X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/blobdiff_plain/a2ef262a164fc735b9b8471ac0c8001eea2b9bf6..dcd23d5355badf66c34ffd63d3c44734e87ebf17:/hotline/server.go

diff --git a/hotline/server.go b/hotline/server.go
index 0ee2dd7..c4d8f7f 100644
--- a/hotline/server.go
+++ b/hotline/server.go
@@ -8,19 +8,14 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
-	"github.com/go-playground/validator/v10"
 	"golang.org/x/text/encoding/charmap"
-	"gopkg.in/yaml.v3"
 	"io"
 	"log"
 	"log/slog"
 	"net"
 	"os"
-	"path"
-	"path/filepath"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
 )
 
@@ -41,57 +36,97 @@ var txtEncoder = charmap.Macintosh.NewEncoder()
 type Server struct {
 	NetInterface string
 	Port         int
-	Accounts     map[string]*Account
-	Agreement    []byte
 
-	Clients       map[[2]byte]*ClientConn
-	fileTransfers map[[4]byte]*FileTransfer
+	handlers map[TranType]HandlerFunc
 
-	Config    *Config
-	ConfigDir string
-	Logger    *slog.Logger
-	banner    []byte
+	Config Config
+	Logger *slog.Logger
 
-	PrivateChatsMu sync.Mutex
-	PrivateChats   map[[4]byte]*PrivateChat
-
-	nextClientID  atomic.Uint32
 	TrackerPassID [4]byte
 
-	statsMu sync.Mutex
-	Stats   *Stats
+	Stats Counter
 
 	FS FileStore // Storage backend to use for File storage
 
 	outbox chan Transaction
-	mux    sync.Mutex
 
-	threadedNewsMux sync.Mutex
-	ThreadedNews    *ThreadedNews
+	Agreement io.ReadSeeker
+	Banner    []byte
+
+	FileTransferMgr FileTransferMgr
+	ChatMgr         ChatManager
+	ClientMgr       ClientManager
+	AccountManager  AccountManager
+	ThreadedNewsMgr ThreadedNewsMgr
+	BanList         BanMgr
+
+	MessageBoard io.ReadWriteSeeker
+}
+
+type Option = func(s *Server)
+
+func WithConfig(config Config) func(s *Server) {
+	return func(s *Server) {
+		s.Config = config
+	}
+}
+
+func WithLogger(logger *slog.Logger) func(s *Server) {
+	return func(s *Server) {
+		s.Logger = logger
+	}
+}
+
+// WithPort optionally overrides the default TCP port.
+func WithPort(port int) func(s *Server) {
+	return func(s *Server) {
+		s.Port = port
+	}
+}
 
-	flatNewsMux sync.Mutex
-	FlatNews    []byte
+// WithInterface optionally sets a specific interface to listen on.
+func WithInterface(netInterface string) func(s *Server) {
+	return func(s *Server) {
+		s.NetInterface = netInterface
+	}
+}
 
-	banListMU sync.Mutex
-	banList   map[string]*time.Time
+type ServerConfig struct {
 }
 
-func (s *Server) CurrentStats() Stats {
-	s.statsMu.Lock()
-	defer s.statsMu.Unlock()
+func NewServer(options ...Option) (*Server, error) {
+	server := Server{
+		handlers:        make(map[TranType]HandlerFunc),
+		outbox:          make(chan Transaction),
+		FS:              &OSFileStore{},
+		ChatMgr:         NewMemChatManager(),
+		ClientMgr:       NewMemClientMgr(),
+		FileTransferMgr: NewMemFileTransferMgr(),
+		Stats:           NewStats(),
+	}
 
-	stats := s.Stats
-	stats.CurrentlyConnected = len(s.Clients)
+	for _, opt := range options {
+		opt(&server)
+	}
+
+	// generate a new random passID for tracker registration
+	_, err := rand.Read(server.TrackerPassID[:])
+	if err != nil {
+		return nil, err
+	}
 
