patch: v0.10.24

[rbdr/mobius] / hotline / server.go

diff --git a/hotline/server.go b/hotline/server.go
index b0ddf2d06d7db5ea233c6db8f37dc749ff98ea80..bfc1c1165eee685a77e0891f89e9fede96c4a721 100644 (file)
--- a/hotline/server.go
+++ b/hotline/server.go
@@ -1,60 +1,77 @@
 package hotline
 
 import (
 package hotline
 
 import (

+       "bufio"

        "context"
        "encoding/binary"
        "errors"
        "fmt"
        "context"
        "encoding/binary"
        "errors"
        "fmt"

+       "github.com/go-playground/validator/v10"

        "go.uber.org/zap"
        "go.uber.org/zap"

+       "gopkg.in/yaml.v3"

        "io"
        "io"

-       "io/ioutil"
+       "io/fs"

        "math/big"
        "math/rand"
        "net"
        "os"
        "math/big"
        "math/rand"
        "net"
        "os"

-       "path"

        "path/filepath"
        "path/filepath"

-       "runtime/debug"
-       "sort"

        "strings"
        "sync"
        "time"
        "strings"
        "sync"
        "time"

-
-       "gopkg.in/yaml.v3"

 )
 
 )
 

-const (
-       userIdleSeconds        = 300 // time in seconds before an inactive user is marked idle
-       idleCheckInterval      = 10  // time in seconds to check for idle users
-       trackerUpdateFrequency = 300 // time in seconds between tracker re-registration
-)
+type contextKey string
+
+var contextKeyReq = contextKey("req")
+
+type requestCtx struct {
+       remoteAddr string
+}

 
 type Server struct {
        Port          int
        Accounts      map[string]*Account
        Agreement     []byte
        Clients       map[uint16]*ClientConn
 
 type Server struct {
        Port          int
        Accounts      map[string]*Account
        Agreement     []byte
        Clients       map[uint16]*ClientConn

-       FlatNews      []byte
-       ThreadedNews  *ThreadedNews
-       FileTransfers map[uint32]*FileTransfer
-       Config        *Config
-       ConfigDir     string
-       Logger        *zap.SugaredLogger
-       PrivateChats  map[uint32]*PrivateChat
+       fileTransfers map[[4]byte]*FileTransfer
+
+       Config    *Config
+       ConfigDir string
+       Logger    *zap.SugaredLogger
+
+       PrivateChatsMu sync.Mutex
+       PrivateChats   map[uint32]*PrivateChat
+

        NextGuestID   *uint16
        NextGuestID   *uint16

-       TrackerPassID []byte
-       Stats         *Stats
+       TrackerPassID [4]byte

 
 

-       APIListener  net.Listener
-       FileListener net.Listener
+       StatsMu sync.Mutex
+       Stats   *Stats

 
 

-       // newsReader io.Reader
-       // newsWriter io.WriteCloser
+       FS FileStore // Storage backend to use for File storage

 
        outbox chan Transaction
 
        outbox chan Transaction

+       mux    sync.Mutex
+
+       threadedNewsMux sync.Mutex
+       ThreadedNews    *ThreadedNews

 
 

-       mux         sync.Mutex

        flatNewsMux sync.Mutex
        flatNewsMux sync.Mutex

+       FlatNews    []byte
+
+       banListMU sync.Mutex
+       banList   map[string]*time.Time
+}
+
+func (s *Server) CurrentStats() Stats {
+       s.StatsMu.Lock()
+       defer s.StatsMu.Unlock()
+
+       stats := s.Stats
+       stats.CurrentlyConnected = len(s.Clients)
+
+       return *stats

 }
 
 type PrivateChat struct {
 }
 
 type PrivateChat struct {


@@ -63,27 +80,40 @@ type PrivateChat struct {
 }
 
 func (s *Server) ListenAndServe(ctx context.Context, cancelRoot context.CancelFunc) error {
 }
 
 func (s *Server) ListenAndServe(ctx context.Context, cancelRoot context.CancelFunc) error {

-       s.Logger.Infow("Hotline server started", "version", VERSION)
+       s.Logger.Infow("Hotline server started",
+               "version", VERSION,
+               "API port", fmt.Sprintf(":%v", s.Port),
+               "Transfer port", fmt.Sprintf(":%v", s.Port+1),
+       )
+

        var wg sync.WaitGroup
 
        wg.Add(1)
        var wg sync.WaitGroup
 
        wg.Add(1)

-       go func() { s.Logger.Fatal(s.Serve(ctx, cancelRoot, s.APIListener)) }()
+       go func() {
+               ln, err := net.Listen("tcp", fmt.Sprintf("%s:%v", "", s.Port))
+               if err != nil {
+                       s.Logger.Fatal(err)
+               }
+
+               s.Logger.Fatal(s.Serve(ctx, ln))
+       }()

 
        wg.Add(1)
 
        wg.Add(1)

-       go func() { s.Logger.Fatal(s.ServeFileTransfers(s.FileListener)) }()
+       go func() {
+               ln, err := net.Listen("tcp", fmt.Sprintf("%s:%v", "", s.Port+1))
+               if err != nil {
+                       s.Logger.Fatal(err)
+               }
+
+               s.Logger.Fatal(s.ServeFileTransfers(ctx, ln))
+       }()

 
        wg.Wait()
 
        return nil
 }
 
 
        wg.Wait()
 
        return nil
 }
 

-func (s *Server) APIPort() int {
-       return s.APIListener.Addr().(*net.TCPAddr).Port
-}
-
-func (s *Server) ServeFileTransfers(ln net.Listener) error {
-       s.Logger.Infow("Hotline file transfer server started", "Addr", fmt.Sprintf(":%v", s.Port+1))
-
+func (s *Server) ServeFileTransfers(ctx context.Context, ln net.Listener) error {

        for {
                conn, err := ln.Accept()
                if err != nil {
        for {
                conn, err := ln.Accept()
                if err != nil {


@@ -91,7 +121,16 @@ func (s *Server) ServeFileTransfers(ln net.Listener) error {
                }
 
                go func() {
                }
 
                go func() {

-                       if err := s.handleFileTransfer(conn); err != nil {
+                       defer func() { _ = conn.Close() }()
+
+                       err = s.handleFileTransfer(
+                               context.WithValue(ctx, contextKeyReq, requestCtx{
+                                       remoteAddr: conn.RemoteAddr().String(),
+                               }),
+                               conn,
+                       )
+
+                       if err != nil {

                                s.Logger.Errorw("file transfer error", "reason", err)
                        }
                }()
                                s.Logger.Errorw("file transfer error", "reason", err)
                        }
                }()


@@ -99,7 +138,6 @@ func (s *Server) ServeFileTransfers(ln net.Listener) error {
 }
 
 func (s *Server) sendTransaction(t Transaction) error {
 }
 
 func (s *Server) sendTransaction(t Transaction) error {

-       requestNum := binary.BigEndian.Uint16(t.Type)

        clientID, err := byteToInt(*t.clientID)
        if err != nil {
                return err
        clientID, err := byteToInt(*t.clientID)
        if err != nil {
                return err


@@ -111,51 +149,48 @@ func (s *Server) sendTransaction(t Transaction) error {
        if client == nil {
                return fmt.Errorf("invalid client id %v", *t.clientID)
        }
        if client == nil {
                return fmt.Errorf("invalid client id %v", *t.clientID)
        }

-       userName := string(client.UserName)
-       login := client.Account.Login
-
-       handler := TransactionHandlers[requestNum]

 
        b, err := t.MarshalBinary()
        if err != nil {
                return err
        }
 
        b, err := t.MarshalBinary()
        if err != nil {
                return err
        }

