Fix for issue #11 https://blitter.com:3000/RLabs/hkexsh/issues/11

Signed-off-by: Russ Magee <rmagee@gmail.com>

hkexnet/hkexnet.go

@@ -1080,3 +1080,74 @@ func (hc *Conn) chaffHelper() {
 		}
 	}()
 }
+
+////////////////////////////////////////////////////
+
+// Copy copies from src to dst until either EOF is reached
+// on src or an error occurs. It returns the number of bytes
+// copied and the first error encountered while copying, if any.
+//
+// A successful Copy returns err == nil, not err == EOF.
+// Because Copy is defined to read from src until EOF, it does
+// not treat an EOF from Read as an error to be reported.
+//
+// If src implements the WriterTo interface,
+// the copy is implemented by calling src.WriteTo(dst).
+// Otherwise, if dst implements the ReaderFrom interface,
+// the copy is implemented by calling dst.ReadFrom(src).
+func Copy(dst io.Writer, src io.Reader) (written int64, err error) {
+	written, err = copyBuffer(dst, src, nil)
+	return
+}
+
+// copyBuffer is the actual implementation of Copy and CopyBuffer.
+// if buf is nil, one is allocated.
+func copyBuffer(dst io.Writer, src io.Reader, buf []byte) (written int64, err error) {
+	// If the reader has a WriteTo method, use it to do the copy.
+	// Avoids an allocation and a copy.
+	if wt, ok := src.(io.WriterTo); ok {
+		return wt.WriteTo(dst)
+	}
+	// Similarly, if the writer has a ReadFrom method, use it to do the copy.
+	if rt, ok := dst.(io.ReaderFrom); ok {
+		return rt.ReadFrom(src)
+	}
+	if buf == nil {
+		size := 32 * 1024
+		if l, ok := src.(*io.LimitedReader); ok && int64(size) > l.N {
+			if l.N < 1 {
+				size = 1
+			} else {
+				size = int(l.N)
+			}
+		}
+		buf = make([]byte, size)
+	}
+	for {
+		nr, er := src.Read(buf)
+		if nr > 0 {
+			nw, ew := dst.Write(buf[0:nr])
+			if nw > 0 {
+				written += int64(nw)
+			}
+			if ew != nil {
+				err = ew
+				break
+			}
+			if nr != nw {
+				err = io.ErrShortWrite
+				break
+			}
+		}
+		if er != nil {
+			if er != io.EOF {
+				err = er
+			}
+			break
+		}
+	}
+	//_,_ = dst.Write([]byte{0x2f})
+	return written, err
+}
+
+////////////////////////////////////////////////////

hkexsh/hkexsh.go

@@ -239,14 +239,17 @@ func doShellMode(isInteractive bool, conn *hkexnet.Conn, oldState *hkexsh.State,
 	// #gv:s/label=\"doShellMode\$1\"/label=\"shellRemoteToStdin\"/
 	// TODO:.gv:doShellMode:1:shellRemoteToStdin
 	shellRemoteToStdin := func() {
-		defer wg.Done()
+		defer func() {
+			wg.Done()
+		}()
+
 		// By deferring a call to wg.Done(),
 		// each goroutine guarantees that it marks
 		// its direction's stream as finished.
 
-		// io.Copy() expects EOF so normally this will
+		// pkg io/Copy expects EOF so normally this will
 		// exit with inerr == nil
-		_, inerr := io.Copy(os.Stdout, conn)
+		_, inerr := hkexnet.Copy(os.Stdout, conn)
 		if inerr != nil {
 			_ = hkexsh.Restore(int(os.Stdin.Fd()), oldState) // #nosec
 			// Copy operations and user logging off will cause
@@ -264,6 +267,7 @@ func doShellMode(isInteractive bool, conn *hkexnet.Conn, oldState *hkexsh.State,
 		if isInteractive {
 			log.Println("[* Got EOF *]")
 			_ = hkexsh.Restore(int(os.Stdin.Fd()), oldState) // #nosec
+			os.Exit(int(rec.Status()))
 		}
 	}
 	go shellRemoteToStdin()
@@ -281,10 +285,9 @@ func doShellMode(isInteractive bool, conn *hkexnet.Conn, oldState *hkexsh.State,
 		shellStdinToRemote := func() {
 			defer wg.Done()
 			//!defer wg.Done()
-			// Copy() expects EOF so this will
-			// exit with outerr == nil
-			//!_, outerr := io.Copy(conn, os.Stdin)
 			_, outerr := func(conn *hkexnet.Conn, r io.Reader) (w int64, e error) {
+				// Copy() expects EOF so this will
+				// exit with outerr == nil
 				w, e = io.Copy(conn, r)
 				return w, e
 			}(conn, os.Stdin)