-	return *stats
+	return &server, nil
 }
 
-type PrivateChat struct {
-	Subject    string
-	ClientConn map[[2]byte]*ClientConn
+func (s *Server) CurrentStats() map[string]interface{} {
+	return s.Stats.Values()
 }
 
 func (s *Server) ListenAndServe(ctx context.Context) error {
+	go s.registerWithTrackers(ctx)
+	go s.keepaliveHandler(ctx)
+	go s.processOutbox()
+
 	var wg sync.WaitGroup
 
 	wg.Add(1)
@@ -142,17 +177,15 @@ func (s *Server) ServeFileTransfers(ctx context.Context, ln net.Listener) error
 }
 
 func (s *Server) sendTransaction(t Transaction) error {
-	s.mux.Lock()
-	client, ok := s.Clients[t.clientID]
-	s.mux.Unlock()
+	client := s.ClientMgr.Get(t.ClientID)
 
-	if !ok || client == nil {
+	if client == nil {
 		return nil
 	}
 
 	_, err := io.Copy(client.Connection, &t)
 	if err != nil {
-		return fmt.Errorf("failed to send transaction to client %v: %v", t.clientID, err)
+		return fmt.Errorf("failed to send transaction to client %v: %v", t.ClientID, err)
 	}
 
 	return nil
@@ -170,380 +203,126 @@ func (s *Server) processOutbox() {
 }
 
 func (s *Server) Serve(ctx context.Context, ln net.Listener) error {
-	go s.processOutbox()
-
 	for {
-		conn, err := ln.Accept()
-		if err != nil {
-			s.Logger.Error("error accepting connection", "err", err)
-		}
-		connCtx := context.WithValue(ctx, contextKeyReq, requestCtx{
-			remoteAddr: conn.RemoteAddr().String(),
-		})
-
-		go func() {
-			s.Logger.Info("Connection established", "RemoteAddr", conn.RemoteAddr())
-
-			defer conn.Close()
-			if err := s.handleNewConnection(connCtx, conn, conn.RemoteAddr().String()); err != nil {
-				if err == io.EOF {
-					s.Logger.Info("Client disconnected", "RemoteAddr", conn.RemoteAddr())
-				} else {
-					s.Logger.Error("error serving request", "RemoteAddr", conn.RemoteAddr(), "err", err)
-				}
+		select {
+		case <-ctx.Done():
+			s.Logger.Info("Server shutting down")
+			return ctx.Err()
+		default:
+			conn, err := ln.Accept()
+			if err != nil {
+				s.Logger.Error("Error accepting connection", "err", err)
+				continue
 			}
-		}()
-	}
-}
-
-const (
-	agreementFile = "Agreement.txt"
-)
-
-// NewServer constructs a new Server from a config dir
-// TODO: move config file reads out of this function
-func NewServer(configDir, netInterface string, netPort int, logger *slog.Logger, fs FileStore) (*Server, error) {
-	server := Server{
-		NetInterface:  netInterface,
-		Port:          netPort,
-		Accounts:      make(map[string]*Account),
-		Config:        new(Config),
-		Clients:       make(map[[2]byte]*ClientConn),
-		fileTransfers: make(map[[4]byte]*FileTransfer),
-		PrivateChats:  make(map[[4]byte]*PrivateChat),
-		ConfigDir:     configDir,
-		Logger:        logger,
-		outbox:        make(chan Transaction),
-		Stats:         &Stats{Since: time.Now()},
-		ThreadedNews:  &ThreadedNews{},
-		FS:            fs,
-		banList:       make(map[string]*time.Time),
-	}
-
-	var err error
-
-	// generate a new random passID for tracker registration
-	if _, err := rand.Read(server.TrackerPassID[:]); err != nil {
-		return nil, err
-	}
-
-	server.Agreement, err = os.ReadFile(filepath.Join(configDir, agreementFile))
-	if err != nil {
-		return nil, err
-	}
-
-	if server.FlatNews, err = os.ReadFile(filepath.Join(configDir, "MessageBoard.txt")); err != nil {
-		return nil, err
-	}
-
-	// try to load the ban list, but ignore errors as this file may not be present or may be empty
-	//_ = server.loadBanList(filepath.Join(configDir, "Banlist.yaml"))
 
-	_ = loadFromYAMLFile(filepath.Join(configDir, "Banlist.yaml"), &server.banList)
+			go func() {
+				connCtx := context.WithValue(ctx, contextKeyReq, requestCtx{
+					remoteAddr: conn.RemoteAddr().String(),
+				})
 