-       var n int
-       if n, err = client.Connection.Write(b); err != nil {
+
+       _, err = client.Connection.Write(b)
+       if err != nil {

                return err
        }
                return err
        }

-       s.Logger.Debugw("Sent Transaction",
-               "name", userName,
-               "login", login,
-               "IsReply", t.IsReply,
-               "type", handler.Name,
-               "sentBytes", n,
-               "remoteAddr", client.Connection.RemoteAddr(),
-       )
+

        return nil
 }
 
        return nil
 }
 

-func (s *Server) Serve(ctx context.Context, cancelRoot context.CancelFunc, ln net.Listener) error {
-       s.Logger.Infow("Hotline server started", "Addr", fmt.Sprintf(":%v", s.Port))
+func (s *Server) processOutbox() {
+       for {
+               t := <-s.outbox
+               go func() {
+                       if err := s.sendTransaction(t); err != nil {
+                               s.Logger.Errorw("error sending transaction", "err", err)
+                       }
+               }()
+       }
+}
+
+func (s *Server) Serve(ctx context.Context, ln net.Listener) error {
+       go s.processOutbox()

 
        for {
                conn, err := ln.Accept()
                if err != nil {
                        s.Logger.Errorw("error accepting connection", "err", err)
                }
 
        for {
                conn, err := ln.Accept()
                if err != nil {
                        s.Logger.Errorw("error accepting connection", "err", err)
                }

+               connCtx := context.WithValue(ctx, contextKeyReq, requestCtx{
+                       remoteAddr: conn.RemoteAddr().String(),
+               })

 
                go func() {
 
                go func() {

-                       for {
-                               t := <-s.outbox
-                               go func() {
-                                       if err := s.sendTransaction(t); err != nil {
-                                               s.Logger.Errorw("error sending transaction", "err", err)
-                                       }
-                               }()
-                       }
-               }()
-               go func() {
-                       if err := s.handleNewConnection(conn); err != nil {
+                       s.Logger.Infow("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.Infow("Client disconnected", "RemoteAddr", conn.RemoteAddr())
                                } else {
                                if err == io.EOF {
                                        s.Logger.Infow("Client disconnected", "RemoteAddr", conn.RemoteAddr())
                                } else {


@@ -171,85 +206,80 @@ const (
 )
 
 // NewServer constructs a new Server from a config dir
 )
 
 // NewServer constructs a new Server from a config dir

-func NewServer(configDir, netInterface string, netPort int, logger *zap.SugaredLogger) (*Server, error) {
+func NewServer(configDir string, netPort int, logger *zap.SugaredLogger, fs FileStore) (*Server, error) {

        server := Server{
                Port:          netPort,
                Accounts:      make(map[string]*Account),
                Config:        new(Config),
                Clients:       make(map[uint16]*ClientConn),
        server := Server{
                Port:          netPort,
                Accounts:      make(map[string]*Account),
                Config:        new(Config),
                Clients:       make(map[uint16]*ClientConn),

-               FileTransfers: make(map[uint32]*FileTransfer),
+               fileTransfers: make(map[[4]byte]*FileTransfer),

                PrivateChats:  make(map[uint32]*PrivateChat),
                ConfigDir:     configDir,
                Logger:        logger,
                NextGuestID:   new(uint16),
                outbox:        make(chan Transaction),
                PrivateChats:  make(map[uint32]*PrivateChat),
                ConfigDir:     configDir,
                Logger:        logger,
                NextGuestID:   new(uint16),
                outbox:        make(chan Transaction),

-               Stats:         &Stats{StartTime: time.Now()},
+               Stats:         &Stats{Since: time.Now()},

                ThreadedNews:  &ThreadedNews{},
                ThreadedNews:  &ThreadedNews{},

-               TrackerPassID: make([]byte, 4),
+               FS:            fs,
+               banList:       make(map[string]*time.Time),

        }
 
        }
 

-       ln, err := net.Listen("tcp", fmt.Sprintf("%s:%v", netInterface, netPort))
-       if err != nil {
-               return nil, err
-       }
-       server.APIListener = ln
-
-       if netPort != 0 {
-               netPort += 1
-       }
-
-       ln2, err := net.Listen("tcp", fmt.Sprintf("%s:%v", netInterface, netPort))
-       server.FileListener = ln2
-       if err != nil {
-               return nil, err
-       }
+       var err error

 
        // generate a new random passID for tracker registration
 
        // generate a new random passID for tracker registration

-       if _, err := rand.Read(server.TrackerPassID); err != nil {
+       if _, err := rand.Read(server.TrackerPassID[:]); err != nil {

                return nil, err
        }
 
                return nil, err
        }
 

-       server.Logger.Debugw("Loading Agreement", "path", configDir+agreementFile)
-       if server.Agreement, err = os.ReadFile(configDir + agreementFile); err != nil {
+       server.Agreement, err = os.ReadFile(filepath.Join(configDir, agreementFile))
+       if err != nil {

                return nil, err
        }
 
                return nil, err
        }
 

-       if server.FlatNews, err = os.ReadFile(configDir + "MessageBoard.txt"); err != nil {
+       if server.FlatNews, err = os.ReadFile(filepath.Join(configDir, "MessageBoard.txt")); err != nil {

                return nil, err
        }
 
                return nil, err
        }
 

-       if err := server.loadThreadedNews(configDir + "ThreadedNews.yaml"); err != nil {
+       // 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"))
+
+       if err := server.loadThreadedNews(filepath.Join(configDir, "ThreadedNews.yaml")); err != nil {

                return nil, err
        }
 
                return nil, err
        }
 

-       if err := server.loadConfig(configDir + "config.yaml"); err != nil {
+       if err := server.loadConfig(filepath.Join(configDir, "config.yaml")); err != nil {

                return nil, err
        }
 
                return nil, err
        }
 

-       if err := server.loadAccounts(configDir + "Users/"); err != nil {
+       if err := server.loadAccounts(filepath.Join(configDir, "Users/")); err != nil {

                return nil, err
        }
 
                return nil, err
        }
 

-       server.Config.FileRoot = configDir + "Files/"
+       server.Config.FileRoot = filepath.Join(configDir, "Files")

 
        *server.NextGuestID = 1
 
        if server.Config.EnableTrackerRegistration {
 
        *server.NextGuestID = 1
 
        if server.Config.EnableTrackerRegistration {

+               server.Logger.Infow(
+                       "Tracker registration enabled",
+                       "frequency", fmt.Sprintf("%vs", trackerUpdateFrequency),
+                       "trackers", server.Config.Trackers,
+               )
+

                go func() {
                        for {
                go func() {
                        for {

-                               tr := TrackerRegistration{
-                                       Port:        []byte{0x15, 0x7c},
+                               tr := &TrackerRegistration{

                                        UserCount:   server.userCount(),
                                        UserCount:   server.userCount(),

-                                       PassID:      server.TrackerPassID,
+                                       PassID:      server.TrackerPassID[:],

                                        Name:        server.Config.Name,
                                        Description: server.Config.Description,
                                }
                                        Name:        server.Config.Name,
                                        Description: server.Config.Description,
                                }

+                               binary.BigEndian.PutUint16(tr.Port[:], uint16(server.Port))

                                for _, t := range server.Config.Trackers {
                                for _, t := range server.Config.Trackers {

-                                       server.Logger.Infof("Registering with tracker %v", t)
-

                                        if err := register(t, tr); err != nil {
                                                server.Logger.Errorw("unable to register with tracker %v", "error", err)
                                        }
                                        if err := register(t, tr); err != nil {
                                                server.Logger.Errorw("unable to register with tracker %v", "error", err)
                                        }

+                                       server.Logger.Debugw("Sent Tracker registration", "addr", t)

                                }
 
                                time.Sleep(trackerUpdateFrequency * time.Second)
                                }
 
                                time.Sleep(trackerUpdateFrequency * time.Second)


@@ -280,16 +310,16 @@ func (s *Server) keepaliveHandler() {
                        if c.IdleTime > userIdleSeconds && !c.Idle {
                                c.Idle = true
 
                        if c.IdleTime > userIdleSeconds && !c.Idle {
                                c.Idle = true
 

-                               flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*c.Flags)))
-                               flagBitmap.SetBit(flagBitmap, userFlagAway, 1)
-                               binary.BigEndian.PutUint16(*c.Flags, uint16(flagBitmap.Int64()))
+                               flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(c.Flags)))
+                               flagBitmap.SetBit(flagBitmap, UserFlagAway, 1)
+                               binary.BigEndian.PutUint16(c.Flags, uint16(flagBitmap.Int64()))

