forked from flannel-io/flannel
/
vxlan.go
148 lines (120 loc) · 3.33 KB
/
vxlan.go
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// Copyright 2015 flannel authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package vxlan
import (
"encoding/json"
"fmt"
"net"
"golang.org/x/net/context"
"github.com/coreos/flannel/backend"
"github.com/coreos/flannel/pkg/ip"
"github.com/coreos/flannel/subnet"
)
func init() {
backend.Register("vxlan", New)
}
const (
defaultVNI = 1
)
type VXLANBackend struct {
sm subnet.Manager
extIface *backend.ExternalInterface
}
func New(sm subnet.Manager, extIface *backend.ExternalInterface) (backend.Backend, error) {
be := &VXLANBackend{
sm: sm,
extIface: extIface,
}
return be, nil
}
func newSubnetAttrs(extEaddr net.IP, mac net.HardwareAddr) (*subnet.LeaseAttrs, error) {
data, err := json.Marshal(&vxlanLeaseAttrs{hardwareAddr(mac)})
if err != nil {
return nil, err
}
return &subnet.LeaseAttrs{
PublicIP: ip.FromIP(extEaddr),
BackendType: "vxlan",
BackendData: json.RawMessage(data),
}, nil
}
func (be *VXLANBackend) Run(ctx context.Context) {
<-ctx.Done()
}
func (be *VXLANBackend) RegisterNetwork(ctx context.Context, network string, config *subnet.Config) (backend.Network, error) {
// Parse our configuration
cfg := struct {
VNI int
Port int
GBP bool
}{
VNI: defaultVNI,
}
if len(config.Backend) > 0 {
if err := json.Unmarshal(config.Backend, &cfg); err != nil {
return nil, fmt.Errorf("error decoding VXLAN backend config: %v", err)
}
}
devAttrs := vxlanDeviceAttrs{
vni: uint32(cfg.VNI),
name: fmt.Sprintf("flannel.%v", cfg.VNI),
vtepIndex: be.extIface.Iface.Index,
vtepAddr: be.extIface.IfaceAddr,
vtepPort: cfg.Port,
gbp: cfg.GBP,
}
dev, err := newVXLANDevice(&devAttrs)
if err != nil {
return nil, err
}
sa, err := newSubnetAttrs(be.extIface.ExtAddr, dev.MACAddr())
if err != nil {
return nil, err
}
l, err := be.sm.AcquireLease(ctx, network, sa)
switch err {
case nil:
case context.Canceled, context.DeadlineExceeded:
return nil, err
default:
return nil, fmt.Errorf("failed to acquire lease: %v", err)
}
// vxlan's subnet is that of the whole overlay network (e.g. /16)
// and not that of the individual host (e.g. /24)
vxlanNet := ip.IP4Net{
IP: l.Subnet.IP,
PrefixLen: config.Network.PrefixLen,
}
if err = dev.Configure(vxlanNet); err != nil {
return nil, err
}
return newNetwork(network, be.sm, be.extIface, dev, vxlanNet, l)
}
// So we can make it JSON (un)marshalable
type hardwareAddr net.HardwareAddr
func (hw hardwareAddr) MarshalJSON() ([]byte, error) {
return []byte(fmt.Sprintf("%q", net.HardwareAddr(hw))), nil
}
func (hw *hardwareAddr) UnmarshalJSON(b []byte) error {
if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
return fmt.Errorf("error parsing hardware addr")
}
b = b[1 : len(b)-1]
mac, err := net.ParseMAC(string(b))
if err != nil {
return err
}
*hw = hardwareAddr(mac)
return nil
}