Fix intermittently failing banner download

[rbdr/mobius] / hotline / server.go

diff --git a/hotline/server.go b/hotline/server.go
index 76cc248ba57088ebf950a449c4af9551d49361d2..21b1316d4f233b0e36ae11e6d12b928e9d0f0bc6 100644 (file)
--- a/hotline/server.go
+++ b/hotline/server.go
@@ -1,6 +1,7 @@
 package hotline
 
 import (
 package hotline
 
 import (

+       "bufio"

        "bytes"
        "context"
        "encoding/binary"
        "bytes"
        "context"
        "encoding/binary"


@@ -8,6 +9,7 @@ import (
        "fmt"
        "github.com/go-playground/validator/v10"
        "go.uber.org/zap"
        "fmt"
        "github.com/go-playground/validator/v10"
        "go.uber.org/zap"

+       "gopkg.in/yaml.v3"

        "io"
        "io/fs"
        "io/ioutil"
        "io"
        "io/fs"
        "io/ioutil"


@@ -15,17 +17,23 @@ import (
        "math/rand"
        "net"
        "os"
        "math/rand"
        "net"
        "os"

-       "path"

        "path/filepath"
        "runtime/debug"
        "path/filepath"
        "runtime/debug"

-       "sort"

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

-
-       "gopkg.in/yaml.v3"

 )
 
 )
 

+type contextKey string
+
+var contextKeyReq = contextKey("req")
+
+type requestCtx struct {
+       remoteAddr string
+       login      string
+       name       string
+}
+

 const (
        userIdleSeconds        = 300 // time in seconds before an inactive user is marked idle
        idleCheckInterval      = 10  // time in seconds to check for idle users
 const (
        userIdleSeconds        = 300 // time in seconds before an inactive user is marked idle
        idleCheckInterval      = 10  // time in seconds to check for idle users


@@ -39,7 +47,6 @@ type Server struct {
        Accounts      map[string]*Account
        Agreement     []byte
        Clients       map[uint16]*ClientConn
        Accounts      map[string]*Account
        Agreement     []byte
        Clients       map[uint16]*ClientConn

-       FlatNews      []byte

        ThreadedNews  *ThreadedNews
        FileTransfers map[uint32]*FileTransfer
        Config        *Config
        ThreadedNews  *ThreadedNews
        FileTransfers map[uint32]*FileTransfer
        Config        *Config


@@ -50,15 +57,13 @@ type Server struct {
        TrackerPassID [4]byte
        Stats         *Stats
 
        TrackerPassID [4]byte
        Stats         *Stats
 

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

 
        outbox chan Transaction
 
        outbox chan Transaction

+       mux    sync.Mutex

 
 

-       mux         sync.Mutex

        flatNewsMux sync.Mutex
        flatNewsMux sync.Mutex

+       FlatNews    []byte

 }
 
 type PrivateChat struct {
 }
 
 type PrivateChat struct {


@@ -82,7 +87,7 @@ func (s *Server) ListenAndServe(ctx context.Context, cancelRoot context.CancelFu
                        s.Logger.Fatal(err)
                }
 
                        s.Logger.Fatal(err)
                }
 

-               s.Logger.Fatal(s.Serve(ctx, cancelRoot, ln))
+               s.Logger.Fatal(s.Serve(ctx, ln))

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


@@ -93,7 +98,7 @@ func (s *Server) ListenAndServe(ctx context.Context, cancelRoot context.CancelFu
 
                }
 
 
                }
 

-               s.Logger.Fatal(s.ServeFileTransfers(ln))
+               s.Logger.Fatal(s.ServeFileTransfers(ctx, ln))

        }()
 
        wg.Wait()
        }()
 
        wg.Wait()


@@ -101,7 +106,7 @@ func (s *Server) ListenAndServe(ctx context.Context, cancelRoot context.CancelFu
        return nil
 }
 
        return nil
 }
 

-func (s *Server) ServeFileTransfers(ln net.Listener) error {
+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 {


@@ -109,7 +114,16 @@ 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)
                        }
                }()


@@ -153,26 +167,32 @@ func (s *Server) sendTransaction(t Transaction) error {
        return nil
 }
 
        return nil
 }
 

-func (s *Server) Serve(ctx context.Context, cancelRoot context.CancelFunc, ln net.Listener) error {
+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, conn.RemoteAddr().String()); err != nil {
+                       if err := s.handleNewConnection(connCtx, conn, conn.RemoteAddr().String()); err != nil {
+                               s.Logger.Infow("New client connection established", "RemoteAddr", conn.RemoteAddr())