 
                                c.sendAll(
 
                                c.sendAll(

-                                       tranNotifyChangeUser,
-                                       NewField(fieldUserID, *c.ID),
-                                       NewField(fieldUserFlags, *c.Flags),
-                                       NewField(fieldUserName, c.UserName),
-                                       NewField(fieldUserIconID, *c.Icon),
+                                       TranNotifyChangeUser,
+                                       NewField(FieldUserID, *c.ID),
+                                       NewField(FieldUserFlags, c.Flags),
+                                       NewField(FieldUserName, c.UserName),
+                                       NewField(FieldUserIconID, c.Icon),

                                )
                        }
                }
                                )
                        }
                }


@@ -297,38 +327,62 @@ func (s *Server) keepaliveHandler() {
        }
 }
 
        }
 }
 

+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 {
 func (s *Server) writeThreadedNews() error {

-       s.mux.Lock()
-       defer s.mux.Unlock()
+       s.threadedNewsMux.Lock()
+       defer s.threadedNewsMux.Unlock()

 
        out, err := yaml.Marshal(s.ThreadedNews)
        if err != nil {
                return err
        }
 
        out, err := yaml.Marshal(s.ThreadedNews)
        if err != nil {
                return err
        }

-       err = ioutil.WriteFile(
-               s.ConfigDir+"ThreadedNews.yaml",
+       err = s.FS.WriteFile(
+               filepath.Join(s.ConfigDir, "ThreadedNews.yaml"),

                out,
                0666,
        )
        return err
 }
 
                out,
                0666,
        )
        return err
 }
 

-func (s *Server) NewClientConn(conn net.Conn) *ClientConn {
+func (s *Server) NewClientConn(conn io.ReadWriteCloser, remoteAddr string) *ClientConn {

        s.mux.Lock()
        defer s.mux.Unlock()
 
        clientConn := &ClientConn{
                ID:         &[]byte{0, 0},
        s.mux.Lock()
        defer s.mux.Unlock()
 
        clientConn := &ClientConn{
                ID:         &[]byte{0, 0},

-               Icon:       &[]byte{0, 0},
-               Flags:      &[]byte{0, 0},
+               Icon:       []byte{0, 0},
+               Flags:      []byte{0, 0},

                UserName:   []byte{},
                Connection: conn,
                Server:     s,
                UserName:   []byte{},
                Connection: conn,
                Server:     s,

-               Version:    &[]byte{},
+               Version:    []byte{},

                AutoReply:  []byte{},
                AutoReply:  []byte{},

-               Transfers:  make(map[int][]*FileTransfer),
-               Agreed:     false,
+               transfers:  map[int]map[[4]byte]*FileTransfer{},
+               RemoteAddr: remoteAddr,
+       }
+       clientConn.transfers = map[int]map[[4]byte]*FileTransfer{
+               FileDownload:   {},
+               FileUpload:     {},
+               FolderDownload: {},
+               FolderUpload:   {},
+               bannerDownload: {},

        }
        }

+

        *s.NextGuestID++
        ID := *s.NextGuestID
 
        *s.NextGuestID++
        ID := *s.NextGuestID
 


@@ -339,7 +393,7 @@ func (s *Server) NewClientConn(conn net.Conn) *ClientConn {
 }
 
 // NewUser creates a new user account entry in the server map and config file
 }
 
 // NewUser creates a new user account entry in the server map and config file

-func (s *Server) NewUser(login, name, password string, access []byte) error {
+func (s *Server) NewUser(login, name, password string, access accessBitmap) error {

        s.mux.Lock()
        defer s.mux.Unlock()
 
        s.mux.Lock()
        defer s.mux.Unlock()
 


@@ -347,7 +401,7 @@ func (s *Server) NewUser(login, name, password string, access []byte) error {
                Login:    login,
                Name:     name,
                Password: hashAndSalt([]byte(password)),
                Login:    login,
                Name:     name,
                Password: hashAndSalt([]byte(password)),

-               Access:   &access,
+               Access:   access,

        }
        out, err := yaml.Marshal(&account)
        if err != nil {
        }
        out, err := yaml.Marshal(&account)
        if err != nil {


@@ -355,7 +409,38 @@ func (s *Server) NewUser(login, name, password string, access []byte) error {
        }
        s.Accounts[login] = &account
 
        }
        s.Accounts[login] = &account
 

-       return FS.WriteFile(s.ConfigDir+"Users/"+login+".yaml", out, 0666)
+       return s.FS.WriteFile(filepath.Join(s.ConfigDir, "Users", login+".yaml"), out, 0666)
+}
+
+func (s *Server) UpdateUser(login, newLogin, name, password string, access accessBitmap) error {
+       s.mux.Lock()
+       defer s.mux.Unlock()
+
+       // update renames the user login
+       if login != newLogin {
+               err := os.Rename(filepath.Join(s.ConfigDir, "Users", login+".yaml"), filepath.Join(s.ConfigDir, "Users", newLogin+".yaml"))
+               if err != nil {
+                       return err
+               }
+               s.Accounts[newLogin] = s.Accounts[login]
+               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 err
+       }
+
+       return nil

 }
 
 // DeleteUser deletes the user account
 }
 
 // DeleteUser deletes the user account


@@ -365,7 +450,7 @@ func (s *Server) DeleteUser(login string) error {
 
        delete(s.Accounts, login)
 
 
        delete(s.Accounts, login)
 

-       return FS.Remove(s.ConfigDir + "Users/" + login + ".yaml")
+       return s.FS.Remove(filepath.Join(s.ConfigDir, "Users", login+".yaml"))

 }
 
 func (s *Server) connectedUsers() []Field {
 }
 
 func (s *Server) connectedUsers() []Field {


@@ -374,20 +459,27 @@ func (s *Server) connectedUsers() []Field {
 
        var connectedUsers []Field
        for _, c := range sortedClients(s.Clients) {
 
        var connectedUsers []Field
        for _, c := range sortedClients(s.Clients) {

-               if !c.Agreed {
-                       continue
-               }

                user := User{
                        ID:    *c.ID,
                user := User{
                        ID:    *c.ID,

-                       Icon:  *c.Icon,
-                       Flags: *c.Flags,
+                       Icon:  c.Icon,
+                       Flags: c.Flags,

                        Name:  string(c.UserName),
                }
                        Name:  string(c.UserName),
                }

-               connectedUsers = append(connectedUsers, NewField(fieldUsernameWithInfo, user.Payload()))
+               connectedUsers = append(connectedUsers, NewField(FieldUsernameWithInfo, user.Payload()))

        }
        return connectedUsers
 }
 
        }
        return connectedUsers
 }
 

+func (s *Server) loadBanList(path string) error {
+       fh, err := os.Open(path)
+       if err != nil {
+               return err
+       }
+       decoder := yaml.NewDecoder(fh)
+
+       return decoder.Decode(s.banList)
+}
+

 // loadThreadedNews loads the threaded news data from disk
 func (s *Server) loadThreadedNews(threadedNewsPath string) error {
        fh, err := os.Open(threadedNewsPath)
 // loadThreadedNews loads the threaded news data from disk
 func (s *Server) loadThreadedNews(threadedNewsPath string) error {
        fh, err := os.Open(threadedNewsPath)


@@ -401,7 +493,7 @@ func (s *Server) loadThreadedNews(threadedNewsPath string) error {
 
 // loadAccounts loads account data from disk
 func (s *Server) loadAccounts(userDir string) error {
 
 // loadAccounts loads account data from disk
 func (s *Server) loadAccounts(userDir string) error {

-       matches, err := filepath.Glob(path.Join(userDir, "*.yaml"))
+       matches, err := filepath.Glob(filepath.Join(userDir, "*.yaml"))

        if err != nil {
                return err
        }
        if err != nil {
                return err
        }


@@ -411,7 +503,7 @@ func (s *Server) loadAccounts(userDir string) error {
        }
 
        for _, file := range matches {
        }
 
        for _, file := range matches {

-               fh, err := FS.Open(file)
+               fh, err := s.FS.Open(file)

                if err != nil {
                        return err
                }
                if err != nil {
                        return err
                }


