Fix and refactor file transfers to handle resource forks

[rbdr/mobius] / hotline / server.go

diff --git a/hotline/server.go b/hotline/server.go
index 0203dc9e67d4b02230ba58fb9739010d83fffaba..90b7ea019db4bc575b62253634a0e70fc19c6f90 100644 (file)
--- a/hotline/server.go
+++ b/hotline/server.go
@@ -1,7 +1,6 @@
 package hotline
 
 import (
 package hotline
 
 import (

-       "bytes"

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


@@ -9,7 +8,6 @@ import (
        "go.uber.org/zap"
        "io"
        "io/ioutil"
        "go.uber.org/zap"
        "io"
        "io/ioutil"

-       "log"

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


@@ -22,7 +20,6 @@ import (
        "sync"
        "time"
 
        "sync"
        "time"
 

-       "golang.org/x/crypto/bcrypt"

        "gopkg.in/yaml.v2"
 )
 
        "gopkg.in/yaml.v2"
 )
 


@@ -33,7 +30,6 @@ const (
 )
 
 type Server struct {
 )
 
 type Server struct {

-       Interface     string

        Port          int
        Accounts      map[string]*Account
        Agreement     []byte
        Port          int
        Accounts      map[string]*Account
        Agreement     []byte


@@ -52,8 +48,8 @@ type Server struct {
        APIListener  net.Listener
        FileListener net.Listener
 
        APIListener  net.Listener
        FileListener net.Listener
 

-       newsReader io.Reader
-       newsWriter io.WriteCloser
+       // newsReader io.Reader
+       // newsWriter io.WriteCloser

 
        outbox chan Transaction
 
 
        outbox chan Transaction
 


@@ -95,7 +91,7 @@ func (s *Server) ServeFileTransfers(ln net.Listener) error {
                }
 
                go func() {
                }
 
                go func() {

-                       if err := s.TransferFile(conn); err != nil {
+                       if err := s.handleFileTransfer(conn); err != nil {

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


@@ -113,15 +109,19 @@ func (s *Server) sendTransaction(t Transaction) error {
        client := s.Clients[uint16(clientID)]
        s.mux.Unlock()
        if client == nil {
        client := s.Clients[uint16(clientID)]
        s.mux.Unlock()
        if client == nil {

-               return errors.New("invalid client")
+               return fmt.Errorf("invalid client id %v", *t.clientID)

        }
        }

-       userName := string(*client.UserName)
+       userName := string(client.UserName)

        login := client.Account.Login
 
        handler := TransactionHandlers[requestNum]
 
        login := client.Account.Login
 
        handler := TransactionHandlers[requestNum]
 

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

        var n int
        var n int

-       if n, err = client.Connection.Write(t.Payload()); err != nil {
+       if n, err = client.Connection.Write(b); err != nil {

                return err
        }
        s.Logger.Debugw("Sent Transaction",
                return err
        }
        s.Logger.Debugw("Sent Transaction",


@@ -167,9 +167,7 @@ func (s *Server) Serve(ctx context.Context, cancelRoot context.CancelFunc, ln ne
 }
 
 const (
 }
 
 const (

-       agreementFile    = "Agreement.txt"
-       messageBoardFile = "MessageBoard.txt"
-       threadedNewsFile = "ThreadedNews.yaml"
+       agreementFile = "Agreement.txt"

 )
 
 // NewServer constructs a new Server from a config dir
 )
 
 // NewServer constructs a new Server from a config dir


@@ -278,8 +276,8 @@ func (s *Server) keepaliveHandler() {
                s.mux.Lock()
 
                for _, c := range s.Clients {
                s.mux.Lock()
 
                for _, c := range s.Clients {

-                       *c.IdleTime += idleCheckInterval
-                       if *c.IdleTime > userIdleSeconds && !c.Idle {
+                       c.IdleTime += idleCheckInterval
+                       if c.IdleTime > userIdleSeconds && !c.Idle {

                                c.Idle = true
 
                                flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*c.Flags)))
                                c.Idle = true
 
                                flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*c.Flags)))