                                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 {


@@ -188,7 +208,7 @@ 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, FS FileStore) (*Server, error) {
+func NewServer(configDir string, netPort int, logger *zap.SugaredLogger, FS FileStore) (*Server, error) {

        server := Server{
                Port:          netPort,
                Accounts:      make(map[string]*Account),
        server := Server{
                Port:          netPort,
                Accounts:      make(map[string]*Account),


@@ -212,28 +232,28 @@ func NewServer(configDir, netInterface string, netPort int, logger *zap.SugaredL
                return nil, err
        }
 
                return nil, err
        }
 

-       server.Agreement, err = os.ReadFile(configDir + agreementFile)
+       server.Agreement, err = os.ReadFile(filepath.Join(configDir, agreementFile))

        if err != nil {
                return nil, err
        }
 
        if err != nil {
                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 {
+       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
 
 
        *server.NextGuestID = 1
 


@@ -314,14 +334,14 @@ func (s *Server) writeThreadedNews() error {
                return err
        }
        err = ioutil.WriteFile(
                return err
        }
        err = ioutil.WriteFile(

-               s.ConfigDir+"ThreadedNews.yaml",
+               filepath.Join(s.ConfigDir, "ThreadedNews.yaml"),

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

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

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


@@ -364,7 +384,7 @@ func (s *Server) NewUser(login, name, password string, access []byte) error {
        }
        s.Accounts[login] = &account
 
        }
        s.Accounts[login] = &account
 

-       return s.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 []byte) error {
 }
 
 func (s *Server) UpdateUser(login, newLogin, name, password string, access []byte) error {


@@ -373,7 +393,7 @@ func (s *Server) UpdateUser(login, newLogin, name, password string, access []byt
 
        // update renames the user login
        if login != newLogin {
 
        // update renames the user login
        if login != newLogin {

-               err := os.Rename(s.ConfigDir+"Users/"+login+".yaml", s.ConfigDir+"Users/"+newLogin+".yaml")
+               err := os.Rename(filepath.Join(s.ConfigDir, "Users", login+".yaml"), filepath.Join(s.ConfigDir, "Users", newLogin+".yaml"))

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


@@ -390,7 +410,8 @@ func (s *Server) UpdateUser(login, newLogin, name, password string, access []byt
        if err != nil {
                return err
        }
        if err != nil {
                return err
        }

-       if err := os.WriteFile(s.ConfigDir+"Users/"+newLogin+".yaml", out, 0666); err != nil {
+
+       if err := os.WriteFile(filepath.Join(s.ConfigDir, "Users", newLogin+".yaml"), out, 0666); err != nil {

                return err
        }
 
                return err
        }
 


@@ -404,7 +425,7 @@ func (s *Server) DeleteUser(login string) error {
 
        delete(s.Accounts, login)
 
 
        delete(s.Accounts, login)
 

-       return s.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 {


@@ -440,7 +461,7 @@ 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
        }


@@ -500,7 +521,7 @@ func dontPanic(logger *zap.SugaredLogger) {
 }
 
 // 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, remoteAddr string) error {
+func (s *Server) handleNewConnection(ctx context.Context, conn io.ReadWriteCloser, remoteAddr string) error {

        defer dontPanic(s.Logger)
 
        if err := Handshake(conn); err != nil {
        defer dontPanic(s.Logger)
 
        if err := Handshake(conn); err != nil {


@@ -564,11 +585,13 @@ func (s *Server) handleNewConnection(conn net.Conn, remoteAddr string) error {
                *c.Flags = []byte{0, 2}
        }
 
                *c.Flags = []byte{0, 2}
        }
 

-       s.Logger.Infow("Client connection received", "login", login, "version", *c.Version, "RemoteAddr", remoteAddr)
+       c.logger = s.Logger.With("remoteAddr", remoteAddr, "login", login)
+
+       c.logger.Infow("Client connection received", "version", fmt.Sprintf("%x", *c.Version))

 
        s.outbox <- c.NewReply(clientLogin,
                NewField(fieldVersion, []byte{0x00, 0xbe}),
 
        s.outbox <- c.NewReply(clientLogin,
                NewField(fieldVersion, []byte{0x00, 0xbe}),