@@ -428,7 +520,7 @@ func (s *Server) loadAccounts(userDir string) error {
 }
 
 func (s *Server) loadConfig(path string) error {
 }
 
 func (s *Server) loadConfig(path string) error {

-       fh, err := FS.Open(path)
+       fh, err := s.FS.Open(path)

        if err != nil {
                return err
        }
        if err != nil {
                return err
        }


@@ -438,50 +530,93 @@ func (s *Server) loadConfig(path string) error {
        if err != nil {
                return err
        }
        if err != nil {
                return err
        }

+
+       validate := validator.New()
+       err = validate.Struct(s.Config)
+       if err != nil {
+               return err
+       }

        return nil
 }
 
        return nil
 }
 

-const (
-       minTransactionLen = 22 // minimum length of any transaction
-)
-

 // handleNewConnection takes a new net.Conn and performs the initial login sequence
 // handleNewConnection takes a new net.Conn and performs the initial login sequence

-func (s *Server) handleNewConnection(conn net.Conn) error {
-       handshakeBuf := make([]byte, 12) // handshakes are always 12 bytes in length
-       if _, err := conn.Read(handshakeBuf); err != nil {
-               return err
-       }
-       if err := Handshake(conn, handshakeBuf[:12]); err != nil {
-               return err
-       }
+func (s *Server) handleNewConnection(ctx context.Context, rwc io.ReadWriteCloser, remoteAddr string) error {
+       defer dontPanic(s.Logger)

 
 

-       buf := make([]byte, 1024)
-       readLen, err := conn.Read(buf)
-       if readLen < minTransactionLen {
+       if err := Handshake(rwc); err != nil {

                return err
        }
                return err
        }

-       if err != nil {
+
+       // Create a new scanner for parsing incoming bytes into transaction tokens
+       scanner := bufio.NewScanner(rwc)
+       scanner.Split(transactionScanner)
+
+       scanner.Scan()
+
+       // Make a new []byte slice and copy the scanner bytes to it.  This is critical to avoid a data race as the
+       // scanner re-uses the buffer for subsequent scans.
+       buf := make([]byte, len(scanner.Bytes()))
+       copy(buf, scanner.Bytes())
+
+       var clientLogin Transaction
+       if _, err := clientLogin.Write(buf); err != nil {

                return err
        }
 
                return err
        }
 

-       clientLogin, _, err := ReadTransaction(buf[:readLen])
-       if err != nil {
-               return err
+       // check if remoteAddr is present in the ban list
+       if banUntil, ok := s.banList[strings.Split(remoteAddr, ":")[0]]; ok {
+               // permaban
+               if banUntil == nil {
+                       t := NewTransaction(
+                               TranServerMsg,
+                               &[]byte{0, 0},
+                               NewField(FieldData, []byte("You are permanently banned on this server")),
+                               NewField(FieldChatOptions, []byte{0, 0}),
+                       )
+
+                       b, err := t.MarshalBinary()
+                       if err != nil {
+                               return err
+                       }
+
+                       _, err = rwc.Write(b)
+                       if err != nil {
+                               return err
+                       }
+
+                       time.Sleep(1 * time.Second)
+                       return nil
+               }
+
+               // temporary ban
+               if time.Now().Before(*banUntil) {
+                       t := NewTransaction(
+                               TranServerMsg,
+                               &[]byte{0, 0},
+                               NewField(FieldData, []byte("You are temporarily banned on this server")),
+                               NewField(FieldChatOptions, []byte{0, 0}),
+                       )
+                       b, err := t.MarshalBinary()
+                       if err != nil {
+                               return err
+                       }
+
+                       _, err = rwc.Write(b)
+                       if err != nil {
+                               return err
+                       }
+
+                       time.Sleep(1 * time.Second)
+                       return nil
+               }

        }
 
        }
 

-       c := s.NewClientConn(conn)
+       c := s.NewClientConn(rwc, remoteAddr)

        defer c.Disconnect()
        defer c.Disconnect()

-       defer func() {
-               if r := recover(); r != nil {
-                       fmt.Println("stacktrace from panic: \n" + string(debug.Stack()))
-                       c.Server.Logger.Errorw("PANIC", "err", r, "trace", string(debug.Stack()))
-                       c.Disconnect()
-               }
-       }()

 
 

-       encodedLogin := clientLogin.GetField(fieldUserLogin).Data
-       encodedPassword := clientLogin.GetField(fieldUserPassword).Data
-       *c.Version = clientLogin.GetField(fieldVersion).Data
+       encodedLogin := clientLogin.GetField(FieldUserLogin).Data
+       encodedPassword := clientLogin.GetField(FieldUserPassword).Data
+       c.Version = clientLogin.GetField(FieldVersion).Data

 
        var login string
        for _, char := range encodedLogin {
 
        var login string
        for _, char := range encodedLogin {


@@ -491,114 +626,120 @@ func (s *Server) handleNewConnection(conn net.Conn) error {
                login = GuestAccount
        }
 
                login = GuestAccount
        }
 

+       c.logger = s.Logger.With("remoteAddr", remoteAddr, "login", login)
+

        // If authentication fails, send error reply and close connection
        if !c.Authenticate(login, encodedPassword) {
        // If authentication fails, send error reply and close connection
        if !c.Authenticate(login, encodedPassword) {

-               t := c.NewErrReply(clientLogin, "Incorrect login.")
+               t := c.NewErrReply(&clientLogin, "Incorrect login.")

                b, err := t.MarshalBinary()
                if err != nil {
                        return err
                }
                b, err := t.MarshalBinary()
                if err != nil {
                        return err
                }

-               if _, err := conn.Write(b); err != nil {
+               if _, err := rwc.Write(b); err != nil {

                        return err
                }
                        return err
                }

-               return fmt.Errorf("incorrect login")
-       }

 
 

-       if clientLogin.GetField(fieldUserName).Data != nil {
-               c.UserName = clientLogin.GetField(fieldUserName).Data
+               c.logger.Infow("Login failed", "clientVersion", fmt.Sprintf("%x", c.Version))
+
+               return nil

        }
 
        }
 

-       if clientLogin.GetField(fieldUserIconID).Data != nil {
-               *c.Icon = clientLogin.GetField(fieldUserIconID).Data
+       if clientLogin.GetField(FieldUserIconID).Data != nil {
+               c.Icon = clientLogin.GetField(FieldUserIconID).Data

        }
 
        c.Account = c.Server.Accounts[login]
 
        }
 
        c.Account = c.Server.Accounts[login]
 

-       if c.Authorize(accessDisconUser) {
-               *c.Flags = []byte{0, 2}
+       if clientLogin.GetField(FieldUserName).Data != nil {
+               if c.Authorize(accessAnyName) {
+                       c.UserName = clientLogin.GetField(FieldUserName).Data
+               } else {
+                       c.UserName = []byte(c.Account.Name)
+               }

        }
 
        }
 

-       s.Logger.Infow("Client connection received", "login", login, "version", *c.Version, "RemoteAddr", conn.RemoteAddr().String())
+       if c.Authorize(accessDisconUser) {
+               c.Flags = []byte{0, 2}
+       }

 
 

-       s.outbox <- c.NewReply(clientLogin,
-               NewField(fieldVersion, []byte{0x00, 0xbe}),
-               NewField(fieldCommunityBannerID, []byte{0x00, 0x01}),
-               NewField(fieldServerName, []byte(s.Config.Name)),
+       s.outbox <- c.NewReply(&clientLogin,
+               NewField(FieldVersion, []byte{0x00, 0xbe}),
+               NewField(FieldCommunityBannerID, []byte{0, 0}),
+               NewField(FieldServerName, []byte(s.Config.Name)),

        )
 
        // Send user access privs so client UI knows how to behave
        )
 
        // Send user access privs so client UI knows how to behave

-       c.Server.outbox <- *NewTransaction(tranUserAccess, c.ID, NewField(fieldUserAccess, *c.Account.Access))
+       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
+       // 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 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))
+       }

