Replace unsafe conn.Read with io.ReadFull

[rbdr/mobius] / hotline / server.go

diff --git a/hotline/server.go b/hotline/server.go
index cf022fc9f9e3a2d3a6649253f1256e371cb079a3..2bd5c04bc01dbe6cd05bb6d9f27848c0cd6b2685 100644 (file)
--- 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
@@ -652,12 +657,7 @@ func (s *Server) handleFileTransfer(conn io.ReadWriteCloser) error {
                }
        }()
 
-       defer func() {
-               if r := recover(); r != nil {
-                       fmt.Println("stacktrace from panic: \n" + string(debug.Stack()))
-                       s.Logger.Errorw("PANIC", "err", r, "trace", string(debug.Stack()))
-               }
-       }()
+       defer dontPanic(s.Logger)
 
        txBuf := make([]byte, 16)
        if _, err := io.ReadFull(conn, txBuf); err != nil {
@@ -799,7 +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
                }
 
@@ -825,7 +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
                        }
 
@@ -838,13 +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
                                }
 
@@ -921,7 +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
                        }
 
@@ -957,7 +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
@@ -1035,7 +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
                                        }