X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/blobdiff_plain/d1cd666473e5d9097b34bad3388c8c0595612089..5c14e4c916d76ce35ee2b07bf832d5f3b6118260:/hotline/server.go

diff --git a/hotline/server.go b/hotline/server.go
index 5ff8842..f164df1 100644
--- a/hotline/server.go
+++ b/hotline/server.go
@@ -236,9 +236,15 @@ func NewServer(configDir, netInterface string, netPort int, logger *zap.SugaredL
 	*server.NextGuestID = 1
 
 	if server.Config.EnableTrackerRegistration {
+		server.Logger.Infow(
+			"Tracker registration enabled",
+			"frequency", fmt.Sprintf("%vs", trackerUpdateFrequency),
+			"trackers", server.Config.Trackers,
+		)
+
 		go func() {
 			for {
-				tr := TrackerRegistration{
+				tr := &TrackerRegistration{
 					Port:        []byte{0x15, 0x7c},
 					UserCount:   server.userCount(),
 					PassID:      server.TrackerPassID,
@@ -246,11 +252,10 @@ func NewServer(configDir, netInterface string, netPort int, logger *zap.SugaredL
 					Description: server.Config.Description,
 				}
 				for _, t := range server.Config.Trackers {
-					server.Logger.Infof("Registering with tracker %v", t)
-
 					if err := register(t, tr); err != nil {
 						server.Logger.Errorw("unable to register with tracker %v", "error", err)
 					}
+					server.Logger.Infow("Sent Tracker registration", "data", tr)
 				}
 
 				time.Sleep(trackerUpdateFrequency * time.Second)
@@ -478,17 +483,29 @@ const (
 	minTransactionLen = 22 // minimum length of any transaction
 )
 
+// dontPanic recovers and logs panics instead of crashing
+// TODO: remove this after known issues are fixed
+func dontPanic(logger *zap.SugaredLogger) {
+	if r := recover(); r != nil {
+		fmt.Println("stacktrace from panic: \n" + string(debug.Stack()))
+		logger.Errorw("PANIC", "err", r, "trace", string(debug.Stack()))
+	}
+}
+
 // handleNewConnection takes a new net.Conn and performs the initial login sequence
 func (s *Server) handleNewConnection(conn net.Conn) error {
-	handshakeBuf := make([]byte, 12) // handshakes are always 12 bytes in length
-	if _, err := conn.Read(handshakeBuf); err != nil {
+	defer dontPanic(s.Logger)
+
+	handshakeBuf := make([]byte, 12)
+	if _, err := io.ReadFull(conn, handshakeBuf); err != nil {
 		return err
 	}
-	if err := Handshake(conn, handshakeBuf[:12]); err != nil {
+	if err := Handshake(conn, handshakeBuf); err != nil {
 		return err
 	}
 
 	buf := make([]byte, 1024)
+	// TODO: fix potential short read with io.ReadFull
 	readLen, err := conn.Read(buf)
 	if readLen < minTransactionLen {
 		return err
@@ -504,13 +521,6 @@ func (s *Server) handleNewConnection(conn net.Conn) error {
 
 	c := s.NewClientConn(conn)
 	defer c.Disconnect()
-	defer func() {
-		if r := recover(); r != nil {
-			fmt.Println("stacktrace from panic: \n" + string(debug.Stack()))
-			c.Server.Logger.Errorw("PANIC", "err", r, "trace", string(debug.Stack()))
-			c.Disconnect()
-		}
-	}()
 
 	encodedLogin := clientLogin.GetField(fieldUserLogin).Data
 	encodedPassword := clientLogin.GetField(fieldUserPassword).Data
@@ -646,28 +656,37 @@ 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)
 		}
 	}()
 
