Initial commit for gocast

controller/bgp.go

@@ -0,0 +1,136 @@
+package controller
+
+import (
+	"context"
+	"fmt"
+	"github.com/golang/protobuf/ptypes"
+	"github.com/golang/protobuf/ptypes/any"
+	api "github.com/osrg/gobgp/api"
+	gobgp "github.com/osrg/gobgp/pkg/server"
+	"net"
+)
+
+type Controller struct {
+	peerAS          int
+	localIP, peerIP net.IP
+	s               *gobgp.BgpServer
+}
+
+func NewController(localAS, peerAS int, peerIP string) (*Controller, error) {
+	c := &Controller{}
+	if peerIP == "" {
+		gw, err := gateway()
+		if err != nil {
+			return nil, err
+		}
+		c.peerIP = gw
+	} else {
+		c.peerIP = net.ParseIP(peerIP)
+	}
+	if c.peerIP == nil {
+		return nil, fmt.Errorf("Unable to get peer IP")
+	}
+	s := gobgp.NewBgpServer()
+	go s.Serve()
+	localAddr, err := localAddress(c.peerIP)
+	if err != nil {
+		return nil, err
+	}
+	c.localIP = localAddr
+	if err := s.StartBgp(context.Background(), &api.StartBgpRequest{
+		Global: &api.Global{
+			As:         uint32(localAS),
+			RouterId:   localAddr.String(),
+			ListenPort: -1, // gobgp won't listen on tcp:179
+		},
+	}); err != nil {
+		return nil, fmt.Errorf("Unable to start bgp: %v", err)
+	}
+	c.s = s
+	c.peerAS = peerAS
+	return c, nil
+}
+
+func (c *Controller) AddPeer(peer string) error {
+	n := &api.Peer{
+		Conf: &api.PeerConf{
+			NeighborAddress: peer,
+			PeerAs:          uint32(c.peerAS),
+		},
+	}
+	return c.s.AddPeer(context.Background(), &api.AddPeerRequest{Peer: n})
+}
+
+func (c *Controller) getApiPath(route *net.IPNet) *api.Path {
+	afi := api.Family_AFI_IP
+	if route.IP.To4() == nil {
+		afi = api.Family_AFI_IP6
+	}
+	prefixlen, _ := route.Mask.Size()
+	nlri, _ := ptypes.MarshalAny(&api.IPAddressPrefix{
+		Prefix:    route.IP.String(),
+		PrefixLen: uint32(prefixlen),
+	})
+	a1, _ := ptypes.MarshalAny(&api.OriginAttribute{
+		Origin: 0,
+	})
+	a2, _ := ptypes.MarshalAny(&api.NextHopAttribute{
+		NextHop: c.localIP.String(),
+	})
+	attrs := []*any.Any{a1, a2}
+	return &api.Path{
+		Family:    &api.Family{Afi: afi, Safi: api.Family_SAFI_UNICAST},
+		AnyNlri:   nlri,
+		AnyPattrs: attrs,
+	}
+}
+
+func (c *Controller) Announce(route *net.IPNet) error {
+	peers, err := c.s.ListPeer(context.Background(), &api.ListPeerRequest{})
+	if err != nil {
+		return err
+	}
+	var found bool
+	for _, p := range peers {
+		if p.Conf.NeighborAddress == c.peerIP.String() {
+			found = true
+			break
+		}
+	}
+	if !found {
+		if err := c.AddPeer(c.peerIP.String()); err != nil {
+			return err
+		}
+	}
+	_, err = c.s.AddPath(context.Background(), &api.AddPathRequest{Path: c.getApiPath(route)})
+	return err
+}
+
+func (c *Controller) Withdraw(route *net.IPNet) error {
+	return c.s.DeletePath(context.Background(), &api.DeletePathRequest{Path: c.getApiPath(route)})
+}
+
+func (c *Controller) PeerInfo() (*api.Peer, error) {
+	peers, err := c.s.ListPeer(context.Background(), &api.ListPeerRequest{})
+	if err != nil {
+		return nil, err
+	}
+	for _, p := range peers {
+		if p.Conf.NeighborAddress == c.peerIP.String() {
+			return p, nil
+		}
+	}
+	return nil, nil
+}
+
+func (c *Controller) Shutdown() error {
+	if err := c.s.ShutdownPeer(context.Background(), &api.ShutdownPeerRequest{
+		Address: c.peerIP.String(),
+	}); err != nil {
+		return err
+	}
+	if err := c.s.StopBgp(context.Background(), &api.StopBgpRequest{}); err != nil {
+		return err
+	}
+	return nil
+}