ssh: mode parameter support, banner support

internal/server/driver/ssh/driver.go

@@ -2,6 +2,7 @@ package ssh
 
 import (
 	"context"
+	"errors"
 	"net"
 	"path"
 	"strconv"
@@ -16,6 +17,8 @@ import (
 	"github.com/Neur0toxine/sshpoke/pkg/proto/ssh"
 )
 
+var ErrAlreadyInUse = errors.New("domain is already in use")
+
 type SSH struct {
 	base.Base
 	params Params
@@ -45,9 +48,15 @@ func New(ctx context.Context, name string, params config.DriverParams) (base.Dri
 }
 
 func (d *SSH) forward(val sshtun.Forward) conn {
-	tun := sshtun.New(d.params.Address, d.params.Auth.User, d.params.FakeRemoteHost, val, d.auth, d.Log())
+	tun := sshtun.New(d.params.Address,
+		d.params.Auth.User,
+		d.params.FakeRemoteHost,
+		val,
+		d.auth,
+		d.Log())
 	ctx, cancel := context.WithCancel(d.Context())
-	go tun.Connect(ctx, sshtun.StdoutPrinterSessionCallback(d.Log().With("ssh-output", val.Remote.String())))
+	tunDbgLog := d.Log().With("ssh-output", val.Remote.String())
+	go tun.Connect(ctx, sshtun.StdoutPrinterBannerCallback(tunDbgLog), sshtun.StdoutPrinterSessionCallback(tunDbgLog))
 	return conn{ctx: ctx, cancel: cancel, tun: tun}
 }
 
@@ -79,6 +88,9 @@ func (d *SSH) Handle(event dto.Event) error {
 	d.rw.Lock()
 	switch event.Type {
 	case dto.EventStart:
+		if d.params.Mode == types.DomainModeSingle && len(d.conns) > 0 {
+			return ErrAlreadyInUse
+		}
 		conn := d.forward(sshtun.Forward{
 			Local:  sshtun.AddrToEndpoint(net.JoinHostPort(event.Container.IP.String(), strconv.Itoa(int(event.Container.Port)))),
 			Remote: d.remoteEndpoint(event.Container.RemoteHost),

internal/server/driver/ssh/sshtun/forward.go

@@ -18,7 +18,7 @@ type Forward struct {
 func AddrToEndpoint(address string) Endpoint {
 	host, port, err := net.SplitHostPort(address)
 	if err != nil && errtools.IsPortMissingErr(err) {
-		return Endpoint{Host: host, Port: 22}
+		return Endpoint{Host: address, Port: 22}
 	}
 	portNum, err := strconv.Atoi(port)
 	if err != nil {

internal/server/driver/ssh/sshtun/printer.go

@@ -19,3 +19,10 @@ func StdoutPrinterSessionCallback(log *zap.SugaredLogger) SessionCallback {
 		}
 	}
 }
+
+func StdoutPrinterBannerCallback(log *zap.SugaredLogger) ssh.BannerCallback {
+	return func(msg string) error {
+		log.Debug(msg)
+		return nil
+	}
+}

internal/server/driver/ssh/sshtun/ssh.go

@@ -41,7 +41,7 @@ func New(address, user string, fakeRemoteHost bool,
 	}
 }
 
-func (c *Tunnel) Connect(ctx context.Context, sessionCb SessionCallback) {
+func (c *Tunnel) Connect(ctx context.Context, bannerCb ssh.BannerCallback, sessionCb SessionCallback) {
 	if c.connected.Load() {
 		return
 	}
@@ -50,7 +50,7 @@ func (c *Tunnel) Connect(ctx context.Context, sessionCb SessionCallback) {
 	backoffTime := backoff.ExponentialWithCappedMax(100*time.Millisecond, 5*time.Second)
 	for {
 		c.connected.Store(true)
-		err := c.connect(ctx, sessionCb)
+		err := c.connect(ctx, bannerCb, sessionCb)
 		if err != nil {
 			c.log.Error("connect error:", err)
 		}
@@ -67,12 +67,13 @@ func (c *Tunnel) Connect(ctx context.Context, sessionCb SessionCallback) {
 
 // connect once to the SSH server. if the connection breaks, we return error and the caller
 // will try to re-connect
-func (c *Tunnel) connect(ctx context.Context, sessionCb SessionCallback) error {
+func (c *Tunnel) connect(ctx context.Context, bannerCb ssh.BannerCallback, sessionCb SessionCallback) error {
 	c.log.Debug("connecting")
 	sshConfig := &ssh.ClientConfig{
 		User:            c.user,
 		Auth:            c.authMethods,
 		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+		BannerCallback:  bannerCb,
 	}
 
 	var sshClient *ssh.Client
@@ -89,6 +90,7 @@ func (c *Tunnel) connect(ctx context.Context, sessionCb SessionCallback) error {
 	c.log.Debug("connected")
 	listenerStopped := make(chan error)
 
+	var wg sync.WaitGroup
 	sess, err := sshClient.NewSession()
 	if err != nil {
 		c.log.Errorf("session error: %s", err)
@@ -96,15 +98,16 @@ func (c *Tunnel) connect(ctx context.Context, sessionCb SessionCallback) error {
 	}
 	defer sess.Close()
 
-	var wg sync.WaitGroup
 	if sessionCb == nil {
 		sessionCb = func(*ssh.Session) {}
 	}
-	wg.Add(2)
+	wg.Add(1)
 	go func() {
 		defer wg.Done()
 		sessionCb(sess)
 	}()
+
+	wg.Add(1)
 	reverseErr := make(chan error)
 	go func() {
 		defer wg.Done()