BGP connection on a speecified interface (including which is associat…

…ed VRF) using syscall SO_BINDTODEVICE

api/gobgp.proto

@@ -771,6 +771,7 @@ message Transport {
   string remote_address = 5;
   uint32 remote_port = 6;
   uint32 tcp_mss = 7;
+  string bind_interface = 8;
 }
 
 message RouteServer {

internal/pkg/config/bgp_configs.go

@@ -2548,6 +2548,10 @@ type TransportState struct {
 	// Remote port being used by the peer for the TCP session
 	// supporting the BGP session.
 	RemotePort uint16 `mapstructure:"remote-port" json:"remote-port,omitempty"`
+	// original -> bgp:bind-interface
+	// bgp:bind-interface's original type is union.
+	// Interface name for binding.
+	BindInterface string `mapstructure:"bind-interface" json:"bind-interface,omitempty"`
 }
 
 // struct for container bgp:config.
@@ -2580,6 +2584,10 @@ type TransportConfig struct {
 	// original -> gobgp:ttl
 	// TTL value for BGP packets.
 	Ttl uint8 `mapstructure:"ttl" json:"ttl,omitempty"`
+	// original -> bgp:bind-interface
+	// bgp:bind-interface's original type is union.
+	// Interface name for binding.
+	BindInterface string `mapstructure:"bind-interface" json:"bind-interface,omitempty"`
 }
 
 func (lhs *TransportConfig) Equal(rhs *TransportConfig) bool {
@@ -2604,6 +2612,9 @@ func (lhs *TransportConfig) Equal(rhs *TransportConfig) bool {
 	if lhs.Ttl != rhs.Ttl {
 		return false
 	}
+	if lhs.BindInterface != rhs.BindInterface {
+		return false
+	}
 	return true
 }
 

internal/pkg/config/util.go

@@ -534,9 +534,10 @@ func NewPeerFromConfigStruct(pconf *Neighbor) *api.Peer {
 			LocalRestarting:     pconf.GracefulRestart.State.LocalRestarting,
 		},
 		Transport: &api.Transport{
-			RemotePort:   uint32(pconf.Transport.Config.RemotePort),
-			LocalAddress: localAddress,
-			PassiveMode:  pconf.Transport.Config.PassiveMode,
+			RemotePort:    uint32(pconf.Transport.Config.RemotePort),
+			LocalAddress:  localAddress,
+			PassiveMode:   pconf.Transport.Config.PassiveMode,
+			BindInterface: pconf.Transport.Config.BindInterface,
 		},
 		AfiSafis: afiSafis,
 	}

pkg/server/fsm.go

@@ -491,7 +491,7 @@ func (h *fsmHandler) connectLoop(ctx context.Context, wg *sync.WaitGroup) {
 	defer wg.Done()
 	fsm := h.fsm
 
-	retry, addr, port, password, ttl, ttlMin, localAddress := func() (int, string, int, string, uint8, uint8, string) {
+	retry, addr, port, password, ttl, ttlMin, localAddress, bindInterface := func() (int, string, int, string, uint8, uint8, string, string) {
 		fsm.lock.RLock()
 		defer fsm.lock.RUnlock()
 
@@ -518,7 +518,7 @@ func (h *fsmHandler) connectLoop(ctx context.Context, wg *sync.WaitGroup) {
 				ttl = fsm.pConf.EbgpMultihop.Config.MultihopTtl
 			}
 		}
-		return tick, addr, port, password, ttl, ttlMin, fsm.pConf.Transport.Config.LocalAddress
+		return tick, addr, port, password, ttl, ttlMin, fsm.pConf.Transport.Config.LocalAddress, fsm.pConf.Transport.Config.BindInterface
 	}()
 
 	tick := minConnectRetryInterval
@@ -553,7 +553,7 @@ func (h *fsmHandler) connectLoop(ctx context.Context, wg *sync.WaitGroup) {
 				LocalAddr: laddr,
 				Timeout:   time.Duration(tick-1) * time.Second,
 				Control: func(network, address string, c syscall.RawConn) error {
-					return dialerControl(network, address, c, ttl, ttlMin, password)
+					return dialerControl(network, address, c, ttl, ttlMin, password, bindInterface)
 				},
 			}
 

