refactor(session): add registry to manage SSH sessions

- Implement thread-safe session registry with sync.RWMutex
- Add Registry interface for session management operations
- Support Get, Register, Update, and Remove session operations
- Enable dynamic slug updates for existing sessions

main.go

@@ -9,6 +9,7 @@ import (
 	"tunnel_pls/internal/config"
 	"tunnel_pls/internal/key"
 	"tunnel_pls/server"
+	"tunnel_pls/session"
 	"tunnel_pls/version"
 
 	"golang.org/x/crypto/ssh"
@@ -58,6 +59,11 @@ func main() {
 	}
 
 	sshConfig.AddHostKey(private)
-	app := server.NewServer(sshConfig)
+	sessionRegistry := session.NewRegistry()
+
+	app, err := server.NewServer(sshConfig, sessionRegistry)
+	if err != nil {
+		log.Fatalf("Failed to start server: %s", err)
+	}
 	app.Start()
 }

server/handler.go

@@ -1,28 +0,0 @@
-package server
-
-import (
-	"log"
-	"net"
-	"tunnel_pls/session"
-
-	"golang.org/x/crypto/ssh"
-)
-
-func (s *Server) handleConnection(conn net.Conn) {
-	sshConn, chans, forwardingReqs, err := ssh.NewServerConn(conn, s.config)
-	if err != nil {
-		log.Printf("failed to establish SSH connection: %v", err)
-		err := conn.Close()
-		if err != nil {
-			log.Printf("failed to close SSH connection: %v", err)
-			return
-		}
-		return
-	}
-
-	log.Println("SSH connection established:", sshConn.User())
-
-	session.New(sshConn, forwardingReqs, chans)
-
-	return
-}

server/http.go

@@ -17,15 +17,9 @@ import (
 	"golang.org/x/crypto/ssh"
 )
 
-type Interaction interface {
-	SendMessage(message string)
-}
-
 type HTTPWriter interface {
 	io.Reader
 	io.Writer
-	SetInteraction(interaction Interaction)
-	AddInteraction(interaction Interaction)
 	GetRemoteAddr() net.Addr
 	GetWriter() io.Writer
 	AddResponseMiddleware(mw ResponseMiddleware)
@@ -42,16 +36,11 @@ type customWriter struct {
 	buf        []byte
 	respHeader ResponseHeaderManager
 	reqHeader  RequestHeaderManager
-	interaction Interaction
 	respMW     []ResponseMiddleware
 	reqStartMW []RequestMiddleware
 	reqEndMW   []RequestMiddleware
 }
 
-func (cw *customWriter) SetInteraction(interaction Interaction) {
-	cw.interaction = interaction
-}
-
 func (cw *customWriter) GetRemoteAddr() net.Addr {
 	return cw.remoteAddr
 }
@@ -139,7 +128,6 @@ func NewCustomWriter(writer io.Writer, reader io.Reader, remoteAddr net.Addr) HT
 		writer:     writer,
 		reader:     reader,
 		buf:        make([]byte, 0, 4096),
-		interaction: nil,
 	}
 }
 
@@ -224,13 +212,23 @@ func (cw *customWriter) Write(p []byte) (int, error) {
 	return len(p), nil
 }
 
-func (cw *customWriter) AddInteraction(interaction Interaction) {
-	cw.interaction = interaction
-}
-
 var redirectTLS = false
 
-func NewHTTPServer() error {
+type HTTPServer interface {
+	ListenAndServe() error
+	ListenAndServeTLS() error
+	handler(conn net.Conn)
+	handlerTLS(conn net.Conn)
+}
+type httpServer struct {
+	sessionRegistry session.Registry
+}
+
+func NewHTTPServer(sessionRegistry session.Registry) HTTPServer {
+	return &httpServer{sessionRegistry: sessionRegistry}
+}
+
+func (hs *httpServer) ListenAndServe() error {
 	httpPort := config.Getenv("HTTP_PORT", "8080")
 	listener, err := net.Listen("tcp", ":"+httpPort)
 	if err != nil {
@@ -251,13 +249,13 @@ func NewHTTPServer() error {
 				continue
 			}
 