@@ -290,7 +288,7 @@ func (s *Server) keepaliveHandler() {
                                        tranNotifyChangeUser,
                                        NewField(fieldUserID, *c.ID),
                                        NewField(fieldUserFlags, *c.Flags),
                                        tranNotifyChangeUser,
                                        NewField(fieldUserID, *c.ID),
                                        NewField(fieldUserFlags, *c.Flags),

-                                       NewField(fieldUserName, *c.UserName),
+                                       NewField(fieldUserName, c.UserName),

                                        NewField(fieldUserIconID, *c.Icon),
                                )
                        }
                                        NewField(fieldUserIconID, *c.Icon),
                                )
                        }


@@ -323,19 +321,17 @@ func (s *Server) NewClientConn(conn net.Conn) *ClientConn {
                ID:         &[]byte{0, 0},
                Icon:       &[]byte{0, 0},
                Flags:      &[]byte{0, 0},
                ID:         &[]byte{0, 0},
                Icon:       &[]byte{0, 0},
                Flags:      &[]byte{0, 0},

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

                Connection: conn,
                Server:     s,
                Version:    &[]byte{},
                Connection: conn,
                Server:     s,
                Version:    &[]byte{},

-               IdleTime:   new(int),
-               AutoReply:  &[]byte{},
+               AutoReply:  []byte{},

                Transfers:  make(map[int][]*FileTransfer),
                Transfers:  make(map[int][]*FileTransfer),

+               Agreed:     false,

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

-       *clientConn.IdleTime = 0
-

        binary.BigEndian.PutUint16(*clientConn.ID, ID)
        s.Clients[ID] = clientConn
 
        binary.BigEndian.PutUint16(*clientConn.ID, ID)
        s.Clients[ID] = clientConn
 


@@ -369,7 +365,7 @@ func (s *Server) DeleteUser(login string) error {
 
        delete(s.Accounts, login)
 
 
        delete(s.Accounts, login)
 

-       return os.Remove(s.ConfigDir + "Users/" + login + ".yaml")
+       return FS.Remove(s.ConfigDir + "Users/" + login + ".yaml")

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


@@ -377,12 +373,15 @@ func (s *Server) connectedUsers() []Field {
        defer s.mux.Unlock()
 
        var connectedUsers []Field
        defer s.mux.Unlock()
 
        var connectedUsers []Field

-       for _, c := range s.Clients {
+       for _, c := range sortedClients(s.Clients) {
+               if !c.Agreed {
+                       continue
+               }

                user := User{
                        ID:    *c.ID,
                        Icon:  *c.Icon,
                        Flags: *c.Flags,
                user := User{
                        ID:    *c.ID,
                        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()))
        }


@@ -413,7 +412,7 @@ func (s *Server) loadAccounts(userDir string) error {
        }
 
        for _, file := range matches {
        }
 
        for _, file := range matches {

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

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


@@ -431,7 +430,7 @@ func (s *Server) loadAccounts(userDir string) error {
 }
 
 func (s *Server) loadConfig(path string) error {
 }
 
 func (s *Server) loadConfig(path string) error {

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

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


@@ -497,15 +496,19 @@ func (s *Server) handleNewConnection(conn net.Conn) error {
 
        // 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) {

-               rep := c.NewErrReply(clientLogin, "Incorrect login.")
-               if _, err := conn.Write(rep.Payload()); err != nil {
+               t := c.NewErrReply(clientLogin, "Incorrect login.")
+               b, err := t.MarshalBinary()
+               if err != nil {
+                       return err
+               }
+               if _, err := conn.Write(b); err != nil {

                        return err
                }
                return fmt.Errorf("incorrect login")
        }
 
        if clientLogin.GetField(fieldUserName).Data != nil {
                        return err
                }
                return fmt.Errorf("incorrect login")
        }
 
        if clientLogin.GetField(fieldUserName).Data != nil {

-               *c.UserName = clientLogin.GetField(fieldUserName).Data
+               c.UserName = clientLogin.GetField(fieldUserName).Data

