From 6836ccb208f8c16824b8c1e330acb077c70c98c6 Mon Sep 17 00:00:00 2001
From: Floris Bos <bos@je-eigen-domein.nl>
Date: Sat, 17 Jan 2015 22:49:48 +0100
Subject: [PATCH] Fix handling of multiple VNC commands per websockets frame

- When processing input, check if there is any extra data
  pending in the internal websocket frame and SSL buffers.
- Prevents input events lagging behind because they get
  stuck in one of the buffers.
  Data pending in our own buffers cannot be detected with
  select() so was not processed until more input arrives
  from the network.
- Closes # 55

Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>
---
 libvncserver/main.c       |  8 ++++++++
 libvncserver/sockets.c    |  8 ++++++++
 libvncserver/websockets.c | 13 +++++++++++++
 rfb/rfb.h                 |  1 +
 4 files changed, 30 insertions(+)

diff --git a/libvncserver/main.c b/libvncserver/main.c
index 9839c85..a8458e4 100644
--- a/libvncserver/main.c
+++ b/libvncserver/main.c
@@ -550,7 +550,15 @@ clientInput(void *data)
             rfbSendFileTransferChunk(cl);
 
         if (FD_ISSET(cl->sock, &rfds) || FD_ISSET(cl->sock, &efds))
+        {
+#ifdef LIBVNCSERVER_WITH_WEBSOCKETS
+            do {
+                rfbProcessClientMessage(cl);
+            } while (webSocketsHasDataInBuffer(cl));
+#else
             rfbProcessClientMessage(cl);
+#endif
+        }
     }
 
     /* Get rid of the output thread. */
diff --git a/libvncserver/sockets.c b/libvncserver/sockets.c
index a9c5a2c..2bb655e 100644
--- a/libvncserver/sockets.c
+++ b/libvncserver/sockets.c
@@ -391,7 +391,15 @@ rfbCheckFds(rfbScreenInfoPtr rfbScreen,long usec)
             if (FD_ISSET(cl->sock, &(rfbScreen->allFds)))
             {
                 if (FD_ISSET(cl->sock, &fds))
+                {
+#ifdef LIBVNCSERVER_WITH_WEBSOCKETS
+                    do {
+                        rfbProcessClientMessage(cl);
+                    } while (webSocketsHasDataInBuffer(cl));
+#else
                     rfbProcessClientMessage(cl);
+#endif
+                }
                 else
                     rfbSendFileTransferChunk(cl);
             }
diff --git a/libvncserver/websockets.c b/libvncserver/websockets.c
index 34f04d7..3585ed5 100644
--- a/libvncserver/websockets.c
+++ b/libvncserver/websockets.c
@@ -905,3 +905,16 @@ webSocketCheckDisconnect(rfbClientPtr cl)
     return FALSE;
 }
 
+/* returns TRUE if there is data waiting to be read in our internal buffer
+ * or if is there any pending data in the buffer of the SSL implementation
+ */
+rfbBool
+webSocketsHasDataInBuffer(rfbClientPtr cl)
+{
+    ws_ctx_t *wsctx = (ws_ctx_t *)cl->wsctx;
+
+    if (wsctx && wsctx->readbuflen)
+      return TRUE;
+
+    return (cl->sslctx && rfbssl_pending(cl) > 0);
+}
diff --git a/rfb/rfb.h b/rfb/rfb.h
index f7919c6..0c34d74 100644
--- a/rfb/rfb.h
+++ b/rfb/rfb.h
@@ -765,6 +765,7 @@ extern rfbBool webSocketsCheck(rfbClientPtr cl);
 extern rfbBool webSocketCheckDisconnect(rfbClientPtr cl);
 extern int webSocketsEncode(rfbClientPtr cl, const char *src, int len, char **dst);
 extern int webSocketsDecode(rfbClientPtr cl, char *dst, int len);
+extern rfbBool webSocketsHasDataInBuffer(rfbClientPtr cl);
 #endif
 
 /* rfbserver.c */