Feature/android dns (#943)

Support DNS feature on mobile systems

---------

Co-authored-by: Givi Khojanashvili <gigovich@gmail.com>
This commit is contained in:
Zoltan Papp 2023-06-12 14:43:55 +02:00 committed by GitHub
parent f8da516128
commit 481465e1ae
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
27 changed files with 749 additions and 702 deletions

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@ -1,3 +1,5 @@
//go:build !android
package dns
import (

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@ -1,3 +1,5 @@
//go:build !android
package dns
import (

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@ -0,0 +1,24 @@
package dns
import (
"github.com/netbirdio/netbird/iface"
)
type androidHostManager struct {
}
func newHostManager(wgInterface *iface.WGIface) (hostManager, error) {
return &androidHostManager{}, nil
}
func (a androidHostManager) applyDNSConfig(config hostDNSConfig) error {
return nil
}
func (a androidHostManager) restoreHostDNS() error {
return nil
}
func (a androidHostManager) supportCustomPort() bool {
return false
}

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@ -1,3 +1,5 @@
//go:build !android
package dns
import (

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@ -22,7 +22,7 @@ func (d *localResolver) stop() {
// ServeDNS handles a DNS request
func (d *localResolver) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
log.Tracef("received question: %#v\n", r.Question[0])
log.Tracef("received question: %#v", r.Question[0])
replyMessage := &dns.Msg{}
replyMessage.SetReply(r)
replyMessage.RecursionAvailable = true

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@ -26,6 +26,10 @@ func (m *MockServer) Stop() {
}
}
func (m *MockServer) DnsIP() string {
return ""
}
// UpdateDNSServer mock implementation of UpdateDNSServer from Server interface
func (m *MockServer) UpdateDNSServer(serial uint64, update nbdns.Config) error {
if m.UpdateDNSServerFunc != nil {

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@ -1,3 +1,5 @@
//go:build !android
package dns
import (

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@ -1,3 +1,5 @@
//go:build !android
package dns
import (