 
 

-       // Show agreement to client
-       c.Server.outbox <- *NewTransaction(tranShowAgreement, c.ID, NewField(fieldData, s.Agreement))
+       // If the client has provided a username as part of the login, we can infer that it is using the 1.2.3 login
+       // flow and not the 1.5+ flow.
+       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))

 
 

-       // assume simplified hotline v1.2.3 login flow that does not require agreement
-       if *c.Version == nil {
-               c.Agreed = true
+               c.logger.Infow("Login successful", "clientVersion", "Not sent (probably 1.2.3)")

 
 

-               c.notifyOthers(
+               // 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(

                        *NewTransaction(
                        *NewTransaction(

-                               tranNotifyChangeUser, nil,
-                               NewField(fieldUserName, c.UserName),
-                               NewField(fieldUserID, *c.ID),
-                               NewField(fieldUserIconID, *c.Icon),
-                               NewField(fieldUserFlags, *c.Flags),
+                               TranNotifyChangeUser, nil,
+                               NewField(FieldUserName, c.UserName),
+                               NewField(FieldUserID, *c.ID),
+                               NewField(FieldUserIconID, c.Icon),
+                               NewField(FieldUserFlags, c.Flags),

                        ),
                        ),

-               )
+               ) {
+                       c.Server.outbox <- t
+               }

        }
 
        }
 

-       c.Server.Stats.LoginCount += 1
+       c.Server.Stats.ConnectionCounter += 1
+       if len(s.Clients) > c.Server.Stats.ConnectionPeak {
+               c.Server.Stats.ConnectionPeak = len(s.Clients)
+       }

 
 

-       const readBuffSize = 1024000 // 1KB - TODO: what should this be?
-       tranBuff := make([]byte, 0)
-       tReadlen := 0
-       // Infinite loop where take action on incoming client requests until the connection is closed
-       for {
-               buf = make([]byte, readBuffSize)
-               tranBuff = tranBuff[tReadlen:]
+       // Scan for new transactions and handle them as they come in.
+       for scanner.Scan() {
+               // Make a new []byte slice and copy the scanner bytes to it.  This is critical to avoid a data race as the
+               // scanner re-uses the buffer for subsequent scans.
+               buf := make([]byte, len(scanner.Bytes()))
+               copy(buf, scanner.Bytes())

 
 

-               readLen, err := c.Connection.Read(buf)
-               if err != nil {
+               var t Transaction
+               if _, err := t.Write(buf); err != nil {

                        return err
                }
                        return err
                }

-               tranBuff = append(tranBuff, buf[:readLen]...)

 
 

-               // We may have read multiple requests worth of bytes from Connection.Read.  readTransactions splits them
-               // into a slice of transactions
-               var transactions []Transaction
-               if transactions, tReadlen, err = readTransactions(tranBuff); err != nil {
-                       c.Server.Logger.Errorw("Error handling transaction", "err", err)
-               }
-
-               // iterate over all of the transactions that were parsed from the byte slice and handle them
-               for _, t := range transactions {
-                       if err := c.handleTransaction(&t); err != nil {
-                               c.Server.Logger.Errorw("Error handling transaction", "err", err)
-                       }
+               if err := c.handleTransaction(t); err != nil {
+                       c.logger.Errorw("Error handling transaction", "err", err)

                }
        }
                }
        }

-}
-
-// NewTransactionRef generates a random ID for the file transfer.  The Hotline client includes this ID
-// in the file transfer request payload, and the file transfer server will use it to map the request
-// to a transfer
-func (s *Server) NewTransactionRef() []byte {
-       transactionRef := make([]byte, 4)
-       rand.Read(transactionRef)
-
-       return transactionRef
+       return nil

 }
 
 func (s *Server) NewPrivateChat(cc *ClientConn) []byte {
 }
 
 func (s *Server) NewPrivateChat(cc *ClientConn) []byte {

-       s.mux.Lock()
-       defer s.mux.Unlock()
+       s.PrivateChatsMu.Lock()
+       defer s.PrivateChatsMu.Unlock()

 
        randID := make([]byte, 4)
        rand.Read(randID)
 
        randID := make([]byte, 4)
        rand.Read(randID)

-       data := binary.BigEndian.Uint32(randID[:])
+       data := binary.BigEndian.Uint32(randID)

 
        s.PrivateChats[data] = &PrivateChat{
 
        s.PrivateChats[data] = &PrivateChat{

-               Subject:    "",

                ClientConn: make(map[uint16]*ClientConn),
        }
        s.PrivateChats[data].ClientConn[cc.uint16ID()] = cc
                ClientConn: make(map[uint16]*ClientConn),
        }
        s.PrivateChats[data].ClientConn[cc.uint16ID()] = cc


@@ -611,136 +752,240 @@ 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
 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(conn io.ReadWriteCloser) error {
-       defer func() {
-               if err := conn.Close(); err != nil {
-                       s.Logger.Errorw("error closing connection", "error", err)
-               }
-       }()
+func (s *Server) handleFileTransfer(ctx context.Context, rwc io.ReadWriter) error {
+       defer dontPanic(s.Logger)

 
        txBuf := make([]byte, 16)
 
        txBuf := make([]byte, 16)

-       _, err := conn.Read(txBuf)
-       if err != nil {
+       if _, err := io.ReadFull(rwc, txBuf); err != nil {

                return err
        }
 
        var t transfer
                return err
        }
 
        var t transfer

-       _, err = t.Write(txBuf)
-       if err != nil {
+       if _, err := t.Write(txBuf); err != nil {

                return err
        }
 
                return err
        }
 

-       transferRefNum := binary.BigEndian.Uint32(t.ReferenceNumber[:])
-       fileTransfer := s.FileTransfers[transferRefNum]
+       defer func() {
+               s.mux.Lock()
+               delete(s.fileTransfers, t.ReferenceNumber)
+               s.mux.Unlock()
+
+               // 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
+               // the server does.  This is gross and seems unnecessary.  TODO: Revisit?
+               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)
+       if err != nil {
+               return err
+       }

 
        switch fileTransfer.Type {
 
        switch fileTransfer.Type {

+       case bannerDownload:
+               if err := s.bannerDownload(rwc); err != nil {
+                       return err
+               }

        case FileDownload:
        case FileDownload:

-               fullFilePath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
+               s.Stats.DownloadCounter += 1
+               s.Stats.DownloadsInProgress += 1
+               defer func() {
+                       s.Stats.DownloadsInProgress -= 1
+               }()
+
+               var dataOffset int64
+               if fileTransfer.fileResumeData != nil {
+                       dataOffset = int64(binary.BigEndian.Uint32(fileTransfer.fileResumeData.ForkInfoList[0].DataSize[:]))
+               }
+
+               fw, err := newFileWrapper(s.FS, fullPath, 0)

                if err != nil {
                        return err
                }
 
                if err != nil {
                        return err
                }
 

-               ffo, err := NewFlattenedFileObject(
-                       s.Config.FileRoot,
-                       fileTransfer.FilePath,
-                       fileTransfer.FileName,
-               )
+               rLogger.Infow("File download started", "filePath", fullPath)
+
+               // if file transfer options are included, that means this is a "quick preview" request from a 1.5+ client
+               if fileTransfer.options == nil {
+                       // Start by sending flat file object to client
+                       if _, err := rwc.Write(fw.ffo.BinaryMarshal()); err != nil {
+                               return err
+                       }
+               }
+
+               file, err := fw.dataForkReader()

                if err != nil {
                        return err
                }
 
                if err != nil {
                        return err
                }
 

-               s.Logger.Infow("File download started", "filePath", fullFilePath, "transactionRef", fileTransfer.ReferenceNumber)
-
-               // Start by sending flat file object to client
-               if _, err := conn.Write(ffo.BinaryMarshal()); err != nil {
+               br := bufio.NewReader(file)
+               if _, err := br.Discard(int(dataOffset)); err != nil {

                        return err
                }
 
                        return err
                }
 

-               file, err := FS.Open(fullFilePath)
-               if err != nil {
+               if _, err = io.Copy(rwc, io.TeeReader(br, fileTransfer.bytesSentCounter)); err != nil {

