kilo/pkg/mesh/mesh.go
Lucas Servén Marín a1af9790ea
Merge pull request #278 from SerialVelocity/fix-peer-node-equality-checking
Fix peer and node equality checking
2022-03-01 21:09:46 +01:00

820 lines
24 KiB
Go

// Copyright 2021 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.
//go:build linux
// +build linux
package mesh
import (
"bytes"
"fmt"
"io/ioutil"
"net"
"os"
"sync"
"time"
"github.com/go-kit/kit/log"
"github.com/go-kit/kit/log/level"
"github.com/prometheus/client_golang/prometheus"
"github.com/vishvananda/netlink"
"golang.zx2c4.com/wireguard/wgctrl"
"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
"github.com/squat/kilo/pkg/encapsulation"
"github.com/squat/kilo/pkg/iproute"
"github.com/squat/kilo/pkg/iptables"
"github.com/squat/kilo/pkg/route"
"github.com/squat/kilo/pkg/wireguard"
)
const (
// kiloPath is the directory where Kilo stores its configuration.
kiloPath = "/var/lib/kilo"
// privateKeyPath is the filepath where the WireGuard private key is stored.
privateKeyPath = kiloPath + "/key"
)
// Mesh is able to create Kilo network meshes.
type Mesh struct {
Backend
cleanUpIface bool
cni bool
cniPath string
enc encapsulation.Encapsulator
externalIP *net.IPNet
granularity Granularity
hostname string
internalIP *net.IPNet
ipTables *iptables.Controller
kiloIface int
kiloIfaceName string
key []byte
local bool
port int
priv wgtypes.Key
privIface int
pub wgtypes.Key
resyncPeriod time.Duration
iptablesForwardRule bool
stop chan struct{}
subnet *net.IPNet
table *route.Table
wireGuardIP *net.IPNet
// nodes and peers are mutable fields in the struct
// and need to be guarded.
nodes map[string]*Node
peers map[string]*Peer
mu sync.Mutex
errorCounter *prometheus.CounterVec
leaderGuage prometheus.Gauge
nodesGuage prometheus.Gauge
peersGuage prometheus.Gauge
reconcileCounter prometheus.Counter
logger log.Logger
}
// New returns a new Mesh instance.
func New(backend Backend, enc encapsulation.Encapsulator, granularity Granularity, hostname string, port int, subnet *net.IPNet, local, cni bool, cniPath, iface string, cleanUpIface bool, createIface bool, mtu uint, resyncPeriod time.Duration, prioritisePrivateAddr, iptablesForwardRule bool, logger log.Logger) (*Mesh, error) {
if err := os.MkdirAll(kiloPath, 0700); err != nil {
return nil, fmt.Errorf("failed to create directory to store configuration: %v", err)
}
privateB, err := ioutil.ReadFile(privateKeyPath)
privateB = bytes.Trim(privateB, "\n")
private, err := wgtypes.ParseKey(string(privateB))
if err != nil {
level.Warn(logger).Log("msg", "no private key found on disk; generating one now")
if private, err = wgtypes.GeneratePrivateKey(); err != nil {
return nil, err
}
}
public := private.PublicKey()
if err != nil {
return nil, err
}
if err := ioutil.WriteFile(privateKeyPath, []byte(private.String()), 0600); err != nil {
return nil, fmt.Errorf("failed to write private key to disk: %v", err)
}
cniIndex, err := cniDeviceIndex()
if err != nil {
return nil, fmt.Errorf("failed to query netlink for CNI device: %v", err)
}
var kiloIface int
if createIface {
kiloIface, _, err = wireguard.New(iface, mtu)
if err != nil {
return nil, fmt.Errorf("failed to create WireGuard interface: %v", err)
}
} else {
link, err := netlink.LinkByName(iface)
if err != nil {
return nil, fmt.Errorf("failed to get interface index: %v", err)
}
kiloIface = link.Attrs().Index
}
privateIP, publicIP, err := getIP(hostname, kiloIface, enc.Index(), cniIndex)
if err != nil {
return nil, fmt.Errorf("failed to find public IP: %v", err)
}
var privIface int
if privateIP != nil {
ifaces, err := interfacesForIP(privateIP)
if err != nil {
return nil, fmt.Errorf("failed to find interface for private IP: %v", err)
}
privIface = ifaces[0].Index
if enc.Strategy() != encapsulation.Never {
if err := enc.Init(privIface); err != nil {