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@ -1,10 +1,597 @@
package dns
import nbdns "github.com/netbirdio/netbird/dns"
import (
"context"
"fmt"
"math/big"
"net"
"net/netip"
"runtime"
"sync"
"time"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
"github.com/miekg/dns"
"github.com/mitchellh/hashstructure/v2"
log "github.com/sirupsen/logrus"
nbdns "github.com/netbirdio/netbird/dns"
"github.com/netbirdio/netbird/iface"
)
const (
defaultPort = 53
customPort = 5053
defaultIP = "127.0.0.1"
customIP = "127.0.0.153"
)
// Server is a dns server interface
type Server interface {
Start()
Stop()
DnsIP() string
UpdateDNSServer(serial uint64, update nbdns.Config) error
}
type registeredHandlerMap map[string]handlerWithStop
// DefaultServer dns server object
type DefaultServer struct {
ctx context.Context
ctxCancel context.CancelFunc
mux sync.Mutex
fakeResolverWG sync.WaitGroup
server *dns.Server
dnsMux *dns.ServeMux
dnsMuxMap registeredHandlerMap
localResolver *localResolver
wgInterface *iface.WGIface
hostManager hostManager
updateSerial uint64
listenerIsRunning bool
runtimePort int
runtimeIP string
previousConfigHash uint64
currentConfig hostDNSConfig
customAddress *netip.AddrPort
enabled bool
}
type handlerWithStop interface {
dns.Handler
stop()
}
type muxUpdate struct {
domain string
handler handlerWithStop
}
// NewDefaultServer returns a new dns server
func NewDefaultServer(ctx context.Context, wgInterface *iface.WGIface, customAddress string, initialDnsCfg *nbdns.Config) (*DefaultServer, error) {
mux := dns.NewServeMux()
var addrPort *netip.AddrPort
if customAddress != "" {
parsedAddrPort, err := netip.ParseAddrPort(customAddress)
if err != nil {
return nil, fmt.Errorf("unable to parse the custom dns address, got error: %s", err)
}
addrPort = &parsedAddrPort
}
hostManager, err := newHostManager(wgInterface)
if err != nil {
return nil, err
}
ctx, stop := context.WithCancel(ctx)
defaultServer := &DefaultServer{
ctx: ctx,
ctxCancel: stop,
server: &dns.Server{
Net: "udp",
Handler: mux,
UDPSize: 65535,
},
dnsMux: mux,
dnsMuxMap: make(registeredHandlerMap),
localResolver: &localResolver{
registeredMap: make(registrationMap),
},
wgInterface: wgInterface,
customAddress: addrPort,
hostManager: hostManager,
}
if initialDnsCfg != nil {
defaultServer.enabled = hasValidDnsServer(initialDnsCfg)
}
defaultServer.evalRuntimeAddress()
return defaultServer, nil
}
// Start runs the listener in a go routine
func (s *DefaultServer) Start() {
// nil check required in unit tests
if s.wgInterface != nil && s.wgInterface.IsUserspaceBind() {
s.fakeResolverWG.Add(1)
go func() {
s.setListenerStatus(true)
defer s.setListenerStatus(false)
hookID := s.filterDNSTraffic()
s.fakeResolverWG.Wait()
if err := s.wgInterface.GetFilter().RemovePacketHook(hookID); err != nil {
log.Errorf("unable to remove DNS packet hook: %s", err)
}
}()
return
}
log.Debugf("starting dns on %s", s.server.Addr)
go func() {
s.setListenerStatus(true)
defer s.setListenerStatus(false)
err := s.server.ListenAndServe()
if err != nil {
log.Errorf("dns server running with %d port returned an error: %v. Will not retry", s.runtimePort, err)
}
}()
}
func (s *DefaultServer) DnsIP() string {
if !s.enabled {
return ""
}
return s.runtimeIP
}
func (s *DefaultServer) getFirstListenerAvailable() (string, int, error) {
ips := []string{defaultIP, customIP}
if runtime.GOOS != "darwin" && s.wgInterface != nil {
ips = append([]string{s.wgInterface.Address().IP.String()}, ips...)
}
ports := []int{defaultPort, customPort}
for _, port := range ports {
for _, ip := range ips {
addrString := fmt.Sprintf("%s:%d", ip, port)
udpAddr := net.UDPAddrFromAddrPort(netip.MustParseAddrPort(addrString))
probeListener, err := net.ListenUDP("udp", udpAddr)
if err == nil {
err = probeListener.Close()
if err != nil {
log.Errorf("got an error closing the probe listener, error: %s", err)
}
return ip, port, nil
}
log.Warnf("binding dns on %s is not available, error: %s", addrString, err)
}
}
return "", 0, fmt.Errorf("unable to find an unused ip and port combination. IPs tested: %v and ports %v", ips, ports)
}
func (s *DefaultServer) setListenerStatus(running bool) {
s.listenerIsRunning = running
}
// Stop stops the server
func (s *DefaultServer) Stop() {
s.mux.Lock()
defer s.mux.Unlock()
s.ctxCancel()
err := s.hostManager.restoreHostDNS()
if err != nil {
log.Error(err)
}
if s.wgInterface != nil && s.wgInterface.IsUserspaceBind() && s.listenerIsRunning {
s.fakeResolverWG.Done()
}
err = s.stopListener()
if err != nil {
log.Error(err)
}
}
func (s *DefaultServer) stopListener() error {
if !s.listenerIsRunning {
return nil
}
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
err := s.server.ShutdownContext(ctx)
if err != nil {
return fmt.Errorf("stopping dns server listener returned an error: %v", err)
}
return nil
}
// UpdateDNSServer processes an update received from the management service
func (s *DefaultServer) UpdateDNSServer(serial uint64, update nbdns.Config) error {
select {
case <-s.ctx.Done():
log.Infof("not updating DNS server as context is closed")
return s.ctx.Err()
default:
if serial < s.updateSerial {
return fmt.Errorf("not applying dns update, error: "+
"network update is %d behind the last applied update", s.updateSerial-serial)
}
s.mux.Lock()
defer s.mux.Unlock()
hash, err := hashstructure.Hash(update, hashstructure.FormatV2, &hashstructure.HashOptions{
ZeroNil: true,
IgnoreZeroValue: true,
SlicesAsSets: true,
UseStringer: true,
})
if err != nil {
log.Errorf("unable to hash the dns configuration update, got error: %s", err)
}
if s.previousConfigHash == hash {
log.Debugf("not applying the dns configuration update as there is nothing new")
s.updateSerial = serial
return nil
}
if err := s.applyConfiguration(update); err != nil {
return err
}
s.updateSerial = serial
s.previousConfigHash = hash
return nil
}
}
func (s *DefaultServer) applyConfiguration(update nbdns.Config) error {
// is the service should be disabled, we stop the listener or fake resolver
// and proceed with a regular update to clean up the handlers and records
if !update.ServiceEnable {
if s.wgInterface != nil && s.wgInterface.IsUserspaceBind() {
s.fakeResolverWG.Done()
} else {
if err := s.stopListener(); err != nil {
log.Error(err)
}
}
} else if !s.listenerIsRunning {
s.Start()
}
localMuxUpdates, localRecords, err := s.buildLocalHandlerUpdate(update.CustomZones)
if err != nil {
return fmt.Errorf("not applying dns update, error: %v", err)
}
upstreamMuxUpdates, err := s.buildUpstreamHandlerUpdate(update.NameServerGroups)
if err != nil {
return fmt.Errorf("not applying dns update, error: %v", err)
}
muxUpdates := append(localMuxUpdates, upstreamMuxUpdates...)
s.updateMux(muxUpdates)
s.updateLocalResolver(localRecords)
s.currentConfig = dnsConfigToHostDNSConfig(update, s.runtimeIP, s.runtimePort)
hostUpdate := s.currentConfig
if s.runtimePort != defaultPort && !s.hostManager.supportCustomPort() {
log.Warnf("the DNS manager of this peer doesn't support custom port. Disabling primary DNS setup. " +
"Learn more at: https://netbird.io/docs/how-to-guides/nameservers#local-resolver")
hostUpdate.routeAll = false
}
if err = s.hostManager.applyDNSConfig(hostUpdate); err != nil {
log.Error(err)
}
return nil
}
func (s *DefaultServer) buildLocalHandlerUpdate(customZones []nbdns.CustomZone) ([]muxUpdate, map[string]nbdns.SimpleRecord, error) {
var muxUpdates []muxUpdate
localRecords := make(map[string]nbdns.SimpleRecord, 0)
for _, customZone := range customZones {
if len(customZone.Records) == 0 {