-			go Handler(conn)
+			go hs.handler(conn)
 		}
 	}()
 	return nil
 }
 
-func Handler(conn net.Conn) {
+func (hs *httpServer) handler(conn net.Conn) {
 	defer func() {
 		err := conn.Close()
 		if err != nil && !errors.Is(err, net.ErrClosed) {
@@ -316,8 +314,8 @@ func Handler(conn net.Conn) {
 		return
 	}
 
-	sshSession, ok := session.Clients[slug]
+	sshSession, exist := hs.sessionRegistry.Get(slug)
-	if !ok {
+	if !exist {
 		_, err = conn.Write([]byte("HTTP/1.1 301 Moved Permanently\r\n" +
 			fmt.Sprintf("Location: https://tunnl.live/tunnel-not-found?slug=%s\r\n", slug) +
 			"Content-Length: 0\r\n" +

server/https.go

@@ -9,10 +9,9 @@ import (
 	"net"
 	"strings"
 	"tunnel_pls/internal/config"
-	"tunnel_pls/session"
 )
 
-func NewHTTPSServer() error {
+func (hs *httpServer) ListenAndServeTLS() error {
 	domain := config.Getenv("DOMAIN", "localhost")
 	httpsPort := config.Getenv("HTTPS_PORT", "8443")
 
@@ -38,13 +37,13 @@ func NewHTTPSServer() error {
 				continue
 			}
 
-			go HandlerTLS(conn)
+			go hs.handlerTLS(conn)
 		}
 	}()
 	return nil
 }
 
-func HandlerTLS(conn net.Conn) {
+func (hs *httpServer) handlerTLS(conn net.Conn) {
 	defer func() {
 		err := conn.Close()
 		if err != nil {
@@ -90,8 +89,8 @@ func HandlerTLS(conn net.Conn) {
 		return
 	}
 
-	sshSession, ok := session.Clients[slug]
+	sshSession, exist := hs.sessionRegistry.Get(slug)
-	if !ok {
+	if !exist {
 		_, err = conn.Write([]byte("HTTP/1.1 301 Moved Permanently\r\n" +
 			fmt.Sprintf("Location: https://tunnl.live/tunnel-not-found?slug=%s\r\n", slug) +
 			"Content-Length: 0\r\n" +

server/server.go

@@ -4,8 +4,8 @@ import (
 	"fmt"
 	"log"
 	"net"
-	"net/http"
 	"tunnel_pls/internal/config"
+	"tunnel_pls/session"
 
 	"golang.org/x/crypto/ssh"
 )
@@ -13,41 +13,36 @@ import (
 type Server struct {
 	conn            *net.Listener
 	config          *ssh.ServerConfig
-	httpServer *http.Server
+	sessionRegistry session.Registry
 }
 
-func (s *Server) GetConn() *net.Listener {
+func NewServer(sshConfig *ssh.ServerConfig, sessionRegistry session.Registry) (*Server, error) {
-	return s.conn
-}
-
-func (s *Server) GetConfig() *ssh.ServerConfig {
-	return s.config
-}
-
-func (s *Server) GetHttpServer() *http.Server {
-	return s.httpServer
-}
-
-func NewServer(sshConfig *ssh.ServerConfig) *Server {
 	listener, err := net.Listen("tcp", fmt.Sprintf(":%s", config.Getenv("PORT", "2200")))
 	if err != nil {
 		log.Fatalf("failed to listen on port 2200: %v", err)
-		return nil
+		return nil, err
 	}
-	if config.Getenv("TLS_ENABLED", "false") == "true" {
+
-		err = NewHTTPSServer()
+	HttpServer := NewHTTPServer(sessionRegistry)
-		if err != nil {
+	err = HttpServer.ListenAndServe()
-			log.Fatalf("failed to start https server: %v", err)
-		}
-	}
-	err = NewHTTPServer()
 	if err != nil {
 		log.Fatalf("failed to start http server: %v", err)
+		return nil, err
 	}
+
+	if config.Getenv("TLS_ENABLED", "false") == "true" {
+		err = HttpServer.ListenAndServeTLS()
+		if err != nil {
+			log.Fatalf("failed to start https server: %v", err)
+			return nil, err
+		}
+	}
+
 	return &Server{
 		conn:            &listener,
 		config:          sshConfig,
-	}
+		sessionRegistry: sessionRegistry,
+	}, nil
 }
 