return nil, fmt.Errorf("failed to initialize encapsulator: %v", err)
}
}
level.Debug(logger).Log("msg", fmt.Sprintf("using %s as the private IP address", privateIP.String()))
} else {
enc = encapsulation.Noop(enc.Strategy())
level.Debug(logger).Log("msg", "running without a private IP address")
}
var externalIP *net.IPNet
if prioritisePrivateAddr && privateIP != nil {
externalIP = privateIP
} else {
externalIP = publicIP
}
level.Debug(logger).Log("msg", fmt.Sprintf("using %s as the public IP address", publicIP.String()))
ipTables, err := iptables.New(iptables.WithLogger(log.With(logger, "component", "iptables")), iptables.WithResyncPeriod(resyncPeriod))
if err != nil {
return nil, fmt.Errorf("failed to IP tables controller: %v", err)
}
return &Mesh{
Backend: backend,
cleanUpIface: cleanUpIface,
cni: cni,
cniPath: cniPath,
enc: enc,
externalIP: externalIP,
granularity: granularity,
hostname: hostname,
internalIP: privateIP,
ipTables: ipTables,
kiloIface: kiloIface,
kiloIfaceName: iface,
nodes: make(map[string]*Node),
peers: make(map[string]*Peer),
port: port,
priv: private,
privIface: privIface,
pub: public,
resyncPeriod: resyncPeriod,
iptablesForwardRule: iptablesForwardRule,
local: local,
stop: make(chan struct{}),
subnet: subnet,
table: route.NewTable(),
errorCounter: prometheus.NewCounterVec(prometheus.CounterOpts{
Name: "kilo_errors_total",
Help: "Number of errors that occurred while administering the mesh.",
}, []string{"event"}),
leaderGuage: prometheus.NewGauge(prometheus.GaugeOpts{
Name: "kilo_leader",
Help: "Leadership status of the node.",
}),
nodesGuage: prometheus.NewGauge(prometheus.GaugeOpts{
Name: "kilo_nodes",
Help: "Number of nodes in the mesh.",
}),
peersGuage: prometheus.NewGauge(prometheus.GaugeOpts{
Name: "kilo_peers",
Help: "Number of peers in the mesh.",
}),
reconcileCounter: prometheus.NewCounter(prometheus.CounterOpts{
Name: "kilo_reconciles_total",
Help: "Number of reconciliation attempts.",
}),
logger: logger,
}, nil
}
// Run starts the mesh.
func (m *Mesh) Run() error {
if err := m.Nodes().Init(m.stop); err != nil {
return fmt.Errorf("failed to initialize node backend: %v", err)
}
// Try to set the CNI config quickly.
if m.cni {
if n, err := m.Nodes().Get(m.hostname); err == nil {
m.nodes[m.hostname] = n
m.updateCNIConfig()
} else {
level.Warn(m.logger).Log("error", fmt.Errorf("failed to get node %q: %v", m.hostname, err))
}
}
if err := m.Peers().Init(m.stop); err != nil {
return fmt.Errorf("failed to initialize peer backend: %v", err)
}
ipTablesErrors, err := m.ipTables.Run(m.stop)
if err != nil {
return fmt.Errorf("failed to watch for IP tables updates: %v", err)
}
routeErrors, err := m.table.Run(m.stop)
if err != nil {
return fmt.Errorf("failed to watch for route table updates: %v", err)
}
go func() {
for {
var err error
select {
case err = <-ipTablesErrors:
case err = <-routeErrors:
case <-m.stop:
return
}
if err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("run").Inc()
}
}
}()
defer m.cleanUp()
resync := time.NewTimer(m.resyncPeriod)
checkIn := time.NewTimer(checkInPeriod)
nw := m.Nodes().Watch()
pw := m.Peers().Watch()
var ne *NodeEvent
var pe *PeerEvent
for {
select {
case ne = <-nw:
m.syncNodes(ne)
case pe = <-pw:
m.syncPeers(pe)
case <-checkIn.C:
m.checkIn()
checkIn.Reset(checkInPeriod)
case <-resync.C:
if m.cni {
m.updateCNIConfig()
}
m.applyTopology()
resync.Reset(m.resyncPeriod)
case <-m.stop:
return nil
}
}
}
func (m *Mesh) syncNodes(e *NodeEvent) {
logger := log.With(m.logger, "event", e.Type)
level.Debug(logger).Log("msg", "syncing nodes", "event", e.Type)
if isSelf(m.hostname, e.Node) {
level.Debug(logger).Log("msg", "processing local node", "node", e.Node)
m.handleLocal(e.Node)
return
}
var diff bool
m.mu.Lock()
if !e.Node.Ready() {
// Trace non ready nodes with their presence in the mesh.