return nil, nil, fmt.Errorf("received an empty list of records")
}
muxUpdates = append(muxUpdates, muxUpdate{
domain: customZone.Domain,
handler: s.localResolver,
})
for _, record := range customZone.Records {
var class uint16 = dns.ClassINET
if record.Class != nbdns.DefaultClass {
return nil, nil, fmt.Errorf("received an invalid class type: %s", record.Class)
}
key := buildRecordKey(record.Name, class, uint16(record.Type))
localRecords[key] = record
}
}
return muxUpdates, localRecords, nil
}
func (s *DefaultServer) buildUpstreamHandlerUpdate(nameServerGroups []*nbdns.NameServerGroup) ([]muxUpdate, error) {
var muxUpdates []muxUpdate
for _, nsGroup := range nameServerGroups {
if len(nsGroup.NameServers) == 0 {
log.Warn("received a nameserver group with empty nameserver list")
continue
}
handler := newUpstreamResolver(s.ctx)
for _, ns := range nsGroup.NameServers {
if ns.NSType != nbdns.UDPNameServerType {
log.Warnf("skiping nameserver %s with type %s, this peer supports only %s",
ns.IP.String(), ns.NSType.String(), nbdns.UDPNameServerType.String())
continue
}
handler.upstreamServers = append(handler.upstreamServers, getNSHostPort(ns))
}
if len(handler.upstreamServers) == 0 {
handler.stop()
log.Errorf("received a nameserver group with an invalid nameserver list")
continue
}
// when upstream fails to resolve domain several times over all it servers
// it will calls this hook to exclude self from the configuration and
// reapply DNS settings, but it not touch the original configuration and serial number
// because it is temporal deactivation until next try
//
// after some period defined by upstream it trys to reactivate self by calling this hook
// everything we need here is just to re-apply current configuration because it already
// contains this upstream settings (temporal deactivation not removed it)
handler.deactivate, handler.reactivate = s.upstreamCallbacks(nsGroup, handler)
if nsGroup.Primary {
muxUpdates = append(muxUpdates, muxUpdate{
domain: nbdns.RootZone,
handler: handler,
})
continue
}
if len(nsGroup.Domains) == 0 {
handler.stop()
return nil, fmt.Errorf("received a non primary nameserver group with an empty domain list")
}
for _, domain := range nsGroup.Domains {
if domain == "" {
handler.stop()
return nil, fmt.Errorf("received a nameserver group with an empty domain element")
}
muxUpdates = append(muxUpdates, muxUpdate{
domain: domain,
handler: handler,
})
}
}
return muxUpdates, nil
}
func (s *DefaultServer) updateMux(muxUpdates []muxUpdate) {
muxUpdateMap := make(registeredHandlerMap)
for _, update := range muxUpdates {
s.registerMux(update.domain, update.handler)
muxUpdateMap[update.domain] = update.handler
if existingHandler, ok := s.dnsMuxMap[update.domain]; ok {
existingHandler.stop()
}
}
for key, existingHandler := range s.dnsMuxMap {
_, found := muxUpdateMap[key]
if !found {
existingHandler.stop()
s.deregisterMux(key)
}
}
s.dnsMuxMap = muxUpdateMap
}
func (s *DefaultServer) updateLocalResolver(update map[string]nbdns.SimpleRecord) {
for key := range s.localResolver.registeredMap {
_, found := update[key]
if !found {
s.localResolver.deleteRecord(key)
}
}
updatedMap := make(registrationMap)
for key, record := range update {
err := s.localResolver.registerRecord(record)
if err != nil {
log.Warnf("got an error while registering the record (%s), error: %v", record.String(), err)
}
updatedMap[key] = struct{}{}
}
s.localResolver.registeredMap = updatedMap
}
func getNSHostPort(ns nbdns.NameServer) string {
return fmt.Sprintf("%s:%d", ns.IP.String(), ns.Port)
}
func (s *DefaultServer) registerMux(pattern string, handler dns.Handler) {
s.dnsMux.Handle(pattern, handler)
}
func (s *DefaultServer) deregisterMux(pattern string) {
s.dnsMux.HandleRemove(pattern)
}
// upstreamCallbacks returns two functions, the first one is used to deactivate
// the upstream resolver from the configuration, the second one is used to
// reactivate it. Not allowed to call reactivate before deactivate.
func (s *DefaultServer) upstreamCallbacks(
nsGroup *nbdns.NameServerGroup,
handler dns.Handler,
) (deactivate func(), reactivate func()) {
var removeIndex map[string]int
deactivate = func() {
s.mux.Lock()
defer s.mux.Unlock()
l := log.WithField("nameservers", nsGroup.NameServers)
l.Info("temporary deactivate nameservers group due timeout")
removeIndex = make(map[string]int)
for _, domain := range nsGroup.Domains {
removeIndex[domain] = -1
}
if nsGroup.Primary {
removeIndex[nbdns.RootZone] = -1
s.currentConfig.routeAll = false
}
for i, item := range s.currentConfig.domains {
if _, found := removeIndex[item.domain]; found {
s.currentConfig.domains[i].disabled = true
s.deregisterMux(item.domain)
removeIndex[item.domain] = i
}
}
if err := s.hostManager.applyDNSConfig(s.currentConfig); err != nil {
l.WithError(err).Error("fail to apply nameserver deactivation on the host")
}
}
reactivate = func() {
s.mux.Lock()
defer s.mux.Unlock()
for domain, i := range removeIndex {
if i == -1 || i >= len(s.currentConfig.domains) || s.currentConfig.domains[i].domain != domain {
continue
}
s.currentConfig.domains[i].disabled = false
s.registerMux(domain, handler)
}
l := log.WithField("nameservers", nsGroup.NameServers)
l.Debug("reactivate temporary disabled nameserver group")
if nsGroup.Primary {
s.currentConfig.routeAll = true
}
if err := s.hostManager.applyDNSConfig(s.currentConfig); err != nil {
l.WithError(err).Error("reactivate temporary disabled nameserver group, DNS update apply")
}
}
return
}
func (s *DefaultServer) filterDNSTraffic() string {
filter := s.wgInterface.GetFilter()
if filter == nil {
log.Error("can't set DNS filter, filter not initialized")
return ""
}
firstLayerDecoder := layers.LayerTypeIPv4
if s.wgInterface.Address().Network.IP.To4() == nil {
firstLayerDecoder = layers.LayerTypeIPv6
}
hook := func(packetData []byte) bool {
// Decode the packet
packet := gopacket.NewPacket(packetData, firstLayerDecoder, gopacket.Default)
// Get the UDP layer
udpLayer := packet.Layer(layers.LayerTypeUDP)
udp := udpLayer.(*layers.UDP)
msg := new(dns.Msg)
if err := msg.Unpack(udp.Payload); err != nil {
log.Tracef("parse DNS request: %v", err)
return true
}
writer := responseWriter{
packet: packet,
device: s.wgInterface.GetDevice().Device,
}
go s.dnsMux.ServeDNS(&writer, msg)
return true
}
return filter.AddUDPPacketHook(false, net.ParseIP(s.runtimeIP), uint16(s.runtimePort), hook)
}
func (s *DefaultServer) evalRuntimeAddress() {
defer func() {
s.server.Addr = fmt.Sprintf("%s:%d", s.runtimeIP, s.runtimePort)
}()
if s.wgInterface != nil && s.wgInterface.IsUserspaceBind() {
s.runtimeIP = getLastIPFromNetwork(s.wgInterface.Address().Network, 1)
s.runtimePort = defaultPort
return
}
if s.customAddress != nil {
s.runtimeIP = s.customAddress.Addr().String()
s.runtimePort = int(s.customAddress.Port())
return
}
ip, port, err := s.getFirstListenerAvailable()
if err != nil {
log.Error(err)
return
}
s.runtimeIP = ip
s.runtimePort = port
}
func getLastIPFromNetwork(network *net.IPNet, fromEnd int) string {
// Calculate the last IP in the CIDR range
var endIP net.IP
for i := 0; i < len(network.IP); i++ {
endIP = append(endIP, network.IP[i]|^network.Mask[i])
}
// convert to big.Int
endInt := big.NewInt(0)
endInt.SetBytes(endIP)
// subtract fromEnd from the last ip
fromEndBig := big.NewInt(int64(fromEnd))
resultInt := big.NewInt(0)
resultInt.Sub(endInt, fromEndBig)
return net.IP(resultInt.Bytes()).String()
}
func hasValidDnsServer(cfg *nbdns.Config) bool {
for _, c := range cfg.NameServerGroups {
if c.Primary {
return true
}
}
return false
}