        }
 
        if clientLogin.GetField(fieldUserIconID).Data != nil {
        }
 
        if clientLogin.GetField(fieldUserIconID).Data != nil {


@@ -532,13 +535,24 @@ func (s *Server) handleNewConnection(conn net.Conn) error {
        // Show agreement to client
        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 _, err := c.notifyNewUserHasJoined(); err != nil {
-               return err
+       // assume simplified hotline v1.2.3 login flow that does not require agreement
+       if *c.Version == nil {
+               c.Agreed = true
+
+               c.notifyOthers(
+                       *NewTransaction(
+                               tranNotifyChangeUser, nil,
+                               NewField(fieldUserName, c.UserName),
+                               NewField(fieldUserID, *c.ID),
+                               NewField(fieldUserIconID, *c.Icon),
+                               NewField(fieldUserFlags, *c.Flags),
+                       ),
+               )

        }
        }

+

        c.Server.Stats.LoginCount += 1
 
        const readBuffSize = 1024000 // 1KB - TODO: what should this be?
        c.Server.Stats.LoginCount += 1
 
        const readBuffSize = 1024000 // 1KB - TODO: what should this be?

-       const maxTranSize = 1024000

        tranBuff := make([]byte, 0)
        tReadlen := 0
        // Infinite loop where take action on incoming client requests until the connection is closed
        tranBuff := make([]byte, 0)
        tReadlen := 0
        // Infinite loop where take action on incoming client requests until the connection is closed


@@ -568,21 +582,6 @@ func (s *Server) handleNewConnection(conn net.Conn) error {
        }
 }
 
        }
 }
 

-func hashAndSalt(pwd []byte) string {
-       // Use GenerateFromPassword to hash & salt pwd.
-       // MinCost is just an integer constant provided by the bcrypt
-       // package along with DefaultCost & MaxCost.
-       // The cost can be any value you want provided it isn't lower
-       // than the MinCost (4)
-       hash, err := bcrypt.GenerateFromPassword(pwd, bcrypt.MinCost)
-       if err != nil {
-               log.Println(err)
-       }
-       // GenerateFromPassword returns a byte slice so we need to
-       // convert the bytes to a string and return it
-       return string(hash)
-}
-

 // 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
 // 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


@@ -614,16 +613,22 @@ const dlFldrActionSendFile = 1
 const dlFldrActionResumeFile = 2
 const dlFldrActionNextFile = 3
 
 const dlFldrActionResumeFile = 2
 const dlFldrActionNextFile = 3
 

-func (s *Server) TransferFile(conn net.Conn) error {
-       defer func() { _ = conn.Close() }()
+// 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)
+               }
+       }()

 
 

-       buf := make([]byte, 1024)
-       if _, err := conn.Read(buf); err != nil {
+       txBuf := make([]byte, 16)
+       _, err := conn.Read(txBuf)
+       if err != nil {

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

-       _, err := t.Write(buf[:16])
+       _, err = t.Write(txBuf)

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


@@ -633,24 +638,28 @@ func (s *Server) TransferFile(conn net.Conn) error {
 
        switch fileTransfer.Type {
        case FileDownload:
 
        switch fileTransfer.Type {
        case FileDownload:

-               fullFilePath := fmt.Sprintf("%v/%v", s.Config.FileRoot+string(fileTransfer.FilePath), string(fileTransfer.FileName))
+               fullFilePath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
+               if err != nil {
+                       return err
+               }

 
                ffo, err := NewFlattenedFileObject(
 
                ffo, err := NewFlattenedFileObject(

-                       s.Config.FileRoot+string(fileTransfer.FilePath),
-                       string(fileTransfer.FileName),
+                       s.Config.FileRoot,
+                       fileTransfer.FilePath,
+                       fileTransfer.FileName,

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

-               s.Logger.Infow("File download started", "filePath", fullFilePath, "transactionRef", fileTransfer.ReferenceNumber, "RemoteAddr", conn.RemoteAddr().String())
+               s.Logger.Infow("File download started", "filePath", fullFilePath, "transactionRef", fileTransfer.ReferenceNumber)