-               NewField(fieldCommunityBannerID, []byte{0x00, 0x01}),
+               NewField(fieldCommunityBannerID, []byte{0, 0}),

                NewField(fieldServerName, []byte(s.Config.Name)),
        )
 
                NewField(fieldServerName, []byte(s.Config.Name)),
        )
 


@@ -581,8 +604,9 @@ func (s *Server) handleNewConnection(conn net.Conn, remoteAddr string) error {
        // Used simplified hotline v1.2.3 login flow for clients that do not send login info in tranAgreed
        if *c.Version == nil || bytes.Equal(*c.Version, nostalgiaVersion) {
                c.Agreed = true
        // Used simplified hotline v1.2.3 login flow for clients that do not send login info in tranAgreed
        if *c.Version == nil || bytes.Equal(*c.Version, nostalgiaVersion) {
                c.Agreed = true

+               c.logger = c.logger.With("name", string(c.UserName))

 
 

-               c.notifyOthers(
+               for _, t := range c.notifyOthers(

                        *NewTransaction(
                                tranNotifyChangeUser, nil,
                                NewField(fieldUserName, c.UserName),
                        *NewTransaction(
                                tranNotifyChangeUser, nil,
                                NewField(fieldUserName, c.UserName),


@@ -590,7 +614,9 @@ func (s *Server) handleNewConnection(conn net.Conn, remoteAddr string) error {
                                NewField(fieldUserIconID, *c.Icon),
                                NewField(fieldUserFlags, *c.Flags),
                        ),
                                NewField(fieldUserIconID, *c.Icon),
                                NewField(fieldUserFlags, *c.Flags),
                        ),

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

        }
 
        c.Server.Stats.LoginCount += 1
        }
 
        c.Server.Stats.LoginCount += 1


@@ -613,20 +639,20 @@ func (s *Server) handleNewConnection(conn net.Conn, remoteAddr string) error {
                // into a slice of transactions
                var transactions []Transaction
                if transactions, tReadlen, err = readTransactions(tranBuff); err != nil {
                // 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)
+                       c.logger.Errorw("Error handling transaction", "err", err)

                }
 
                }
 

-               // iterate over all of the transactions that were parsed from the byte slice and handle them
+               // iterate over all the transactions that were parsed from the byte slice and handle them

                for _, t := range transactions {
                        if err := c.handleTransaction(&t); err != nil {
                for _, t := range transactions {
                        if err := c.handleTransaction(&t); err != nil {

-                               c.Server.Logger.Errorw("Error handling transaction", "err", err)
+                               c.logger.Errorw("Error handling transaction", "err", err)

                        }
                }
        }
 }
 
 // NewTransactionRef generates a random ID for the file transfer.  The Hotline client includes this ID
                        }
                }
        }
 }
 
 // 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
+// in the 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)
 // to a transfer
 func (s *Server) NewTransactionRef() []byte {
        transactionRef := make([]byte, 4)


@@ -657,18 +683,11 @@ 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)
        defer dontPanic(s.Logger)
 
        txBuf := make([]byte, 16)

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

                return err
        }
 
                return err
        }
 


@@ -691,7 +710,16 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                return errors.New("invalid transaction ID")
        }
 
                return errors.New("invalid transaction ID")
        }
 

+       rLogger := s.Logger.With(
+               "remoteAddr", ctx.Value(contextKeyReq).(requestCtx).remoteAddr,
+               "xferID", transferRefNum,
+       )
+

        switch fileTransfer.Type {
        switch fileTransfer.Type {

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

        case FileDownload:
                s.Stats.DownloadCounter += 1
 
        case FileDownload:
                s.Stats.DownloadCounter += 1
 


@@ -705,50 +733,68 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                        dataOffset = int64(binary.BigEndian.Uint32(fileTransfer.fileResumeData.ForkInfoList[0].DataSize[:]))
                }
 
                        dataOffset = int64(binary.BigEndian.Uint32(fileTransfer.fileResumeData.ForkInfoList[0].DataSize[:]))
                }
 

-               ffo, err := NewFlattenedFileObject(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName, dataOffset)
+               fw, err := newFileWrapper(s.FS, fullFilePath, 0)

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

-               s.Logger.Infow("File download started", "filePath", fullFilePath, "transactionRef", fileTransfer.ReferenceNumber)
+               rLogger.Infow("File download started", "filePath", fullFilePath, "transactionRef", fileTransfer.ReferenceNumber)
+
+               wr := bufio.NewWriterSize(rwc, 1460)