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@ -1,32 +0,0 @@
package dns
import (
"context"
nbdns "github.com/netbirdio/netbird/dns"
"github.com/netbirdio/netbird/iface"
)
// DefaultServer dummy dns server
type DefaultServer struct {
}
// NewDefaultServer On Android the DNS feature is not supported yet
func NewDefaultServer(ctx context.Context, wgInterface *iface.WGIface, customAddress string) (*DefaultServer, error) {
return &DefaultServer{}, nil
}
// Start dummy implementation
func (s DefaultServer) Start() {
}
// Stop dummy implementation
func (s DefaultServer) Stop() {
}
// UpdateDNSServer dummy implementation
func (s DefaultServer) UpdateDNSServer(serial uint64, update nbdns.Config) error {
return nil
}

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@ -1,565 +0,0 @@
//go:build !android
package dns
import (
"context"
"fmt"
"math/big"
"net"
"net/netip"
"runtime"
"sync"
"time"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
"github.com/miekg/dns"
"github.com/mitchellh/hashstructure/v2"
log "github.com/sirupsen/logrus"
nbdns "github.com/netbirdio/netbird/dns"
"github.com/netbirdio/netbird/iface"
)
const (
defaultPort = 53
customPort = 5053
defaultIP = "127.0.0.1"
customIP = "127.0.0.153"
)
type registeredHandlerMap map[string]handlerWithStop
// DefaultServer dns server object
type DefaultServer struct {
ctx context.Context
ctxCancel context.CancelFunc
mux sync.Mutex
fakeResolverWG sync.WaitGroup
server *dns.Server
dnsMux *dns.ServeMux
dnsMuxMap registeredHandlerMap
localResolver *localResolver
wgInterface *iface.WGIface
hostManager hostManager
updateSerial uint64
listenerIsRunning bool
runtimePort int
runtimeIP string
previousConfigHash uint64
currentConfig hostDNSConfig
customAddress *netip.AddrPort
}
type handlerWithStop interface {
dns.Handler
stop()
}
type muxUpdate struct {
domain string
handler handlerWithStop
}
// NewDefaultServer returns a new dns server
func NewDefaultServer(ctx context.Context, wgInterface *iface.WGIface, customAddress string) (*DefaultServer, error) {
mux := dns.NewServeMux()
dnsServer := &dns.Server{
Net: "udp",
Handler: mux,
UDPSize: 65535,
}
ctx, stop := context.WithCancel(ctx)
var addrPort *netip.AddrPort
if customAddress != "" {
parsedAddrPort, err := netip.ParseAddrPort(customAddress)
if err != nil {
stop()
return nil, fmt.Errorf("unable to parse the custom dns address, got error: %s", err)
}
addrPort = &parsedAddrPort
}
defaultServer := &DefaultServer{
ctx: ctx,
ctxCancel: stop,
server: dnsServer,
dnsMux: mux,
dnsMuxMap: make(registeredHandlerMap),
localResolver: &localResolver{
registeredMap: make(registrationMap),
},
wgInterface: wgInterface,
runtimePort: defaultPort,
customAddress: addrPort,
}
hostmanager, err := newHostManager(wgInterface)
if err != nil {
stop()
return nil, err
}
defaultServer.hostManager = hostmanager
return defaultServer, err
}
// Start runs the listener in a go routine
func (s *DefaultServer) Start() {
if s.wgInterface != nil && s.wgInterface.IsUserspaceBind() {
s.runtimeIP = getLastIPFromNetwork(s.wgInterface.Address().Network, 1)
s.runtimePort = 53
s.server.Addr = fmt.Sprintf("%s:%d", s.runtimeIP, s.runtimePort)
s.fakeResolverWG.Add(1)
go func() {
s.setListenerStatus(true)
defer s.setListenerStatus(false)
hookID := s.filterDNSTraffic()
s.fakeResolverWG.Wait()
if err := s.wgInterface.GetFilter().RemovePacketHook(hookID); err != nil {
log.Errorf("unable to remove DNS packet hook: %s", err)
}
}()
return
}
if s.customAddress != nil {
s.runtimeIP = s.customAddress.Addr().String()
s.runtimePort = int(s.customAddress.Port())
} else {
ip, port, err := s.getFirstListenerAvailable()
if err != nil {
log.Error(err)
return
}
s.runtimeIP = ip
s.runtimePort = port
}
s.server.Addr = fmt.Sprintf("%s:%d", s.runtimeIP, s.runtimePort)
log.Debugf("starting dns on %s", s.server.Addr)
go func() {
s.setListenerStatus(true)
defer s.setListenerStatus(false)
err := s.server.ListenAndServe()
if err != nil {
log.Errorf("dns server running with %d port returned an error: %v. Will not retry", s.runtimePort, err)
}
}()
}
func (s *DefaultServer) getFirstListenerAvailable() (string, int, error) {
ips := []string{defaultIP, customIP}
if runtime.GOOS != "darwin" && s.wgInterface != nil {
ips = append([]string{s.wgInterface.Address().IP.String()}, ips...)
}
ports := []int{defaultPort, customPort}
for _, port := range ports {
for _, ip := range ips {
addrString := fmt.Sprintf("%s:%d", ip, port)
udpAddr := net.UDPAddrFromAddrPort(netip.MustParseAddrPort(addrString))
probeListener, err := net.ListenUDP("udp", udpAddr)
if err == nil {
err = probeListener.Close()
if err != nil {
log.Errorf("got an error closing the probe listener, error: %s", err)
}
return ip, port, nil
}
log.Warnf("binding dns on %s is not available, error: %s", addrString, err)
}
}
return "", 0, fmt.Errorf("unable to find an unused ip and port combination. IPs tested: %v and ports %v", ips, ports)
}
func (s *DefaultServer) setListenerStatus(running bool) {
s.listenerIsRunning = running
}
// Stop stops the server
func (s *DefaultServer) Stop() {
s.mux.Lock()