 func (s *Server) Start() {
@@ -62,3 +57,26 @@ func (s *Server) Start() {
 		go s.handleConnection(conn)
 	}
 }
+
+func (s *Server) handleConnection(conn net.Conn) {
+	sshConn, chans, forwardingReqs, err := ssh.NewServerConn(conn, s.config)
+	if err != nil {
+		log.Printf("failed to establish SSH connection: %v", err)
+		err := conn.Close()
+		if err != nil {
+			log.Printf("failed to close SSH connection: %v", err)
+			return
+		}
+		return
+	}
+
+	log.Println("SSH connection established:", sshConn.User())
+
+	sshSession := session.New(sshConn, forwardingReqs, chans, s.sessionRegistry)
+	err = sshSession.Start()
+	if err != nil {
+		log.Printf("SSH session ended with error: %v", err)
+		return
+	}
+	return
+}

session/handler.go

@@ -164,16 +164,9 @@ func (s *SSHSession) HandleTCPIPForward(req *ssh.Request) {
 }
 
 func (s *SSHSession) HandleHTTPForward(req *ssh.Request, portToBind uint16) {
-	slug := generateUniqueSlug()
+	slug := random.GenerateRandomString(20)
-	if slug == "" {
-		err := req.Reply(false, nil)
-		if err != nil {
-			log.Println("Failed to reply to request:", err)
-		}
-		return
-	}
 
-	if !registerClient(slug, s) {
+	if !s.registry.Register(slug, s) {
 		log.Printf("Failed to register client with slug: %s", slug)
 		err := req.Reply(false, nil)
 		if err != nil {
@@ -186,7 +179,7 @@ func (s *SSHSession) HandleHTTPForward(req *ssh.Request, portToBind uint16) {
 	err := binary.Write(buf, binary.BigEndian, uint32(portToBind))
 	if err != nil {
 		log.Println("Failed to write port to buffer:", err)
-		unregisterClient(slug)
+		s.registry.Remove(slug)
 		err = req.Reply(false, nil)
 		if err != nil {
 			log.Println("Failed to reply to request:", err)
@@ -198,7 +191,7 @@ func (s *SSHSession) HandleHTTPForward(req *ssh.Request, portToBind uint16) {
 	err = req.Reply(true, buf.Bytes())
 	if err != nil {
 		log.Println("Failed to reply to request:", err)
-		unregisterClient(slug)
+		s.registry.Remove(slug)
 		err = req.Reply(false, nil)
 		if err != nil {
 			log.Println("Failed to reply to request:", err)
@@ -271,25 +264,6 @@ func (s *SSHSession) HandleTCPForward(req *ssh.Request, addr string, portToBind
 	s.interaction.Start()
 }
 
-func generateUniqueSlug() string {
-	maxAttempts := 5
-
-	for i := 0; i < maxAttempts; i++ {
-		slug := random.GenerateRandomString(20)
-
-		clientsMutex.RLock()
-		_, exists := Clients[slug]
-		clientsMutex.RUnlock()
-
-		if !exists {
-			return slug
-		}
-	}
-
-	log.Println("Failed to generate unique slug after multiple attempts")
-	return ""
-}
-
 func readSSHString(reader *bytes.Reader) (string, error) {
 	var length uint32
 	if err := binary.Read(reader, binary.BigEndian, &length); err != nil {

session/interaction/interaction.go

@@ -114,7 +114,7 @@ func (i *Interaction) SetChannel(channel ssh.Channel) {
 	i.channel = channel
 }
 
