lib/connections: Add connection benchmarks, allow binding to port zero addresses (#7648)

* Add connbench

* Refactor port fixup

* More cleanup

* touch for build

Co-authored-by: Jakob Borg <jakob@kastelo.net>

lib/connections/connections_test.go

@@ -8,12 +8,26 @@ package connections
 
 import (
 	"context"
+	"crypto/tls"
 	"errors"
+	"fmt"
+	"io/ioutil"
+	"math/rand"
+	"net"
 	"net/url"
+	"os"
+	"strings"
 	"testing"
+	"time"
+
+	"github.com/thejerf/suture/v4"
 
 	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/events"
+	"github.com/syncthing/syncthing/lib/nat"
 	"github.com/syncthing/syncthing/lib/protocol"
+	"github.com/syncthing/syncthing/lib/sync"
+	"github.com/syncthing/syncthing/lib/tlsutil"
 )
 
 func TestFixupPort(t *testing.T) {
@@ -216,3 +230,196 @@ func TestConnectionStatus(t *testing.T) {
 
 	check(nil, nil)
 }
+
+func BenchmarkConnections(pb *testing.B) {
+	addrs := []string{
+		"tcp://127.0.0.1:0",
+		"quic://127.0.0.1:0",
+		"relay://127.0.0.1:22067",
+	}
+	sizes := []int{
+		1 << 10,
+		1 << 15,
+		1 << 20,
+		1 << 22,
+	}
+	haveRelay := false
+	// Check if we have a relay running locally
+	conn, err := net.DialTimeout("tcp", "127.0.0.1:22067", 100*time.Millisecond)
+	if err == nil {
+		haveRelay = true
+		_ = conn.Close()
+	}
+	for _, addr := range addrs {
+		for _, sz := range sizes {
+			for _, direction := range []string{"cs", "sc"} {
+				proto := strings.SplitN(addr, ":", 2)[0]
+				pb.Run(fmt.Sprintf("%s_%d_%s", proto, sz, direction), func(b *testing.B) {
+					if proto == "relay" && !haveRelay {
+						b.Skip("could not connect to relay")
+					}
+					withConnectionPair(b, addr, func(client, server internalConn) {
+						if direction == "sc" {
+							server, client = client, server
+						}
+						data := make([]byte, sz)
+						if _, err := rand.Read(data); err != nil {
+							b.Fatal(err)
+						}
+
+						total := 0
+						wg := sync.NewWaitGroup()
+						b.ResetTimer()
+						for i := 0; i < b.N; i++ {
+							wg.Add(2)
+							go func() {
+								if err := sendMsg(client, data); err != nil {
+									b.Fatal(err)
+								}
+								wg.Done()
+							}()
+							go func() {
+								if err := recvMsg(server, data); err != nil {
+									b.Fatal(err)
+								}
+								total += sz
+								wg.Done()
+							}()
+							wg.Wait()
+						}
+						b.ReportAllocs()
+						b.SetBytes(int64(total / b.N))
+					})
+				})
+			}
+
+		}
+	}
+}
+
+func sendMsg(c internalConn, buf []byte) error {
+	n, err := c.Write(buf)
+	if n != len(buf) || err != nil {
+		return err
+	}
+	return nil
+}
+
+func recvMsg(c internalConn, buf []byte) error {
+	for read := 0; read != len(buf); {
+		n, err := c.Read(buf)
+		read += n
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func withConnectionPair(b *testing.B, connUri string, h func(client, server internalConn)) {
+	// Root of the service tree.
+	supervisor := suture.New("main", suture.Spec{
+		PassThroughPanics: true,
+	})
+
+	cert := mustGetCert(b)
+	deviceId := protocol.NewDeviceID(cert.Certificate[0])
+	tlsCfg := tlsutil.SecureDefaultTLS13()
+	tlsCfg.Certificates = []tls.Certificate{cert}
+	tlsCfg.NextProtos = []string{"bench"}
+	tlsCfg.ClientAuth = tls.RequestClientCert
+	tlsCfg.SessionTicketsDisabled = true
+	tlsCfg.InsecureSkipVerify = true
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	supervisor.ServeBackground(ctx)
+
+	cfg := config.Configuration{
+		Options: config.OptionsConfiguration{
+			RelaysEnabled: true,
+		},
+	}
+	wcfg := config.Wrap("", cfg, deviceId, events.NoopLogger)
+	uri, err := url.Parse(connUri)
+	if err != nil {
+		b.Fatal(err)
+	}
+	lf, err := getListenerFactory(cfg, uri)
+	if err != nil {
+		b.Fatal(err)
+	}
+	natSvc := nat.NewService(deviceId, wcfg)
+	conns := make(chan internalConn, 1)
+	listenSvc := lf.New(uri, wcfg, tlsCfg, conns, natSvc)
+	supervisor.Add(listenSvc)
+
+	var addr *url.URL
+	for {
+		addrs := listenSvc.LANAddresses()
+		if len(addrs) > 0 {
+			if !strings.HasSuffix(addrs[0].Host, ":0") {
+				addr = addrs[0]
+				break
+			}
+		}
+		time.Sleep(time.Millisecond)
+	}
+
+	df, err := getDialerFactory(cfg, addr)
+	if err != nil {
+		b.Fatal(err)
+	}
+	dialer := df.New(cfg.Options, tlsCfg)
+
+	// Relays might take some time to register the device, so dial multiple times
+	clientConn, err := dialer.Dial(ctx, deviceId, addr)
+	if err != nil {
+		for i := 0; i < 10 && err != nil; i++ {
+			clientConn, err = dialer.Dial(ctx, deviceId, addr)
+			time.Sleep(100 * time.Millisecond)
+		}
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+
+	data := []byte("hello")
+
+	// Quic does not start a stream until some data is sent through, so send something for the AcceptStream
+	// to fire on the other side.
+	if err := sendMsg(clientConn, data); err != nil {
+		b.Fatal(err)
+	}
+
+	serverConn := <-conns
+
+	if err := recvMsg(serverConn, data); err != nil {
+		b.Fatal(err)
+	}
+
+	h(clientConn, serverConn)
+
+	_ = clientConn.Close()
+	_ = serverConn.Close()
+}
+
+func mustGetCert(b *testing.B) tls.Certificate {
+	f1, err := ioutil.TempFile("", "")
+	if err != nil {
+		b.Fatal(err)
+	}
+	f1.Close()
+	f2, err := ioutil.TempFile("", "")
+	if err != nil {
+		b.Fatal(err)
+	}
+	f2.Close()
+	cert, err := tlsutil.NewCertificate(f1.Name(), f2.Name(), "bench", 10)
+	if err != nil {
+		b.Fatal(err)
+	}
+	_ = os.Remove(f1.Name())
+	_ = os.Remove(f2.Name())
+	return cert
+}