defer s.mux.Unlock()
s.ctxCancel()
err := s.hostManager.restoreHostDNS()
if err != nil {
log.Error(err)
}
if s.wgInterface != nil && s.wgInterface.IsUserspaceBind() && s.listenerIsRunning {
s.fakeResolverWG.Done()
}
err = s.stopListener()
if err != nil {
log.Error(err)
}
}
func (s *DefaultServer) stopListener() error {
if !s.listenerIsRunning {
return nil
}
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
err := s.server.ShutdownContext(ctx)
if err != nil {
return fmt.Errorf("stopping dns server listener returned an error: %v", err)
}
return nil
}
// UpdateDNSServer processes an update received from the management service
func (s *DefaultServer) UpdateDNSServer(serial uint64, update nbdns.Config) error {
select {
case <-s.ctx.Done():
log.Infof("not updating DNS server as context is closed")
return s.ctx.Err()
default:
if serial < s.updateSerial {
return fmt.Errorf("not applying dns update, error: "+
"network update is %d behind the last applied update", s.updateSerial-serial)
}
s.mux.Lock()
defer s.mux.Unlock()
hash, err := hashstructure.Hash(update, hashstructure.FormatV2, &hashstructure.HashOptions{
ZeroNil: true,
IgnoreZeroValue: true,
SlicesAsSets: true,
UseStringer: true,
})
if err != nil {
log.Errorf("unable to hash the dns configuration update, got error: %s", err)
}
if s.previousConfigHash == hash {
log.Debugf("not applying the dns configuration update as there is nothing new")
s.updateSerial = serial
return nil
}
if err := s.applyConfiguration(update); err != nil {
return err
}
s.updateSerial = serial
s.previousConfigHash = hash
return nil
}
}
func (s *DefaultServer) applyConfiguration(update nbdns.Config) error {
// is the service should be disabled, we stop the listener or fake resolver
// and proceed with a regular update to clean up the handlers and records
if !update.ServiceEnable {
if s.wgInterface != nil && s.wgInterface.IsUserspaceBind() && s.listenerIsRunning {
s.fakeResolverWG.Done()
} else {
if err := s.stopListener(); err != nil {
log.Error(err)
}
}
} else if !s.listenerIsRunning {
s.Start()
}
localMuxUpdates, localRecords, err := s.buildLocalHandlerUpdate(update.CustomZones)
if err != nil {
return fmt.Errorf("not applying dns update, error: %v", err)
}
upstreamMuxUpdates, err := s.buildUpstreamHandlerUpdate(update.NameServerGroups)
if err != nil {
return fmt.Errorf("not applying dns update, error: %v", err)
}
muxUpdates := append(localMuxUpdates, upstreamMuxUpdates...)
s.updateMux(muxUpdates)
s.updateLocalResolver(localRecords)
s.currentConfig = dnsConfigToHostDNSConfig(update, s.runtimeIP, s.runtimePort)
hostUpdate := s.currentConfig
if s.runtimePort != defaultPort && !s.hostManager.supportCustomPort() {
log.Warnf("the DNS manager of this peer doesn't support custom port. Disabling primary DNS setup. " +
"Learn more at: https://netbird.io/docs/how-to-guides/nameservers#local-resolver")
hostUpdate.routeAll = false
}
if err = s.hostManager.applyDNSConfig(hostUpdate); err != nil {
log.Error(err)
}
return nil
}
func (s *DefaultServer) buildLocalHandlerUpdate(customZones []nbdns.CustomZone) ([]muxUpdate, map[string]nbdns.SimpleRecord, error) {
var muxUpdates []muxUpdate
localRecords := make(map[string]nbdns.SimpleRecord, 0)
for _, customZone := range customZones {
if len(customZone.Records) == 0 {
return nil, nil, fmt.Errorf("received an empty list of records")
}
muxUpdates = append(muxUpdates, muxUpdate{
domain: customZone.Domain,
handler: s.localResolver,
})
for _, record := range customZone.Records {
var class uint16 = dns.ClassINET
if record.Class != nbdns.DefaultClass {
return nil, nil, fmt.Errorf("received an invalid class type: %s", record.Class)
}
key := buildRecordKey(record.Name, class, uint16(record.Type))
localRecords[key] = record
}
}
return muxUpdates, localRecords, nil
}
func (s *DefaultServer) buildUpstreamHandlerUpdate(nameServerGroups []*nbdns.NameServerGroup) ([]muxUpdate, error) {
var muxUpdates []muxUpdate
for _, nsGroup := range nameServerGroups {
if len(nsGroup.NameServers) == 0 {
log.Warn("received a nameserver group with empty nameserver list")
continue
}
handler := newUpstreamResolver(s.ctx)
for _, ns := range nsGroup.NameServers {
if ns.NSType != nbdns.UDPNameServerType {
log.Warnf("skiping nameserver %s with type %s, this peer supports only %s",
ns.IP.String(), ns.NSType.String(), nbdns.UDPNameServerType.String())
continue
}
handler.upstreamServers = append(handler.upstreamServers, getNSHostPort(ns))
}
if len(handler.upstreamServers) == 0 {
handler.stop()
log.Errorf("received a nameserver group with an invalid nameserver list")
continue
}
// when upstream fails to resolve domain several times over all it servers
// it will calls this hook to exclude self from the configuration and
// reapply DNS settings, but it not touch the original configuration and serial number
// because it is temporal deactivation until next try
//
// after some period defined by upstream it trys to reactivate self by calling this hook
// everything we need here is just to re-apply current configuration because it already
