vnc: added initial websocket protocol support

This patch adds basic Websocket Protocol version 13 - RFC 6455 - support
to QEMU VNC. Binary encoding support on the client side is mandatory.

Because of the GnuTLS requirement the Websockets implementation is
optional (--enable-vnc-ws).

To activate Websocket support the VNC option "websocket"is used, for
example "-vnc :0,websocket".
The listen port for Websocket connections is (5700 + display) so if
QEMU VNC is started with :0 the Websocket port would be 5700.
As an alternative the Websocket port could be manually specified by
using ",websocket=<port>" instead.

Parts of the implementation base on Anthony Liguori's QEMU Websocket
patch from 2010 and on Joel Martin's LibVNC Websocket implementation.

Signed-off-by: Tim Hardeck <thardeck@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 86 insertions, 0 deletions

diff --git a/ui/vnc-ws.h b/ui/vnc-ws.h
new file mode 100644
index 0000000..039a587
--- /dev/null
+++ b/ui/vnc-ws.h
@@ -0,0 +1,86 @@
+/*
+ * QEMU VNC display driver: Websockets support
+ *
+ * Copyright (C) 2010 Joel Martin
+ * Copyright (C) 2012 Tim Hardeck
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __QEMU_UI_VNC_WS_H
+#define __QEMU_UI_VNC_WS_H
+
+#include <gnutls/gnutls.h>
+
+#define B64LEN(__x) (((__x + 2) / 3) * 12 / 3)
+#define SHA1_DIGEST_LEN 20
+
+#define WS_ACCEPT_LEN (B64LEN(SHA1_DIGEST_LEN) + 1)
+#define WS_CLIENT_KEY_LEN 24
+#define WS_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+#define WS_GUID_LEN strlen(WS_GUID)
+
+#define WS_HANDSHAKE "HTTP/1.1 101 Switching Protocols\r\n\
+Upgrade: websocket\r\n\
+Connection: Upgrade\r\n\
+Sec-WebSocket-Accept: %s\r\n\
+Sec-WebSocket-Protocol: binary\r\n\
+\r\n"
+#define WS_HANDSHAKE_DELIM "\r\n"
+#define WS_HANDSHAKE_END "\r\n\r\n"
+#define WS_SUPPORTED_VERSION "13"
+
+#define WS_HEAD_MIN_LEN sizeof(uint16_t)
+#define WS_HEAD_MAX_LEN (WS_HEAD_MIN_LEN + sizeof(uint64_t) + sizeof(uint32_t))
+
+typedef union WsMask {
+    char c[4];
+    uint32_t u;
+} WsMask;
+
+typedef struct QEMU_PACKED WsHeader {
+    unsigned char b0;
+    unsigned char b1;
+    union {
+        struct QEMU_PACKED {
+            uint16_t l16;
+            WsMask m16;
+        } s16;
+        struct QEMU_PACKED {
+            uint64_t l64;
+            WsMask m64;
+        } s64;
+        WsMask m;
+    } u;
+} WsHeader;
+
+enum {
+    WS_OPCODE_CONTINUATION = 0x0,
+    WS_OPCODE_TEXT_FRAME = 0x1,
+    WS_OPCODE_BINARY_FRAME = 0x2,
+    WS_OPCODE_CLOSE = 0x8,
+    WS_OPCODE_PING = 0x9,
+    WS_OPCODE_PONG = 0xA
+};
+
+void vncws_handshake_read(void *opaque);
+long vnc_client_write_ws(VncState *vs);
+long vnc_client_read_ws(VncState *vs);
+void vncws_process_handshake(VncState *vs, uint8_t *line, size_t size);
+void vncws_encode_frame(Buffer *output, const void *payload,
+            const size_t payload_size);
+int vncws_decode_frame(Buffer *input, uint8_t **payload,
+                               size_t *payload_size, size_t *frame_size);
+
+#endif /* __QEMU_UI_VNC_WS_H */