pkg/server/grpc_server.go

@@ -655,6 +655,7 @@ func newNeighborFromAPIStruct(a *api.Peer) (*config.Neighbor, error) {
 		pconf.Transport.Config.LocalAddress = a.Transport.LocalAddress
 		pconf.Transport.Config.PassiveMode = a.Transport.PassiveMode
 		pconf.Transport.Config.RemotePort = uint16(a.Transport.RemotePort)
+		pconf.Transport.Config.BindInterface = a.Transport.BindInterface
 	}
 	if a.EbgpMultihop != nil {
 		pconf.EbgpMultihop.Config.Enabled = a.EbgpMultihop.Enabled

pkg/server/server.go

@@ -250,6 +250,7 @@ func (s *BgpServer) passConnToPeer(conn *net.TCPConn) {
 		}
 		peer.fsm.lock.RLock()
 		localAddr := peer.fsm.pConf.Transport.Config.LocalAddress
+		bindInterface := peer.fsm.pConf.Transport.Config.BindInterface
 		peer.fsm.lock.RUnlock()
 		localAddrValid := func(laddr string) bool {
 			if laddr == "0.0.0.0" || laddr == "::" {
@@ -262,12 +263,13 @@ func (s *BgpServer) passConnToPeer(conn *net.TCPConn) {
 			}
 
 			host, _, _ := net.SplitHostPort(l.String())
-			if host != laddr {
+			if host != laddr && bindInterface == "" {
 				log.WithFields(log.Fields{
 					"Topic":           "Peer",
 					"Key":             remoteAddr,
 					"Configured addr": laddr,
 					"Addr":            host,
+					"BindInterface":   bindInterface,
 				}).Info("Mismatched local address")
 				return false
 			}

pkg/server/sockopt.go

@@ -39,7 +39,7 @@ func setTCPMinTTLSockopt(conn *net.TCPConn, ttl int) error {
 	return setTcpMinTTLSockopt(conn, ttl)
 }
 
-func dialerControl(network, address string, c syscall.RawConn, ttl, ttlMin uint8, password string) error {
+func dialerControl(network, address string, c syscall.RawConn, ttl, ttlMin uint8, password string, bindInterface string) error {
 	if password != "" {
 		log.WithFields(log.Fields{
 			"Topic": "Peer",

pkg/server/sockopt_linux.go

@@ -103,7 +103,7 @@ func setTCPMinTTLSockopt(conn *net.TCPConn, ttl int) error {
 	return setsockOptInt(sc, level, name, ttl)
 }
 
-func dialerControl(network, address string, c syscall.RawConn, ttl, minTtl uint8, password string) error {
+func dialerControl(network, address string, c syscall.RawConn, ttl, minTtl uint8, password string, bindInterface string) error {
 	family := syscall.AF_INET
 	raddr, _ := net.ResolveTCPAddr("tcp", address)
 	if raddr.IP.To4() == nil {
@@ -161,5 +161,15 @@ func dialerControl(network, address string, c syscall.RawConn, ttl, minTtl uint8
 			return sockerr
 		}
 	}
+	if bindInterface != "" {
+		if err := c.Control(func(fd uintptr) {
+			sockerr = os.NewSyscallError("setsockopt", syscall.SetsockoptString(int(fd), syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, bindInterface))
+		}); err != nil {
+			return err
+		}
+		if sockerr != nil {
+			return sockerr
+		}
+	}
 	return nil
 }

pkg/server/sockopt_openbsd.go

@@ -403,7 +403,7 @@ func setTCPMinTTLSockopt(conn *net.TCPConn, ttl int) error {
 	return setsockOptInt(sc, level, name, ttl)
 }
 
-func dialerControl(network, address string, c syscall.RawConn, ttl, minTtl uint8, password string) error {
+func dialerControl(network, address string, c syscall.RawConn, ttl, minTtl uint8, password string, bindInterface string) error {
 	if password != "" {
 		log.WithFields(log.Fields{
 			"Topic": "Peer",

tools/pyang_plugins/gobgp.yang

@@ -920,6 +920,11 @@ module gobgp {
       description "TTL value for BGP packets";
       type uint8;
     }
+
+    leaf bind-interface {
+      description "Interface name for binding.";
+      type string;
+    }
   }
 
   augment "/bgp:bgp/bgp:neighbors/bgp:neighbor/bgp:timers/bgp:config" {
@@ -1239,6 +1244,12 @@ module gobgp {
         "Configure MPLS label range size which will be requested to
         FRR/Zebra.";
     }
+    leaf software-name {
+      type string;
+      description
+        "Configure zebra software name.
+        quagga, frr3, frr4, frr5, frr6, frr7 can be used.";
+    }
   }
 
   grouping zebra-set {