                        return err
                }
 
                        return err
                }
 

-               sendBuffer := make([]byte, 1048576)
-               for {
-                       var bytesRead int
-                       if bytesRead, err = file.Read(sendBuffer); err == io.EOF {
-                               break
+               // if the client requested to resume transfer, do not send the resource fork header, or it will be appended into the fileWrapper data
+               if fileTransfer.fileResumeData == nil {
+                       err = binary.Write(rwc, binary.BigEndian, fw.rsrcForkHeader())
+                       if err != nil {
+                               return err

                        }
                        }

+               }

 
 

-                       fileTransfer.BytesSent += bytesRead
+               rFile, err := fw.rsrcForkFile()
+               if err != nil {
+                       return nil
+               }

 
 

-                       delete(s.FileTransfers, transferRefNum)
+               if _, err = io.Copy(rwc, io.TeeReader(rFile, fileTransfer.bytesSentCounter)); err != nil {
+                       return err
+               }

 
 

-                       if _, err := conn.Write(sendBuffer[:bytesRead]); err != nil {
+       case FileUpload:
+               s.Stats.UploadCounter += 1
+               s.Stats.UploadsInProgress += 1
+               defer func() { s.Stats.UploadsInProgress -= 1 }()
+
+               var file *os.File
+
+               // A file upload has three possible cases:
+               // 1) Upload a new file
+               // 2) Resume a partially transferred file
+               // 3) Replace a fully uploaded file
+               //  We have to infer which case applies by inspecting what is already on the filesystem
+
+               // 1) Check for existing file:
+               _, err = os.Stat(fullPath)
+               if err == nil {
+                       return errors.New("existing file found at " + fullPath)
+               }
+               if errors.Is(err, fs.ErrNotExist) {
+                       // If not found, open or create a new .incomplete file
+                       file, err = os.OpenFile(fullPath+incompleteFileSuffix, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
+                       if err != nil {

                                return err
                        }
                }
                                return err
                        }
                }

-       case FileUpload:
-               destinationFile := s.Config.FileRoot + ReadFilePath(fileTransfer.FilePath) + "/" + string(fileTransfer.FileName)
-               newFile, err := FS.Create(destinationFile)
+
+               f, err := newFileWrapper(s.FS, fullPath, 0)

                if err != nil {
                        return err
                }
                if err != nil {
                        return err
                }

-               defer func() { _ = newFile.Close() }()

 
 

-               s.Logger.Infow("File upload started", "transactionRef", fileTransfer.ReferenceNumber, "dstFile", destinationFile)
+               rLogger.Infow("File upload started", "dstFile", fullPath)
+
+               rForkWriter := io.Discard
+               iForkWriter := io.Discard
+               if s.Config.PreserveResourceForks {
+                       rForkWriter, err = f.rsrcForkWriter()
+                       if err != nil {
+                               return err
+                       }
+
+                       iForkWriter, err = f.infoForkWriter()
+                       if err != nil {
+                               return err
+                       }
+               }
+
+               if err := receiveFile(rwc, file, rForkWriter, iForkWriter, fileTransfer.bytesSentCounter); err != nil {
+                       s.Logger.Error(err)
+               }
+
+               if err := file.Close(); err != nil {
+                       return err
+               }

 
 

-               if err := receiveFile(conn, newFile, nil); err != nil {
-                       s.Logger.Errorw("file upload error", "error", err)
+               if err := s.FS.Rename(fullPath+".incomplete", fullPath); err != nil {
+                       return err

                }
 
                }
 

-               s.Logger.Infow("File upload complete", "transactionRef", fileTransfer.ReferenceNumber, "dstFile", destinationFile)
+               rLogger.Infow("File upload complete", "dstFile", fullPath)
+

        case FolderDownload:
        case FolderDownload:

+               s.Stats.DownloadCounter += 1
+               s.Stats.DownloadsInProgress += 1
+               defer func() { s.Stats.DownloadsInProgress -= 1 }()
+

                // Folder Download flow:
                // 1. Get filePath from the transfer
                // 2. Iterate over files
                // Folder Download flow:
                // 1. Get filePath from the transfer
                // 2. Iterate over files

-               // 3. For each file:
-               //       Send file header to client
+               // 3. For each fileWrapper:
+               //       Send fileWrapper header to client

                // The client can reply in 3 ways:
                //
                // The client can reply in 3 ways:
                //

-               // 1. If type is an odd number (unknown type?), or file download for the current file is completed:
-               //              client sends []byte{0x00, 0x03} to tell the server to continue to the next file
+               // 1. If type is an odd number (unknown type?), or fileWrapper download for the current fileWrapper is completed:
+               //              client sends []byte{0x00, 0x03} to tell the server to continue to the next fileWrapper

                //
                //

-               // 2. If download of a file is to be resumed:
+               // 2. If download of a fileWrapper is to be resumed:

                //              client sends:
                //                      []byte{0x00, 0x02} // download folder action
                //                      [2]byte // Resume data size
                //              client sends:
                //                      []byte{0x00, 0x02} // download folder action
                //                      [2]byte // Resume data size

-               //                      []byte file resume data (see myField_FileResumeData)
+               //                      []byte fileWrapper resume data (see myField_FileResumeData)

                //
                //

-               // 3. Otherwise download of the file is requested and client sends []byte{0x00, 0x01}
+               // 3. Otherwise, download of the fileWrapper is requested and client sends []byte{0x00, 0x01}

                //
                // When download is requested (case 2 or 3), server replies with:
                //
                // When download is requested (case 2 or 3), server replies with:

-               //                      [4]byte - file size
+               //                      [4]byte - fileWrapper size

                //                      []byte  - Flattened File Object
                //
                //                      []byte  - Flattened File Object
                //

-               // After every file download, client could request next file with:
+               // After every fileWrapper download, client could request next fileWrapper with:

                //                      []byte{0x00, 0x03}
                //
                // This notifies the server to send the next item header
 
                //                      []byte{0x00, 0x03}
                //
                // This notifies the server to send the next item header
 

-               fullFilePath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
-               if err != nil {
-                       return err
-               }
-
-               basePathLen := len(fullFilePath)
+               basePathLen := len(fullPath)

 
 

-               s.Logger.Infow("Start folder download", "path", fullFilePath, "ReferenceNumber", fileTransfer.ReferenceNumber)
+               rLogger.Infow("Start folder download", "path", fullPath)

 
                nextAction := make([]byte, 2)
 
                nextAction := make([]byte, 2)

-               if _, err := conn.Read(nextAction); err != nil {
+               if _, err := io.ReadFull(rwc, nextAction); err != nil {

                        return err
                }
 
                i := 0
                        return err
                }
 
                i := 0

-               err = filepath.Walk(fullFilePath+"/", func(path string, info os.FileInfo, err error) error {
+               err = filepath.Walk(fullPath+"/", func(path string, info os.FileInfo, err error) error {
+                       s.Stats.DownloadCounter += 1
+                       i += 1
+

                        if err != nil {
                                return err
                        }
                        if err != nil {
                                return err
                        }

-                       i += 1
+
+                       // skip dot files
+                       if strings.HasPrefix(info.Name(), ".") {
+                               return nil
+                       }
+
+                       hlFile, err := newFileWrapper(s.FS, path, 0)
+                       if err != nil {
+                               return err
+                       }
+

                        subPath := path[basePathLen+1:]
                        subPath := path[basePathLen+1:]

-                       s.Logger.Infow("Sending fileheader", "i", i, "path", path, "fullFilePath", fullFilePath, "subPath", subPath, "IsDir", info.IsDir())
+                       rLogger.Debugw("Sending fileheader", "i", i, "path", path, "fullFilePath", fullPath, "subPath", subPath, "IsDir", info.IsDir())

 
                        if i == 1 {
                                return nil
 
                        if i == 1 {
                                return nil


@@ -748,180 +993,277 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 
                        fileHeader := NewFileHeader(subPath, info.IsDir())
 
 
                        fileHeader := NewFileHeader(subPath, info.IsDir())
 