+	defer dontPanic(s.Logger)
+
 	txBuf := make([]byte, 16)
-	_, err := conn.Read(txBuf)
-	if err != nil {
+	if _, err := io.ReadFull(conn, txBuf); err != nil {
 		return err
 	}
 
 	var t transfer
-	_, err = t.Write(txBuf)
-	if err != nil {
+	if _, err := t.Write(txBuf); err != nil {
 		return err
 	}
 
 	transferRefNum := binary.BigEndian.Uint32(t.ReferenceNumber[:])
-	fileTransfer := s.FileTransfers[transferRefNum]
+	defer func() {
+		s.mux.Lock()
+		delete(s.FileTransfers, transferRefNum)
+		s.mux.Unlock()
+	}()
 
-	// delete single use transferRefNum
-	delete(s.FileTransfers, transferRefNum)
+	s.mux.Lock()
+	fileTransfer, ok := s.FileTransfers[transferRefNum]
+	s.mux.Unlock()
+	if !ok {
+		return errors.New("invalid transaction ID")
+	}
 
 	switch fileTransfer.Type {
 	case FileDownload:
@@ -723,11 +742,27 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 		}
 	case FileUpload:
 		destinationFile := s.Config.FileRoot + ReadFilePath(fileTransfer.FilePath) + "/" + string(fileTransfer.FileName)
-		tmpFile := destinationFile + ".incomplete"
 
-		file, err := effectiveFile(destinationFile)
+		var file *os.File
+
+		// A file upload has three possible cases:
+		// 1) Upload a new file
+		// 2) Resume a partially transferred file
+		// 3) Replace a fully uploaded file
+		// Unfortunately we have to infer which case applies by inspecting what is already on the file system
+
+		// 1) Check for existing file:
+		_, 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 {
+				return err
+			}
+			file, err = os.Create(destinationFile + incompleteFileSuffix)
+		}
 		if errors.Is(err, fs.ErrNotExist) {
-			file, err = FS.Create(tmpFile)
+			// 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
 			}
@@ -785,7 +820,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 		s.Logger.Infow("Start folder download", "path", fullFilePath, "ReferenceNumber", fileTransfer.ReferenceNumber)
 
 		nextAction := make([]byte, 2)
-		if _, err := conn.Read(nextAction); err != nil {
+		if _, err := io.ReadFull(conn, nextAction); err != nil {
 			return err
 		}
 
@@ -811,7 +846,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 			}
 
 			// Read the client's Next Action request
-			if _, err := conn.Read(nextAction); err != nil {
+			if _, err := io.ReadFull(conn, nextAction); err != nil {
 				return err
 			}
 
@@ -824,13 +859,13 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 				// client asked to resume this file
 				var frd FileResumeData
 				// get size of resumeData
-				if _, err := conn.Read(nextAction); err != nil {
+				if _, err := io.ReadFull(conn, nextAction); err != nil {
 					return err
 				}
 
 				resumeDataLen := binary.BigEndian.Uint16(nextAction)
 				resumeDataBytes := make([]byte, resumeDataLen)
-				if _, err := conn.Read(resumeDataBytes); err != nil {
+				if _, err := io.ReadFull(conn, resumeDataBytes); err != nil {
 					return err
 				}
 
@@ -907,7 +942,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 			// TODO: optionally send resource fork header and resource fork data
 
 			// Read the client's Next Action request.  This is always 3, I think?
-			if _, err := conn.Read(nextAction); err != nil {
+			if _, err := io.ReadFull(conn, nextAction); err != nil {
 				return err
 			}
 
@@ -943,7 +978,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 		readBuffer := make([]byte, 1024)
 
 		for i := 0; i < fileTransfer.ItemCount(); i++ {
-
+			// TODO: fix potential short read with io.ReadFull
 			_, err := conn.Read(readBuffer)
 			if err != nil {
 				return err
@@ -1021,7 +1056,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
 						return err
 					}
 
-					if _, err := conn.Read(fileSize); err != nil {
+					if _, err := io.ReadFull(conn, fileSize); err != nil {
 						return err
 					}