forked from flannel-io/flannel
/
hostgw.go
87 lines (73 loc) · 2.2 KB
/
hostgw.go
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// +build !windows
// 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.
// +build !windows
package hostgw
import (
"fmt"
"github.com/coreos/flannel/backend"
"github.com/coreos/flannel/pkg/ip"
"github.com/coreos/flannel/subnet"
"github.com/vishvananda/netlink"
"golang.org/x/net/context"
)
func init() {
backend.Register("host-gw", New)
}
type HostgwBackend struct {
sm subnet.Manager
extIface *backend.ExternalInterface
}
func New(sm subnet.Manager, extIface *backend.ExternalInterface) (backend.Backend, error) {
if !extIface.ExtAddr.Equal(extIface.IfaceAddr) {
return nil, fmt.Errorf("your PublicIP differs from interface IP, meaning that probably you're on a NAT, which is not supported by host-gw backend")
}
be := &HostgwBackend{
sm: sm,
extIface: extIface,
}
return be, nil
}
func (be *HostgwBackend) RegisterNetwork(ctx context.Context, config *subnet.Config) (backend.Network, error) {
n := &backend.RouteNetwork{
SimpleNetwork: backend.SimpleNetwork{
ExtIface: be.extIface,
},
SM: be.sm,
BackendType: "host-gw",
Mtu: be.extIface.Iface.MTU,
LinkIndex: be.extIface.Iface.Index,
}
n.GetRoute = func(lease *subnet.Lease) *netlink.Route {
return &netlink.Route{
Dst: lease.Subnet.ToIPNet(),
Gw: lease.Attrs.PublicIP.ToIP(),
LinkIndex: n.LinkIndex,
}
}
attrs := subnet.LeaseAttrs{
PublicIP: ip.FromIP(be.extIface.ExtAddr),
BackendType: "host-gw",
}
l, err := be.sm.AcquireLease(ctx, &attrs)
switch err {
case nil:
n.SubnetLease = l
case context.Canceled, context.DeadlineExceeded:
return nil, err
default:
return nil, fmt.Errorf("failed to acquire lease: %v", err)
}
return n, nil
}