tsnet: add test for Funnel connections

For the logic added in b797f77.

Signed-off-by: Maisem Ali <maisem@tailscale.com>

tsnet/tsnet.go

@@ -100,6 +100,8 @@ type Server struct {
 	// If empty, the Tailscale default is used.
 	ControlURL string
 
+	getCertForTesting func(*tls.ClientHelloInfo) (*tls.Certificate, error)
+
 	initOnce         sync.Once
 	initErr          error
 	lb               *ipnlocal.LocalBackend
@@ -842,18 +844,28 @@ func (s *Server) ListenTLS(network, addr string) (net.Listener, error) {
 		return nil, errors.New("tsnet: you must enable HTTPS in the admin panel to proceed. See https://tailscale.com/s/https")
 	}
 
-	lc, err := s.LocalClient() // do local client first before listening.
+	ln, err := s.listen(network, addr, listenOnTailnet)
 	if err != nil {
 		return nil, err
 	}
+	return tls.NewListener(ln, &tls.Config{
+		GetCertificate: s.getCert,
+	}), nil
+}
 
-	ln, err := s.listen(network, addr, listenOnTailnet)
+// getCert is the GetCertificate function used by ListenTLS.
+//
+// It calls GetCertificate on the localClient, passing in the ClientHelloInfo.
+// For testing, if s.getCertForTesting is set, it will call that instead.
+func (s *Server) getCert(hi *tls.ClientHelloInfo) (*tls.Certificate, error) {
+	if s.getCertForTesting != nil {
+		return s.getCertForTesting(hi)
+	}
+	lc, err := s.LocalClient()
 	if err != nil {
 		return nil, err
 	}
-	return tls.NewListener(ln, &tls.Config{
-		GetCertificate: lc.GetCertificate,
-	}), nil
+	return lc.GetCertificate(hi)
 }
 
 // FunnelOption is an option passed to ListenFunnel to configure the listener.
@@ -909,10 +921,7 @@ func (s *Server) ListenFunnel(network, addr string, opts ...FunnelOption) (net.L
 		return nil, err
 	}
 
-	lc, err := s.LocalClient()
-	if err != nil {
-		return nil, err
-	}
+	lc := s.localClient
 
 	// May not have funnel enabled. Enable it.
 	srvConfig, err := lc.GetServeConfig(ctx)
@@ -944,7 +953,7 @@ func (s *Server) ListenFunnel(network, addr string, opts ...FunnelOption) (net.L
 		return nil, err
 	}
 	return tls.NewListener(ln, &tls.Config{
-		GetCertificate: lc.GetCertificate,
+		GetCertificate: s.getCert,
 	}), nil
 }
 

tsnet/tsnet_test.go

@@ -4,27 +4,40 @@
 package tsnet
 
 import (
+	"bufio"
 	"context"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
 	"errors"
 	"flag"
 	"fmt"
 	"io"
+	"io/ioutil"
+	"math/big"
 	"net"
 	"net/http"
 	"net/http/httptest"
 	"net/netip"
 	"os"
 	"path/filepath"
+	"strings"
+	"sync"
 	"testing"
 	"time"
 
 	"golang.org/x/net/proxy"
+	"tailscale.com/ipn"
 	"tailscale.com/ipn/store/mem"
 	"tailscale.com/net/netns"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tstest/integration"
 	"tailscale.com/tstest/integration/testcontrol"
 	"tailscale.com/types/logger"
+	"tailscale.com/util/must"
 )
 
 // TestListener_Server ensures that the listener type always keeps the Server
@@ -93,6 +106,10 @@ func startControl(t *testing.T) (controlURL string) {
 	derpMap := integration.RunDERPAndSTUN(t, derpLogf, "127.0.0.1")
 	control := &testcontrol.Server{
 		DERPMap: derpMap,
+		DNSConfig: &tailcfg.DNSConfig{
+			Proxied: true,
+		},
+		MagicDNSDomain: "tail-scale.ts.net",
 	}
 	control.HTTPTestServer = httptest.NewUnstartedServer(control)
 	control.HTTPTestServer.Start()
@@ -102,6 +119,84 @@ func startControl(t *testing.T) (controlURL string) {
 	return controlURL
 }
 