_, ok := m.nodes[e.Node.Name]
level.Debug(logger).Log("msg", "received non ready node", "node", e.Node, "in-mesh", ok)
}
switch e.Type {
case AddEvent:
fallthrough
case UpdateEvent:
if !nodesAreEqual(m.nodes[e.Node.Name], e.Node) {
diff = true
}
// Even if the nodes are the same,
// overwrite the old node to update the timestamp.
m.nodes[e.Node.Name] = e.Node
case DeleteEvent:
delete(m.nodes, e.Node.Name)
diff = true
}
m.mu.Unlock()
if diff {
level.Info(logger).Log("node", e.Node)
m.applyTopology()
}
}
func (m *Mesh) syncPeers(e *PeerEvent) {
logger := log.With(m.logger, "event", e.Type)
level.Debug(logger).Log("msg", "syncing peers", "event", e.Type)
var diff bool
m.mu.Lock()
// Peers are indexed by public key.
key := e.Peer.PublicKey.String()
if !e.Peer.Ready() {
// Trace non ready peer with their presence in the mesh.
_, ok := m.peers[key]
level.Debug(logger).Log("msg", "received non ready peer", "peer", e.Peer, "in-mesh", ok)
}
switch e.Type {
case AddEvent:
fallthrough
case UpdateEvent:
if e.Old != nil && key != e.Old.PublicKey.String() {
delete(m.peers, e.Old.PublicKey.String())
diff = true
}
if !peersAreEqual(m.peers[key], e.Peer) {
m.peers[key] = e.Peer
diff = true
}
case DeleteEvent:
delete(m.peers, key)
diff = true
}
m.mu.Unlock()
if diff {
level.Info(logger).Log("peer", e.Peer)
m.applyTopology()
}
}
// checkIn will try to update the local node's LastSeen timestamp
// in the backend.
func (m *Mesh) checkIn() {
m.mu.Lock()
defer m.mu.Unlock()
n := m.nodes[m.hostname]
if n == nil {
level.Debug(m.logger).Log("msg", "no local node found in backend")
return
}
oldTime := n.LastSeen
n.LastSeen = time.Now().Unix()
if err := m.Nodes().Set(m.hostname, n); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to set local node: %v", err), "node", n)
m.errorCounter.WithLabelValues("checkin").Inc()
// Revert time.
n.LastSeen = oldTime
return
}
level.Debug(m.logger).Log("msg", "successfully checked in local node in backend")
}
func (m *Mesh) handleLocal(n *Node) {
// Allow the IPs to be overridden.
if !n.Endpoint.Ready() {
e := wireguard.NewEndpoint(m.externalIP.IP, m.port)
level.Info(m.logger).Log("msg", "overriding endpoint", "node", m.hostname, "old endpoint", n.Endpoint.String(), "new endpoint", e.String())
n.Endpoint = e
}
if n.InternalIP == nil && !n.NoInternalIP {
n.InternalIP = m.internalIP
}
// Compare the given node to the calculated local node.