 
                // Start by sending flat file object to client
 
                // Start by sending flat file object to client

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

                        return err
                }
 
                        return err
                }
 

-               file, err := os.Open(fullFilePath)
+               file, err := FS.Open(fullFilePath)

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


@@ -671,60 +680,20 @@ func (s *Server) TransferFile(conn net.Conn) error {
                        }
                }
        case FileUpload:
                        }
                }
        case FileUpload:

-               if _, err := conn.Read(buf); err != nil {
-                       return err
-               }
-
-               ffo := ReadFlattenedFileObject(buf)
-               payloadLen := len(ffo.Payload())
-               fileSize := int(binary.BigEndian.Uint32(ffo.FlatFileDataForkHeader.DataSize))
-

                destinationFile := s.Config.FileRoot + ReadFilePath(fileTransfer.FilePath) + "/" + string(fileTransfer.FileName)
                destinationFile := s.Config.FileRoot + ReadFilePath(fileTransfer.FilePath) + "/" + string(fileTransfer.FileName)

-               s.Logger.Infow(
-                       "File upload started",
-                       "transactionRef", fileTransfer.ReferenceNumber,
-                       "RemoteAddr", conn.RemoteAddr().String(),
-                       "size", fileSize,
-                       "dstFile", destinationFile,
-               )
-
-               newFile, err := os.Create(destinationFile)
+               newFile, err := FS.Create(destinationFile)

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

-

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

-               const buffSize = 1024
+               s.Logger.Infow("File upload started", "transactionRef", fileTransfer.ReferenceNumber, "dstFile", destinationFile)

 
 

-               if _, err := newFile.Write(buf[payloadLen:]); err != nil {
-                       return err
+               if err := receiveFile(conn, newFile, nil); err != nil {
+                       s.Logger.Errorw("file upload error", "error", err)

                }
                }

-               receivedBytes := buffSize - payloadLen
-
-               for {
-                       if (fileSize - receivedBytes) < buffSize {
-                               s.Logger.Infow(
-                                       "File upload complete",
-                                       "transactionRef", fileTransfer.ReferenceNumber,
-                                       "RemoteAddr", conn.RemoteAddr().String(),
-                                       "size", fileSize,
-                                       "dstFile", destinationFile,
-                               )

 
 

-                               if _, err := io.CopyN(newFile, conn, int64(fileSize-receivedBytes)); err != nil {
-                                       return fmt.Errorf("file transfer failed: %s", err)
-                               }
-                               return nil
-                       }
-
-                       // Copy N bytes from conn to upload file
-                       n, err := io.CopyN(newFile, conn, buffSize)
-                       if err != nil {
-                               return err
-                       }
-                       receivedBytes += int(n)
-               }
+               s.Logger.Infow("File upload complete", "transactionRef", fileTransfer.ReferenceNumber, "dstFile", destinationFile)

        case FolderDownload:
                // Folder Download flow:
                // 1. Get filePath from the transfer
        case FolderDownload:
                // Folder Download flow:
                // 1. Get filePath from the transfer


@@ -753,27 +722,35 @@ func (s *Server) TransferFile(conn net.Conn) error {
                //
                // This notifies the server to send the next item header
 
                //
                // This notifies the server to send the next item header
 

-               fh := NewFilePath(fileTransfer.FilePath)
-               fullFilePath := fmt.Sprintf("%v/%v", s.Config.FileRoot+fh.String(), string(fileTransfer.FileName))
+               fullFilePath, err := readPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
+               if err != nil {
+                       return err
+               }

 
                basePathLen := len(fullFilePath)
 
 
                basePathLen := len(fullFilePath)
 

-               readBuffer := make([]byte, 1024)
+               s.Logger.Infow("Start folder download", "path", fullFilePath, "ReferenceNumber", fileTransfer.ReferenceNumber)

 
 