+type testCertIssuer struct {
+	mu    sync.Mutex
+	certs map[string]*tls.Certificate
+
+	root    *x509.Certificate
+	rootKey *ecdsa.PrivateKey
+}
+
+func newCertIssuer() *testCertIssuer {
+	rootKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		panic(err)
+	}
+	t := &x509.Certificate{
+		SerialNumber: big.NewInt(1),
+		Subject: pkix.Name{
+			CommonName: "root",
+		},
+		NotBefore:             time.Now(),
+		NotAfter:              time.Now().Add(time.Hour),
+		IsCA:                  true,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		KeyUsage:              x509.KeyUsageCertSign,
+		BasicConstraintsValid: true,
+	}
+	rootDER, err := x509.CreateCertificate(rand.Reader, t, t, &rootKey.PublicKey, rootKey)
+	if err != nil {
+		panic(err)
+	}
+	rootCA, err := x509.ParseCertificate(rootDER)
+	if err != nil {
+		panic(err)
+	}
+	return &testCertIssuer{
+		certs:   make(map[string]*tls.Certificate),
+		root:    rootCA,
+		rootKey: rootKey,
+	}
+}
+
+func (tci *testCertIssuer) getCert(chi *tls.ClientHelloInfo) (*tls.Certificate, error) {
+	tci.mu.Lock()
+	defer tci.mu.Unlock()
+	cert, ok := tci.certs[chi.ServerName]
+	if ok {
+		return cert, nil
+	}
+
+	certPrivKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+	certTmpl := &x509.Certificate{
+		SerialNumber: big.NewInt(1),
+		DNSNames:     []string{chi.ServerName},
+		NotBefore:    time.Now(),
+		NotAfter:     time.Now().Add(time.Hour),
+	}
+	certDER, err := x509.CreateCertificate(rand.Reader, certTmpl, tci.root, &certPrivKey.PublicKey, tci.rootKey)
+	if err != nil {
+		return nil, err
+	}
+	cert = &tls.Certificate{
+		Certificate: [][]byte{certDER, tci.root.Raw},
+		PrivateKey:  certPrivKey,
+	}
+	tci.certs[chi.ServerName] = cert
+	return cert, nil
+}
+
+func (tci *testCertIssuer) Pool() *x509.CertPool {
+	p := x509.NewCertPool()
+	p.AddCert(tci.root)
+	return p
+}
+
+var testCertRoot = newCertIssuer()
+
 func startServer(t *testing.T, ctx context.Context, controlURL, hostname string) (*Server, netip.Addr) {
 	t.Helper()
 