// Take leader, location, and subnet from the argument, as these
// are not determined by kilo.
local := &Node{
Endpoint: n.Endpoint,
Key: m.pub,
NoInternalIP: n.NoInternalIP,
InternalIP: n.InternalIP,
LastSeen: time.Now().Unix(),
Leader: n.Leader,
Location: n.Location,
Name: m.hostname,
PersistentKeepalive: n.PersistentKeepalive,
Subnet: n.Subnet,
WireGuardIP: m.wireGuardIP,
DiscoveredEndpoints: n.DiscoveredEndpoints,
AllowedLocationIPs: n.AllowedLocationIPs,
Granularity: m.granularity,
}
if !nodesAreEqual(n, local) {
level.Debug(m.logger).Log("msg", "local node differs from backend")
if err := m.Nodes().Set(m.hostname, local); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to set local node: %v", err), "node", local)
m.errorCounter.WithLabelValues("local").Inc()
return
}
level.Debug(m.logger).Log("msg", "successfully reconciled local node against backend")
}
m.mu.Lock()
n = m.nodes[m.hostname]
if n == nil {
n = &Node{}
}
m.mu.Unlock()
if !nodesAreEqual(n, local) {
m.mu.Lock()
m.nodes[local.Name] = local
m.mu.Unlock()
m.applyTopology()
}
}
func (m *Mesh) applyTopology() {
m.reconcileCounter.Inc()
m.mu.Lock()
defer m.mu.Unlock()
// If we can't resolve an endpoint, then fail and retry later.
if err := m.resolveEndpoints(); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
// Ensure only ready nodes are considered.
nodes := make(map[string]*Node)
var readyNodes float64
for k := range m.nodes {
m.nodes[k].Granularity = m.granularity
if !m.nodes[k].Ready() {
continue
}
// Make it point to the node without copy.
nodes[k] = m.nodes[k]
readyNodes++
}
// Ensure only ready nodes are considered.
peers := make(map[string]*Peer)
var readyPeers float64
for k := range m.peers {
if !m.peers[k].Ready() {
continue
}
// Make it point the peer without copy.
peers[k] = m.peers[k]
readyPeers++
}
m.nodesGuage.Set(readyNodes)
m.peersGuage.Set(readyPeers)
// We cannot do anything with the topology until the local node is available.
if nodes[m.hostname] == nil {
return
}
// Find the Kilo interface name.
link, err := linkByIndex(m.kiloIface)
if err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
wgClient, err := wgctrl.New()
if err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
defer wgClient.Close()
// wgDevice is the current configuration of the wg interface.
wgDevice, err := wgClient.Device(m.kiloIfaceName)
if err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
natEndpoints := discoverNATEndpoints(nodes, peers, wgDevice, m.logger)
nodes[m.hostname].DiscoveredEndpoints = natEndpoints
t, err := NewTopology(nodes, peers, m.granularity, m.hostname, nodes[m.hostname].Endpoint.Port(), m.priv, m.subnet, nodes[m.hostname].PersistentKeepalive, m.logger)
if err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
// Update the node's WireGuard IP.
if t.leader {
m.wireGuardIP = t.wireGuardCIDR
} else {
m.wireGuardIP = nil
}
ipRules := t.Rules(m.cni, m.iptablesForwardRule)
// If we are handling local routes, ensure the local
// tunnel has an IP address and IPIP traffic is allowed.
if m.enc.Strategy() != encapsulation.Never && m.local {
var cidrs []*net.IPNet
for _, s := range t.segments {
// If the location prefix is not logicalLocation, but nodeLocation,
// we don't need to set any extra rules for encapsulation anyways
// because traffic will go over WireGuard.
if s.location == logicalLocationPrefix+nodes[m.hostname].Location {
for i := range s.privateIPs {
cidrs = append(cidrs, oneAddressCIDR(s.privateIPs[i]))
}
break
}
}
ipRules = append(ipRules, m.enc.Rules(cidrs)...)
// If we are handling local routes, ensure the local
// tunnel has an IP address.
if err := m.enc.Set(oneAddressCIDR(newAllocator(*nodes[m.hostname].Subnet).next().IP)); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
}
if err := m.ipTables.Set(ipRules); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
if t.leader {
m.leaderGuage.Set(1)
if err := iproute.SetAddress(m.kiloIface, t.wireGuardCIDR); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
// Setting the WireGuard configuration interrupts existing connections
// so only set the configuration if it has changed.
conf := t.Conf()
equal, diff := conf.Equal(wgDevice)
if !equal {
level.Info(m.logger).Log("msg", "WireGuard configurations are different", "diff", diff)
level.Debug(m.logger).Log("msg", "changing wg config", "config", conf.WGConfig())
if err := wgClient.ConfigureDevice(m.kiloIfaceName, conf.WGConfig()); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
}
if err := iproute.Set(m.kiloIface, true); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
} else {
m.leaderGuage.Set(0)
level.Debug(m.logger).Log("msg", "local node is not the leader")
if err := iproute.Set(m.kiloIface, false); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
return
}
}
// We need to add routes last since they may depend
// on the WireGuard interface.