-               s.Logger.Infow("Start folder download", "path", fullFilePath, "ReferenceNumber", fileTransfer.ReferenceNumber, "RemoteAddr", conn.RemoteAddr())
+               nextAction := make([]byte, 2)
+               if _, err := conn.Read(nextAction); err != nil {
+                       return err
+               }

 
                i := 0
 
                i := 0

-               _ = filepath.Walk(fullFilePath+"/", func(path string, info os.FileInfo, _ error) error {
+               err = filepath.Walk(fullFilePath+"/", func(path string, info os.FileInfo, err error) error {
+                       if err != nil {
+                               return err
+                       }

                        i += 1
                        i += 1

-                       subPath := path[basePathLen-2:]
+                       subPath := path[basePathLen+1:]

                        s.Logger.Infow("Sending fileheader", "i", i, "path", path, "fullFilePath", fullFilePath, "subPath", subPath, "IsDir", info.IsDir())
 
                        s.Logger.Infow("Sending fileheader", "i", i, "path", path, "fullFilePath", fullFilePath, "subPath", subPath, "IsDir", info.IsDir())
 

-                       fileHeader := NewFileHeader(subPath, info.IsDir())
-

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

+                       fileHeader := NewFileHeader(subPath, info.IsDir())
+

                        // Send the file header to client
                        if _, err := conn.Write(fileHeader.Payload()); err != nil {
                                s.Logger.Errorf("error sending file header: %v", err)
                        // Send the file header to client
                        if _, err := conn.Write(fileHeader.Payload()); err != nil {
                                s.Logger.Errorf("error sending file header: %v", err)


@@ -781,29 +758,32 @@ func (s *Server) TransferFile(conn net.Conn) error {
                        }
 
                        // Read the client's Next Action request
                        }
 
                        // Read the client's Next Action request

-                       //TODO: Remove hardcoded behavior and switch behaviors based on the next action send
-                       if _, err := conn.Read(readBuffer); err != nil {
-                               s.Logger.Errorf("error reading next action: %v", err)
+                       if _, err := conn.Read(nextAction); err != nil {

                                return err
                        }
                                return err
                        }

+                       if nextAction[1] == 3 {
+                               return nil
+                       }

 
 

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

 
                        if info.IsDir() {
                                return nil
                        }
 
                        splitPath := strings.Split(path, "/")
 
                        if info.IsDir() {
                                return nil
                        }
 
                        splitPath := strings.Split(path, "/")

-                       //strings.Join(splitPath[:len(splitPath)-1], "/")

 
 

-                       ffo, err := NewFlattenedFileObject(strings.Join(splitPath[:len(splitPath)-1], "/"), info.Name())
+                       ffo, err := NewFlattenedFileObject(
+                               strings.Join(splitPath[:len(splitPath)-1], "/"),
+                               nil,
+                               []byte(info.Name()),
+                       )

                        if err != nil {
                                return err
                        }
                        s.Logger.Infow("File download started",
                                "fileName", info.Name(),
                                "transactionRef", fileTransfer.ReferenceNumber,
                        if err != nil {
                                return err
                        }
                        s.Logger.Infow("File download started",
                                "fileName", info.Name(),
                                "transactionRef", fileTransfer.ReferenceNumber,

-                               "RemoteAddr", conn.RemoteAddr().String(),

                                "TransferSize", fmt.Sprintf("%x", ffo.TransferSize()),
                        )
 
                                "TransferSize", fmt.Sprintf("%x", ffo.TransferSize()),
                        )
 


@@ -813,62 +793,56 @@ func (s *Server) TransferFile(conn net.Conn) error {
                                return err
                        }
 
                                return err
                        }
 

-                       // Send file bytes to client
-                       if _, err := conn.Write(ffo.Payload()); err != nil {
+                       // Send ffo bytes to client
+                       if _, err := conn.Write(ffo.BinaryMarshal()); err != nil {

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

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

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

-                       sendBuffer := make([]byte, 1048576)
-                       totalBytesSent := len(ffo.Payload())
+                       // 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()

 
 