@@ -113,6 +208,7 @@ func startServer(t *testing.T, ctx context.Context, controlURL, hostname string)
 		Hostname:          hostname,
 		Store:             new(mem.Store),
 		Ephemeral:         true,
+		getCertForTesting: testCertRoot.getCert,
 	}
 	if !*verboseNodes {
 		s.Logf = logger.Discard
@@ -368,3 +464,112 @@ func TestListenerCleanup(t *testing.T) {
 		t.Fatalf("second ln.Close error: %v, want net.ErrClosed", err)
 	}
 }
+
+func TestFunnel(t *testing.T) {
+	ctx, dialCancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer dialCancel()
+
+	controlURL := startControl(t)
+	s1, _ := startServer(t, ctx, controlURL, "s1")
+	s2, _ := startServer(t, ctx, controlURL, "s2")
+
+	ln := must.Get(s1.ListenFunnel("tcp", ":443"))
+	defer ln.Close()
+	wantSrcAddrPort := netip.MustParseAddrPort("127.0.0.1:1234")
+	wantTarget := ipn.HostPort("s1.tail-scale.ts.net:443")
+	srv := &http.Server{
+		ConnContext: func(ctx context.Context, c net.Conn) context.Context {
+			tc, ok := c.(*tls.Conn)
+			if !ok {
+				t.Errorf("ConnContext called with non-TLS conn: %T", c)
+			}
+			if fc, ok := tc.NetConn().(*ipn.FunnelConn); !ok {
+				t.Errorf("ConnContext called with non-FunnelConn: %T", c)
+			} else if fc.Src != wantSrcAddrPort {
+				t.Errorf("ConnContext called with wrong SrcAddrPort; got %v, want %v", fc.Src, wantSrcAddrPort)
+			} else if fc.Target != wantTarget {
+				t.Errorf("ConnContext called with wrong Target; got %q, want %q", fc.Target, wantTarget)
+			}
+			return ctx
+		},
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			fmt.Fprintf(w, "hello")
+		}),
+	}
+	go srv.Serve(ln)
+
+	c := &http.Client{
+		Transport: &http.Transport{
+			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				return dialIngressConn(s2, s1, addr)
+			},
+			TLSClientConfig: &tls.Config{
+				RootCAs: testCertRoot.Pool(),
+			},
+		},
+	}
+	resp, err := c.Get("https://s1.tail-scale.ts.net:443")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != 200 {
+		t.Errorf("unexpected status code: %v", resp.StatusCode)
+		return
+	}
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(body) != "hello" {
+		t.Errorf("unexpected body: %q", body)
+	}
+}
+
+func dialIngressConn(from, to *Server, target string) (net.Conn, error) {
+	toLC := must.Get(to.LocalClient())
+	toStatus := must.Get(toLC.StatusWithoutPeers(context.Background()))
+	peer6 := toStatus.Self.PeerAPIURL[1] // IPv6
+	toPeerAPI, ok := strings.CutPrefix(peer6, "http://")
+	if !ok {
+		return nil, fmt.Errorf("unexpected PeerAPIURL %q", peer6)
+	}
+
+	dialCtx, dialCancel := context.WithTimeout(context.Background(), 30*time.Second)
+	outConn, err := from.Dial(dialCtx, "tcp", toPeerAPI)
+	dialCancel()
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("POST", "/v0/ingress", nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Host = toPeerAPI
+	req.Header.Set("Tailscale-Ingress-Src", "127.0.0.1:1234")
+	req.Header.Set("Tailscale-Ingress-Target", target)
+	if err := req.Write(outConn); err != nil {
+		return nil, err
+	}
+
+	br := bufio.NewReader(outConn)
+	res, err := http.ReadResponse(br, req)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close() // just to appease vet
+	if res.StatusCode != 101 {
+		return nil, fmt.Errorf("unexpected status code: %v", res.StatusCode)
+	}
+	return &bufferedConn{outConn, br}, nil
+}
+
+type bufferedConn struct {
+	net.Conn
+	reader *bufio.Reader
+}
+
+func (c *bufferedConn) Read(b []byte) (int, error) {
+	return c.reader.Read(b)
+}

tstest/integration/testcontrol/testcontrol.go

@@ -26,6 +26,7 @@ import (
 
 	"github.com/klauspost/compress/zstd"
 	"go4.org/mem"
+	"golang.org/x/exp/slices"
 	"tailscale.com/net/netaddr"
 	"tailscale.com/net/tsaddr"
 	"tailscale.com/smallzstd"
@@ -44,6 +45,7 @@ type Server struct {
 	RequireAuth    bool
 	Verbose        bool
 	DNSConfig      *tailcfg.DNSConfig // nil means no DNS config
+	MagicDNSDomain string
 