 
 

+               // 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 fileTransfer.options == nil {
                        // Start by sending flat file object to client

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

                                return err
                        }
                }
 
                                return err
                        }
                }
 

-               file, err := s.FS.Open(fullFilePath)
+               file, err := fw.dataForkReader()

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

-               sendBuffer := make([]byte, 1048576)
-               var totalSent int64
-               for {
-                       var bytesRead int
-                       if bytesRead, err = file.ReadAt(sendBuffer, dataOffset+totalSent); err == io.EOF {
-                               if _, err := conn.Write(sendBuffer[:bytesRead]); err != nil {
-                                       return err
-                               }
-                               break
-                       }
+               if err := sendFile(wr, file, int(dataOffset)); err != nil {
+                       return err
+               }
+
+               if err := wr.Flush(); err != nil {
+                       return err
+               }
+
+               // if the client requested to resume transfer, do not send the resource fork, or it will be appended into the fileWrapper data
+               if fileTransfer.fileResumeData == nil {
+                       err = binary.Write(wr, binary.BigEndian, fw.rsrcForkHeader())

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

-                       totalSent += int64(bytesRead)
-
-                       fileTransfer.BytesSent += bytesRead
-
-                       if _, err := conn.Write(sendBuffer[:bytesRead]); err != nil {
+                       if err := wr.Flush(); err != nil {

                                return err
                        }
                }
                                return err
                        }
                }

+
+               rFile, err := fw.rsrcForkFile()
+               if err != nil {
+                       return nil
+               }
+
+               err = sendFile(wr, rFile, int(dataOffset))
+               if err != nil {
+                       return err
+               }
+
+               if err := wr.Flush(); err != nil {
+                       return err
+               }
+

        case FileUpload:
                s.Stats.UploadCounter += 1
 
        case FileUpload:
                s.Stats.UploadCounter += 1
 

-               destinationFile := s.Config.FileRoot + ReadFilePath(fileTransfer.FilePath) + "/" + string(fileTransfer.FileName)
+               destinationFile, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
+               if err != nil {
+                       return err
+               }

 
                var file *os.File
 
 
                var file *os.File
 


@@ -756,10 +802,10 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                // 1) Upload a new file
                // 2) Resume a partially transferred file
                // 3) Replace a fully uploaded file
                // 1) Upload a new file
                // 2) Resume a partially transferred file
                // 3) Replace a fully uploaded file

-               // Unfortunately we have to infer which case applies by inspecting what is already on the file system
+               //  We have to infer which case applies by inspecting what is already on the filesystem

 
                // 1) Check for existing file:
 
                // 1) Check for existing file:

-               _, err := os.Stat(destinationFile)
+               _, err = os.Stat(destinationFile)

                if err == nil {
                        // If found, that means this upload is intended to replace the file
                        if err = os.Remove(destinationFile); err != nil {
                if err == nil {
                        // If found, that means this upload is intended to replace the file
                        if err = os.Remove(destinationFile); err != nil {


@@ -768,23 +814,43 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                        file, err = os.Create(destinationFile + incompleteFileSuffix)
                }
                if errors.Is(err, fs.ErrNotExist) {
                        file, err = os.Create(destinationFile + incompleteFileSuffix)
                }
                if errors.Is(err, fs.ErrNotExist) {

-                       // If not found, open or create a new incomplete file
+                       // If not found, open or create a new .incomplete file

                        file, err = os.OpenFile(destinationFile+incompleteFileSuffix, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
                        if err != nil {
                                return err
                        }
                }
 
                        file, err = os.OpenFile(destinationFile+incompleteFileSuffix, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0644)
                        if err != nil {
                                return err
                        }
                }
 

-               defer func() { _ = file.Close() }()
+               f, err := newFileWrapper(s.FS, destinationFile, 0)
+               if err != nil {
+                       return err
+               }

 
                s.Logger.Infow("File upload started", "transactionRef", fileTransfer.ReferenceNumber, "dstFile", destinationFile)
 
 
                s.Logger.Infow("File upload started", "transactionRef", fileTransfer.ReferenceNumber, "dstFile", destinationFile)
 

-               // TODO: replace io.Discard with a real file when ready to implement storing of resource fork data
-               if err := receiveFile(conn, file, io.Discard); err != nil {
+               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); err != nil {