// contains this upstream settings (temporal deactivation not removed it)
handler.deactivate, handler.reactivate = s.upstreamCallbacks(nsGroup, handler)
if nsGroup.Primary {
muxUpdates = append(muxUpdates, muxUpdate{
domain: nbdns.RootZone,
handler: handler,
})
continue
}
if len(nsGroup.Domains) == 0 {
handler.stop()
return nil, fmt.Errorf("received a non primary nameserver group with an empty domain list")
}
for _, domain := range nsGroup.Domains {
if domain == "" {
handler.stop()
return nil, fmt.Errorf("received a nameserver group with an empty domain element")
}
muxUpdates = append(muxUpdates, muxUpdate{
domain: domain,
handler: handler,
})
}
}
return muxUpdates, nil
}
func (s *DefaultServer) updateMux(muxUpdates []muxUpdate) {
muxUpdateMap := make(registeredHandlerMap)
for _, update := range muxUpdates {
s.registerMux(update.domain, update.handler)
muxUpdateMap[update.domain] = update.handler
if existingHandler, ok := s.dnsMuxMap[update.domain]; ok {
existingHandler.stop()
}
}
for key, existingHandler := range s.dnsMuxMap {
_, found := muxUpdateMap[key]
if !found {
existingHandler.stop()
s.deregisterMux(key)
}
}
s.dnsMuxMap = muxUpdateMap
}
func (s *DefaultServer) updateLocalResolver(update map[string]nbdns.SimpleRecord) {
for key := range s.localResolver.registeredMap {
_, found := update[key]
if !found {
s.localResolver.deleteRecord(key)
}
}
updatedMap := make(registrationMap)
for key, record := range update {
err := s.localResolver.registerRecord(record)
if err != nil {
log.Warnf("got an error while registering the record (%s), error: %v", record.String(), err)
}
updatedMap[key] = struct{}{}
}
s.localResolver.registeredMap = updatedMap
}
func getNSHostPort(ns nbdns.NameServer) string {
return fmt.Sprintf("%s:%d", ns.IP.String(), ns.Port)
}
func (s *DefaultServer) registerMux(pattern string, handler dns.Handler) {
s.dnsMux.Handle(pattern, handler)
}
func (s *DefaultServer) deregisterMux(pattern string) {
s.dnsMux.HandleRemove(pattern)
}
// upstreamCallbacks returns two functions, the first one is used to deactivate
// the upstream resolver from the configuration, the second one is used to
// reactivate it. Not allowed to call reactivate before deactivate.
func (s *DefaultServer) upstreamCallbacks(
nsGroup *nbdns.NameServerGroup,
handler dns.Handler,
) (deactivate func(), reactivate func()) {
var removeIndex map[string]int
deactivate = func() {
s.mux.Lock()
defer s.mux.Unlock()
l := log.WithField("nameservers", nsGroup.NameServers)
l.Info("temporary deactivate nameservers group due timeout")
removeIndex = make(map[string]int)
for _, domain := range nsGroup.Domains {
removeIndex[domain] = -1
}
if nsGroup.Primary {
removeIndex[nbdns.RootZone] = -1
s.currentConfig.routeAll = false
}
for i, item := range s.currentConfig.domains {
if _, found := removeIndex[item.domain]; found {
s.currentConfig.domains[i].disabled = true
s.deregisterMux(item.domain)
removeIndex[item.domain] = i
}
}
if err := s.hostManager.applyDNSConfig(s.currentConfig); err != nil {
l.WithError(err).Error("fail to apply nameserver deactivation on the host")
}
}
reactivate = func() {
s.mux.Lock()
defer s.mux.Unlock()
for domain, i := range removeIndex {
if i == -1 || i >= len(s.currentConfig.domains) || s.currentConfig.domains[i].domain != domain {
continue
}
s.currentConfig.domains[i].disabled = false
s.registerMux(domain, handler)
}
l := log.WithField("nameservers", nsGroup.NameServers)
l.Debug("reactivate temporary disabled nameserver group")
if nsGroup.Primary {
s.currentConfig.routeAll = true
}
if err := s.hostManager.applyDNSConfig(s.currentConfig); err != nil {
l.WithError(err).Error("reactivate temporary disabled nameserver group, DNS update apply")
}
}
return
}
func (s *DefaultServer) filterDNSTraffic() string {
filter := s.wgInterface.GetFilter()
if filter == nil {
log.Error("can't set DNS filter, filter not initialized")
return ""
}
firstLayerDecoder := layers.LayerTypeIPv4
if s.wgInterface.Address().Network.IP.To4() == nil {
firstLayerDecoder = layers.LayerTypeIPv6
}
hook := func(packetData []byte) bool {
// Decode the packet
packet := gopacket.NewPacket(packetData, firstLayerDecoder, gopacket.Default)
// Get the UDP layer
udpLayer := packet.Layer(layers.LayerTypeUDP)
udp := udpLayer.(*layers.UDP)
msg := new(dns.Msg)
if err := msg.Unpack(udp.Payload); err != nil {
log.Tracef("parse DNS request: %v", err)
return true
}
writer := responseWriter{
packet: packet,
device: s.wgInterface.GetDevice().Device,
}
go s.dnsMux.ServeDNS(&writer, msg)
return true
}
return filter.AddUDPPacketHook(false, net.ParseIP(s.runtimeIP), uint16(s.runtimePort), hook)
}
func getLastIPFromNetwork(network *net.IPNet, fromEnd int) string {
// Calculate the last IP in the CIDR range
var endIP net.IP
for i := 0; i < len(network.IP); i++ {
endIP = append(endIP, network.IP[i]|^network.Mask[i])
}
// convert to big.Int
endInt := big.NewInt(0)
endInt.SetBytes(endIP)
// subtract fromEnd from the last ip
fromEndBig := big.NewInt(int64(fromEnd))
resultInt := big.NewInt(0)
resultInt.Sub(endInt, fromEndBig)
return net.IP(resultInt.Bytes()).String()
}

