kowarp

README

About

This is Kowarp, Kowabunga VRRP (Virtual Router Redundancy Protocol) implementation library.

Current Releases

Project	Release Badge
Kowarp

Local testing

To test kowarp in a non-kowabunga environment and load a virtual router manually:

Replace the following (*Kowarp) loadConfig with the following code and build it (replace yours IPs and config up to your desires):

func (*Kowarp) loadTestConfig() ([]*virtualRouter, error) {
	var (
		peer_ips []net.IP
		priority uint8
		vrs      []*virtualRouter
	)
	ips := []string{"10.69.64.139", "10.69.64.140"}
	localip := getLocalIP()

	for _, ip := range ips {
		if ip != localip {
			peer_ips = append(peer_ips, net.ParseIP(ip))
		}
	}

	if localip == ips[0] {
		priority = 255
	} else {
		priority = 0
	}
	ip, err := netlink.ParseAddr("10.69.68.141/24")
	vips := []netlink.Addr{*ip}

	advitf, _ := findFirstPrivateInterface()
	vr, err := NewVirtualRouter(1, peer_ips, priority, vips, 100, advitf.Name, advitf.Name, net.ParseIP(localip), false, nil)
	if err != nil {
		return nil, err
	}
	vrs = append(vrs, vr)

	klog.Infof("Loaded VR : \n%#v", *vr)
	return vrs, nil
}

func getLocalIP() string {
	addrs, err := net.InterfaceAddrs()
	if err != nil {
		return ""
	}
	for _, address := range addrs {
		// check the address type and if it is not a loopback the display it
		if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() && ipnet.IP.IsPrivate() {
			if ipnet.IP.To4() != nil {
				return ipnet.IP.String()
			}
		}
	}
	return ""
}

License

Licensed under Apache License, Version 2.0, see LICENSE.

Documentation

Index

• Constants
• Variables
• func NewVirtualRouter(id uint8, peers []net.IP, priority uint8, ipAddrs []netlink.Addr, ...) (*virtualRouter, error)
• func VRRPConn(src net.IP, isForMulticastTarget bool) (*net.IPConn, error)
• func VRRPMulticastReaderConn(multicastAddress, local net.IP) (*net.IPConn, error)
• type EVENT
• type KowabungaVRRP
  • func (v *KowabungaVRRP) DecodeFromBytes(data []byte) error
  • func (v *KowabungaVRRP) Serialize(source, dest *net.IP, computeChecksum bool) ([]byte, error)
  • func (v *KowabungaVRRP) ValidateChecksum(source, dest *net.IP) (bool, uint16, error)
• type KowabungaVRRPAuthType
  • func (v KowabungaVRRPAuthType) String() string
• type KowabungaVRRPType
  • func (v KowabungaVRRPType) String() string
• type Kowarp
  • func (k *Kowarp) LoadAndConfigureRouters(routinesErrorsFeedback chan<- error)
  • func (k *Kowarp) Run()
• type PseudoHeader
  • func (header PseudoHeader) Serialize() []byte
• type RxBroker
  • func (rb *RxBroker) Run(routineUnhandledError chan error)
  • func (rb *RxBroker) Stop()
• type STATE
• type VirtualRoute
  • func (r1 *VirtualRoute) Equal(r2 *VirtualRoute) bool

Constants

const (
	KowabungaVRRPDefaultAdvertisementInterval uint16 = 100 //in centisecond
	KowabungaVRRPDefaultRouteMetric           int    = 50
)

const (
	KowabungaVRRPVersion        uint8                 = 15
	KowabungaVRRPAuthNoAuth     KowabungaVRRPAuthType = 0x00 // No Authentication
	KowabungaVRRPAuthReserved1  KowabungaVRRPAuthType = 0x01 // Reserved field 1
	KowabungaVRRPAuthReserved2  KowabungaVRRPAuthType = 0x02 // Reserved field 2
	KowabungaVRRPTTL            uint8                 = 255
	KowabungaVRRPIPv4BaseLength uint16                = 8
	VRRPReservedProtocolId      uint16                = 112
)

const (
	BroadcastAddress              = "ff:ff:ff:ff:ff:ff"
	KowabungaVRRPMulticastAddress = "224.0.0.18"
)

const (
	ErrorKowarpNotRoot = "Kowarp is not running with root privileges"
)