-                       for {
-                               bytesRead, err := file.Read(sendBuffer)
-                               if err == io.EOF {
-                                       // Read the client's Next Action request
-                                       //TODO: Remove hardcoded behavior and switch behaviors based on the next action send
-                                       if _, err := conn.Read(readBuffer); err != nil {
-                                               s.Logger.Errorf("error reading next action: %v", err)
-                                               return err
-                                       }
-                                       break
-                               }
+                       // TODO: optionally send resource fork header and resource fork data

 
 

-                               sentBytes, readErr := conn.Write(sendBuffer[:bytesRead])
-                               totalBytesSent += sentBytes
-                               if readErr != nil {
-                                       return err
-                               }
+                       // Read the client's Next Action request
+                       if _, err := conn.Read(nextAction); err != nil {
+                               return err

                        }
                        }

-                       return nil
+                       // TODO: switch behavior based on possible next action
+
+                       return err

                })
 
        case FolderUpload:
                })
 
        case FolderUpload:

-               dstPath := s.Config.FileRoot + ReadFilePath(fileTransfer.FilePath) + "/" + string(fileTransfer.FileName)
+               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,

-                       "RemoteAddr", conn.RemoteAddr().String(),

                        "dstPath", dstPath,
                        "dstPath", dstPath,

-                       "TransferSize", fileTransfer.TransferSize,
+                       "TransferSize", fmt.Sprintf("%x", 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 := os.Stat(dstPath); os.IsNotExist(err) {
-                       s.Logger.Infow("Target path does not exist; Creating...", "dstPath", dstPath)
-                       if err := os.Mkdir(dstPath, 0777); err != nil {
+               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)
                        }
                }
 
                                s.Logger.Error(err)
                        }
                }
 

-               readBuffer := make([]byte, 1024)
-

                // Begin the folder upload flow by sending the "next file action" to client
                if _, err := conn.Write([]byte{0, dlFldrActionNextFile}); err != nil {
                        return err
                // Begin the folder upload flow by sending the "next file action" to client
                if _, err := conn.Write([]byte{0, dlFldrActionNextFile}); err != nil {
                        return err


@@ -877,8 +851,10 @@ func (s *Server) TransferFile(conn net.Conn) error {
                fileSize := make([]byte, 4)
                itemCount := binary.BigEndian.Uint16(fileTransfer.FolderItemCount)
 
                fileSize := make([]byte, 4)
                itemCount := binary.BigEndian.Uint16(fileTransfer.FolderItemCount)
 

+               readBuffer := make([]byte, 1024)

                for i := uint16(0); i < itemCount; i++ {
                for i := uint16(0); i < itemCount; i++ {

-                       if _, err := conn.Read(readBuffer); err != nil {
+                       _, err := conn.Read(readBuffer)
+                       if err != nil {

                                return err
                        }
                        fu := readFolderUpload(readBuffer)
                                return err
                        }
                        fu := readFolderUpload(readBuffer)


@@ -886,13 +862,12 @@ func (s *Server) TransferFile(conn net.Conn) error {
                        s.Logger.Infow(
                                "Folder upload continued",
                                "transactionRef", fmt.Sprintf("%x", fileTransfer.ReferenceNumber),
                        s.Logger.Infow(
                                "Folder upload continued",
                                "transactionRef", fmt.Sprintf("%x", fileTransfer.ReferenceNumber),

-                               "RemoteAddr", conn.RemoteAddr().String(),

                                "FormattedPath", fu.FormattedPath(),
                                "IsFolder", fmt.Sprintf("%x", fu.IsFolder),
                                "FormattedPath", fu.FormattedPath(),
                                "IsFolder", fmt.Sprintf("%x", fu.IsFolder),

-                               "PathItemCount", binary.BigEndian.Uint16(fu.PathItemCount),
+                               "PathItemCount", binary.BigEndian.Uint16(fu.PathItemCount[:]),

                        )
 
                        )
 

-                       if bytes.Equal(fu.IsFolder, []byte{0, 1}) {
+                       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 {
                                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 {


@@ -914,14 +889,21 @@ func (s *Server) TransferFile(conn net.Conn) error {
                                }
 
