > 0 {
-			SetTcpMD5SigSockopts(listener(net.ParseIP(addr)), addr, arg.Peer.Conf.AuthPassword)
+			for _, l := range server.Listeners(addr) {
+				SetTcpMD5SigSockopts(l, addr, arg.Peer.Conf.AuthPassword)
+			}
 		}
 		apitoConfig := func(a *api.Peer) (config.Neighbor, error) {
 			var pconf config.Neighbor
@@ -2245,7 +2256,9 @@ func (server *BgpServer) handleGrpcModNeighbor(grpcReq *GrpcRequest) (sMsgs []*S
 		peer.startFSMHandler(server.fsmincomingCh, server.fsmStateCh)
 		server.broadcastPeerState(peer, bgp.BGP_FSM_IDLE)
 	case api.Operation_DEL:
-		SetTcpMD5SigSockopts(listener(net.ParseIP(addr)), addr, "")
+		for _, l := range server.Listeners(addr) {
+			SetTcpMD5SigSockopts(l, addr, "")
+		}
 		log.Info("Delete a peer configuration for ", addr)
 		go func(addr string) {
 			t := time.AfterFunc(time.Minute*5, func() { log.Fatal("failed to free the fsm.h.t for ", addr) })
diff --git a/tools/pyang_plugins/gobgp.yang b/tools/pyang_plugins/gobgp.yang
index 29e3342d..0a60ac6f 100644
--- a/tools/pyang_plugins/gobgp.yang
+++ b/tools/pyang_plugins/gobgp.yang
@@ -726,6 +726,9 @@ module gobgp {
         leaf port {
             type int32;
         }
+        leaf-list local-address {
+            type string;
+        }
     }
   }
 }