View File

@ -1,31 +0,0 @@
package dns
import (
"net"
"testing"
)
func TestGetLastIPFromNetwork(t *testing.T) {
tests := []struct {
addr string
ip string
}{
{"2001:db8::/32", "2001:db8:ffff:ffff:ffff:ffff:ffff:fffe"},
{"192.168.0.0/30", "192.168.0.2"},
{"192.168.0.0/16", "192.168.255.254"},
{"192.168.0.0/24", "192.168.0.254"},
}
for _, tt := range tests {
_, ipnet, err := net.ParseCIDR(tt.addr)
if err != nil {
t.Errorf("Error parsing CIDR: %v", err)
return
}
lastIP := getLastIPFromNetwork(ipnet, 1)
if lastIP != tt.ip {
t.Errorf("wrong IP address, expected %s: got %s", tt.ip, lastIP)
}
}
}

View File

@ -221,7 +221,7 @@ func TestUpdateDNSServer(t *testing.T) {
t.Log(err)
}
}()
dnsServer, err := NewDefaultServer(context.Background(), wgIface, "")
dnsServer, err := NewDefaultServer(context.Background(), wgIface, "", nil)
if err != nil {
t.Fatal(err)
}
@ -428,7 +428,7 @@ func getDefaultServerWithNoHostManager(t *testing.T, addrPort string) *DefaultSe
ctx, cancel := context.WithCancel(context.TODO())
return &DefaultServer{
ds := &DefaultServer{
ctx: ctx,
ctxCancel: cancel,
server: dnsServer,
@ -439,4 +439,31 @@ func getDefaultServerWithNoHostManager(t *testing.T, addrPort string) *DefaultSe
},
customAddress: parsedAddrPort,
}
ds.evalRuntimeAddress()
return ds
}
func TestGetLastIPFromNetwork(t *testing.T) {
tests := []struct {
addr string
ip string
}{
{"2001:db8::/32", "2001:db8:ffff:ffff:ffff:ffff:ffff:fffe"},
{"192.168.0.0/30", "192.168.0.2"},
{"192.168.0.0/16", "192.168.255.254"},
{"192.168.0.0/24", "192.168.0.254"},
}
for _, tt := range tests {
_, ipnet, err := net.ParseCIDR(tt.addr)
if err != nil {
t.Errorf("Error parsing CIDR: %v", err)
return
}
lastIP := getLastIPFromNetwork(ipnet, 1)
if lastIP != tt.ip {
t.Errorf("wrong IP address, expected %s: got %s", tt.ip, lastIP)
}
}
}

View File

@ -1,3 +1,5 @@
//go:build !android
package dns
import (

View File

@ -189,14 +189,37 @@ func (e *Engine) Start() error {
return err
}
routes, err := e.readInitialRoutes()
if err != nil {
return err
var routes []*route.Route
var dnsCfg *nbdns.Config
if runtime.GOOS == "android" {
routes, dnsCfg, err = e.readInitialSettings()
if err != nil {
return err
}
}
if e.dnsServer == nil {
// todo fix custom address
dnsServer, err := dns.NewDefaultServer(e.ctx, e.wgInterface, e.config.CustomDNSAddress, dnsCfg)
if err != nil {
e.close()
return err
}
e.dnsServer = dnsServer
}
e.routeManager = routemanager.NewManager(e.ctx, e.config.WgPrivateKey.PublicKey().String(), e.wgInterface, e.statusRecorder, routes)
e.routeManager.SetRouteChangeListener(e.mobileDep.RouteListener)
err = e.wgInterface.Create()
if runtime.GOOS != "android" {
err = e.wgInterface.Create()
} else {
err = e.wgInterface.CreateOnMobile(iface.MobileIFaceArguments{
Routes: e.routeManager.InitialRouteRange(),
Dns: e.dnsServer.DnsIP(),
})
}
if err != nil {
log.Errorf("failed creating tunnel interface %s: [%s]", wgIFaceName, err.Error())
e.close()
@ -236,16 +259,6 @@ func (e *Engine) Start() error {
e.acl = acl
}
if e.dnsServer == nil {
// todo fix custom address
dnsServer, err := dns.NewDefaultServer(e.ctx, e.wgInterface, e.config.CustomDNSAddress)
if err != nil {
e.close()
return err
}
e.dnsServer = dnsServer
}
e.receiveSignalEvents()
e.receiveManagementEvents()
@ -1027,17 +1040,14 @@ func (e *Engine) close() {
}
}
func (e *Engine) readInitialRoutes() ([]*route.Route, error) {
if runtime.GOOS != "android" {
return nil, nil
}
routesResp, err := e.mgmClient.GetRoutes()
func (e *Engine) readInitialSettings() ([]*route.Route, *nbdns.Config, error) {
netMap, err := e.mgmClient.GetNetworkMap()
if err != nil {
return nil, err
return nil, nil, err
}
return toRoutes(routesResp), nil
routes := toRoutes(netMap.GetRoutes())
dnsCfg := toDNSConfig(netMap.GetDNSConfig())
return routes, &dnsCfg, nil
}
func findIPFromInterfaceName(ifaceName string) (net.IP, error) {

View File

@ -17,6 +17,7 @@ import (
type Manager interface {
UpdateRoutes(updateSerial uint64, newRoutes []*route.Route) error
SetRouteChangeListener(listener RouteListener)
InitialRouteRange() []string
Stop()
}
@ -51,10 +52,6 @@ func NewManager(ctx context.Context, pubKey string, wgInterface *iface.WGIface,
if runtime.GOOS == "android" {
cr := dm.clientRoutes(initialRoutes)
dm.notifier.setInitialClientRoutes(cr)
networks := readRouteNetworks(cr)
// make sense to call before create interface
wgInterface.SetInitialRoutes(networks)
}
return dm
}
@ -94,6 +91,11 @@ func (m *DefaultManager) SetRouteChangeListener(listener RouteListener) {
m.notifier.setListener(listener)
}
// InitialRouteRange return the list of initial routes. It used by mobile systems
func (m *DefaultManager) InitialRouteRange() []string {
return m.notifier.initialRouteRanges()
}
func (m *DefaultManager) updateClientNetworks(updateSerial uint64, networks map[string][]*route.Route) {
// removing routes that do not exist as per the update from the Management service.
for id, client := range m.clientNetworks {
@ -163,11 +165,3 @@ func (m *DefaultManager) clientRoutes(initialRoutes []*route.Route) []*route.Rou
}
return rs
}
func readRouteNetworks(cr []*route.Route) []string {
routesNetworks := make([]string, 0)
for _, r := range cr {
routesNetworks = append(routesNetworks, r.Network.String())
}
return routesNetworks
}

View File

@ -14,8 +14,8 @@ type MockManager struct {
StopFunc func()
}
// InitialClientRoutesNetworks mock implementation of InitialClientRoutesNetworks from Manager interface
func (m *MockManager) InitialClientRoutesNetworks() []string {
// InitialRouteRange mock implementation of InitialRouteRange from Manager interface
func (m *MockManager) InitialRouteRange() []string {
return nil
}

View File

@ -84,3 +84,7 @@ func (n *notifier) hasDiff(a []string, b []string) bool {
}
return false
}
func (n *notifier) initialRouteRanges() []string {
return n.initialRouteRangers
}

View File

@ -36,15 +36,6 @@ func (w *WGIface) GetBind() *bind.ICEBind {
return w.tun.iceBind
}
// Create creates a new Wireguard interface, sets a given IP and brings it up.
// Will reuse an existing one.
func (w *WGIface) Create() error {
w.mu.Lock()
defer w.mu.Unlock()
log.Debugf("create WireGuard interface %s", w.tun.DeviceName())
return w.tun.Create()
}
// Name returns the interface name
func (w *WGIface) Name() string {
return w.tun.DeviceName()

