[client] Enhance DNS forwarder to track resolved IPs with resource IDs on routing peers (#3620)

[client] Enhance DNS forwarder to track resolved IPs with resource IDs on routing peers (#3620)

client/internal/dnsfwd/forwarder.go

@@ -5,11 +5,14 @@ import (
 	"errors"
 	"net"
 	"net/netip"
+	"strings"
+	"sync"
 	"time"
 
 	"github.com/miekg/dns"
 	log "github.com/sirupsen/logrus"
 
+	"github.com/netbirdio/netbird/client/internal/peer"
 	nbdns "github.com/netbirdio/netbird/dns"
 )
 
@@ -17,23 +20,27 @@ const errResolveFailed = "failed to resolve query for domain=%s: %v"
 const upstreamTimeout = 15 * time.Second
 
 type DNSForwarder struct {
-	listenAddress string
-	ttl           uint32
-	domains       []string
+	listenAddress  string
+	ttl            uint32
+	domains        []string
+	statusRecorder *peer.Status
 
 	dnsServer *dns.Server
 	mux       *dns.ServeMux
+
+	resId sync.Map
 }
 
-func NewDNSForwarder(listenAddress string, ttl uint32) *DNSForwarder {
+func NewDNSForwarder(listenAddress string, ttl uint32, statusRecorder *peer.Status) *DNSForwarder {
 	log.Debugf("creating DNS forwarder with listen_address=%s ttl=%d", listenAddress, ttl)
 	return &DNSForwarder{
-		listenAddress: listenAddress,
-		ttl:           ttl,
+		listenAddress:  listenAddress,
+		ttl:            ttl,
+		statusRecorder: statusRecorder,
 	}
 }
 
-func (f *DNSForwarder) Listen(domains []string) error {
+func (f *DNSForwarder) Listen(domains []string, resIds map[string]string) error {
 	log.Infof("listen DNS forwarder on address=%s", f.listenAddress)
 	mux := dns.NewServeMux()
 
@@ -45,22 +52,31 @@ func (f *DNSForwarder) Listen(domains []string) error {
 	f.dnsServer = dnsServer
 	f.mux = mux
 
-	f.UpdateDomains(domains)
+	f.UpdateDomains(domains, resIds)
 
 	return dnsServer.ListenAndServe()
 }
 
-func (f *DNSForwarder) UpdateDomains(domains []string) {
+func (f *DNSForwarder) UpdateDomains(domains []string, resIds map[string]string) {
 	log.Debugf("Updating domains from %v to %v", f.domains, domains)
 
 	for _, d := range f.domains {
 		f.mux.HandleRemove(d)
+		f.statusRecorder.RemoveResolvedIPLookupEntry(d)
 	}
+	f.resId.Clear()
 
 	newDomains := filterDomains(domains)
 	for _, d := range newDomains {
 		f.mux.HandleFunc(d, f.handleDNSQuery)
 	}
+
+	for domain, resId := range resIds {
+		if domain != "" {
+			f.resId.Store(domain, resId)
+		}
+	}
+
 	f.domains = newDomains
 }
 
@@ -106,6 +122,21 @@ func (f *DNSForwarder) handleDNSQuery(w dns.ResponseWriter, query *dns.Msg) {
 		return
 	}
 
+	resId, ok := f.resId.Load(strings.TrimSuffix(domain, "."))
+	if ok {
+		for _, ip := range ips {
+			var ipWithSuffix string
+			if ip.Is4() {
+				ipWithSuffix = ip.String() + "/32"
+				log.Tracef("resolved domain=%s to IPv4=%s", domain, ipWithSuffix)
+			} else {
+				ipWithSuffix = ip.String() + "/128"
+				log.Tracef("resolved domain=%s to IPv6=%s", domain, ipWithSuffix)
+			}
+			f.statusRecorder.AddResolvedIPLookupEntry(ipWithSuffix, resId.(string))
+		}
+	}
+
 	f.addIPsToResponse(resp, domain, ips)
 
 	if err := w.WriteMsg(resp); err != nil {

client/internal/dnsfwd/manager.go

@@ -10,6 +10,7 @@ import (
 
 	nberrors "github.com/netbirdio/netbird/client/errors"
 	firewall "github.com/netbirdio/netbird/client/firewall/manager"
+	"github.com/netbirdio/netbird/client/internal/peer"
 )
 
 const (
@@ -19,19 +20,21 @@ const (
 )
 
 type Manager struct {
-	firewall firewall.Manager
+	firewall       firewall.Manager
+	statusRecorder *peer.Status
 
 	fwRules      []firewall.Rule
 	dnsForwarder *DNSForwarder
 }
 
-func NewManager(fw firewall.Manager) *Manager {
+func NewManager(fw firewall.Manager, statusRecorder *peer.Status) *Manager {
 	return &Manager{
-		firewall: fw,
+		firewall:       fw,
+		statusRecorder: statusRecorder,
 	}
 }
 
-func (m *Manager) Start(domains []string) error {
+func (m *Manager) Start(domains []string, resIds map[string]string) error {
 	log.Infof("starting DNS forwarder")
 	if m.dnsForwarder != nil {
 		return nil
@@ -41,9 +44,9 @@ func (m *Manager) Start(domains []string) error {
 		return err
 	}
 
-	m.dnsForwarder = NewDNSForwarder(fmt.Sprintf(":%d", ListenPort), dnsTTL)
+	m.dnsForwarder = NewDNSForwarder(fmt.Sprintf(":%d", ListenPort), dnsTTL, m.statusRecorder)
 	go func() {
-		if err := m.dnsForwarder.Listen(domains); err != nil {
+		if err := m.dnsForwarder.Listen(domains, resIds); err != nil {
 			// todo handle close error if it is exists
 			log.Errorf("failed to start DNS forwarder, err: %v", err)
 		}
@@ -52,12 +55,12 @@ func (m *Manager) Start(domains []string) error {
 	return nil
 }
 
-func (m *Manager) UpdateDomains(domains []string) {
+func (m *Manager) UpdateDomains(domains []string, resIds map[string]string) {
 	if m.dnsForwarder == nil {
 		return
 	}
 
-	m.dnsForwarder.UpdateDomains(domains)
+	m.dnsForwarder.UpdateDomains(domains, resIds)
 }
 
 func (m *Manager) Stop(ctx context.Context) error {