-	err = loadFromYAMLFile(filepath.Join(configDir, "ThreadedNews.yaml"), &server.ThreadedNews)
-	if err != nil {
-		return nil, fmt.Errorf("error loading threaded news: %w", err)
-	}
-
-	err = server.loadConfig(filepath.Join(configDir, "config.yaml"))
-	if err != nil {
-		return nil, fmt.Errorf("error loading config: %w", err)
-	}
-
-	if err := server.loadAccounts(filepath.Join(configDir, "Users/")); err != nil {
-		return nil, err
-	}
-
-	// If the FileRoot is an absolute path, use it, otherwise treat as a relative path to the config dir.
-	if !filepath.IsAbs(server.Config.FileRoot) {
-		server.Config.FileRoot = filepath.Join(configDir, server.Config.FileRoot)
-	}
+				s.Logger.Info("Connection established", "addr", conn.RemoteAddr())
+				defer conn.Close()
 
-	server.banner, err = os.ReadFile(filepath.Join(server.ConfigDir, server.Config.BannerFile))
-	if err != nil {
-		return nil, fmt.Errorf("error opening banner: %w", err)
+				if err := s.handleNewConnection(connCtx, conn, conn.RemoteAddr().String()); err != nil {
+					if err == io.EOF {
+						s.Logger.Info("Client disconnected", "RemoteAddr", conn.RemoteAddr())
+					} else {
+						s.Logger.Error("Error serving request", "RemoteAddr", conn.RemoteAddr(), "err", err)
+					}
+				}
+			}()
+		}
 	}
+}
 
-	if server.Config.EnableTrackerRegistration {
-		server.Logger.Info(
-			"Tracker registration enabled",
-			"frequency", fmt.Sprintf("%vs", trackerUpdateFrequency),
-			"trackers", server.Config.Trackers,
-		)
+// time in seconds between tracker re-registration
+const trackerUpdateFrequency = 300
 
-		go func() {
-			for {
+// registerWithTrackers runs every trackerUpdateFrequency seconds to update the server's tracker entry on all configured
+// trackers.
+func (s *Server) registerWithTrackers(ctx context.Context) {
+	for {
+		if s.Config.EnableTrackerRegistration {
+			for _, t := range s.Config.Trackers {
 				tr := &TrackerRegistration{
-					UserCount:   server.userCount(),
-					PassID:      server.TrackerPassID,
-					Name:        server.Config.Name,
-					Description: server.Config.Description,
+					UserCount:   len(s.ClientMgr.List()),
+					PassID:      s.TrackerPassID,
+					Name:        s.Config.Name,
+					Description: s.Config.Description,
 				}
-				binary.BigEndian.PutUint16(tr.Port[:], uint16(server.Port))
-				for _, t := range server.Config.Trackers {
-					if err := register(&RealDialer{}, t, tr); err != nil {
-						server.Logger.Error("unable to register with tracker %v", "error", err)
-					}
-					server.Logger.Debug("Sent Tracker registration", "addr", t)
+				binary.BigEndian.PutUint16(tr.Port[:], uint16(s.Port))
+
+				// Check the tracker string for a password.  This is janky but avoids a breaking change to the Config
+				// Trackers field.
+				splitAddr := strings.Split(":", t)
+				if len(splitAddr) == 3 {
+					tr.Password = splitAddr[2]
 				}
 
-				time.Sleep(trackerUpdateFrequency * time.Second)
+				if err := register(&RealDialer{}, t, tr); err != nil {
+					s.Logger.Error(fmt.Sprintf("Unable to register with tracker %v", t), "error", err)
+				}
 			}
-		}()
+		}
+		// Using time.Ticker with for/select would be more idiomatic, but it's super annoying that it doesn't tick on
+		// first pass.  Revist, maybe.
+		// https://github.com/golang/go/issues/17601
+		time.Sleep(trackerUpdateFrequency * time.Second)
 	}
-
-	// Start Client Keepalive go routine
-	go server.keepaliveHandler()
-
-	return &server, nil
 }
 
-func (s *Server) userCount() int {
-	s.mux.Lock()
-	defer s.mux.Unlock()
+const (
+	userIdleSeconds   = 300 // time in seconds before an inactive user is marked idle
+	idleCheckInterval = 10  // time in seconds to check for idle users
+)
 
