kilo/pkg/encapsulation/ipip.go

108 lines
2.9 KiB
Go

// Copyright 2019 the Kilo 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 encapsulation
import (
"fmt"
"net"
"github.com/squat/kilo/pkg/iproute"
"github.com/squat/kilo/pkg/iptables"
)
// Strategy identifies which packets within a location should
// be encapsulated.
type Strategy string
const (
// Never indicates that no packets within a location
// should be encapsulated.
Never Strategy = "never"
// CrossSubnet indicates that only packets that
// traverse subnets within a location should be encapsulated.
CrossSubnet Strategy = "crosssubnet"
// Always indicates that all packets within a location
// should be encapsulated.
Always Strategy = "always"
)
// Interface can configure
// the encapsulation interface, init itself,
// get the encapsulation interface index,
// set the interface IP address,
// return the required IPTables rules,
// return the encapsulation strategy,
// and clean up any changes applied to the backend.
type Interface interface {
CleanUp() error
Index() int
Init(int) error
Rules([]*net.IPNet) []iptables.Rule
Set(*net.IPNet) error
Strategy() Strategy
}
type ipip struct {
iface int
strategy Strategy
}
// NewIPIP returns an encapsulation that uses IPIP.
func NewIPIP(strategy Strategy) Interface {
return &ipip{strategy: strategy}
}
// CleanUp will remove any created IPIP devices.
func (i *ipip) CleanUp() error {
if err := iproute.DeleteAddresses(i.iface); err != nil {
return nil
}
return iproute.RemoveInterface(i.iface)
}
// Index returns the index of the IPIP interface.
func (i *ipip) Index() int {
return i.iface
}
// Init initializes the IPIP interface.
func (i *ipip) Init(base int) error {
iface, err := iproute.NewIPIP(base)
if err != nil {
return fmt.Errorf("failed to create tunnel interface: %v", err)
}
if err := iproute.Set(iface, true); err != nil {
return fmt.Errorf("failed to set tunnel interface up: %v", err)
}
i.iface = iface
return nil
}
// Rules returns a set of iptables rules that are necessary
// when traffic between nodes must be encapsulated.
func (i *ipip) Rules(nodes []*net.IPNet) []iptables.Rule {
return iptables.IPIPRules(nodes)
}
// Set sets the IP address of the IPIP interface.
func (i *ipip) Set(cidr *net.IPNet) error {
return iproute.SetAddress(i.iface, cidr)
}
// Strategy returns the configured strategy for encapsulation.
func (i *ipip) Strategy() Strategy {
return i.strategy
}