                        return err
                }
 
                        return err
                }
 

-               if err := os.Rename(destinationFile+".incomplete", destinationFile); err != nil {
+               if err := file.Close(); err != nil {
+                       return err
+               }
+
+               if err := s.FS.Rename(destinationFile+".incomplete", destinationFile); err != nil {

                        return err
                }
 
                        return err
                }
 


@@ -793,26 +859,26 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                // 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


@@ -827,18 +893,29 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                s.Logger.Infow("Start folder download", "path", fullFilePath, "ReferenceNumber", fileTransfer.ReferenceNumber)
 
                nextAction := make([]byte, 2)
                s.Logger.Infow("Start folder download", "path", fullFilePath, "ReferenceNumber", fileTransfer.ReferenceNumber)
 
                nextAction := make([]byte, 2)

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

                        return err
                }
 
                i := 0
                err = filepath.Walk(fullFilePath+"/", func(path string, info os.FileInfo, err error) error {
                        s.Stats.DownloadCounter += 1
                        return err
                }
 
                i := 0
                err = filepath.Walk(fullFilePath+"/", 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:]
                        s.Logger.Infow("Sending fileheader", "i", i, "path", path, "fullFilePath", fullFilePath, "subPath", subPath, "IsDir", info.IsDir())
 
                        subPath := path[basePathLen+1:]
                        s.Logger.Infow("Sending fileheader", "i", i, "path", path, "fullFilePath", fullFilePath, "subPath", subPath, "IsDir", info.IsDir())
 


@@ -848,14 +925,14 @@ 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 := io.ReadFull(conn, nextAction); err != nil {
+                       if _, err := io.ReadFull(rwc, nextAction); err != nil {

                                return err
                        }
 
                                return err
                        }
 


@@ -865,19 +942,19 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 
                        switch nextAction[1] {
                        case dlFldrActionResumeFile:
 
                        switch nextAction[1] {
                        case dlFldrActionResumeFile:

-                               // client asked to resume this file
-                               var frd FileResumeData

                                // get size of resumeData
                                // get size of resumeData

-                               if _, err := io.ReadFull(conn, nextAction); err != nil {
+                               resumeDataByteLen := make([]byte, 2)
+                               if _, err := io.ReadFull(rwc, resumeDataByteLen); err != nil {

                                        return err
                                }
 
                                        return err
                                }
 

-                               resumeDataLen := binary.BigEndian.Uint16(nextAction)
+                               resumeDataLen := binary.BigEndian.Uint16(resumeDataByteLen)

                                resumeDataBytes := make([]byte, resumeDataLen)
                                resumeDataBytes := make([]byte, resumeDataLen)

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

                                        return err
                                }
 
                                        return err
                                }
 

+                               var frd FileResumeData

                                if err := frd.UnmarshalBinary(resumeDataBytes); err != nil {
                                        return err
                                }
                                if err := frd.UnmarshalBinary(resumeDataBytes); err != nil {
                                        return err
                                }


@@ -891,26 +968,20 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                                return nil
                        }
 
                                return nil
                        }
 

-                       splitPath := strings.Split(path, "/")
-
-                       ffo, err := NewFlattenedFileObject(strings.Join(splitPath[:len(splitPath)-1], "/"), nil, []byte(info.Name()), dataOffset)
-                       if err != nil {
-                               return err
-                       }

                        s.Logger.Infow("File download started",
                                "fileName", info.Name(),
                                "transactionRef", fileTransfer.ReferenceNumber,
                        s.Logger.Infow("File download started",
                                "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
                        }


@@ -920,49 +991,47 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                                return err
                        }
 
                                return err
                        }
 

-                       // // Copy N bytes from file to connection
-                       // _, err = io.CopyN(conn, file, int64(binary.BigEndian.Uint32(ffo.FlatFileDataForkHeader.DataSize[:])))
-                       // if err != nil {
-                       //      return err
-                       // }
-                       // file.Close()
-                       sendBuffer := make([]byte, 1048576)
-                       var totalSent int64
-                       for {
-                               var bytesRead int
-                               if bytesRead, err = file.ReadAt(sendBuffer, dataOffset+totalSent); err == io.EOF {
-                                       if _, err := conn.Write(sendBuffer[:bytesRead]); err != nil {
-                                               return err
-                                       }
-                                       break
-                               }
+                       // wr := bufio.NewWriterSize(rwc, 1460)
+                       err = sendFile(rwc, file, int(dataOffset))
+                       if err != nil {
+                               return err
+                       }
+
+                       if nextAction[1] != 2 && hlFile.ffo.FlatFileHeader.ForkCount[1] == 3 {
+                               err = binary.Write(rwc, binary.BigEndian, hlFile.rsrcForkHeader())