-                       // Send the file header to client
-                       if _, err := conn.Write(fileHeader.Payload()); err != nil {
+                       // Send the fileWrapper header to client
+                       if _, err := rwc.Write(fileHeader.Payload()); err != nil {

                                s.Logger.Errorf("error sending file header: %v", err)
                                return err
                        }
 
                        // Read the client's Next Action request
                                s.Logger.Errorf("error sending file header: %v", err)
                                return err
                        }
 
                        // Read the client's Next Action request

-                       if _, err := conn.Read(nextAction); err != nil {
+                       if _, err := io.ReadFull(rwc, nextAction); err != nil {

                                return err
                        }
                                return err
                        }

-                       if nextAction[1] == 3 {
+
+                       rLogger.Debugw("Client folder download action", "action", fmt.Sprintf("%X", nextAction[0:2]))
+
+                       var dataOffset int64
+
+                       switch nextAction[1] {
+                       case dlFldrActionResumeFile:
+                               // get size of resumeData
+                               resumeDataByteLen := make([]byte, 2)
+                               if _, err := io.ReadFull(rwc, resumeDataByteLen); err != nil {
+                                       return err
+                               }
+
+                               resumeDataLen := binary.BigEndian.Uint16(resumeDataByteLen)
+                               resumeDataBytes := make([]byte, resumeDataLen)
+                               if _, err := io.ReadFull(rwc, resumeDataBytes); err != nil {
+                                       return err
+                               }
+
+                               var frd FileResumeData
+                               if err := frd.UnmarshalBinary(resumeDataBytes); err != nil {
+                                       return err
+                               }
+                               dataOffset = int64(binary.BigEndian.Uint32(frd.ForkInfoList[0].DataSize[:]))
+                       case dlFldrActionNextFile:
+                               // client asked to skip this file

                                return nil
                        }
 
                                return nil
                        }
 

-                       s.Logger.Infow("Client folder download action", "action", fmt.Sprintf("%X", nextAction[0:2]))
-

                        if info.IsDir() {
                                return nil
                        }
 
                        if info.IsDir() {
                                return nil
                        }
 

-                       splitPath := strings.Split(path, "/")
-
-                       ffo, err := NewFlattenedFileObject(
-                               strings.Join(splitPath[:len(splitPath)-1], "/"),
-                               nil,
-                               []byte(info.Name()),
-                       )
-                       if err != nil {
-                               return err
-                       }
-                       s.Logger.Infow("File download started",
+                       rLogger.Infow("File download started",

                                "fileName", info.Name(),
                                "fileName", info.Name(),

-                               "transactionRef", fileTransfer.ReferenceNumber,
-                               "TransferSize", fmt.Sprintf("%x", ffo.TransferSize()),
+                               "TransferSize", fmt.Sprintf("%x", hlFile.ffo.TransferSize(dataOffset)),

                        )
 
                        // Send file size to client
                        )
 
                        // Send file size to client

-                       if _, err := conn.Write(ffo.TransferSize()); err != nil {
+                       if _, err := rwc.Write(hlFile.ffo.TransferSize(dataOffset)); err != nil {

                                s.Logger.Error(err)
                                return err
                        }
 
                        // Send ffo bytes to client
                                s.Logger.Error(err)
                                return err
                        }
 
                        // Send ffo bytes to client

-                       if _, err := conn.Write(ffo.BinaryMarshal()); err != nil {
+                       if _, err := rwc.Write(hlFile.ffo.BinaryMarshal()); err != nil {

                                s.Logger.Error(err)
                                return err
                        }
 
                                s.Logger.Error(err)
                                return err
                        }
 

-                       file, err := FS.Open(path)
+                       file, err := s.FS.Open(path)

                        if err != nil {
                                return err
                        }
 
                        if err != nil {
                                return err
                        }
 

-                       // Copy N bytes from file to connection
-                       _, err = io.CopyN(conn, file, int64(binary.BigEndian.Uint32(ffo.FlatFileDataForkHeader.DataSize[:])))
-                       if err != nil {
+                       // wr := bufio.NewWriterSize(rwc, 1460)
+                       if _, err = io.Copy(rwc, io.TeeReader(file, fileTransfer.bytesSentCounter)); err != nil {

                                return err
                        }
                                return err
                        }

-                       file.Close()

 
 

-                       // TODO: optionally send resource fork header and resource fork data
+                       if nextAction[1] != 2 && hlFile.ffo.FlatFileHeader.ForkCount[1] == 3 {
+                               err = binary.Write(rwc, binary.BigEndian, hlFile.rsrcForkHeader())
+                               if err != nil {
+                                       return err
+                               }

 
 

-                       // Read the client's Next Action request
-                       if _, err := conn.Read(nextAction); err != nil {
+                               rFile, err := hlFile.rsrcForkFile()
+                               if err != nil {
+                                       return err
+                               }
+
+                               if _, err = io.Copy(rwc, io.TeeReader(rFile, fileTransfer.bytesSentCounter)); err != nil {
+                                       return err
+                               }
+                       }
+
+                       // Read the client's Next Action request.  This is always 3, I think?
+                       if _, err := io.ReadFull(rwc, nextAction); err != nil {

                                return err
                        }
                                return err
                        }

-                       // TODO: switch behavior based on possible next action

 
 

-                       return err
+                       return nil

                })
 
                })
 

-       case FolderUpload:
-               dstPath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)

                if err != nil {
                        return err
                }
                if err != nil {
                        return err
                }

-               s.Logger.Infow(
+
+       case FolderUpload:
+               s.Stats.UploadCounter += 1
+               s.Stats.UploadsInProgress += 1
+               defer func() { s.Stats.UploadsInProgress -= 1 }()
+               rLogger.Infow(

                        "Folder upload started",
                        "Folder upload started",

-                       "transactionRef", fileTransfer.ReferenceNumber,
-                       "dstPath", dstPath,
-                       "TransferSize", fmt.Sprintf("%x", fileTransfer.TransferSize),
+                       "dstPath", fullPath,
+                       "TransferSize", binary.BigEndian.Uint32(fileTransfer.TransferSize),

                        "FolderItemCount", fileTransfer.FolderItemCount,
                )
 
                // Check if the target folder exists.  If not, create it.
                        "FolderItemCount", fileTransfer.FolderItemCount,
                )
 
                // Check if the target folder exists.  If not, create it.

-               if _, err := FS.Stat(dstPath); os.IsNotExist(err) {
-                       s.Logger.Infow("Creating target path", "dstPath", dstPath)
-                       if err := FS.Mkdir(dstPath, 0777); err != nil {
-                               s.Logger.Error(err)
+               if _, err := s.FS.Stat(fullPath); os.IsNotExist(err) {
+                       if err := s.FS.Mkdir(fullPath, 0777); err != nil {
+                               return err

                        }
                }
 
                // Begin the folder upload flow by sending the "next file action" to client
                        }
                }
 
                // Begin the folder upload flow by sending the "next file action" to client

-               if _, err := conn.Write([]byte{0, dlFldrActionNextFile}); err != nil {
+               if _, err := rwc.Write([]byte{0, dlFldrActionNextFile}); err != nil {

                        return err
                }
 
                fileSize := make([]byte, 4)
                        return err
                }
 
                fileSize := make([]byte, 4)

-               itemCount := binary.BigEndian.Uint16(fileTransfer.FolderItemCount)

 
 

-               readBuffer := make([]byte, 1024)
-               for i := uint16(0); i < itemCount; i++ {
-                       _, err := conn.Read(readBuffer)
-                       if err != nil {
+               for i := 0; i < fileTransfer.ItemCount(); i++ {
+                       s.Stats.UploadCounter += 1
+
+                       var fu folderUpload
+                       if _, err := io.ReadFull(rwc, fu.DataSize[:]); err != nil {
+                               return err
+                       }
+                       if _, err := io.ReadFull(rwc, fu.IsFolder[:]); err != nil {
+                               return err
+                       }
+                       if _, err := io.ReadFull(rwc, fu.PathItemCount[:]); err != nil {

                                return err
                        }
                                return err
                        }