 	// ExplicitBaseURL or HTTPTestServer must be set.
 	ExplicitBaseURL string           // e.g. "http://127.0.0.1:1234" with no trailing URL
@@ -328,6 +330,15 @@ func (s *Server) AddFakeNode() {
 	// TODO: send updates to other (non-fake?) nodes
 }
 
+func (s *Server) AllUsers() (users []*tailcfg.User) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for _, u := range s.users {
+		users = append(users, u.Clone())
+	}
+	return users
+}
+
 func (s *Server) AllNodes() (nodes []*tailcfg.Node) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
@@ -494,6 +505,11 @@ func (s *Server) serveRegister(w http.ResponseWriter, r *http.Request, mkey key.
 		Addresses:         allowedIPs,
 		AllowedIPs:        allowedIPs,
 		Hostinfo:          req.Hostinfo.View(),
+		Name:              req.Hostinfo.Hostname,
+		Capabilities: []string{
+			tailcfg.NodeAttrFunnel,
+			tailcfg.CapabilityFunnelPorts + "?ports=8080,443",
+		},
 	}
 	requireAuth := s.RequireAuth
 	if requireAuth && s.nodeKeyAuthed[nk] {
@@ -729,6 +745,20 @@ var keepAliveMsg = &struct {
 	KeepAlive: true,
 }
 
+func packetFilterWithIngressCaps() []tailcfg.FilterRule {
+	out := slices.Clone(tailcfg.FilterAllowAll)
+	out = append(out, tailcfg.FilterRule{
+		SrcIPs: []string{"*"},
+		CapGrant: []tailcfg.CapGrant{
+			{
+				Dsts: []netip.Prefix{tsaddr.AllIPv4(), tsaddr.AllIPv6()},
+				Caps: []string{tailcfg.CapabilityIngress},
+			},
+		},
+	})
+	return out
+}
+
 // MapResponse generates a MapResponse for a MapRequest.
 //
 // No updates to s are done here.
@@ -741,16 +771,24 @@ func (s *Server) MapResponse(req *tailcfg.MapRequest) (res *tailcfg.MapResponse,
 	}
 	user, _ := s.getUser(nk)
 	t := time.Date(2020, 8, 3, 0, 0, 0, 1, time.UTC)
+	dns := s.DNSConfig
+	if dns != nil && s.MagicDNSDomain != "" {
+		dns = dns.Clone()
+		dns.CertDomains = []string{
+			fmt.Sprintf(node.Hostinfo.Hostname() + "." + s.MagicDNSDomain),
+		}
+	}
+
 	res = &tailcfg.MapResponse{
 		Node:            node,
 		DERPMap:         s.DERPMap,
 		Domain:          string(user.Domain),
 		CollectServices: "true",
-		PacketFilter:    tailcfg.FilterAllowAll,
+		PacketFilter:    packetFilterWithIngressCaps(),
 		Debug: &tailcfg.Debug{
 			DisableUPnP: "true",
 		},
-		DNSConfig:   s.DNSConfig,
+		DNSConfig:   dns,
 		ControlTime: &t,
 	}
 	for _, p := range s.AllNodes() {
@@ -761,6 +799,13 @@ func (s *Server) MapResponse(req *tailcfg.MapRequest) (res *tailcfg.MapResponse,
 	sort.Slice(res.Peers, func(i, j int) bool {
 		return res.Peers[i].ID < res.Peers[j].ID
 	})
+	for _, u := range s.AllUsers() {
+		res.UserProfiles = append(res.UserProfiles, tailcfg.UserProfile{
+			ID:          u.ID,
+			LoginName:   u.LoginName,
+			DisplayName: u.DisplayName,
+		})
+	}
 
 	v4Prefix := netip.PrefixFrom(netaddr.IPv4(100, 64, uint8(tailcfg.NodeID(user.ID)>>8), uint8(tailcfg.NodeID(user.ID))), 32)
 	v6Prefix := netip.PrefixFrom(tsaddr.Tailscale4To6(v4Prefix.Addr()), 128)