-	return len(s.Clients)
-}
+// keepaliveHandler runs every idleCheckInterval seconds and increments a user's idle time by idleCheckInterval seconds.
+// If the updated idle time exceeds userIdleSeconds and the user was not previously idle, we notify all connected clients
+// that the user has gone idle.  For most clients, this turns the user grey in the user list.
+func (s *Server) keepaliveHandler(ctx context.Context) {
+	ticker := time.NewTicker(idleCheckInterval * time.Second)
+	defer ticker.Stop()
 
-func (s *Server) keepaliveHandler() {
 	for {
-		time.Sleep(idleCheckInterval * time.Second)
-		s.mux.Lock()
-
-		for _, c := range s.Clients {
-			c.IdleTime += idleCheckInterval
-			if c.IdleTime > userIdleSeconds && !c.Idle {
-				c.Idle = true
-
-				c.flagsMU.Lock()
-				c.Flags.Set(UserFlagAway, 1)
-				c.flagsMU.Unlock()
-				c.sendAll(
-					TranNotifyChangeUser,
-					NewField(FieldUserID, c.ID[:]),
-					NewField(FieldUserFlags, c.Flags[:]),
-					NewField(FieldUserName, c.UserName),
-					NewField(FieldUserIconID, c.Icon),
-				)
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			for _, c := range s.ClientMgr.List() {
+				c.mu.Lock()
+				c.IdleTime += idleCheckInterval
+
+				// Check if the user
+				if c.IdleTime > userIdleSeconds && !c.Flags.IsSet(UserFlagAway) {
+					c.Flags.Set(UserFlagAway, 1)
+
+					c.SendAll(
+						TranNotifyChangeUser,
+						NewField(FieldUserID, c.ID[:]),
+						NewField(FieldUserFlags, c.Flags[:]),
+						NewField(FieldUserName, c.UserName),
+						NewField(FieldUserIconID, c.Icon),
+					)
+				}
+				c.mu.Unlock()
 			}
 		}
-		s.mux.Unlock()
-	}
-}
-
-func (s *Server) writeBanList() error {
-	s.banListMU.Lock()
-	defer s.banListMU.Unlock()
-
-	out, err := yaml.Marshal(s.banList)
-	if err != nil {
-		return err
-	}
-	err = os.WriteFile(
-		filepath.Join(s.ConfigDir, "Banlist.yaml"),
-		out,
-		0666,
-	)
-	return err
-}
-
-func (s *Server) writeThreadedNews() error {
-	s.threadedNewsMux.Lock()
-	defer s.threadedNewsMux.Unlock()
-
-	out, err := yaml.Marshal(s.ThreadedNews)
-	if err != nil {
-		return err
 	}
-	err = s.FS.WriteFile(
-		filepath.Join(s.ConfigDir, "ThreadedNews.yaml"),
-		out,
-		0666,
-	)
-	return err
 }
 
 func (s *Server) NewClientConn(conn io.ReadWriteCloser, remoteAddr string) *ClientConn {
-	s.mux.Lock()
-	defer s.mux.Unlock()
-
 	clientConn := &ClientConn{
 		Icon:       []byte{0, 0}, // TODO: make array type
 		Connection: conn,
 		Server:     s,
 		RemoteAddr: remoteAddr,
-		transfers: map[int]map[[4]byte]*FileTransfer{
-			FileDownload:   {},
-			FileUpload:     {},
-			FolderDownload: {},
-			FolderUpload:   {},
-			bannerDownload: {},
-		},
-	}
-
-	s.nextClientID.Add(1)
-
-	binary.BigEndian.PutUint16(clientConn.ID[:], uint16(s.nextClientID.Load()))
-	s.Clients[clientConn.ID] = clientConn
-
-	return clientConn
-}
-
-// NewUser creates a new user account entry in the server map and config file
-func (s *Server) NewUser(login, name, password string, access accessBitmap) error {
-	s.mux.Lock()
-	defer s.mux.Unlock()
-
-	account := NewAccount(login, name, password, access)
 
-	// Create account file, returning an error if one already exists.
-	file, err := os.OpenFile(
-		filepath.Join(s.ConfigDir, "Users", path.Join("/", login)+".yaml"),
-		os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0644,
-	)
-	if err != nil {
-		return fmt.Errorf("error creating account file: %w", err)
+		ClientFileTransferMgr: NewClientFileTransferMgr(),
 	}
-	defer file.Close()
 
