refactor: move server package to internal

internal/server/server.go

@@ -0,0 +1,117 @@
+package server
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"time"
+	"tunnel_pls/internal/config"
+	"tunnel_pls/internal/grpc/client"
+	"tunnel_pls/internal/port"
+	"tunnel_pls/internal/random"
+	"tunnel_pls/internal/registry"
+	"tunnel_pls/session"
+
+	"golang.org/x/crypto/ssh"
+)
+
+type Server interface {
+	Start()
+	Close() error
+}
+type server struct {
+	randomizer      random.Random
+	config          config.Config
+	sshPort         string
+	sshListener     net.Listener
+	sshConfig       *ssh.ServerConfig
+	grpcClient      client.Client
+	sessionRegistry registry.Registry
+	portRegistry    port.Port
+}
+
+func New(randomizer random.Random, config config.Config, sshConfig *ssh.ServerConfig, sessionRegistry registry.Registry, grpcClient client.Client, portRegistry port.Port, sshPort string) (Server, error) {
+	listener, err := net.Listen("tcp", fmt.Sprintf(":%s", sshPort))
+	if err != nil {
+		return nil, err
+	}
+
+	return &server{
+		randomizer:      randomizer,
+		config:          config,
+		sshPort:         sshPort,
+		sshListener:     listener,
+		sshConfig:       sshConfig,
+		grpcClient:      grpcClient,
+		sessionRegistry: sessionRegistry,
+		portRegistry:    portRegistry,
+	}, nil
+}
+
+func (s *server) Start() {
+	log.Printf("SSH server is starting on port %s", s.sshPort)
+	for {
+		conn, err := s.sshListener.Accept()
+		if err != nil {
+			if errors.Is(err, net.ErrClosed) {
+				log.Println("listener closed, stopping server")
+				return
+			}
+			log.Printf("failed to accept connection: %v", err)
+			continue
+		}
+
+		go s.handleConnection(conn)
+	}
+}
+
+func (s *server) Close() error {
+	return s.sshListener.Close()
+}
+
+func (s *server) handleConnection(conn net.Conn) {
+	sshConn, chans, forwardingReqs, err := ssh.NewServerConn(conn, s.sshConfig)
+	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
+	}
+
+	defer func(sshConn *ssh.ServerConn) {
+		err = sshConn.Close()
+		if err != nil && !errors.Is(err, net.ErrClosed) && !errors.Is(err, io.EOF) {
+			log.Printf("failed to close SSH server: %v", err)
+		}
+	}(sshConn)
+
+	user := "UNAUTHORIZED"
+	if s.grpcClient != nil {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+		_, u, _ := s.grpcClient.AuthorizeConn(ctx, sshConn.User())
+		user = u
+		cancel()
+	}
+	log.Println("SSH connection established:", sshConn.User())
+	sshSession := session.New(&session.Config{
+		Randomizer:      s.randomizer,
+		Config:          s.config,
+		Conn:            sshConn,
+		InitialReq:      forwardingReqs,
+		SshChan:         chans,
+		SessionRegistry: s.sessionRegistry,
+		PortRegistry:    s.portRegistry,
+		User:            user,
+	})
+	err = sshSession.Start()
+	if err != nil {
+		log.Printf("SSH session ended with error: %s", err.Error())
+		return
+	}
+}