routes, rules := t.Routes(link.Attrs().Name, m.kiloIface, m.privIface, m.enc.Index(), m.local, m.enc)
if err := m.table.Set(routes, rules); err != nil {
level.Error(m.logger).Log("error", err)
m.errorCounter.WithLabelValues("apply").Inc()
}
}
// RegisterMetrics registers Prometheus metrics on the given Prometheus
// registerer.
func (m *Mesh) RegisterMetrics(r prometheus.Registerer) {
r.MustRegister(
m.errorCounter,
m.leaderGuage,
m.nodesGuage,
m.peersGuage,
m.reconcileCounter,
)
}
// Stop stops the mesh.
func (m *Mesh) Stop() {
close(m.stop)
}
func (m *Mesh) cleanUp() {
if err := m.ipTables.CleanUp(); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to clean up IP tables: %v", err))
m.errorCounter.WithLabelValues("cleanUp").Inc()
}
if err := m.table.CleanUp(); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to clean up routes: %v", err))
m.errorCounter.WithLabelValues("cleanUp").Inc()
}
if m.cleanUpIface {
if err := iproute.RemoveInterface(m.kiloIface); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to remove WireGuard interface: %v", err))
m.errorCounter.WithLabelValues("cleanUp").Inc()
}
}
if err := m.Nodes().CleanUp(m.hostname); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to clean up node backend: %v", err))
m.errorCounter.WithLabelValues("cleanUp").Inc()
}
if err := m.Peers().CleanUp(m.hostname); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to clean up peer backend: %v", err))
m.errorCounter.WithLabelValues("cleanUp").Inc()
}
if err := m.enc.CleanUp(); err != nil {
level.Error(m.logger).Log("error", fmt.Sprintf("failed to clean up encapsulator: %v", err))
m.errorCounter.WithLabelValues("cleanUp").Inc()
}
}
func (m *Mesh) resolveEndpoints() error {
for k := range m.nodes {
// Skip unready nodes, since they will not be used
// in the topology anyways.
if !m.nodes[k].Ready() {
continue
}
// Resolve the Endpoint
if _, err := m.nodes[k].Endpoint.UDPAddr(true); err != nil {
return err
}
}
for k := range m.peers {
// Skip unready peers, since they will not be used
// in the topology anyways.
if !m.peers[k].Ready() {
continue
}
// Peers may have nil endpoints.
if !m.peers[k].Endpoint.Ready() {
continue
}
if _, err := m.peers[k].Endpoint.UDPAddr(true); err != nil {
return err
}
}
return nil
}
func isSelf(hostname string, node *Node) bool {
return node != nil && node.Name == hostname
}
func nodesAreEqual(a, b *Node) bool {
if (a != nil) != (b != nil) {
return false
}
if a == b {
return true
}
// Check the DNS name first since this package
// is doing the DNS resolution.
if !a.Endpoint.Equal(b.Endpoint, true) {
return false
}
// Ignore LastSeen when comparing equality we want to check if the nodes are
// equivalent. However, we do want to check if LastSeen has transitioned
// between valid and invalid.
return a.Key.String() == b.Key.String() &&
ipNetsEqual(a.WireGuardIP, b.WireGuardIP) &&
ipNetsEqual(a.InternalIP, b.InternalIP) &&
a.Leader == b.Leader &&
a.Location == b.Location &&
a.Name == b.Name &&
subnetsEqual(a.Subnet, b.Subnet) &&
a.Ready() == b.Ready() &&
a.PersistentKeepalive == b.PersistentKeepalive &&
discoveredEndpointsAreEqual(a.DiscoveredEndpoints, b.DiscoveredEndpoints) &&
ipNetSlicesEqual(a.AllowedLocationIPs, b.AllowedLocationIPs) &&
a.Granularity == b.Granularity
}
func peersAreEqual(a, b *Peer) bool {
if !(a != nil) == (b != nil) {
return false
}
if a == b {
return true
}
// Check the DNS name first since this package
// is doing the DNS resolution.
