Files
gocast/controller/bgp.go
2018-10-22 19:03:42 -07:00

137 lines
3.1 KiB
Go

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
}