-	b, err := yaml.Marshal(account)
-	if err != nil {
-		return err
-	}
-
-	_, err = file.Write(b)
-	if err != nil {
-		return fmt.Errorf("error writing account file: %w", err)
-	}
-
-	s.Accounts[login] = account
-
-	return nil
-}
-
-func (s *Server) UpdateUser(login, newLogin, name, password string, access accessBitmap) error {
-	s.mux.Lock()
-	defer s.mux.Unlock()
-
-	// If the login has changed, rename the account file.
-	if login != newLogin {
-		err := os.Rename(
-			filepath.Join(s.ConfigDir, "Users", path.Join("/", login)+".yaml"),
-			filepath.Join(s.ConfigDir, "Users", path.Join("/", newLogin)+".yaml"),
-		)
-		if err != nil {
-			return fmt.Errorf("error renaming account file: %w", err)
-		}
-		s.Accounts[newLogin] = s.Accounts[login]
-		s.Accounts[newLogin].Login = newLogin
-		delete(s.Accounts, login)
-	}
-
-	account := s.Accounts[newLogin]
-	account.Access = access
-	account.Name = name
-	account.Password = password
-
-	out, err := yaml.Marshal(&account)
-	if err != nil {
-		return err
-	}
-
-	if err := os.WriteFile(filepath.Join(s.ConfigDir, "Users", newLogin+".yaml"), out, 0666); err != nil {
-		return fmt.Errorf("error writing account file: %w", err)
-	}
-
-	return nil
-}
-
-// DeleteUser deletes the user account
-func (s *Server) DeleteUser(login string) error {
-	s.mux.Lock()
-	defer s.mux.Unlock()
-
-	err := s.FS.Remove(filepath.Join(s.ConfigDir, "Users", path.Join("/", login)+".yaml"))
-	if err != nil {
-		return err
-	}
-
-	delete(s.Accounts, login)
-
-	return nil
-}
-
-func (s *Server) connectedUsers() []Field {
-	//s.mux.Lock()
-	//defer s.mux.Unlock()
-
-	var connectedUsers []Field
-	for _, c := range sortedClients(s.Clients) {
-		b, err := io.ReadAll(&User{
-			ID:    c.ID,
-			Icon:  c.Icon,
-			Flags: c.Flags[:],
-			Name:  string(c.UserName),
-		})
-		if err != nil {
-			return nil
-		}
-		connectedUsers = append(connectedUsers, NewField(FieldUsernameWithInfo, b))
-	}
-	return connectedUsers
-}
-
-// loadFromYAMLFile loads data from a YAML file into the provided data structure.
-func loadFromYAMLFile(path string, data interface{}) error {
-	fh, err := os.Open(path)
-	if err != nil {
-		return err
-	}
-	defer fh.Close()
-
-	decoder := yaml.NewDecoder(fh)
-	return decoder.Decode(data)
-}
-
-// loadAccounts loads account data from disk
-func (s *Server) loadAccounts(userDir string) error {
-	matches, err := filepath.Glob(filepath.Join(userDir, "*.yaml"))
-	if err != nil {
-		return err
-	}
-
-	if len(matches) == 0 {
-		return fmt.Errorf("no accounts found in directory: %s", userDir)
-	}
+	s.ClientMgr.Add(clientConn)
 
-	for _, file := range matches {
-		var account Account
-		if err = loadFromYAMLFile(file, &account); err != nil {
-			return fmt.Errorf("error loading account %s: %w", file, err)
-		}
-
-		s.Accounts[account.Login] = &account
-	}
-	return nil
-}
-
-func (s *Server) loadConfig(path string) error {
-	fh, err := s.FS.Open(path)
-	if err != nil {
-		return err
-	}
-
-	decoder := yaml.NewDecoder(fh)
-	err = decoder.Decode(s.Config)
-	if err != nil {
-		return err
-	}
-
-	validate := validator.New()
-	err = validate.Struct(s.Config)
-	if err != nil {
-		return err
-	}
-	return nil
+	return clientConn
 }
 
 func sendBanMessage(rwc io.Writer, message string) {
@@ -561,9 +340,13 @@ func sendBanMessage(rwc io.Writer, message string) {
 func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser, remoteAddr string) error {
 	defer dontPanic(s.Logger)
 