                                if _, err := conn.Read(fileSize); err != nil {
                                }
 
                                if _, err := conn.Read(fileSize); err != nil {

-                                       fmt.Println("Error reading:", err.Error()) // TODO: handle
+                                       return err

                                }
 
                                }
 

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

 
 

-                               if err := transferFile(conn, dstPath+"/"+fu.FormattedPath()); err != nil {
+                               newFile, err := FS.Create(filePath)
+                               if err != nil {
+                                       return err
+                               }
+
+                               if err := receiveFile(conn, newFile, ioutil.Discard); err != nil {

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

+                               _ = newFile.Close()

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


@@ -929,11 +911,6 @@ func (s *Server) TransferFile(conn net.Conn) error {
                                        return err
                                }
 
                                        return err
                                }
 

-                               // Client sends "MACR" after the file.  Read and discard.
-                               // TODO: This doesn't seem to be documented.  What is this?  Maybe resource fork?
-                               if _, err := conn.Read(readBuffer); err != nil {
-                                       return err
-                               }

                        }
                }
                s.Logger.Infof("Folder upload complete")
                        }
                }
                s.Logger.Infof("Folder upload complete")


@@ -942,89 +919,6 @@ func (s *Server) TransferFile(conn net.Conn) error {
        return nil
 }
 
        return nil
 }
 

-func transferFile(conn net.Conn, dst string) error {
-       const buffSize = 1024
-       buf := make([]byte, buffSize)
-
-       // Read first chunk of bytes from conn; this will be the Flat File Object and initial chunk of file bytes
-       if _, err := conn.Read(buf); err != nil {
-               return err
-       }
-       ffo := ReadFlattenedFileObject(buf)
-       payloadLen := len(ffo.Payload())
-       fileSize := int(binary.BigEndian.Uint32(ffo.FlatFileDataForkHeader.DataSize))
-
-       newFile, err := os.Create(dst)
-       if err != nil {
-               return err
-       }
-       defer func() { _ = newFile.Close() }()
-       if _, err := newFile.Write(buf[payloadLen:]); err != nil {
-               return err
-       }
-       receivedBytes := buffSize - payloadLen
-
-       for {
-               if (fileSize - receivedBytes) < buffSize {
-                       _, err := io.CopyN(newFile, conn, int64(fileSize-receivedBytes))
-                       return err
-               }
-
-               // Copy N bytes from conn to upload file
-               n, err := io.CopyN(newFile, conn, buffSize)
-               if err != nil {
-                       return err
-               }
-               receivedBytes += int(n)
-       }
-}
-
-// 00 28 // DataSize
-// 00 00 // IsFolder
-// 00 02 // PathItemCount
-//
-// 00 00
-// 09
-// 73 75 62 66 6f 6c 64 65 72 // "subfolder"
-//
-// 00 00
-// 15
-// 73 75 62 66 6f 6c 64 65 72 2d 74 65 73 74 66 69 6c 65 2d 35 6b // "subfolder-testfile-5k"
-func readFolderUpload(buf []byte) folderUpload {
-       dataLen := binary.BigEndian.Uint16(buf[0:2])
-
-       fu := folderUpload{
-               DataSize:      buf[0:2], // Size of this structure (not including data size element itself)
-               IsFolder:      buf[2:4],
-               PathItemCount: buf[4:6],
-               FileNamePath:  buf[6 : dataLen+2],
-       }
-
-       return fu
-}
-
-type folderUpload struct {
-       DataSize      []byte
-       IsFolder      []byte
-       PathItemCount []byte
-       FileNamePath  []byte
-}
-
-func (fu *folderUpload) FormattedPath() string {
-       pathItemLen := binary.BigEndian.Uint16(fu.PathItemCount)
-
-       var pathSegments []string
-       pathData := fu.FileNamePath
-
-       for i := uint16(0); i < pathItemLen; i++ {
-               segLen := pathData[2]
-               pathSegments = append(pathSegments, string(pathData[3:3+segLen]))
-               pathData = pathData[3+segLen:]
-       }
-
-       return strings.Join(pathSegments, pathSeparator)
-}
-

 // 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) {
 // 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) {