if !a.Endpoint.Equal(b.Endpoint, true) {
return false
}
if len(a.AllowedIPs) != len(b.AllowedIPs) {
return false
}
for i := range a.AllowedIPs {
if !ipNetsEqual(&a.AllowedIPs[i], &b.AllowedIPs[i]) {
return false
}
}
return a.PublicKey.String() == b.PublicKey.String() &&
(a.PresharedKey == nil) == (b.PresharedKey == nil) &&
(a.PresharedKey == nil || a.PresharedKey.String() == b.PresharedKey.String()) &&
(a.PersistentKeepaliveInterval == nil) == (b.PersistentKeepaliveInterval == nil) &&
(a.PersistentKeepaliveInterval == nil || *a.PersistentKeepaliveInterval == *b.PersistentKeepaliveInterval)
}
func ipNetsEqual(a, b *net.IPNet) bool {
if a == nil && b == nil {
return true
}
if (a != nil) != (b != nil) {
return false
}
if a.Mask.String() != b.Mask.String() {
return false
}
return a.IP.Equal(b.IP)
}
func ipNetSlicesEqual(a, b []net.IPNet) bool {
if len(a) != len(b) {
return false
}
for i := range a {
if !ipNetsEqual(&a[i], &b[i]) {
return false
}
}
return true
}
func subnetsEqual(a, b *net.IPNet) bool {
if a == nil && b == nil {
return true
}
if (a != nil) != (b != nil) {
return false
}
if a.Mask.String() != b.Mask.String() {
return false
}
if !a.Contains(b.IP) {
return false
}
if !b.Contains(a.IP) {
return false
}
return true
}
func udpAddrsEqual(a, b *net.UDPAddr) bool {
if a == nil && b == nil {
return true
}
if (a != nil) != (b != nil) {
return false
}
if a.Zone != b.Zone {
return false
}
if a.Port != b.Port {
return false
}
return a.IP.Equal(b.IP)
}
func discoveredEndpointsAreEqual(a, b map[string]*net.UDPAddr) bool {
if a == nil && b == nil {
return true
}
if len(a) != len(b) {
return false
}
for k := range a {
if !udpAddrsEqual(a[k], b[k]) {
return false
}
}
return true
}
func linkByIndex(index int) (netlink.Link, error) {
link, err := netlink.LinkByIndex(index)
if err != nil {
return nil, fmt.Errorf("failed to get interface: %v", err)
}
return link, nil
}
// discoverNATEndpoints uses the node's WireGuard configuration to returns a list of the most recently discovered endpoints for all nodes and peers behind NAT so that they can roam.
// Discovered endpionts will never be DNS names, because WireGuard will always resolve them to net.UDPAddr.
func discoverNATEndpoints(nodes map[string]*Node, peers map[string]*Peer, conf *wgtypes.Device, logger log.Logger) map[string]*net.UDPAddr {
natEndpoints := make(map[string]*net.UDPAddr)
keys := make(map[string]wgtypes.Peer)
for i := range conf.Peers {
keys[conf.Peers[i].PublicKey.String()] = conf.Peers[i]
}
for _, n := range nodes {
if peer, ok := keys[n.Key.String()]; ok && n.PersistentKeepalive != time.Duration(0) {
level.Debug(logger).Log("msg", "WireGuard Update NAT Endpoint", "node", n.Name, "endpoint", peer.Endpoint, "former-endpoint", n.Endpoint, "same", peer.Endpoint.String() == n.Endpoint.String(), "latest-handshake", peer.LastHandshakeTime)
// Don't update the endpoint, if there was never any handshake.
if !peer.LastHandshakeTime.Equal(time.Time{}) {
natEndpoints[n.Key.String()] = peer.Endpoint
}
}
}
for _, p := range peers {
if peer, ok := keys[p.PublicKey.String()]; ok && p.PersistentKeepaliveInterval != nil {
if !peer.LastHandshakeTime.Equal(time.Time{}) {
natEndpoints[p.PublicKey.String()] = peer.Endpoint
}
}
}
level.Debug(logger).Log("msg", "Discovered WireGuard NAT Endpoints", "DiscoveredEndpoints", natEndpoints)
return natEndpoints
}