websockets: Initial WebSockets support.

Has a bug: WebSocket client disconnects are not detected.
rfbSendFramebufferUpdate is doing a MSG_PEEK recv to determine if
enough data is available which prevents a disconnect from being
detected.

Otherwise it's working pretty well.

[jes: moved added struct members to the end for binary compatibility with
previous LibVNCServer versions, removed an unused variable]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

1 files changed, 83 insertions, 0 deletions

diff --git a/libvncserver/sockets.c b/libvncserver/sockets.c
index 188a8fd..267287d 100644
--- a/libvncserver/sockets.c
+++ b/libvncserver/sockets.c
@@ -457,7 +457,15 @@ rfbReadExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout)
     struct timeval tv;
 
     while (len > 0) {
+#ifdef LIBVNCSERVER_WITH_WEBSOCKETS
+        if (cl->webSockets) {
+            n = webSocketsDecode(cl, buf, len);
+        } else {
+            n = read(sock, buf, len);
+        }
+#else
         n = read(sock, buf, len);
+#endif
 
         if (n > 0) {
 
@@ -518,6 +526,71 @@ int rfbReadExact(rfbClientPtr cl,char* buf,int len)
 }
 
 /*
+ * PeekExact peeks at an exact number of bytes from a client.  Returns 1 if
+ * those bytes have been read, 0 if the other end has closed, or -1 if an
+ * error occurred (errno is set to ETIMEDOUT if it timed out).
+ */
+
+int
+rfbPeekExactTimeout(rfbClientPtr cl, char* buf, int len, int timeout)
+{
+    int sock = cl->sock;
+    int n;
+    fd_set fds;
+    struct timeval tv;
+
+    while (len > 0) {
+        n = recv(sock, buf, len, MSG_PEEK);
+
+        if (n == len) {
+
+            break;
+
+        } else if (n == 0) {
+
+            return 0;
+
+        } else {
+#ifdef WIN32
+	    errno = WSAGetLastError();
+#endif
+	    if (errno == EINTR)
+		continue;
+
+#ifdef LIBVNCSERVER_ENOENT_WORKAROUND
+	    if (errno != ENOENT)
+#endif
+            if (errno != EWOULDBLOCK && errno != EAGAIN) {
+                return n;
+            }
+
+            FD_ZERO(&fds);
+            FD_SET(sock, &fds);
+            tv.tv_sec = timeout / 1000;
+            tv.tv_usec = (timeout % 1000) * 1000;
+            n = select(sock+1, &fds, NULL, &fds, &tv);
+            if (n < 0) {
+                rfbLogPerror("ReadExact: select");
+                return n;
+            }
+            if (n == 0) {
+                errno = ETIMEDOUT;
+                return -1;
+            }
+        }
+    }
+#undef DEBUG_READ_EXACT
+#ifdef DEBUG_READ_EXACT
+    rfbLog("ReadExact %d bytes\n",len);
+    for(n=0;n<len;n++)
+	    fprintf(stderr,"%02x ",(unsigned char)buf[n]);
+    fprintf(stderr,"\n");
+#endif
+
+    return 1;
+}
+
+/*
  * WriteExact writes an exact number of bytes to a client.  Returns 1 if
  * those bytes have been written, or -1 if an error occurred (errno is set to
  * ETIMEDOUT if it timed out).
@@ -543,6 +616,16 @@ rfbWriteExact(rfbClientPtr cl,
     fprintf(stderr,"\n");
 #endif
 
+#ifdef LIBVNCSERVER_WITH_WEBSOCKETS
+    if (cl->webSockets) {
+        if ((len = webSocketsEncode(cl, buf, len)) < 0) {
+            rfbErr("WriteExact: WebSockets encode error\n");
+            return -1;
+        }
+        buf = cl->encodeBuf;
+    }
+#endif
+
     LOCK(cl->outputMutex);
     while (len > 0) {
         n = write(sock, buf, len);