-func (i *Interaction) SetSlugModificator(modificator func(oldSlug, newSlug string) bool) {
+func (i *Interaction) SetSlugModificator(modificator func(oldSlug, newSlug string) (success bool)) {
 	i.updateClientSlug = modificator
 }
 

session/registry.go

@@ -0,0 +1,66 @@
+package session
+
+import "sync"
+
+type Registry interface {
+	Get(slug string) (session *SSHSession, exist bool)
+	Update(oldSlug, newSlug string) (success bool)
+	Register(slug string, session *SSHSession) (success bool)
+	Remove(slug string)
+}
+type registry struct {
+	mu      sync.RWMutex
+	clients map[string]*SSHSession
+}
+
+func NewRegistry() Registry {
+	return &registry{
+		clients: make(map[string]*SSHSession),
+	}
+}
+
+func (r *registry) Get(slug string) (session *SSHSession, exist bool) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+
+	session, exist = r.clients[slug]
+	return
+}
+
+func (r *registry) Update(oldSlug, newSlug string) (success bool) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if _, exists := r.clients[newSlug]; exists && newSlug != oldSlug {
+		return false
+	}
+
+	client, ok := r.clients[oldSlug]
+	if !ok {
+		return false
+	}
+
+	delete(r.clients, oldSlug)
+	client.slugManager.Set(newSlug)
+	r.clients[newSlug] = client
+	return true
+}
+
+func (r *registry) Register(slug string, session *SSHSession) (success bool) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if _, exists := r.clients[slug]; exists {
+		return false
+	}
+
+	r.clients[slug] = session
+	return true
+}
+
+func (r *registry) Remove(slug string) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	delete(r.clients, slug)
+}

session/session.go

@@ -1,8 +1,8 @@
 package session
 
 import (
+	"fmt"
 	"log"
-	"sync"
 	"time"
 	"tunnel_pls/internal/config"
 	"tunnel_pls/session/forwarder"
@@ -13,11 +13,6 @@ import (
 	"golang.org/x/crypto/ssh"
 )
 
-var (
-	clientsMutex sync.RWMutex
-	Clients      = make(map[string]*SSHSession)
-)
-
 type Session interface {
 	HandleGlobalRequest(ch <-chan *ssh.Request)
 	HandleTCPIPForward(req *ssh.Request)
@@ -26,10 +21,13 @@ type Session interface {
 }
 
 type SSHSession struct {
+	initialReq    <-chan *ssh.Request
+	sshReqChannel <-chan ssh.NewChannel
 	lifecycle     lifecycle.SessionLifecycle
 	interaction   interaction.Controller
 	forwarder     forwarder.ForwardingController
 	slugManager   slug.Manager
+	registry      Registry
 }
 
 func (s *SSHSession) GetLifecycle() lifecycle.SessionLifecycle {
@@ -48,55 +46,64 @@ func (s *SSHSession) GetSlugManager() slug.Manager {
 	return s.slugManager
 }
 
-func New(conn *ssh.ServerConn, forwardingReq <-chan *ssh.Request, sshChan <-chan ssh.NewChannel) {
+func New(conn *ssh.ServerConn, forwardingReq <-chan *ssh.Request, sshChan <-chan ssh.NewChannel, sessionRegistry Registry) *SSHSession {
 	slugManager := slug.NewManager()
 	forwarderManager := forwarder.NewForwarder(slugManager)
 	interactionManager := interaction.NewInteraction(slugManager, forwarderManager)
 	lifecycleManager := lifecycle.NewLifecycle(conn, forwarderManager, slugManager)
 
 	interactionManager.SetLifecycle(lifecycleManager)
-	interactionManager.SetSlugModificator(updateClientSlug)
+	interactionManager.SetSlugModificator(sessionRegistry.Update)
 	forwarderManager.SetLifecycle(lifecycleManager)
-	lifecycleManager.SetUnregisterClient(unregisterClient)
+	lifecycleManager.SetUnregisterClient(sessionRegistry.Remove)
 
-	session := &SSHSession{
+	return &SSHSession{
+		initialReq:    forwardingReq,
+		sshReqChannel: sshChan,
 		lifecycle:     lifecycleManager,
 		interaction:   interactionManager,
 		forwarder:     forwarderManager,
 		slugManager:   slugManager,
-	}
+		registry:      sessionRegistry,
-
-	var once sync.Once
-	for channel := range sshChan {
-		ch, reqs, err := channel.Accept()
-		if err != nil {
-			log.Printf("failed to accept channel: %v", err)
-			continue
-		}
-		once.Do(func() {
-			session.lifecycle.SetChannel(ch)
-			session.interaction.SetChannel(ch)
-
-			tcpipReq := session.waitForTCPIPForward(forwardingReq)
-			if tcpipReq == nil {
-				log.Printf("Port forwarding request not received. Ensure you ran the correct command with -R flag. Example: ssh %s -p %s -R 80:localhost:3000", config.Getenv("DOMAIN", "localhost"), config.Getenv("PORT", "2200"))
-				if err := session.lifecycle.Close(); err != nil {
-					log.Printf("failed to close session: %v", err)
-				}
-				return
-			}
-			go session.HandleTCPIPForward(tcpipReq)
-		})
-		session.HandleGlobalRequest(reqs)
-	}
-	if err := session.lifecycle.Close(); err != nil {
-		log.Printf("failed to close session: %v", err)
 	}
 }
 