+	if err := performHandshake(rwc); err != nil {
+		return fmt.Errorf("perform handshake: %w", err)
+	}
+
 	// Check if remoteAddr is present in the ban list
 	ipAddr := strings.Split(remoteAddr, ":")[0]
-	if banUntil, ok := s.banList[ipAddr]; ok {
+	if isBanned, banUntil := s.BanList.IsBanned(ipAddr); isBanned {
 		// permaban
 		if banUntil == nil {
 			sendBanMessage(rwc, "You are permanently banned on this server")
@@ -579,10 +362,6 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 		}
 	}
 
-	if err := performHandshake(rwc); err != nil {
-		return fmt.Errorf("error performing handshake: %w", err)
-	}
-
 	// Create a new scanner for parsing incoming bytes into transaction tokens
 	scanner := bufio.NewScanner(rwc)
 	scanner.Split(transactionScanner)
@@ -605,12 +384,12 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 	encodedPassword := clientLogin.GetField(FieldUserPassword).Data
 	c.Version = clientLogin.GetField(FieldVersion).Data
 
-	login := string(encodeString(clientLogin.GetField(FieldUserLogin).Data))
+	login := clientLogin.GetField(FieldUserLogin).DecodeObfuscatedString()
 	if login == "" {
 		login = GuestAccount
 	}
 
-	c.logger = s.Logger.With("remoteAddr", remoteAddr, "login", login)
+	c.Logger = s.Logger.With("ip", ipAddr, "login", login)
 
 	// If authentication fails, send error reply and close connection
 	if !c.Authenticate(login, encodedPassword) {
@@ -621,7 +400,7 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 			return err
 		}
 
-		c.logger.Info("Login failed", "clientVersion", fmt.Sprintf("%x", c.Version))
+		c.Logger.Info("Login failed", "clientVersion", fmt.Sprintf("%x", c.Version))
 
 		return nil
 	}
@@ -630,19 +409,20 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 		c.Icon = clientLogin.GetField(FieldUserIconID).Data
 	}
 
-	c.Lock()
-	c.Account = c.Server.Accounts[login]
-	c.Unlock()
+	c.Account = c.Server.AccountManager.Get(login)
+	if c.Account == nil {
+		return nil
+	}
 
 	if clientLogin.GetField(FieldUserName).Data != nil {
-		if c.Authorize(accessAnyName) {
+		if c.Authorize(AccessAnyName) {
 			c.UserName = clientLogin.GetField(FieldUserName).Data
 		} else {
 			c.UserName = []byte(c.Account.Name)
 		}
 	}
 
-	if c.Authorize(accessDisconUser) {
+	if c.Authorize(AccessDisconUser) {
 		c.Flags.Set(UserFlagAdmin, 1)
 	}
 
@@ -655,16 +435,19 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 	// Send user access privs so client UI knows how to behave
 	c.Server.outbox <- NewTransaction(TranUserAccess, c.ID, NewField(FieldUserAccess, c.Account.Access[:]))
 
-	// Accounts with accessNoAgreement do not receive the server agreement on login.  The behavior is different between
+	// Accounts with AccessNoAgreement do not receive the server agreement on login.  The behavior is different between
 	// client versions.  For 1.2.3 client, we do not send TranShowAgreement.  For other client versions, we send
 	// TranShowAgreement but with the NoServerAgreement field set to 1.
-	if c.Authorize(accessNoAgreement) {
+	if c.Authorize(AccessNoAgreement) {
 		// If client version is nil, then the client uses the 1.2.3 login behavior
 		if c.Version != nil {
 			c.Server.outbox <- NewTransaction(TranShowAgreement, c.ID, NewField(FieldNoServerAgreement, []byte{1}))
 		}
 	} else {
-		c.Server.outbox <- NewTransaction(TranShowAgreement, c.ID, NewField(FieldData, s.Agreement))
+		_, _ = c.Server.Agreement.Seek(0, 0)
+		data, _ := io.ReadAll(c.Server.Agreement)
+
+		c.Server.outbox <- NewTransaction(TranShowAgreement, c.ID, NewField(FieldData, data))
 	}
 
 	// If the client has provided a username as part of the login, we can infer that it is using the 1.2.3 login
@@ -672,12 +455,12 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 	if len(c.UserName) != 0 {
 		// Add the client username to the logger.  For 1.5+ clients, we don't have this information yet as it comes as
 		// part of TranAgreed
-		c.logger = c.logger.With("Name", string(c.UserName))
-		c.logger.Info("Login successful", "clientVersion", "Not sent (probably 1.2.3)")
+		c.Logger = c.Logger.With("name", string(c.UserName))
+		c.Logger.Info("Login successful")
 