View File

@ -1,9 +1,11 @@
package iface
import (
"fmt"
"sync"
"github.com/pion/transport/v2"
log "github.com/sirupsen/logrus"
)
// NewWGIFace Creates a new WireGuard interface instance
@ -27,7 +29,16 @@ func NewWGIFace(ifaceName string, address string, mtu int, tunAdapter TunAdapter
return wgIFace, nil
}
// SetInitialRoutes store the given routes and on the tun creation will be used
func (w *WGIface) SetInitialRoutes(routes []string) {
w.tun.SetRoutes(routes)
// CreateOnMobile creates a new Wireguard interface, sets a given IP and brings it up.
// Will reuse an existing one.
func (w *WGIface) CreateOnMobile(mIFaceArgs MobileIFaceArguments) error {
w.mu.Lock()
defer w.mu.Unlock()
log.Debugf("create WireGuard interface %s", w.tun.DeviceName())
return w.tun.Create(mIFaceArgs)
}
// Create this function make sense on mobile only
func (w *WGIface) Create() error {
return fmt.Errorf("this function has not implemented on mobile")
}

View File

@ -3,9 +3,11 @@
package iface
import (
"fmt"
"sync"
"github.com/pion/transport/v2"
log "github.com/sirupsen/logrus"
)
// NewWGIFace Creates a new WireGuard interface instance
@ -26,7 +28,16 @@ func NewWGIFace(iFaceName string, address string, mtu int, tunAdapter TunAdapter
return wgIFace, nil
}
// SetInitialRoutes unused function on non Android
func (w *WGIface) SetInitialRoutes(routes []string) {
// CreateOnMobile this function make sense on mobile only
func (w *WGIface) CreateOnMobile(mIFaceArgs MobileIFaceArguments) error {
return fmt.Errorf("this function has not implemented on non mobile")
}
// Create creates a new Wireguard interface, sets a given IP and brings it up.
// Will reuse an existing one.
func (w *WGIface) Create() error {
w.mu.Lock()
defer w.mu.Unlock()
log.Debugf("create WireGuard interface %s", w.tun.DeviceName())
return w.tun.Create()
}

View File

@ -1,5 +1,10 @@
package iface
type MobileIFaceArguments struct {
Routes []string
Dns string
}
// NetInterface represents a generic network tunnel interface
type NetInterface interface {
Close() error

View File

@ -2,6 +2,6 @@ package iface
// TunAdapter is an interface for create tun device from externel service
type TunAdapter interface {
ConfigureInterface(address string, mtu int, routes string) (int, error)
ConfigureInterface(address string, mtu int, dns string, routes string) (int, error)
UpdateAddr(address string) error
}

View File

@ -15,13 +15,12 @@ import (
type tunDevice struct {
address WGAddress
mtu int
routes []string
tunAdapter TunAdapter
iceBind *bind.ICEBind
fd int
name string
device *device.Device
iceBind *bind.ICEBind
wrapper *DeviceWrapper
}
@ -34,14 +33,10 @@ func newTunDevice(address WGAddress, mtu int, tunAdapter TunAdapter, transportNe
}
}
func (t *tunDevice) SetRoutes(routes []string) {
t.routes = routes
}
func (t *tunDevice) Create() error {
func (t *tunDevice) Create(mIFaceArgs MobileIFaceArguments) error {
var err error
routesString := t.routesToString()
t.fd, err = t.tunAdapter.ConfigureInterface(t.address.String(), t.mtu, routesString)
routesString := t.routesToString(mIFaceArgs.Routes)
t.fd, err = t.tunAdapter.ConfigureInterface(t.address.String(), t.mtu, mIFaceArgs.Dns, routesString)
if err != nil {
log.Errorf("failed to create Android interface: %s", err)
return err
@ -95,6 +90,6 @@ func (t *tunDevice) Close() (err error) {
return
}
func (t *tunDevice) routesToString() string {
return strings.Join(t.routes, ";")
func (t *tunDevice) routesToString(routes []string) string {
return strings.Join(routes, ";")
}

View File

@ -15,5 +15,5 @@ type Client interface {
Register(serverKey wgtypes.Key, setupKey string, jwtToken string, sysInfo *system.Info, sshKey []byte) (*proto.LoginResponse, error)
Login(serverKey wgtypes.Key, sysInfo *system.Info, sshKey []byte) (*proto.LoginResponse, error)
GetDeviceAuthorizationFlow(serverKey wgtypes.Key) (*proto.DeviceAuthorizationFlow, error)
GetRoutes() ([]*proto.Route, error)
GetNetworkMap() (*proto.NetworkMap, error)
}

View File

@ -172,8 +172,8 @@ func (c *GrpcClient) Sync(msgHandler func(msg *proto.SyncResponse) error) error
return nil
}
// GetRoutes return with the routes
func (c *GrpcClient) GetRoutes() ([]*proto.Route, error) {
// GetNetworkMap return with the network map
func (c *GrpcClient) GetNetworkMap() (*proto.NetworkMap, error) {
serverPubKey, err := c.GetServerPublicKey()
if err != nil {
log.Debugf("failed getting Management Service public key: %s", err)
@ -212,7 +212,7 @@ func (c *GrpcClient) GetRoutes() ([]*proto.Route, error) {
return nil, fmt.Errorf("invalid msg, required network map")
}
return decryptedResp.GetNetworkMap().GetRoutes(), nil
return decryptedResp.GetNetworkMap(), nil
}
func (c *GrpcClient) connectToStream(ctx context.Context, serverPubKey wgtypes.Key) (proto.ManagementService_SyncClient, error) {

View File

@ -57,7 +57,7 @@ func (m *MockClient) GetDeviceAuthorizationFlow(serverKey wgtypes.Key) (*proto.D
return m.GetDeviceAuthorizationFlowFunc(serverKey)
}
// GetRoutes mock implementation of GetRoutes from mgm.Client interface
func (m *MockClient) GetRoutes() ([]*proto.Route, error) {
// GetNetworkMap mock implementation of GetNetworkMap from mgm.Client interface
func (m *MockClient) GetNetworkMap() (*proto.NetworkMap, error) {
return nil, nil
}