-func (s *SSHSession) waitForTCPIPForward(forwardingReq <-chan *ssh.Request) *ssh.Request {
+func (s *SSHSession) Start() error {
+	channel := <-s.sshReqChannel
+	ch, reqs, err := channel.Accept()
+	if err != nil {
+		log.Printf("failed to accept channel: %v", err)
+		return err
+	}
+	go s.HandleGlobalRequest(reqs)
+
+	tcpipReq := s.waitForTCPIPForward()
+	if tcpipReq == nil {
+		_, err := ch.Write([]byte(fmt.Sprintf("Port forwarding request not received. Ensure you ran the correct command with -R flag. Example: ssh %s -p %s -R 80:localhost:3000", config.Getenv("DOMAIN", "localhost"), config.Getenv("PORT", "2200"))))
+		if err != nil {
+			return err
+		}
+		if err := s.lifecycle.Close(); err != nil {
+			log.Printf("failed to close session: %v", err)
+		}
+		return fmt.Errorf("No forwarding Request")
+	}
+
+	s.lifecycle.SetChannel(ch)
+	s.interaction.SetChannel(ch)
+
+	go s.HandleTCPIPForward(tcpipReq)
+
+	if err := s.lifecycle.Close(); err != nil {
+		log.Printf("failed to close session: %v", err)
+		return err
+	}
+	return nil
+}
+
+func (s *SSHSession) waitForTCPIPForward() *ssh.Request {
 	select {
-	case req, ok := <-forwardingReq:
+	case req, ok := <-s.initialReq:
 		if !ok {
 			log.Println("Forwarding request channel closed")
 			return nil
@@ -114,41 +121,3 @@ func (s *SSHSession) waitForTCPIPForward(forwardingReq <-chan *ssh.Request) *ssh
 		return nil
 	}
 }
-
-func updateClientSlug(oldSlug, newSlug string) bool {
-	clientsMutex.Lock()
-	defer clientsMutex.Unlock()
-
-	if _, exists := Clients[newSlug]; exists && newSlug != oldSlug {
-		return false
-	}
-
-	client, ok := Clients[oldSlug]
-	if !ok {
-		return false
-	}
-
-	delete(Clients, oldSlug)
-	client.slugManager.Set(newSlug)
-	Clients[newSlug] = client
-	return true
-}
-
-func registerClient(slug string, session *SSHSession) bool {
-	clientsMutex.Lock()
-	defer clientsMutex.Unlock()
-
-	if _, exists := Clients[slug]; exists {
-		return false
-	}
-
-	Clients[slug] = session
-	return true
-}
-
-func unregisterClient(slug string) {
-	clientsMutex.Lock()
-	defer clientsMutex.Unlock()
-
-	delete(Clients, slug)
-}

session/slug/slug.go

@@ -1,7 +1,5 @@
 package slug
 
-import "sync"
-
 type Manager interface {
 	Get() string
 	Set(slug string)
@@ -9,24 +7,18 @@ type Manager interface {
 
 type manager struct {
 	slug string
-	slugMu sync.RWMutex
 }
 
 func NewManager() Manager {
 	return &manager{
 		slug: "",
-		slugMu: sync.RWMutex{},
 	}
 }
 
 func (s *manager) Get() string {
-	s.slugMu.RLock()
-	defer s.slugMu.RUnlock()
 	return s.slug
 }
 
 func (s *manager) Set(slug string) {
-	s.slugMu.Lock()
 	s.slug = slug
-	s.slugMu.Unlock()
 }