 		// Notify other clients on the server that the new user has logged in.  For 1.5+ clients we don't have this
 		// information yet, so we do it in TranAgreed instead
-		for _, t := range c.notifyOthers(
+		for _, t := range c.NotifyOthers(
 			NewTransaction(
 				TranNotifyChangeUser, [2]byte{0, 0},
 				NewField(FieldUserName, c.UserName),
@@ -690,21 +473,21 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 		}
 	}
 
-	c.Server.mux.Lock()
-	c.Server.Stats.ConnectionCounter += 1
-	if len(s.Clients) > c.Server.Stats.ConnectionPeak {
-		c.Server.Stats.ConnectionPeak = len(s.Clients)
+	c.Server.Stats.Increment(StatConnectionCounter, StatCurrentlyConnected)
+	defer c.Server.Stats.Decrement(StatCurrentlyConnected)
+
+	if len(s.ClientMgr.List()) > c.Server.Stats.Get(StatConnectionPeak) {
+		c.Server.Stats.Set(StatConnectionPeak, len(s.ClientMgr.List()))
 	}
-	c.Server.mux.Unlock()
 
 	// Scan for new transactions and handle them as they come in.
 	for scanner.Scan() {
 		// Copy the scanner bytes to a new slice to it to avoid a data race when the scanner re-uses the buffer.
-		buf := make([]byte, len(scanner.Bytes()))
-		copy(buf, scanner.Bytes())
+		tmpBuf := make([]byte, len(scanner.Bytes()))
+		copy(tmpBuf, scanner.Bytes())
 
 		var t Transaction
-		if _, err := t.Write(buf); err != nil {
+		if _, err := t.Write(tmpBuf); err != nil {
 			return err
 		}
 
@@ -713,25 +496,6 @@ func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser
 	return nil
 }
 
-func (s *Server) NewPrivateChat(cc *ClientConn) [4]byte {
-	s.PrivateChatsMu.Lock()
-	defer s.PrivateChatsMu.Unlock()
-
-	var randID [4]byte
-	_, _ = rand.Read(randID[:])
-
-	s.PrivateChats[randID] = &PrivateChat{
-		ClientConn: make(map[[2]byte]*ClientConn),
-	}
-	s.PrivateChats[randID].ClientConn[cc.ID] = cc
-
-	return randID
-}
-
-const dlFldrActionSendFile = 1
-const dlFldrActionResumeFile = 2
-const dlFldrActionNextFile = 3
-
 // handleFileTransfer receives a client net.Conn from the file transfer server, performs the requested transfer type, then closes the connection
 func (s *Server) handleFileTransfer(ctx context.Context, rwc io.ReadWriter) error {
 	defer dontPanic(s.Logger)
@@ -742,10 +506,13 @@ func (s *Server) handleFileTransfer(ctx context.Context, rwc io.ReadWriter) erro
 		return fmt.Errorf("error reading file transfer: %w", err)
 	}
 
+	fileTransfer := s.FileTransferMgr.Get(t.ReferenceNumber)
+	if fileTransfer == nil {
+		return errors.New("invalid transaction ID")
+	}
+
 	defer func() {
-		s.mux.Lock()
-		delete(s.fileTransfers, t.ReferenceNumber)
-		s.mux.Unlock()
+		s.FileTransferMgr.Delete(t.ReferenceNumber)
 
 		// Wait a few seconds before closing the connection: this is a workaround for problems
 		// observed with Windows clients where the client must initiate close of the TCP connection before
@@ -753,71 +520,61 @@ func (s *Server) handleFileTransfer(ctx context.Context, rwc io.ReadWriter) erro
 		time.Sleep(3 * time.Second)
 	}()
 
-	s.mux.Lock()
-	fileTransfer, ok := s.fileTransfers[t.ReferenceNumber]
-	s.mux.Unlock()
-	if !ok {
-		return errors.New("invalid transaction ID")
-	}
-
-	defer func() {
-		fileTransfer.ClientConn.transfersMU.Lock()
-		delete(fileTransfer.ClientConn.transfers[fileTransfer.Type], t.ReferenceNumber)
-		fileTransfer.ClientConn.transfersMU.Unlock()
-	}()
-
 	rLogger := s.Logger.With(
 		"remoteAddr", ctx.Value(contextKeyReq).(requestCtx).remoteAddr,
 		"login", fileTransfer.ClientConn.Account.Login,
 		"Name", string(fileTransfer.ClientConn.UserName),
 	)
 