                                if err != nil {
                                if err != nil {

-                                       panic(err)
+                                       return err

                                }
                                }

-                               totalSent += int64(bytesRead)

 
 

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

 
 

-                               if _, err := conn.Write(sendBuffer[:bytesRead]); err != nil {
+                               err = sendFile(rwc, rFile, int(dataOffset))
+                               if err != nil {

                                        return err
                                }
                        }
 
                                        return err
                                }
                        }
 

-                       // TODO: optionally send resource fork header and resource fork data
-

                        // Read the client's Next Action request.  This is always 3, I think?
                        // Read the client's Next Action request.  This is always 3, I think?

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

                                return err
                        }
 
                        return nil
                })
 
                                return err
                        }
 
                        return nil
                })
 

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

        case FolderUpload:
                dstPath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
                if err != nil {
                        return err
                }
        case FolderUpload:
                dstPath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
                if err != nil {
                        return err
                }

+

                s.Logger.Infow(
                        "Folder upload started",
                        "transactionRef", fileTransfer.ReferenceNumber,
                s.Logger.Infow(
                        "Folder upload started",
                        "transactionRef", fileTransfer.ReferenceNumber,


@@ -979,7 +1048,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                }
 
                // 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
                }
 
                        return err
                }
 


@@ -989,19 +1058,19 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                        s.Stats.UploadCounter += 1
 
                        var fu folderUpload
                        s.Stats.UploadCounter += 1
 
                        var fu folderUpload

-                       if _, err := io.ReadFull(conn, fu.DataSize[:]); err != nil {
+                       if _, err := io.ReadFull(rwc, fu.DataSize[:]); err != nil {

                                return err
                        }
                                return err
                        }

-
-                       if _, err := io.ReadFull(conn, fu.IsFolder[:]); err != nil {
+                       if _, err := io.ReadFull(rwc, fu.IsFolder[:]); err != nil {

                                return err
                        }
                                return err
                        }

-                       if _, err := io.ReadFull(conn, fu.PathItemCount[:]); err != nil {
+                       if _, err := io.ReadFull(rwc, fu.PathItemCount[:]); err != nil {

                                return err
                        }
                                return err
                        }

-                       fu.FileNamePath = make([]byte, binary.BigEndian.Uint16(fu.DataSize[:])-4)

 
 

-                       if _, err := io.ReadFull(conn, fu.FileNamePath); err != nil {
+                       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
                        }
 
                                return err
                        }
 


@@ -1014,21 +1083,21 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                        )
 
                        if fu.IsFolder == [2]byte{0, 1} {
                        )
 
                        if fu.IsFolder == [2]byte{0, 1} {

-                               if _, err := os.Stat(dstPath + "/" + fu.FormattedPath()); os.IsNotExist(err) {
-                                       if err := os.Mkdir(dstPath+"/"+fu.FormattedPath(), 0777); err != nil {
+                               if _, err := os.Stat(filepath.Join(dstPath, fu.FormattedPath())); os.IsNotExist(err) {
+                                       if err := os.Mkdir(filepath.Join(dstPath, fu.FormattedPath()), 0777); err != nil {

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

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

                                        return err
                                }
                        } else {
                                nextAction := dlFldrActionSendFile
 
                                // Check if we have the full file already.  If so, send dlFldrAction_NextFile to client to skip.
                                        return err
                                }
                        } else {
                                nextAction := dlFldrActionSendFile
 
                                // Check if we have the full file already.  If so, send dlFldrAction_NextFile to client to skip.

-                               _, err := os.Stat(dstPath + "/" + fu.FormattedPath())
+                               _, err = os.Stat(filepath.Join(dstPath, fu.FormattedPath()))

                                if err != nil && !errors.Is(err, fs.ErrNotExist) {
                                        return err
                                }
                                if err != nil && !errors.Is(err, fs.ErrNotExist) {
                                        return err
                                }


@@ -1037,7 +1106,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                                }
 
                                //  Check if we have a partial file already.  If so, send dlFldrAction_ResumeFile to client to resume upload.
                                }
 
                                //  Check if we have a partial file already.  If so, send dlFldrAction_ResumeFile to client to resume upload.