Variables

var KowabungaVRRPVMacPrefix = "00-00-5E-00-01-"

var VRRPNetworkBroker vrrpNet = vrrpNet{
	// contains filtered or unexported fields
}

var VirtualRouters map[uint8]*virtualRouter

Functions

func NewVirtualRouter

func NewVirtualRouter(
	id uint8,
	peers []net.IP,
	priority uint8,
	ipAddrs []netlink.Addr,
	advertisementInterval uint16,
	advertisementInterfaceName string,
	vrrpInterfaceName string,
	preferredSourceIP net.IP,
	useVmac bool,
	virtualRoutes []VirtualRoute) (*virtualRouter, error)

func VRRPConn

func VRRPConn(src net.IP, isForMulticastTarget bool) (*net.IPConn, error)

Prepare Multicast OR Unicast

func VRRPMulticastReaderConn

func VRRPMulticastReaderConn(multicastAddress, local net.IP) (*net.IPConn, error)

Types

type EVENT

type EVENT byte

const (
	SHUTDOWN EVENT = iota
	START
	DOWN
)

type KowabungaVRRP

type KowabungaVRRP struct {
	Version      uint8             // The version field specifies the VRRP protocol version of this packet (v255 KowabungaCustom)
	Type         KowabungaVRRPType // The type field specifies the type of this VRRP packet.  The only type defined is ADVERTISEMENT
	VirtualRtrID uint8             // identifies the virtual router this packet is reporting status for
	Priority     uint8             // specifies the sending VRRP router's priority for the virtual router (100 = default)
	CountIPAddr  uint8             // The number of IP addresses contained in this VRRP advertisement.
	AdverInt     uint16            // The Advertisement interval indicates the time interval (in centiseconds) between ADVERTISEMENTS.  The default must be 100 centiseconds (1 second).
	Checksum     uint16            // used to detect data corruption in the VRRP message.
	IPAddresses  []net.IP          // one or more IP addresses associated with the virtual router. Specified in the CountIPAddr field.
	// contains filtered or unexported fields
}

KowabungaVRRP represents an VRRP v15 message. Derived from VRRP3 impl. IPV4 only 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Fields | ... ... | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Version| Type | Virtual Rtr ID| Priority |Count IPvX Addr| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |(rsvd) | Max Adver Int | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | IPvX Address(es) | + + + + + + + + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

func (*KowabungaVRRP) DecodeFromBytes

func (v *KowabungaVRRP) DecodeFromBytes(data []byte) error

func (*KowabungaVRRP) Serialize

func (v *KowabungaVRRP) Serialize(source, dest *net.IP, computeChecksum bool) ([]byte, error)

computeChecksum=true to send packet computeChecksum=false when receive

func (*KowabungaVRRP) ValidateChecksum

func (v *KowabungaVRRP) ValidateChecksum(source, dest *net.IP) (bool, uint16, error)

type KowabungaVRRPAuthType

type KowabungaVRRPAuthType uint8

func (KowabungaVRRPAuthType) String

func (v KowabungaVRRPAuthType) String() string

type KowabungaVRRPType

type KowabungaVRRPType uint8

const (
	KowabungaVRRPAdvertisement KowabungaVRRPType = 0x01 // router advertisement
)

func (KowabungaVRRPType) String

func (v KowabungaVRRPType) String() string

String conversions for VRRP message types

type Kowarp

type Kowarp struct{}

func (*Kowarp) LoadAndConfigureRouters

func (k *Kowarp) LoadAndConfigureRouters(routinesErrorsFeedback chan<- error)

func (*Kowarp) Run

func (k *Kowarp) Run()

type PseudoHeader

type PseudoHeader struct {
	SourceAddress      net.IP
	DestinationAddress net.IP
	// contains filtered or unexported fields
}

Pseudo header required for checksum computation. see RFC2460

func (PseudoHeader) Serialize

func (header PseudoHeader) Serialize() []byte

type RxBroker

type RxBroker struct {
	// contains filtered or unexported fields
}

var VRRPBroker *RxBroker = &RxBroker{
	registerVirtualRouters:   make(chan *virtualRouter),
	deregisterVirtualRouters: make(chan *virtualRouter),
	packet:                   make(chan *KowabungaVRRP),
	event:                    make(chan EVENT),
}

func (*RxBroker) Run

func (rb *RxBroker) Run(routineUnhandledError chan error)

func (*RxBroker) Stop

func (rb *RxBroker) Stop()

type STATE

type STATE byte

const (
	INIT STATE = iota
	MASTER
	BACKUP
)

type VirtualRoute

type VirtualRoute struct {
	Destination net.IPNet
	Gateway     net.IP
	Interface   net.Interface
	Metric      int
}

func (*VirtualRoute) Equal

func (r1 *VirtualRoute) Equal(r2 *VirtualRoute) bool