X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/blobdiff_plain/d1cd666473e5d9097b34bad3388c8c0595612089..b365559d0b92cbd2193d72365d32baa62c62a98e:/hotline/server.go

diff --git a/hotline/server.go b/hotline/server.go
index 5ff8842..2bd5c04 100644
--- a/hotline/server.go
+++ b/hotline/server.go
@@ -478,17 +478,29 @@ 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 +516,6 @@ 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 +651,37 @@ 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:
@@ -785,7 +799,7 @@ 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 +825,7 @@ 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 +838,13 @@ 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 +921,7 @@ 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 +957,7 @@ 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 +1035,7 @@ 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
 					}