-                               inccompleteFile, err := os.Stat(dstPath + "/" + fu.FormattedPath() + incompleteFileSuffix)
+                               incompleteFile, err := os.Stat(filepath.Join(dstPath, fu.FormattedPath()+incompleteFileSuffix))

                                if err != nil && !errors.Is(err, fs.ErrNotExist) {
                                        return err
                                }
                                if err != nil && !errors.Is(err, fs.ErrNotExist) {
                                        return err
                                }


@@ -1045,7 +1114,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                                        nextAction = dlFldrActionResumeFile
                                }
 
                                        nextAction = dlFldrActionResumeFile
                                }
 

-                               if _, err := conn.Write([]byte{0, uint8(nextAction)}); err != nil {
+                               if _, err := rwc.Write([]byte{0, uint8(nextAction)}); err != nil {

                                        return err
                                }
 
                                        return err
                                }
 


@@ -1054,31 +1123,29 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                                        continue
                                case dlFldrActionResumeFile:
                                        offset := make([]byte, 4)
                                        continue
                                case dlFldrActionResumeFile:
                                        offset := make([]byte, 4)

-                                       binary.BigEndian.PutUint32(offset, uint32(inccompleteFile.Size()))
+                                       binary.BigEndian.PutUint32(offset, uint32(incompleteFile.Size()))

 
                                        file, err := os.OpenFile(dstPath+"/"+fu.FormattedPath()+incompleteFileSuffix, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
                                        if err != nil {
                                                return err
                                        }
 
 
                                        file, err := os.OpenFile(dstPath+"/"+fu.FormattedPath()+incompleteFileSuffix, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
                                        if err != nil {
                                                return err
                                        }
 

-                                       fileResumeData := NewFileResumeData([]ForkInfoList{
-                                               *NewForkInfoList(offset),
-                                       })
+                                       fileResumeData := NewFileResumeData([]ForkInfoList{*NewForkInfoList(offset)})

 
                                        b, _ := fileResumeData.BinaryMarshal()
 
                                        bs := make([]byte, 2)
                                        binary.BigEndian.PutUint16(bs, uint16(len(b)))
 
 
                                        b, _ := fileResumeData.BinaryMarshal()
 
                                        bs := make([]byte, 2)
                                        binary.BigEndian.PutUint16(bs, uint16(len(b)))
 

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

                                                return err
                                        }
 
                                                return err
                                        }
 

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

                                                return err
                                        }
 
                                                return err
                                        }
 

-                                       if err := receiveFile(conn, file, ioutil.Discard); err != nil {
+                                       if err := receiveFile(rwc, file, ioutil.Discard, ioutil.Discard); err != nil {

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


@@ -1088,29 +1155,48 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                                        }
 
                                case dlFldrActionSendFile:
                                        }
 
                                case dlFldrActionSendFile:

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

                                                return err
                                        }
 
                                                return err
                                        }
 

-                                       filePath := dstPath + "/" + fu.FormattedPath()
-                                       s.Logger.Infow("Starting file transfer", "path", filePath, "fileNum", i+1, "totalFiles", "zz", "fileSize", binary.BigEndian.Uint32(fileSize))
+                                       filePath := filepath.Join(dstPath, fu.FormattedPath())

 
 

-                                       newFile, err := s.FS.Create(filePath + ".incomplete")
+                                       hlFile, err := newFileWrapper(s.FS, filePath, 0)

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

-                                       if err := receiveFile(conn, newFile, ioutil.Discard); err != nil {
-                                               s.Logger.Error(err)
+                                       s.Logger.Infow("Starting file transfer", "path", filePath, "fileNum", i+1, "fileSize", binary.BigEndian.Uint32(fileSize))
+
+                                       incWriter, err := hlFile.incFileWriter()
+                                       if err != nil {
+                                               return err

                                        }
                                        }

-                                       _ = newFile.Close()
+
+                                       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); err != nil {
+                                               return err
+                                       }
+                                       // _ = newFile.Close()

                                        if err := os.Rename(filePath+".incomplete", filePath); err != nil {
                                                return err
                                        }
                                }
 
                                        if err := os.Rename(filePath+".incomplete", filePath); err != nil {
                                                return err
                                        }
                                }
 

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

                                        return err
                                }
                        }
                                        return err
                                }
                        }


@@ -1120,13 +1206,3 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 
        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
-}