-	fullPath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
+	fullPath, err := ReadPath(fileTransfer.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
 	if err != nil {
 		return err
 	}
 
 	switch fileTransfer.Type {
-	case bannerDownload:
-		if _, err := io.Copy(rwc, bytes.NewBuffer(s.banner)); err != nil {
-			return fmt.Errorf("error sending banner: %w", err)
+	case BannerDownload:
+		if _, err := io.Copy(rwc, bytes.NewBuffer(s.Banner)); err != nil {
+			return fmt.Errorf("banner download: %w", err)
 		}
 	case FileDownload:
-		s.Stats.DownloadCounter += 1
-		s.Stats.DownloadsInProgress += 1
+		s.Stats.Increment(StatDownloadCounter, StatDownloadsInProgress)
 		defer func() {
-			s.Stats.DownloadsInProgress -= 1
+			s.Stats.Decrement(StatDownloadsInProgress)
 		}()
 
 		err = DownloadHandler(rwc, fullPath, fileTransfer, s.FS, rLogger, true)
 		if err != nil {
-			return fmt.Errorf("file download error: %w", err)
+			return fmt.Errorf("file download: %w", err)
 		}
 
 	case FileUpload:
-		s.Stats.UploadCounter += 1
-		s.Stats.UploadsInProgress += 1
-		defer func() { s.Stats.UploadsInProgress -= 1 }()
+		s.Stats.Increment(StatUploadCounter, StatUploadsInProgress)
+		defer func() {
+			s.Stats.Decrement(StatUploadsInProgress)
+		}()
 
 		err = UploadHandler(rwc, fullPath, fileTransfer, s.FS, rLogger, s.Config.PreserveResourceForks)
 		if err != nil {
-			return fmt.Errorf("file upload error: %w", err)
+			return fmt.Errorf("file upload: %w", err)
 		}
 
 	case FolderDownload:
-		s.Stats.DownloadCounter += 1
-		s.Stats.DownloadsInProgress += 1
-		defer func() { s.Stats.DownloadsInProgress -= 1 }()
+		s.Stats.Increment(StatDownloadCounter, StatDownloadsInProgress)
+		defer func() {
+			s.Stats.Decrement(StatDownloadsInProgress)
+		}()
 
 		err = DownloadFolderHandler(rwc, fullPath, fileTransfer, s.FS, rLogger, s.Config.PreserveResourceForks)
 		if err != nil {
-			return fmt.Errorf("file upload error: %w", err)
+			return fmt.Errorf("folder download: %w", err)
 		}
 
 	case FolderUpload:
-		s.Stats.UploadCounter += 1
-		s.Stats.UploadsInProgress += 1
-		defer func() { s.Stats.UploadsInProgress -= 1 }()
+		s.Stats.Increment(StatUploadCounter, StatUploadsInProgress)
+		defer func() {
+			s.Stats.Decrement(StatUploadsInProgress)
+		}()
+
 		rLogger.Info(
 			"Folder upload started",
 			"dstPath", fullPath,
@@ -827,8 +584,23 @@ func (s *Server) handleFileTransfer(ctx context.Context, rwc io.ReadWriter) erro
 
 		err = UploadFolderHandler(rwc, fullPath, fileTransfer, s.FS, rLogger, s.Config.PreserveResourceForks)
 		if err != nil {
-			return fmt.Errorf("file upload error: %w", err)
+			return fmt.Errorf("folder upload: %w", err)
 		}
 	}
 	return nil
 }
+
+func (s *Server) SendAll(t TranType, fields ...Field) {
+	for _, c := range s.ClientMgr.List() {
+		s.outbox <- NewTransaction(t, c.ID, fields...)
+	}
+}
+
+func (s *Server) Shutdown(msg []byte) {
+	s.Logger.Info("Shutdown signal received")
+	s.SendAll(TranDisconnectMsg, NewField(FieldData, msg))
+
+	time.Sleep(3 * time.Second)
+
+	os.Exit(0)
+}