-                       fu := readFolderUpload(readBuffer)

 
 

-                       s.Logger.Infow(
+                       fu.FileNamePath = make([]byte, binary.BigEndian.Uint16(fu.DataSize[:])-4) // -4 to subtract the path separator bytes
+
+                       if _, err := io.ReadFull(rwc, fu.FileNamePath); err != nil {
+                               return err
+                       }
+
+                       rLogger.Infow(

                                "Folder upload continued",
                                "Folder upload continued",

-                               "transactionRef", fmt.Sprintf("%x", fileTransfer.ReferenceNumber),

                                "FormattedPath", fu.FormattedPath(),
                                "IsFolder", fmt.Sprintf("%x", fu.IsFolder),
                                "PathItemCount", binary.BigEndian.Uint16(fu.PathItemCount[:]),
                        )
 
                        if fu.IsFolder == [2]byte{0, 1} {
                                "FormattedPath", fu.FormattedPath(),
                                "IsFolder", fmt.Sprintf("%x", fu.IsFolder),
                                "PathItemCount", binary.BigEndian.Uint16(fu.PathItemCount[:]),
                        )
 
                        if fu.IsFolder == [2]byte{0, 1} {

-                               if _, err := os.Stat(dstPath + "/" + fu.FormattedPath()); os.IsNotExist(err) {
-                                       s.Logger.Infow("Target path does not exist; Creating...", "dstPath", dstPath)
-                                       if err := os.Mkdir(dstPath+"/"+fu.FormattedPath(), 0777); err != nil {
-                                               s.Logger.Error(err)
+                               if _, err := os.Stat(filepath.Join(fullPath, fu.FormattedPath())); os.IsNotExist(err) {
+                                       if err := os.Mkdir(filepath.Join(fullPath, fu.FormattedPath()), 0777); err != nil {
+                                               return err

                                        }
                                }
 
                                // Tell client to send next file
                                        }
                                }
 
                                // Tell client to send next file

-                               if _, err := conn.Write([]byte{0, dlFldrActionNextFile}); err != nil {
-                                       s.Logger.Error(err)
+                               if _, err := rwc.Write([]byte{0, dlFldrActionNextFile}); err != nil {

                                        return err
                                }
                        } else {
                                        return err
                                }
                        } else {

-                               // TODO: Check if we have the full file already.  If so, send dlFldrAction_NextFile to client to skip.
-                               // TODO: Check if we have a partial file already.  If so, send dlFldrAction_ResumeFile to client to resume upload.
-                               // Send dlFldrAction_SendFile to client to begin transfer
-                               if _, err := conn.Write([]byte{0, dlFldrActionSendFile}); err != nil {
+                               nextAction := dlFldrActionSendFile
+
+                               // Check if we have the full file already.  If so, send dlFldrAction_NextFile to client to skip.
+                               _, err = os.Stat(filepath.Join(fullPath, fu.FormattedPath()))
+                               if err != nil && !errors.Is(err, fs.ErrNotExist) {

                                        return err
                                }
                                        return err
                                }

+                               if err == nil {
+                                       nextAction = dlFldrActionNextFile
+                               }

 
 

-                               if _, err := conn.Read(fileSize); err != nil {
+                               //  Check if we have a partial file already.  If so, send dlFldrAction_ResumeFile to client to resume upload.
+                               incompleteFile, err := os.Stat(filepath.Join(fullPath, fu.FormattedPath()+incompleteFileSuffix))
+                               if err != nil && !errors.Is(err, fs.ErrNotExist) {

                                        return err
                                }
                                        return err
                                }

+                               if err == nil {
+                                       nextAction = dlFldrActionResumeFile
+                               }

 
 

-                               filePath := dstPath + "/" + fu.FormattedPath()
-                               s.Logger.Infow("Starting file transfer", "path", filePath, "fileNum", i+1, "totalFiles", itemCount, "fileSize", binary.BigEndian.Uint32(fileSize))
-
-                               newFile, err := FS.Create(filePath)
-                               if err != nil {
+                               if _, err := rwc.Write([]byte{0, uint8(nextAction)}); err != nil {

                                        return err
                                }
 
                                        return err
                                }
 

-                               if err := receiveFile(conn, newFile, ioutil.Discard); err != nil {
-                                       s.Logger.Error(err)
+                               switch nextAction {
+                               case dlFldrActionNextFile:
+                                       continue
+                               case dlFldrActionResumeFile:
+                                       offset := make([]byte, 4)
+                                       binary.BigEndian.PutUint32(offset, uint32(incompleteFile.Size()))
+
+                                       file, err := os.OpenFile(fullPath+"/"+fu.FormattedPath()+incompleteFileSuffix, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+                                       if err != nil {
+                                               return err
+                                       }
+
+                                       fileResumeData := NewFileResumeData([]ForkInfoList{*NewForkInfoList(offset)})
+
+                                       b, _ := fileResumeData.BinaryMarshal()
+
+                                       bs := make([]byte, 2)
+                                       binary.BigEndian.PutUint16(bs, uint16(len(b)))
+
+                                       if _, err := rwc.Write(append(bs, b...)); err != nil {
+                                               return err
+                                       }
+
+                                       if _, err := io.ReadFull(rwc, fileSize); err != nil {
+                                               return err
+                                       }
+
+                                       if err := receiveFile(rwc, file, io.Discard, io.Discard, fileTransfer.bytesSentCounter); err != nil {
+                                               s.Logger.Error(err)
+                                       }
+
+                                       err = os.Rename(fullPath+"/"+fu.FormattedPath()+".incomplete", fullPath+"/"+fu.FormattedPath())
+                                       if err != nil {
+                                               return err
+                                       }
+
+                               case dlFldrActionSendFile:
+                                       if _, err := io.ReadFull(rwc, fileSize); err != nil {
+                                               return err
+                                       }
+
+                                       filePath := filepath.Join(fullPath, fu.FormattedPath())
+
+                                       hlFile, err := newFileWrapper(s.FS, filePath, 0)
+                                       if err != nil {
+                                               return err
+                                       }
+
+                                       rLogger.Infow("Starting file transfer", "path", filePath, "fileNum", i+1, "fileSize", binary.BigEndian.Uint32(fileSize))
+
+                                       incWriter, err := hlFile.incFileWriter()
+                                       if err != nil {
+                                               return err
+                                       }
+
+                                       rForkWriter := io.Discard
+                                       iForkWriter := io.Discard
+                                       if s.Config.PreserveResourceForks {
+                                               iForkWriter, err = hlFile.infoForkWriter()
+                                               if err != nil {
+                                                       return err
+                                               }
+
+                                               rForkWriter, err = hlFile.rsrcForkWriter()
+                                               if err != nil {
+                                                       return err
+                                               }
+                                       }
+                                       if err := receiveFile(rwc, incWriter, rForkWriter, iForkWriter, fileTransfer.bytesSentCounter); err != nil {
+                                               return err
+                                       }
+
+                                       if err := os.Rename(filePath+".incomplete", filePath); err != nil {
+                                               return err
+                                       }

                                }
                                }

-                               _ = newFile.Close()

 
 

-                               // Tell client to send next file
-                               if _, err := conn.Write([]byte{0, dlFldrActionNextFile}); err != nil {
-                                       s.Logger.Error(err)
+                               // Tell client to send next fileWrapper
+                               if _, err := rwc.Write([]byte{0, dlFldrActionNextFile}); err != nil {

                                        return err
                                }
                                        return err
                                }

-

                        }
                }
                        }
                }

-               s.Logger.Infof("Folder upload complete")
+               rLogger.Infof("Folder upload complete")

        }
 
        return nil
 }
        }
 
        return nil
 }

-
-// sortedClients is a utility function that takes a map of *ClientConn and returns a sorted slice of the values.
-// The purpose of this is to ensure that the ordering of client connections is deterministic so that test assertions work.
-func sortedClients(unsortedClients map[uint16]*ClientConn) (clients []*ClientConn) {
-       for _, c := range unsortedClients {
-               clients = append(clients, c)
-       }
-       sort.Sort(byClientID(clients))
-       return clients
-}